86 results on '"Tessarolo, Alberto"'
Search Results
2. On the impact of photovoltaic module characterization on the prediction of PV plant productivity
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Barbini, Nicola, Lughi, Vanni, Mellit, A., P. a. v. a. n., . A. M., Tessarolo, Alberto, MASSI PAVAN, Alessandro, IEEE, Barbini, Nicola, Lughi, Vanni, Mellit, A., P. a. v. a. n., . A. M., Tessarolo, Alberto, and MASSI PAVAN, Alessandro
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photovoltaic module ,Engineering ,Standards ,photovoltaic cell characterization ,photovoltaic cells ,photovoltaic module characterization ,key factor ,photovoltaic cell ,Fill factor ,PV plant productivity ,Electronic engineering ,Productivity ,nominal fill factor ,Photovoltaic systems ,data sheets information ,photovoltaic power systems ,business.industry ,Photovoltaic system ,module efficiency ,Temperature ,photovoltaic field productivity ,Reliability engineering ,Characterization (materials science) ,Europe ,photovoltaic cells,photovoltaic power systems,PV plant productivity,data sheets information,key factor,module efficiency,nominal fill factor,nominal power,photovoltaic fields,photovoltaic module characterization,Europe,Photovoltaic systems,Productivity,Standards,Temperature,Fill factor,photovoltaic cell,photovoltaic cell characterization,photovoltaic field productivity,photovoltaic module ,Key (cryptography) ,Pv plant ,business ,nominal power ,photovoltaic fields ,Nominal power (photovoltaic) - Abstract
A key factor in the design of photovoltaic fields is their yearly productivity and normally the nominal power is the only module parameter taken into account in the productivity predictions. The present paper intends to demonstrate how this approach disregards an important parameter, the nominal fill factor, that may significantly affect module efficiency when working in realistic environmental conditions. A complete calculation method is presented to compute a module productivity in any operating condition, using data sheets information. As an example two commercial module characteristics with different fill factors are compared to illustrate the concept in quantitative terms.
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- 2014
3. 5-Phase PM brushless DC motor current optimization — Part I: Modelization and analytical solution for a healthy drive
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Giuseppe Buja, Nicola Barbini, Alberto Tessarolo, IEEE, Barbini, Nicola, Tessarolo, Alberto, and Buja, Giuseppe
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Engineering ,Optimization problem ,Maximum power principle ,Computer Networks and Communications ,current supply optimization ,Phase (waves) ,Energy Engineering and Power Technology ,Information System ,02 engineering and technology ,DC motor ,Artificial Intelligence ,Control theory ,Management of Technology and Innovation ,0202 electrical engineering, electronic engineering, information engineering ,Electrical and Electronic Engineering ,Ampere ,Instrumentation ,multi-phase ,Signal processing ,business.industry ,020208 electrical & electronic engineering ,020206 networking & telecommunications ,Fault tolerance ,fault tolerance ,PM BLDC motor ,Information Systems ,Signal Processing ,Computer Networks and Communication ,Magnet ,business - Abstract
This paper deals with the optimal fault-tolerant operation of a 5-phase permanent magnet (PM) brushless DC (BLDC) drive. In particular, this paper (Part I) proposes the modelization used to optimize the motor current supply to obtain the maximum power in healthy conditions and its analytical solution is presented. In the companion paper (Part II) the drive is considered both in healthy and faulty conditions and the optimization problem is solved numerically. In all cases the solution is compared with the one obtained with a “Maximum Torque Per Ampere” objective.
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- 2017
4. Design for Manufacturability of an Off-Shore Direct-Drive Wind Generator: An Insight into Additional Loss Prediction and Mitigation
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Alberto Tessarolo, Mauro Bortolozzi, Matteo De Martin, Stefano Pieri, F. Luise, Andrea Benedetti, Tessarolo, Alberto, Luise, Fabio, Pieri, Stefano, Benedetti, Andrea, Bortolozzi, Mauro, and DE MARTIN, Matteo
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Engineering ,Stator ,Electric generator ,wind generators ,02 engineering and technology ,01 natural sciences ,Automotive engineering ,Industrial and Manufacturing Engineering ,law.invention ,Generator (circuit theory) ,off-shore wind farms ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,wind generator ,Electrical and Electronic Engineering ,interior permanent-magnet (IPM) machines ,010302 applied physics ,Concentrated winding ,direct drive ,fault tolerance ,Control and Systems Engineering ,business.industry ,020208 electrical & electronic engineering ,interior permanent-magnet (IPM) machine ,Fault tolerance ,Reliability engineering ,Design for manufacturability ,Work (electrical) ,off-shore wind farm ,Scalability ,Reduction (mathematics) ,business - Abstract
Direct-drive generators to be used in off-shore wind farms are very large low-speed electric machines which pose remarkable design and manufacturing challenges. Demand forecasts for this kind of machines are urging manufacturers to work out design and technological solutions capable of facilitating series production at competitive costs. This paper presents the development of an interior-permanent magnet generator design and technology aimed at reducing series manufacturing costs while preserving good performance levels. The focus is placed on two of the most critical issues in the machine design and analysis, namely the prediction and reduction of eddy-current losses in stator conductors and in permanent magnets. The proposed design solutions are validated through the construction and testing of a 780 kVA generator prototype conceived for easy scalability to higher power ratings (up to around 2.5 MVA) by core length increase.
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- 2017
5. 5-Phase PM brushless DC motor current optimization - Part II: Modelization and numerical solution for a healthy or faulty drive
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Giuseppe Buja, Nicola Barbini, Alberto Tessarolo, IEEE, Barbini, Nicola, Tessarolo, Alberto, and Buja, Giuseppe
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Engineering ,Schedule ,Optimization problem ,Maximum power principle ,Computer Networks and Communications ,current supply optimization ,Energy Engineering and Power Technology ,Information System ,Fault (power engineering) ,DC motor ,Control theory ,Artificial Intelligence ,Management of Technology and Innovation ,Torque ,Electrical and Electronic Engineering ,Instrumentation ,multi-phase ,business.industry ,fault tolerance ,PM BLDC motor ,Information Systems ,Signal Processing ,Power (physics) ,Computer Networks and Communication ,Magnet ,business - Abstract
This paper deals with the optimal fault-tolerant operation of a 5-phase permanent magnet (PM) brushless DC (BLDC) drive. In particular, the companion paper (Part I) proposes the optimization of the current supply to obtain the maximum power in healthy conditions and its analytical solution. In the present paper (Part II), by constraining the proposed model with healthy and fault specific conditions, the magnitude schedule of the currents in the surviving phases is determined in order to obtain the maximum average power and the optimization problem is solved through a numerical approach. In all cases the solution is compared with the one obtained with a “Maximum Torque Per Ampere” criterion.
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- 2017
6. Shipboard Power Generation: Design and Development of a Medium-Voltage dc Generation System
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Alberto Tessarolo, A. Millerani Trapani, Giorgio Sulligoi, V. Benucci, M. Baret, F. Luise, Sulligoi, Giorgio, Tessarolo, Alberto, V., Benucci, A., Millerani Trapani, M., Baret, and F., Luise
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Alternator (automotive) ,Engineering ,Integrated power systems ,MVDC ,Energy Engineering and Power Technology ,Industrial and Manufacturing Engineering ,law.invention ,Electric power system ,law ,Power electronics ,ultra-high speed generators ,Electronic engineering ,Electrical and Electronic Engineering ,business.industry ,ultra-high speed generator ,Electrical engineering ,Integrated power system ,Insulated-gate bipolar transistor ,Converters ,Current injection technique ,Electricity generation ,all electric ship ,Control and Systems Engineering ,business ,Voltage - Abstract
This article reports on the design, development, and validation of advanced prototype 2 MVA generation equipment [i.e., naval package (NP)] for a shipboard medium-voltage dc integrated power system (MVDC IPS). The generation equipment is based on an ultrahigh-speed 22,500-r/min 12-phase alternator, which feeds an ac/dc power electronics converter comprising four diode rectifiers and four insulated-gate bipolar transistor (IGBT) choppers. The prototype realization constitutes a follow-up of a previous NP version employing a wound-field 6,300-r/min alternator feeding noncontrolled ac/dc converters. The major technical challenges faced in the design and development of the advanced NP prototype are outlined in this article, taking the previous lower-speed version as a technology reference. The system performance, as determined by the testing campaign, and lessons learned for future studies are addressed.
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- 2013
7. Investigation Into the High-Frequency Limits and Performance of Load Commutated Inverters for High-Speed Synchronous Motor Drives
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Roberto Menis, C. Bassi, A. Tessarolo, D. Giulivo, R. Macuglia, G. Ferrari, Tessarolo, Alberto, Bassi, C., Ferrari, G., Giulivo, D., Macuglia, R., and Menis, Roberto
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AC–AC power conversion ,variable-speed drives ,Engineering ,thyristor motor drives ,Stator ,AC motor ,rotating machine transient analysis ,law.invention ,rotating machine transient analysi ,law ,Control theory ,Thyristor drive ,Electronic engineering ,Electrical and Electronic Engineering ,synchronous motor drives ,business.industry ,synchronous motor drive ,thyristor motor drive ,Thyristor ,synchronous motor ,modeling ,synchronous motors ,Direct torque control ,Control and Systems Engineering ,Electromagnetic coil ,Synchronous motor ,business ,Induction motor - Abstract
Load commutated inverters (LCIs) are still widely used for their robustness and reliability in high-power synchronous motor drives, in either single or multiple three-phase configurations. A restriction to their use in high-speed applications is due to the criticalities of thyristor operation at high switching frequencies. The upper frequency limits of LCIs are usually addressed in the existing literature as something independent of the drive architecture. On the contrary, this paper highlights how the maximum frequency that can be safely attained closely relates to the number of LCIs that are used to supply the synchronous motor. In fact, moving from a single to multiple three-phase arrangements is proved to introduce more stringent frequency constraints due to the mutual interaction between stator windings during commutations. Frequency limits for safe operation of single- and multiple-LCI drives are derived in quantitative terms and experimentally assessed on a 2-MW synchronous motor fed by a couple of LCIs. Practical implications of such limits in the design of high-power high-speed drives are finally discussed.
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- 2013
8. Accurate Computation of Multiphase Synchronous Machine Inductances Based on Winding Function Theory
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Alberto Tessarolo and Tessarolo, Alberto
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Engineering ,business.product_category ,analysi ,analysis ,Stator ,Computation ,Energy Engineering and Power Technology ,Permanent magnet synchronous generator ,law.invention ,Quantitative Biology::Subcellular Processes ,law ,Control theory ,Electric machine design ,finite element methods ,Electrical and Electronic Engineering ,Electric machine ,business.industry ,analytical method ,modeling ,Finite element method ,Inductance ,analytical methods ,Synchronous motor ,business ,Air gap (plumbing) - Abstract
An electric machine equipped with n stator phases is characterized by a set of n × n phase inductances as concerns the stator section. In the case of nonuniform air gap, these inductances vary as the rotor moves. For their numerical determination as functions of the rotor position an accurate computation algorithm is proposed in this paper based on winding function theory. For permeance function identification, a numerically efficient method is employed based on the magnetostatic finite-element analysis of only three appropriately simplified machine models. In the presence of a field circuit, computation of mutual inductances among it and stator phases is also covered with the same approach. An extension of the method to permanent-magnet machines is also presented. Results are assessed on a six-phase synchronous generator prototype equipped with either a salient-pole wound-field rotor or with an interior permanent-magnet rotor.
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- 2012
9. Distributed current control for multi-three phase synchronous machines in fault conditions
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Alessandro Costabeber, S. Castellan, Chris Gerada, Alessandro Galassini, Michele Degano, Alberto Tessarolo, IEEE, Galassini, A., Costabeber, A., Degano, Michele, Gerada, C., Tessarolo, Alberto, and Castellan, Simone
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Engineering ,Reliability (computer networking) ,current control ,fault tolerance, Multi-three phase machine, current control ,02 engineering and technology ,Fault (power engineering) ,0202 electrical engineering, electronic engineering, information engineering ,Electronic engineering ,0501 psychology and cognitive sciences ,Aerospace ,MATLAB ,050107 human factors ,computer.programming_language ,Multi-three phase machine ,business.industry ,020208 electrical & electronic engineering ,05 social sciences ,Process (computing) ,Fault tolerance ,Control engineering ,Three-phase ,fault tolerance ,business ,computer ,Reference frame - Abstract
Among challenges and requirements of on-going electrification process and future transportation systems there is demand for arrangements with both increased fault tolerance and reliability. Next aerospace, power-train and automotive systems exploiting new technologies are delving for new features and functionalities. Multi-three phase arrangements are one of these novel approaches where future implementation of aforementioned applications will benefit from. This paper presents and analyses distributed current control design for asymmetrical split-phase schemes composed by symmetrical three phase sections with even number of phases. The proposed design within the dq0 reference frame in nominal, open and short circuit condition of one three-phase system is compared with the vector space decomposition technique and further validated by mean of Matlab/Simulink ~R simulations.
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- 2016
10. Design and testing of a new linear topology for electric machines
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Mario Mezzarobba, Alberto Tessarolo, IEEE, Mezzarobba, Mario, and Tessarolo, Alberto
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Electric motor ,Engineering ,business.product_category ,linear motor ,Stator ,02 engineering and technology ,01 natural sciences ,Wound rotor motor ,law.invention ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,wind generator ,outer permanent-magnet rotor ,rotating electrical machine ,track motor ,010302 applied physics ,Electric machine ,business.industry ,Squirrel-cage rotor ,020208 electrical & electronic engineering ,Electrical engineering ,Linear motor ,Linear motion ,business ,Linear topology - Abstract
A new linear topology is proposed in this paper for rotating electric machines. The design presented consists of an outer permanent-magnet rotor featuring the same structure as a flexible chain or track made of a sequence of ferromagnetic links connected together by hinges. Toothed wheels are used to convert the linear motion of the track-like rotor into a rotary torque to be transferred to the shaft. The stator portion is the same as for a double-sided linear electric machine. The proposed linear topology makes the electric machine suitable for installation in long thin compartments. A perspective application can be envisioned to direct drive wind generators: the linear machine topology makes the generator suitable for installation inside the wind tower, while conventional cylindrical generators need to be fit into the nacelle. The proposed design has been investigated by finite element analysis simulations and has been implemented into a technology demonstrator for experimental validation.
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- 2016
11. Failure root-cause analysis of end-ring torsional resonances and bar breakages in fabricated-cage induction motors
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Ezio Santini, Claudio Bruzzese, Alberto Tessarolo, IEEE, Bruzzese, C., Tessarolo, Alberto, and Santini, E.
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Engineering ,Bar (music) ,020209 energy ,02 engineering and technology ,Bending ,end ring ,bar breakage ,fabricated cage ,fatigue ,fault root-cause ,harmonic torque ,induction motor ,railway drive ,torsional resonance ,vibration ,law.invention ,Traction motor ,Bar breakage ,law ,0202 electrical engineering, electronic engineering, information engineering ,Torque ,business.industry ,Rotor (electric) ,020208 electrical & electronic engineering ,vibration, Bar breakage, end ring, fabricated cage, fatigue, fault root-cause, harmonic torque, induction motor, railway drive, torsional resonance ,Structural engineering ,Vibration ,Harmonic ,business ,Induction motor - Abstract
This work shows experimental evidences of abnormal end-ring torsional vibrations in fabricated cage induction motors and their role as root cause of bar breakages. A case-study of cage torsional resonances in railway traction motors is presented, which led to bar breakages with a peculiar failure pattern. A particular cage resonant mode (the second natural mode with both the rings vibrating in phase-opposition with respect to the rotor iron stack) is shown as responsible of excessive bar bending, fatigue, and bar fractures, through direct measurements of ring-stack oscillations in working motors. Cage torsions were excited by large harmonic torques due to inverter supply in the case considered. The mechanism of resonance-induced bar solicitations and fatigue is discussed, and the difference of failure pattern with respect to more common bar breakage mechanisms (overloads, heavy start-ups, etc.) is evidenced. Some theoretical models for modal frequency calculation are presented, which may help to identify the origin of vibrations and the fault root-cause in faulted drives. Dynamic simulations of the drive have been carried out for airgap torque calculation and bar length optimization.
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- 2016
12. Investigation into electrical resonance phenomena in the field circuit of wound-rotor synchronous machines
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Alberto Tessarolo, Edi Ciceran, F. Luise, IEEE, Tessarolo, Alberto, Ciceran, Edi, and Luise, Fabio
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Engineering ,02 engineering and technology ,Field circuit ,01 natural sciences ,Wound rotor motor ,law.invention ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Electronic engineering ,Exciter ,Overvoltage ,Electrical and Electronic Engineering ,Electrical resonance ,010302 applied physics ,Field excitation ,business.industry ,020208 electrical & electronic engineering ,Electrical engineering ,Line (electrical engineering) ,Overvoltages ,Wound rotor sunchronous machine ,Control and Systems Engineering ,Harmonics ,business ,Synchronous motor ,Pulse-width modulation ,Excitation - Abstract
The field circuit of wound-rotor synchronous machines can be supplied in various ways, including brushed and brushless excitation systems. Regardless of whether the synchronous machine is equipped with a rotating exciter or not, the external excitation power source necessarily injects some high-frequency harmonics into the field circuit. The frequency of these harmonics can be particularly large if Pulse-Width-Modulated (PWM) converters are used as excitation voltage supply. This paper investigates the possibility that the excitation supply harmonics can produce electrical resonance phenomena resulting in possibly harmful overvoltages. The investigation is carried out through different approaches: by experiments on a low-voltage salient-pole 20-kVA laboratory prototype; by experiments on a large (multi-MW) round-rotor synchronous motor; through an analytical model. The results obtained from the analytical model are shown to well match measurements provided that a resistive parameter (affected by eddy-current loss effects) is properly calibrated. Another important conclusion is that the possible overvoltages due to electrical resonance would occur between internal points of the field (not between its terminals) and would not be thereby damped by conventional field circuit protection devices.
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- 2016
13. Study of eccentric round-rotor synchronous machines through conformal mapping. Part I: Inductances and air-gap field
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Alberto Tessarolo, Claudio Bruzzese, IEEE, Tessarolo, Alberto, and Bruzzese, C.
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electric machine modeling ,Engineering ,business.industry ,020208 electrical & electronic engineering ,Mathematical analysis ,Conformal map ,conformal mapping ,Moebius transformation ,rotor eccentricity ,02 engineering and technology ,Permeance ,Finite element method ,Conformal mapping ,symbols.namesake ,Classical mechanics ,0202 electrical engineering, electronic engineering, information engineering ,symbols ,Eccentric ,Series expansion ,Rotor eccentricity ,Air gap (plumbing) ,business ,Möbius transformation - Abstract
The study of electric machines subject to rotor eccentricity is usually performed using a winding and permeance function approach. In this paper, an alternative method is investigated based on conformal mapping. The geometry of a an eccentric round-rotor machine is mapped into a uniform air-gap topology by means of Moebius conformal map. The mathematical details of the method are provided along with explicit formulas to compute the air-gap field and inductances of the eccentric machine. It shown how, unlike conventional winding-function theory, the proposed method yields closed-form formulas which do not involve series expansions nor require numerical integrations and are thus particularly fit for implementation into fast simulation programs. Such expressions are assessed by comparison with Finite Element Analysis (FEA).
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- 2016
14. Actuation of ship stabilizing fins by a permanent magnet linear synchronous motor drive servoed to the hydraulic motor
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Ezio Santini, T. Mazzuca, Claudio Bruzzese, M. Rafiei, G. Lipardi, D. Zito, Alberto Tessarolo, IEEE, Zito, D., Bruzzese, C., Rafiei, M., Santini, E., Mazzuca, T., Tessarolo, Alberto, and Lipardi, G.
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Direct drive ,Engineering ,fullelectric drive ,ship ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Thrust ,02 engineering and technology ,AC motor ,Automotive engineering ,0203 mechanical engineering ,Control theory ,direct drive ,efficiency ,fault tolerance ,fin stabilizer ,hydraulic drive ,permanent magnet linear motor ,stabilizing fins ,renewable energy, sustainability and the environment ,automotive engineering ,0202 electrical engineering, electronic engineering, information engineering ,Hydraulic machinery ,stabilizing fin ,Hydraulic motor ,business.industry ,020208 electrical & electronic engineering ,020302 automobile design & engineering ,Fault tolerance ,Linear motor ,renewable energy ,Dual (category theory) ,sustainability and the environment ,Synchronous motor ,business - Abstract
This paper investigates the hydraulic system drive used onboard ships to actuate stabilizing fins. The hydraulic drives are often characterized by low efficiencies, heavy maintenance, frequent oil leaks and large weight and size. To overcome these draw-backs, in this paper a concept design of a full-scale permanent magnet linear synchronous motor directly coupled to the shipboard fin stabilizer, is presented, used as a servo-motor. The innovative electric drive is based on prototype of high thrust linear motor built in a previous research. A complete Simulink model, where electric, mechanical and hydraulic domains can be connected, has been realized. Simulations has been performed to evaluate the hydraulic drive efficiency and in order to assess the servo-assistance capabilities. The results show the feasibility of the proposed solution for a future practical application. This research has been carried out in the framework of the Italian Defence Research National Program for the development of ‘dual use’ technologies.
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- 2016
15. Study of eccentric round-rotor synchronous machines through conformal mapping. Part II: Unbalanced magnetic pull
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Claudio Bruzzese, Alberto Tessarolo, IEEE, Tessarolo, Alberto, and Bruzzese, C.
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Engineering ,Conformal map ,Geometry ,Topology (electrical circuits) ,02 engineering and technology ,Permeance ,conformal mapping ,electric machine modeling ,Moebius transformation ,rotor eccentricity ,Topology ,law.invention ,Conformal mapping ,symbols.namesake ,law ,0202 electrical engineering, electronic engineering, information engineering ,Möbius transformation ,Rotor (electric) ,business.industry ,020208 electrical & electronic engineering ,Function (mathematics) ,Finite element method ,symbols ,Series expansion ,business - Abstract
The study of electric machines subject to rotor eccentricity is usually performed using a winding and permeance function approach. In a companion paper, an alternative method is investigated based on conformal mapping. The geometry of a an eccentric round-rotor machine has been mapped into a uniform air-gap topology by means of Moebius conformal map. In this paper, the approach is used to derive explicit formulas to compute the unbalanced magnetic pull of the eccentric machine. It shown how, unlike conventional winding-function theory, the proposed method yields closed-form formulas which do not involve series expansions nor require numerical integrations and are thus particularly fit for implementation into fast simulation programs. Such expressions are assessed by comparison with Finite Element Analysis (FEA).
- Published
- 2016
16. A new method for the analytical determination of the complex relative permeance function in linear electric machines with slotted air gap
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Matteo Olivo, Alberto Tessarolo, IEEE, Tessarolo, Alberto, and Olivo, Matteo
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Engineering ,Control and Optimization ,Field (physics) ,Conformal map ,Carter coefficient ,02 engineering and technology ,Permeance ,Air gap field ,analytical methods ,modeling ,permeance function ,slotting effect ,Automotive Engineering ,Mechanical Engineering ,Electrical and Electronic Engineering ,01 natural sciences ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Electronic engineering ,Boundary value problem ,010302 applied physics ,business.industry ,020208 electrical & electronic engineering ,Mathematical analysis ,analytical method ,Function (mathematics) ,Finite element method ,Magnetic field ,business ,Air gap (plumbing) - Abstract
The complex relative permeance function is a useful mathematical tool to study the magnetic field of electric machines with slotted air gap. In the literature, the complex permeance function is usually identified by means of numerical techniques based on conformal mapping. In this paper an alternative analytical approach is proposed. The method is based on solving the magnetostatic differential field equation over a portion of the slotted air gap by imposing suitable boundary conditions in the slot opening region. Such boundary conditions exploit the mathematical law which governs the divergence of the magnetic field in the neighborhood of corner-shaped ferromagnetic regions. Furthermore, the results of Carter theory on slot fringing effects on the air gap field are used. A simple easy-to-compute formula is obtained for the complex permeance function. Its accuracy is assessed by comparison with Finite Element Analysis (FEA).
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- 2016
17. Efficiency issues of a ship stabilizing fin assisted by a permanent magnet linear synchronous actuator
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M. Rafiei, Alberto Tessarolo, Claudio Bruzzese, T. Mazzuca, G. Lipardi, Ezio Santini, D. Zito, IEEE, Zito, D., Bruzzese, C., Rafiei, M., Santini, E., Mazzuca, T., Tessarolo, Alberto, and Lipardi, G.
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Electric motor ,Engineering ,Fin ,electrical and electronic engineering ,02 engineering and technology ,Automotive engineering ,0203 mechanical engineering ,Encumbrance ,0202 electrical engineering, electronic engineering, information engineering ,Hydraulic machinery ,direct drive ,efficiency ,full-electric drive ,hydraulic drive ,permanent magnet linear motor ,stabilizing fins ,mechanical engineering ,business.industry ,020208 electrical & electronic engineering ,020302 automobile design & engineering ,Control engineering ,Linear actuator ,Navy ,stabilizing fins, Direct drive, efficiency, full-electric drive, hydraulic drive, permanent magnet linear motor ,Magnet ,Actuator ,business - Abstract
Alternatives to hydraulic drives used on board ship are under study for the Italian Navy in order to reduce the use of the oil which cause environmental problems and high cost. The hydraulic system drive used onboard ship are affected by low efficiencies and generally require intensive maintenance, very high encumbrance. So that the Italian Navy has commissioned a research project for the construction and installation of an innovative oil-free electric drive based on a permanent magnet linear actuator. The new electric motor is more efficient, fault-tolerant, reduces the encumbrance and ensures a greater control.
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- 2016
18. Optimization of a SPM machine using a non-isotropic magnetic wedge with an analytical method for cogging torque estimation
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Lorenzo Branz, Alberto Tessarolo, Mario Mezzarobba, IEEE, Tessarolo, Alberto, Branz, Lorenzo, and Mezzarobba, Mario
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Engineering ,business.product_category ,magnetic wedges ,Stator ,finite element analysis ,Machine design ,01 natural sciences ,law.invention ,cogging torque ,Control theory ,law ,Analytical methods ,0103 physical sciences ,genetic algorithm ,surface permanent magnet machines, Analytical methods, cogging torque, design optimization, finite element analysis, genetic algorithm, magnetic wedges ,010302 applied physics ,business.industry ,Isotropy ,Cogging torque ,design optimization ,Wedge (mechanical device) ,Finite element method ,Quantitative Biology::Quantitative Methods ,Magnet ,surface permanent magnet machines ,Minification ,business - Abstract
Cogging torque is a known disadvantage of surface permanent magnet (SPM) machines, especially if equipped with open stator slots. A possible strategy to reduce the cogging torque is to use suitably designed non-isotropic magnetic wedges. The design of such wedges for cogging torque minimization requires a genetic optimization approach. This has been done in previous works using Finite Element Analysis (FEA) simulations to predict the cogging torque for each machine design being explored, leading to a very time consuming optimization process. In this paper, the same optimization is performed using an analytical method to compute the cogging torque. It is shown that the optimization process, based on the analytical formula for cogging torque prediction, leads to the same result as the FEA-based procedure, but with a significant reduction in the computational burden.
- Published
- 2016
19. Improved four-layer winding design for a 12-slot 10-pole permanent magnet machine using unequal tooth coils
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Mario Mezzarobba, Alberto Tessarolo, Nicola Barbini, IEEE, Tessarolo, Alberto, Mezzarobba, Mario, and Barbini, Nicola
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Engineering ,02 engineering and technology ,Topology ,Network topology ,01 natural sciences ,law.invention ,Tooth coil ,Permanent magnet machine ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Unequal coil ,Torque ripple ,Electrical and Electronic Engineering ,Armature (electrical engineering) ,010302 applied physics ,Unequal coils ,Concentrated winding ,business.industry ,Permanent magnet machines ,020208 electrical & electronic engineering ,Electrical engineering ,Finite element method ,Fractional slot winding ,Multiple layer ,Tooth coils ,Control and Systems Engineering ,Electromagnetic coil ,Harmonics ,Magnet ,business ,Air gap (plumbing) - Abstract
Fractional slot windings based on concentrated tooth coils are frequently used in today's electric machines. A drawback of these windings is the occurrence of large space harmonics in the air gap, which can cause torque ripple issues and rotor additional losses. Various provisions have been proposed in the literature to improve the air-gap harmonic content due to concentrated-winding armature reaction. This paper proposes an enhancement based on a multiple-layer design characterized by tooth coils with different number of turns. The improvement is proposed for 12-slot 10-pole permanent magnet machines but can be generalized to other possible topologies. It is shown that the proposed approach leads to the same air-gap field harmonic content as for a dual-three-phase dual-layer winding with all space harmonics reduced by the same coefficient (equal to 0.928). Pros and contras of the proposed design with respect to other existing improved solutions are highlighted in the paper. Comparisons and assessments are provided based on Finite Element Analysis (FEA).
- Published
- 2016
20. Time-Stepping Finite-Element Analysis of a 14-MVA Salient-Pole Shipboard Alternator for Different Damper Winding Design Solutions
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D. Giulivo, Alberto Tessarolo, C. Bassi, Bassi, C., Giulivo, D., and Tessarolo, Alberto
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Alternator (automotive) ,Engineering ,business.industry ,design ,modeling ,Control engineering ,Electric machine ,finite element analysis ,Electric machines ,Finite element method ,Damper ,law.invention ,Generator (circuit theory) ,Inductance ,Shock absorber ,Control and Systems Engineering ,law ,Control theory ,Calibration ,Electrical and Electronic Engineering ,business ,Electrical impedance - Abstract
Salient-pole synchronous machines are conventional electric machines which have been widely used and studied over decades. Some aspects of their modeling and analysis, however, still constitute a challenge for designers and require state-of-the-art methodologies to be applied. As an example, this paper addresses a 14-MVA salient-pole shipboard alternator, of which full-scale prototypes are built and tested with different damper cage designs. A time-stepping finite-element (FE) analysis is assessed against test results as a method to predict generator performance for the various damper cage design alternatives. FE simulations are shown to give accurate results even without model tuning if continuous end rings are used to short circuit damper bars. For the design solution with partial end arcs, model tuning is required, instead. For this purpose, a calibration method is proposed and successfully validated, which only requires a set of impedance measurements to be taken on the machine at standstill
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- 2012
21. Sizing and simulation of an inverter-fed permanent-magnet linear synchronous drive for servo-assistance of a ship steering gear
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D. Zito, Ezio Santini, Alberto Tessarolo, Claudio Bruzzese, A. Raimo, IEEE, Zito, D., Bruzzese, C., Raimo, A., Santini, E., and Tessarolo, Alberto
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Direct drive ,Engineering ,ship ,Energy Engineering and Power Technology ,permanent magnet linear motor ,electric drives ,hydraulic drives ,Automotive engineering ,rudder steering gear ,efficiency ,fault tolerance ,force-performance ,full-electric drive ,hydraulic drive ,servo-assistance ,Renewable Energy, Sustainability and the Environment ,Renewable Energy ,Oscilloscope ,Winch ,Sustainability and the Environment ,business.industry ,Control engineering ,Fault tolerance ,Rudder ,Sizing ,Magnet ,Inverter ,business ,Servo - Abstract
Hydraulic drives used on board ship to empower rudders, stabilizing fins, anchor winches, etc., are often characterized by low efficiencies, heavy maintenance, frequent oil leaks and large weight and size. To overcome these drawbacks, oil-free inverter-fed alternative drives can be conceived. In this paper a concept design of a full-scale permanent magnet linear synchronous motor directly coupled to a twin rudder on board ship is presented, used as a servo-motor. The servo-assistance capabilities are simulated and evaluated by using a complete model of the electro-mechanic-hydraulic system in Simulink environment. The results show the effectiveness of the electromagnetic drive servo-assistance. This research has been carried out in the framework of the Italian Defence Research National Program for the development of `dual use' technologies.
- Published
- 2015
22. An improved analytical expression for computing the leakage inductance of a circular bar in a semi-closed slot
- Author
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Lorenzo Branz, Mauro Bortolozzi, Claudio Bruzzese, Alberto Tessarolo, IEEE, Bortolozzi, Mauro, Branz, Lorenzo, Tessarolo, Alberto, and Bruzzese, Claudio
- Subjects
semiclosed slot ,Engineering ,quirrel cage induction motors ,Saturation magnetization ,Poisson equation ,conductors (electric) ,finite element analysis ,induction motors ,magnetic leakage ,FEA ,approximated analytical formula ,circular bar leakage inductance computing ,electric machinery construction ,induction motor ,round conductive bar ,Geometry ,Inductance ,Induction motors ,Magnetic analysis ,Magnetic domains ,Analytical methods ,Poisson's equation ,rotor leakage inductance ,semi-closed slots ,squirrel cage induction motors ,Analytical method ,law.invention ,Magnetic analysi ,law ,Eddy current ,Electronic engineering ,Electrical conductor ,Leakage inductance ,business.industry ,Squirrel-cage rotor ,Mathematical analysis ,emi-closed slot ,finite element analysi ,Finite element method ,analytical methods ,emiclosed slot ,business ,Induction motor ,Magnetic domain - Abstract
Round conductive bars embedded in semi-closed slots are frequently used in the construction of electric machinery, for instance in the squirrel cage of induction motors. Frequently, such as in the study of induction motor steady-state performance at rated slip, it is useful to estimate the slot leakage inductance of these conductors under the hypothesis of no eddy currents and no magnetic saturation. This is usually done through simple approximated analytical formulas available in the literature. In this paper, an improved explicit ready-to-use leakage inductance expression for circular bars embedded in semi-closed slots is derived by solving Poisson's equation in the slot domain. The precision of the proposed formulation is assessed against Finite Element Analysis (FEA) for various slot geometries and is shown to always give very accurate results, with errors below 2%. Conversely, approximated simplified formulas available from the literature are demonstrated to possibly give large errors, which exceed 20% for some explored slot geometries.
- Published
- 2015
23. Improved analytical computation of rotor rectangular slot leakage inductance in squirrel-cage induction motors
- Author
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Alberto Tessarolo, Lorenzo Branz, Claudio Bruzzese, Mauro Bortolozzi, IEEE, Bortolozzi, Mauro, Branz, Lorenzo, Tessarolo, Alberto, and Bruzzese, Claudio
- Subjects
Engineering ,Xenon ,squirrel-cage induction motor ,squirrel cage motors ,squirrel cage motor ,bars ,finite element analysis ,electric machinery ,Poisson equation ,Analytical method ,inductance ,bar ,Mathematical model ,Radio frequency ,Yttrium ,Induction motor ,Leakage (electronics) ,equivalent circuit parameters ,rotor leakage inductance ,equivalent circuit ,Finite element method ,rotors ,Inductance ,Poisson's equation ,rectangular-shaped bars ,rotor rectangular slot leakage inductance improved analytical computation ,squirrel cage induction motors ,equivalent circuits ,magnetic leakage ,FEA ,slot domain ,time-consuming finite-element analyses ,Induction motors ,Analytical methods ,rectangular-shaped bar ,analytical methods ,Control theory ,Electronic engineering ,equivalent circuit parameter ,Leakage inductance ,business.industry ,Squirrel-cage rotor ,finite element analysi ,time-consuming finite-element analyse ,Equivalent circuit ,rotor ,business - Abstract
Squirrel-cage induction motors are the most widely used type of electric machinery in industrial applications thanks to their rugged, cheap and robust construction. For the fast prediction of induction motor steady-state performance without the need for time-consuming finite-element analyses, the equivalent circuit parameters of the machine need to be calculated, including rotor slot leakage inductances. This paper, in particular, proposes a new improved analytical formula to determine the rotor slot leakage inductance in squirrel-cage induction motors with rectangular-shaped bars. The formula is obtained by solving Poisson's equation in the slot domain. Results are assessed by comparison against Finite Element Analysis (FEA). The precision of the presented methodology is also compared to that of approximated analytical models available from the literature. The comparison shows that the accurate formula proposed is in excellent agreement with FEA with errors below 2%, while the simplified model generally leads to errors above 10% which increase as the height-to-width bar ratio decreases.
- Published
- 2015
24. Stator inductance matrix diagonalization algorithms for different multi-phase winding schemes of round-rotor electric machines part I. theory
- Author
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Alberto Tessarolo, Mauro Bortolozzi, Lorenzo Branz, IEEE, Tessarolo, Alberto, Branz, Lorenzo, and Bortolozzi, Mauro
- Subjects
leakage inductances ,Engineering ,Stator ,multiphase winding ,inductance ,law.invention ,stator inductance matrix diagonalization algorithms ,Harmonic analysis ,Matrix (mathematics) ,law ,round rotor electric machines ,control system synthesi ,Diagonalization ,Symmetric matrix ,stator harmonic impedance determination ,Air gaps ,control system analysi ,multiphase windings ,stator ,split-phase windings ,Stator winding ,Winding ,machine control ,multiphase machine ,Inductance ,control system synthesis ,stator inductance matrix diagonalization algorithm ,Air gap ,Algorithm ,Symmetric matrice ,Diagonalizable matrix ,multiphase machines ,independently controllable system ,leakage inductance ,stators ,Windings ,Symmetric matrices ,modelling ,stator winding ,Control theory ,control system analysis ,matrix algebra ,Stator windings ,Machine control ,round rotor electric machine ,business.industry ,Electromagnetic coil ,business ,Harmonic analysi - Abstract
The stator winding of multi-phase machines can be designed according to different schemes, which differ by either the number or the spatial arrangement of phases. For control and analysis purposes, it is often useful that the stator inductance matrix is reduced to a diagonal form. This allows for the multiphase machine to be split into independently-controllable systems and directly leads to stator harmonic impedance determination. Simple and compact diagonalization algorithms are established in this paper covering all possible multi-phase schemes of practical importance with a unified approach, under the hypothesis of uniform air-gap and negligible magnetic saturation. In a companion paper, All the proposed equations are experimentally assessed though dedicated tests on several multiphase winding schemes.
- Published
- 2015
25. Design for manufacturability of an off-shore direct-drive wind generator
- Author
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Stefano Pieri, M. De Martin, Alberto Tessarolo, F. Luise, IEEE, Tessarolo, Alberto, Luise, Fabio, Pieri, Stefano, and DE MARTIN, Matteo
- Subjects
Shore ,geography ,Engineering ,geography.geographical_feature_category ,Wind generator ,Concentrated winding ,business.industry ,wind generators ,Fault tolerance ,Permanent magnet synchronous generator ,Automotive engineering ,direct-drive ,Design for manufacturability ,off-shore wind farms ,fault tolerance ,interior permanent magnet machines ,Generator (circuit theory) ,Work (electrical) ,off-shore wind farm ,Scalability ,interior permanent magnet machine ,business - Abstract
Direct-drive generators to be used in off-shore wind farms are very large low-speed electric machines which pose remarkable design and manufacturing challenges. Demand forecasts for this kind of machines are urging manufacturers to work out design and technological solutions that can facilitate series production at competitive costs. This paper presents the development of an interior-permanent magnet generator design and technology aimed at reducing series manufacturing costs while preserving high performance levels. The proposed solutions are validated through the construction and testing of a 780 kVA generator prototype conceived for easy scalability to higher power ratings (up to around 2.5 MVA) by core length increase.
- Published
- 2015
26. Leakage Field Analytical Computation in Semiclosed Slots of Unsaturated Electric Machines
- Author
-
Alberto Tessarolo and Tessarolo, Alberto
- Subjects
leakage inductances ,Engineering ,electric machines ,Magnetic domain ,Computation ,Energy Engineering and Power Technology ,Geometry ,Boundary condition ,Electric machine ,leakage inductance ,Analytical method ,Magnetic cores ,Mathematical model ,Magnetic core ,Analytical methods ,Electronic engineering ,Boundary value problem ,Electrical and Electronic Engineering ,Inductance ,Leakage (electronics) ,Magnetic domains ,Boundary conditions ,Electric machines ,semiclosed slots ,business.industry ,Magnetic flux leakage ,Mechanics ,Finite element method ,business - Abstract
Slot leakage field accounts for an important quota of the total leakage flux in electric machines. The computation of unsaturated slot leakage inductances can rely on analytical formulas for simple open slot shapes, while the case of semiclosed slots is more critical and typically requires finite element analysis (FEA) or analytically solving the field over the whole machine domain. This paper sets forth an analytical procedure for computing the leakage field in semiclosed slots of unsaturated electric machines. The method is based on solving Maxwell's equations in the slot domain alone, which is made possible by appropriately defining boundary conditions in the slot opening region. The method proposed is assessed by comparison with FEA. Validations indicate that a good accuracy is achieved by the presented approach in predicting unsaturated leakage inductances, while FEA is required when magnetic saturation effects need to be taken into account.
- Published
- 2015
27. An Algebraic Approach to Determine the Current Supply in a Faulty 5-Phase PM BLDC Drive. Part II – Application to the Cases of Two and Three Open Phase Faults
- Author
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Giuseppe Buja, Syamnaresh Garlapati, Alberto Tessarolo, IEEE, Garlapati, Syamnaresh, Buja, Giuseppe, and Tessarolo, Alberto
- Subjects
Engineering ,Integrated circuit ,DC motor drives ,permanent magnet motor ,5-phase permanent magnet brushless DC drive fault-tolerant operation ,torque ,Integrated circuits ,5-phase PM BLDC drive ,torque ripple ,law.invention ,Scheduling (computing) ,motor torque reduction ,Root mean square ,three open phase fault location ,two open phase fault ,Control theory ,law ,current supply determination ,current supply modeling ,Torque ,brushless DC motor ,Torque ripple ,fault location ,Algebraic number ,business.industry ,brushless DC motors ,DC motor drive ,Motor torque ,algebraic approach ,permanent magnet motors ,nominal RMS value ,fault-tolerant applications ,Magnet ,business - Abstract
This paper (Part II), together with a companion one (Part I), deals with the fault-tolerant operation of a 5-phase permanent magnet (PM) brushless DC (BLDC) drive. In particular, this paper takes advantage of the drive model formulated in Part I to determine automatically the motor current supply, namely scheduling and magnitude of the currents for the surviving phases, in the cases of a drive with two and three open phase faults. Maximum magnitude of the supply currents is also determined by equating the rms value of current in the most solicited phase to the nominal rms value Open faults of adjacent and non-adjacent phases are studied and for each fault location, besides determining the motor current supply, the torque developed by the motor is calculated. The results indicate that the reduction in the motor torque as well as the extent of the torque ripple is depending on the relative location of the faults.
- Published
- 2015
28. Numerical multi-objective optimization of a squirrel cage induction motor for industrial application
- Author
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Stefano Pieri, F. Luise, Matteo De Martin, Alberto Tessarolo, Carlo Poloni, IEEE, DE MARTIN, Matteo, Luise, Fabio, Pieri, Stefano, Tessarolo, Alberto, and Poloni, Carlo
- Subjects
Engineering ,geometry ,magnetostatic finite elements analysis ,optimisation ,punctual frequency values ,squirrel cage motor ,squirrel cage motors ,punctual frequency value ,finite element analysis ,optimization process ,Multi-objective optimization ,geometrical variable ,punctual current values ,equivalent circuits ,gas industry ,magnetostatics ,petroleum industry ,FEA ,ModeFRONTIER commercial software ,T-type equivalent circuit ,geometrical variables ,induction machine power density maximization ,industrial applications ,international oil&gas industry regulations ,numerical multiobjective optimization ,squirrel cage induction motor ,time harmonic finite elements analysis ,Equivalent circuits ,Induction motors ,Optimization ,Rotors ,Stator windings ,Torque ,Equivalent circuit ,finite elements analysis Induction motor ,international oil&gas industry regulation ,Rotor ,Induction motor ,magnetostatic ,Stator winding ,industrial application ,magnetostatic finite elements analysi ,Performance prediction ,Commercial software ,business.industry ,Squirrel-cage rotor ,punctual current value ,Control engineering ,finite element analysi ,business ,time harmonic finite elements analysi ,Voltage - Abstract
This paper reports the optimization process of a MW-size, medium voltage, squirrel cage induction motor for industrial applications. Starting from an existing construction, the aim of the optimization is to maximize the induction machine power density, while fulfilling high demanding, specific international Oil&Gas industry regulations. For every considered design, the motor performance is estimated by means of an algorithm based on T-type equivalent circuit. The circuit parameters are determined with a combination of magnetostatic and time harmonic Finite Elements Analysis (FEA), together with analytical formulas. This approach allows the evaluation of the precise parameters dependency on punctual current and frequency values, and allows good performance prediction ability. The multi-objective optimization process input are geometrical variables related to the motor electromagnetic configuration having direct impact on the output performance, is based on Genetic Algorithms (GA), and has been developed with the commercial software ModeFRONTIER®.
- Published
- 2015
29. Multiphase electrical machines and drives in the transportation electrification
- Author
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Alberto Tenconi, Silvio Vaschetto, A. Tessarolo, Radu Bojoi, Andrea Cavagnino, IEEE, Bojoi, R., Cavagnino, A., Tenconi, A., Tessarolo, Alberto, and Vaschetto, S.
- Subjects
Engineering ,transportation electrification ,Powertrain ,business.industry ,redundancy ,multiphase electrical machines ,Fault tolerance ,transportation electrificat ion ,Propulsion ,Technical literature ,Automotive engineering ,Electrification ,multiphase drive ,fault tolerance ,multiphase drives ,Paradigm shift ,Torque ,business ,Actuator ,multiphase electrical machine ,multiphase electrical machines, multiphase drives, transportation electrificat ion, fault tolerance, redundancy - Abstract
Transport industry is facing a paradigm shift towards the most promising and sustainable solution represented by the transportation electrification. This concept has not only been adopted for the propulsion powertrains, but also for the auxiliary systems. Indeed, in the last few decades electrification has come to smart actuators to improve both safety and comfort of the passengers. In this contest, multiphase electrical machines and drives represent a promising solution to satisfy the challenging requirements imposed by the applications, such as reduced weight and volume, high efficiency, low vibrations and noise, robustness and fault tolerance. With reference to the technical literature and applications, this paper presents an overview of the multiphase technology for the transportation electrification in road vehicle, rail vehicles, air transports and shipboard applications.
- Published
- 2015
30. Design for Improved Fault Tolerance in Large Synchronous Machines
- Author
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A. Tessarolo, F. Luise, IEEE, Tessarolo, Alberto, and Luise, Fabio
- Subjects
Electric motor ,Engineering ,Wind power generation ,Concentrated winding ,business.industry ,Condition monitoring ,Control engineering ,Fault tolerance ,Propulsion ,Fault (power engineering) ,Concentrated windings ,large synchronous machines ,large synchronous machine ,Scalability ,fault tolerance ,permanent magnet ,wound field ,Systems design ,business - Abstract
Fault tolerance is a basic requirement for modern electric motors and generators and can be achieved with a number of integrated approaches, like condition monitoring, post-fault control strategies and suitable system design architectures. In particular, this paper focuses on large synchronous machines (both permanent-magnet and wound-field ones) and discusses the main design provisions that can be adopted to improve their ability to withstand various kinds of fault. The fault-tolerant design solutions recommended for small-power machines are critically reviewed and their scalability to higher machine sizes is discussed also referring to practical industrial realizations. The most promising potential for fault-tolerance design is recognized in large low-speed high-pole-count permanent-magnet synchronous machines (e.g. for ship propulsion and wind power generation) thanks to their suitability for highly-modular multi-unit fractional-slot concentrated-winding architectures.
- Published
- 2015
31. Stator inductance matrix diagonalization algorithms for different multi-phase winding schemes of round-rotor electric machines. Part II, Examples and validations
- Author
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Lorenzo Branz, Mauro Bortolozzi, Alberto Tessarolo, IEEE, Tessarolo, Alberto, Branz, Lorenzo, and Bortolozzi, Mauro
- Subjects
leakage inductances ,Engineering ,Stator ,multiphase winding ,prototypes ,controllable systems ,inductance ,law.invention ,Harmonic analysis ,stator inductance matrix diagonalization algorithms ,windings ,symmetric matrice ,law ,spatial arrangement ,Symmetric matrix ,stator harmonic impedance determination ,reconfigurable stator winding ,multiphase windings ,stator ,multiphase winding scheme ,split-phase windings ,controllable system ,machine control ,multiphase machine ,winding ,Inductance ,rotors ,round-rotor electric machine ,symmetric matrices ,Air gap (plumbing) ,stator inductance matrix diagonalization algorithm ,Algorithm ,electric machines ,air gap ,harmonic analysi ,Diagonalizable matrix ,multiphase machines ,leakage inductance ,round-rotor electric machines ,stators ,multiphase schemes ,modelling ,air gaps ,stator winding ,multiphase scheme ,magnetic saturation ,Machine control ,multiphase winding schemes ,business.industry ,diagonalization ,stator windings ,electric machine ,Electromagnetic coil ,harmonic analysis ,rotor ,prototype ,business ,air-gap - Abstract
The stator winding of multi-phase machines can be designed according to different schemes, which differ by either the number or the spatial arrangement of phases. For control and analysis purposes, it is often useful that the stator inductance matrix is reduced to a diagonal form. This allows for the multiphase machine to be split into independently-controllable systems and directly leads to stator harmonic impedance determination. Simple and compact diagonalization algorithms have been established in a companion paper covering all possible multiphase schemes of practical importance with a unified approach, under the hypothesis of uniform air-gap and negligible magnetic saturation. In this paper, the theory and algorithms proposed for inductance matrix diagonalizations are illustrated and validated by applying them on a on several multi-phase winding schemes implemented in a prototype machine with a reconfigurable stator winding.
- Published
- 2015
32. A hybrid experimental drive concept of permanent magnet linear direct actuator servoed to a ship's hydraulic rudder
- Author
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D. Zito, Alberto Tessarolo, Claudio Bruzzese, Ezio Santini, A. Raimo, IEEE, Zito, D., Bruzzese, C., Raimo, A., Santini, E., and Tessarolo, Alberto
- Subjects
linear machine ,Engineering ,linear synchronous motor ,ship ,gears ,hydraulic actuators ,hydraulic drives ,invertors ,linear synchronous motors ,permanent magnet motors ,ships ,synchronous motor drives ,Italian Defence Research National Program ,electromagnetic drive servo-assistance ,electromechanichydraulic system ,fins stabilization ,hydraulic drive ,linear machines ,oil-free inverter-fed alternative drive ,permanent magnet linear direct actuator hybrid experimental drive concept ,permanent magnet linear synchronous motor ,servomotor ,ship hydraulic rudder ,steering gear ,twin rudder ,Gears ,Hydraulic drives ,Direct drive ,efficiency ,fault tolerance ,force-performance ,full-electric drive ,permanent magnet linear motor ,rudder steering gear ,servo-assistance ,Gear ,Field (computer science) ,Automotive engineering ,invertor ,Winch ,Hydraulic motor ,synchronous motor drive ,Hydraulic drive ,Rudder ,Efficient energy use ,permanent magnet motor ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,business.industry ,Control engineering ,Fault tolerance ,hydraulic actuator ,direct drive ,forceperformance ,Magnet ,business ,Actuator - Abstract
The use of linear machines (LMs) is increasing in research and industry fields. All kinds of LMs are studied: synchronous, induction, flux switching. Research is leading to overcome the known drawbacks of all these machines. Anyway the use of innovative direct-drive solutions are under study to obtain more efficient energy conversion, such as for marine field. As alternative to classical systems, linear force can be used to obtain a more efficient plant. Hydraulic drives used on board ship to empower rudders, stabilizing fins, anchor winches, etc., are often characterized by low efficiencies, heavy maintenance, frequent oil leaks and large weight and size. To overcome these drawbacks, an oil-free inverter-fed alternative drives can be conceived. In this paper a concept design of full-scale permanent magnet linear synchronous motor directly coupled to a twin rudder on board ship is presented, used as a servo-motor. A complete model of the electro-mechanic-hydraulic system in Simulink environment was built. Several simulations are performed to evaluate the servo-assistance capabilities. The results show the effectiveness of the electromagnetic drive servo-assistance and an increased overall efficiency of the steering gear. This research has been carried out in the framework of the Italian Defence Research National Program for the development of `dual use' technologies.
- Published
- 2015
33. Performance and Efficiency Improvement of a Hydraulic Ship Steering Gear by a Permanent Magnet Linear Synchronous Servo-Motor
- Author
-
Ezio Santini, D. Zito, Claudio Bruzzese, A. Raimo, Alberto Tessarolo, IEEE, Zito, D., Bruzzese, C., Santini, E., Raimo, A., and Tessarolo, Alberto
- Subjects
Engineering ,ship ,Force measurement ,Torque measurement ,Automotive engineering ,Permanent magnet linear motor ,servomotors ,Inverter ,synchronous motor drives ,synchronous motor drive ,full-electric drive ,hydraulic drives ,hydrostatics ,linear motors ,permanent magnet motors ,ships ,steering systems ,hydraulic ship steering gear ,hydrostatic drives ,oil-free inverter-fed alternative drives ,permanent magnet linear synchronous servo-motor ,ship rudder hydraulic drive ,Current measurement ,Force ,Inverters ,Size measurement ,Voltage measurement ,Direct drive ,efficiency ,fault tolerance ,hydraulic drive ,permanent magnet linear motor ,rudder steering gear ,Rudder ,On board ,direct drive ,fullelectric drive ,oil-free inverter-fed alternative drive ,steering system ,servomotor ,hydrostatic drive ,linear motor ,permanent magnet motor ,Servomotor ,hydrostatic ,Control theory ,Permanent magnet linear synchronous motor ,business.industry ,Fault tolerance ,Linear motor ,Magnet ,business - Abstract
Hydrostatic drives used on board ships are often characterized by low efficiencies, heavy maintenance, frequent oil leaks and large weight and size. To overcome these drawbacks, oil-free inverter-fed alternative drives can be proposed. This paper analyzes the ship rudder hydraulic drive performances, and a proposal for improvements is shown. A full-scale permanent magnet linear synchronous motor directly coupled to a twin rudder is presented, used as a servo-motor. Both servo-assistance features and performance and efficiency improvements are evaluated by using a complete physical model in Simulink environment.
- Published
- 2015
34. An Algebraic Approach to Determine the Current Supply in a Faulty 5-Phase PM BLDC Drive. Part I –Model Setup and its Application to the case of One Open Phase Fault
- Author
-
Syamnaresh Garlapati, Alberto Tessarolo, Giuseppe Buja, IEEE, Garlapati, Syamnaresh, Buja, Giuseppe, and Tessarolo, Alberto
- Subjects
drives ,Engineering ,Silicon ,permanent magnet motor ,drive ,Phase (waves) ,Scheduling (production processes) ,5-phase PM BLDC drive ,Fault (power engineering) ,faulty 5-phase PM BLDC drive ,Set (abstract data type) ,Control theory ,current supply modeling ,faulty drive ,brushless DC motors ,fault tolerance ,permanent magnet motors ,5-phase permanent magnet brushless DC drive ,fault-tolerant operation ,motor current supply ,open phase fault ,Circuit faults ,fault-tolerant applications ,brushless DC motor ,Algebraic number ,Circuit fault ,business.industry ,Control engineering ,Fault tolerance ,Magnet ,Current (fluid) ,business - Abstract
This paper (Part I), together with a companion one (Part II), deals with the fault-tolerant operation of a 5-phase permanent magnet (PM) brushless DC (BLDC) drive. In particular, this paper proposes an algebraic approach to set up a model of the motor current supply in healthy conditions. Afterwards, a faulty drive is considered with one or more open phases and, by constraining the proposed model with fault-specific conditions, scheduling and magnitude of the currents in the surviving phases are determined automatically as well as the maximum magnitude of the currents and the maximum torque developed by the motor. At last, the paper applies the model to the case of a drive with one open phase fault. In the companion paper the model is applied to the cases of more-than-one open phase faults.
- Published
- 2015
35. A New Method for Determining the Leakage Inductances of a Nine-Phase Synchronous Machine From No-Load and Short-Circuit Tests
- Author
-
Alberto Tessarolo, Sobhan Mohamadian, Mauro Bortolozzi, Tessarolo, Alberto, Mohamadian, Sobhan, and Bortolozzi, Mauro
- Subjects
Engineering ,stator leakage inductances ,Nine-phase machines ,parameter identification ,synchronous machines ,vector space decomposition ,Stator ,business.industry ,Energy Engineering and Power Technology ,Permanent magnet synchronous generator ,Magnetostatics ,law.invention ,Harmonic analysis ,Inductance ,Nine-phase machines, parameter identification, stator leakage inductances, synchronous machines, vector space decomposition ,law ,Control theory ,Electronic engineering ,Electrical and Electronic Engineering ,Synchronous motor ,business ,Short circuit ,Leakage (electronics) - Abstract
The accurate determination of stator leakage inductances is presently an open issue in the analysis and testing of multi- phase electric machines. Calculation methods are available, which involve complicated and often poorly precise three-dimensional (3-D) analyses. Experimental determination techniques, using measurements on the wound stator with the rotor removed, are also possible, but quite impractical, as they need to be performed during machine manufacturing or require rotor withdrawal. In this paper, a new approach is proposed to determine all the stator self- and mutual leakage inductances of a nine-phase synchronous machine based on a minimal set (a couple) of magnetostatic finite- element (FE) simulations, and on the measurements taken during no-load and short-circuit routine tests. The procedure is applied to a wound-field salient pole nine-phase synchronous generator for validation, showing good accordance with the results obtained from measurements on the machine with the rotor removed. A discussion is also proposed on the possibility to extend the presented procedure to other multiphase topologies
- Published
- 2015
36. Torque capabilities of a five-phase PM BLDC drive vs. a three-phase one and various supply modes
- Author
-
Alberto Tessarolo, Syamnaresh Garlapati, Giuseppe Buja, Ritesh Kumar Keshri, IEEE, Keshri, Ritesh, Garlapati, Syamnaresh, Tessarolo, Alberto, and Buja, Giuseppe
- Subjects
Standards ,Engineering ,Stall torque ,Phase (waves) ,Brushless motors ,Propulsion ,Automotive engineering ,Five-phase PM BLDC drive ,Control theory ,Five-phase PM BLDC drives ,upply mode ,Torque sensor ,Torque ,five-phase vs. three-phase PM BLDC drives ,supply modes ,Fault tolerant systems ,five-phase vs. three-phase PM BLDC drive ,Fault tolerant system ,Brushless motor ,business.industry ,Fault tolerance ,Conductors ,Copper ,torque capabilities ,Sense (electronics) ,Conductor ,Standard ,Three-phase ,Direct torque control ,business - Abstract
Electric drives with a three-phase structure are commonly utilized in road vehicles for propulsion and in aeronautics as control-surface actuators. In recent times, some concerns have emerged on the use of three-phase drives in such applications in regard to power capability, efficiency and fault-tolerance. A way to effectively cope with these concerns is the adoption of multiphase drives. In this sense, a five-phase drive is a promising solution as it does not imply an excessively complicated structure. In this paper a five-phase PM BLDC drive is considered and its torque capabilities are investigated for square-wave current supply. Specifically, the torque developed by a five-phase drive is first compared to the three-phase counterpart; torque comparison is carried out by keeping motor size and loading unchanged and by considering two hypotheses: equal phase back-emf and equal phase rms current. Then the torque available from a five-phase drive is determined under various supply modes, characterized by the simultaneous conduction of a reduced number of phases; the torque available is determined by imposing an equal rms phase current in the supply modes.
- Published
- 2014
37. Hybrid synchronous motor-alternator with dual AC/DC excitation system for shipboard generation and propulsion applications
- Author
-
M. Groppo, Alberto Tessarolo, S. Bonato, G. Stanic, IEEE, Stanic, G., Bonato, S., Groppo, M., and Tessarolo, Alberto
- Subjects
Alternator (automotive) ,Engineering ,dual-excitation arrangement ,hybrid synchronous motor-alternator ,business.product_category ,numerical analysis ,variable speed propulsion motor ,rectifying circuits ,dual AC-DC excitation system ,independent rotating rectifier ,Propulsion ,fuel saving ,AC motor ,law.invention ,marine propulsion ,PTO-PTI system ,law ,synchronous machine ,vessel performance ,Electric machine ,Rectifiers ,business.industry ,Rotor (electric) ,alternators ,electric propulsion ,Electrical engineering ,coaxial rotating excitation system ,Motor-generators. Rotating exciter design. Salient-pole synchronous machines. Synchronous generators. Synchronous motors ,synchronous motors ,electric machine ,Propellers ,rotors ,innovative marine solution ,Torque ,Electrically powered spacecraft propulsion ,numerical simulation ,shaft generator ,electromagnetic interaction ,shafts ,rotor ,business ,Synchronous motor ,ships ,Stator windings ,Induction motor ,alternators,electric propulsion,marine propulsion,numerical analysis,rectifying circuits,rotors,shafts,ships,synchronous motors,PTO-PTI system,coaxial rotating excitation system,dual AC-DC excitation system,dual-excitation arrangement,electric machine,electromagnetic interaction,fuel saving,hybrid synchronous motor-alternator,independent rotating rectifier,innovative marine solution,numerical simulation,rotor,shaft generator,shipboard generation application,synchronous machine,variable speed propulsion motor,vessel performance,Propellers,Rectifiers,Rotors,Stator windings,Torque,Motor-generators. Rotating exciter design. Salient-pole synchronous machines. Synchronous generators. Synchronous motors ,shipboard generation application - Abstract
State-of-the-art ships focus on enhancing vessel performance, lower emissions, optimize space on board and save fuel. This paper describes an innovative marine solution in which the same electric machine can be operated as a conventional shaft generator and also as a variable speed propulsion motors. The distinctive design (patent pending) consists of a special synchronous machine provided with two separate exciters (one AC and the second DC) each capable to energize the same main rotor field through two independent rotating rectifiers. Whilst the conventional PTO/PTI systems may use the synchronous machine in a very narrow speed range - the presence of the independent AC exciter allows to energize the main field from zero rpm. The propeller can therefore be fully electrically operated. The dual-excitation arrangement is described in the paper highlighting its benefits compared to the conventional design. Numerical simulations are presented to assess the possible electromagnetic interactions between the two coaxial rotating excitation systems. Extensive testing campaign validated the design expectations.
- Published
- 2014
38. Finite reluctance approach: A systematic method for the construction of magnetic network-based dynamic models of electrical machines
- Author
-
Alberto Tessarolo, D. Zito, Claudio Bruzzese, IEEE, Bruzzese, C., Zito, D., and Tessarolo, Alberto
- Subjects
linear machine ,Engineering ,State variable ,reluctance ,ComputingMilieux_THECOMPUTINGPROFESSION ,business.industry ,Magnetic reluctance ,magnetic network ,Permanent magnet synchronous generator ,Linear motor ,Dynamic model ,Finite element method ,Switched reluctance motor ,Reluctance motor ,Dynamic model, dynamic simulation, linear machine, magnetic network, permanent magnet, reluctance ,Dynamic simulation ,Control theory ,permanent magnet ,dynamic simulation ,business - Abstract
The finite reluctance approach is based on a simple synergy between a basic magnetic domain decomposition rule and the voltage balance at the terminals of any winding acting in the domain. The finite reluctance approach is thought as a tool for fast dynamic simulations of any kind of machine, but it is particularly adapt for irregular flux geometries as in fractional-slot surface-mounted permanent magnet machines with large slots and high slot flux leakages, for which only the finite element method has found good usage. This approach is based on the definition of a complementary mesh interlaced with the reluctance mesh, on the concept of material cell, and on unique rules to carry out both reluctances and magneto-motive forces. At this scope, definitions of mesh nodes, co-nodes, and auxiliary nodes are shown. The iron saturation can be easily taken in account, as well as motion effects. The circuit flux linkages are elected as state variables for integration, and they are directly linked to the loop fluxes in the magnetic network. The finite reluctance approach has been applied in this paper for dynamic modeling of an inverter-fed permanent-magnet linear synchronous motor.
- Published
- 2014
39. Fault tolerant electric generation systems for DC distribution network supply
- Author
-
Giorgio Sulligoi, Alberto Tessarolo, Simone Castellan, Roberto Menis, IEEE, Tessarolo, Alberto, Castellan, Simone, Menis, Roberto, and Sulligoi, Giorgio
- Subjects
Engineering ,business.industry ,modular design ,power electronics rectifiers ,Fault tolerance ,Control engineering ,Single-phase electric power ,AC power ,DC distribution network ,Electric power system ,Electricity generation ,Power electronics ,Power module ,fault tolerance ,Power engineering ,DC distribution network, electric power generation, fault tolerance, modular design, power electronics rectifiers ,business ,electric power generation - Abstract
DC distribution is being considered as an attractive alternative to its traditional AC counterpart in many fields of applications and, in particular, for shipboard power systems. The adoption of a DC distribution network makes it possible and sometimes necessary to radically revise the technology of the generation systems in many regards. Not only frequency-related constraints are removed, allowing for high-speed smaller generators to be used, but new fault-tolerant configurations, involving power electronics, generation control and management too, become feasible as a natural alternative to the traditional arrangement of AC power plants. In this paper some of these new technological scenarios are outlined, referring to state-of-the-art realizations as well as to novel concept designs presently under development and investigation.
- Published
- 2014
40. A high-performance 640-kW 10.000-rpm Halbach-array PM slotless motor with active magnetic bearings. Part II: Manufacturing and testing
- Author
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Alberto Tessarolo, F. Luise, F. Agnolet, M. Scalabrin, P. Raffin, Stefano Pieri, IEEE, Luise, F., Tessarolo, Alberto, Agnolet, F., Pieri, S., Scalabrin, M., and Raffin, P.
- Subjects
converter supply ,high speed motors ,Electric motor ,cost reduction,gas industry,machine testing,magnetic bearings,manufacturing processes,permanent magnet motors,research and development,turbomachinery,Halbach-array PM slotless motor,active magnetic bearing,converter supply,efficiency 98 percent,electric machine supplier,gas industry expansion,industrial R&D project,manufacturing process,motor efficiency target,optimization design,performance target,permanent magnet motor,power 640 kW,production cost reduction,prototype testing,turbomachinery-coupled high-speed electric motor,Manufacturing,Permanent magnet motors,Prototypes,Stator windings,Temperature measurement,Testing,Halbach array permanent magnet rotor,high efficiency motors,high speed motors,magnetic bearings,oil and gas industry,slotless stator design ,Engineering ,business.product_category ,power 640 kW ,permanent magnet motor ,Testing ,oil and gas industry ,Permanent magnet motors ,Magnetic bearing ,optimization design ,gas industry expansion ,motor efficiency target ,AC motor ,Automotive engineering ,research and development ,industrial R&D project ,high efficiency motors ,Halbach array permanent magnet rotor ,electric machine supplier ,Reliability (semiconductor) ,prototype testing ,Prototypes ,slotless stator design ,Halbach-array PM slotless motor ,gas industry ,turbomachinery ,production cost reduction ,Electric machine ,Temperature measurement ,Manufacturing process ,business.industry ,Production cost ,turbomachinery-coupled high-speed electric motor ,magnetic bearings ,active magnetic bearing ,performance target ,manufacturing processes ,Manufacturing ,Halbach array ,manufacturing process ,cost reduction ,machine testing ,efficiency 98 percent ,business ,Stator windings - Abstract
The ongoing gas industry expansion calls for quick and strong advances in turbomachinery-coupled highspeed electric motors. Very high efficiency, dynamic performance and reliability are among the main requirements to be met at competitive costs by electric machine suppliers. This paper reports on an industrial R&D project aimed at finding the best compromise between performance targets and production cost reduction through the realization of a 640-kW 10.000-rpm PM motor prototype. The preliminary and optimization design of the motor have been covered in a companion paper (Part I). Here the manufacturing and testing of the prototype are covered. The main technology challenges encountered throughout the manufacturing process are addressed. Furthermore, the paper reports on the testing campaign conducted on the motor under converter supply and in different load and speed conditions. The prototype testing was successful and proved the possibility to reach and exceed a 98% motor efficiency target with affordable costs and available technologies.
- Published
- 2014
41. An accurate fourier-series expansion for round-rotor electric machine permeance function including large eccentricity effects
- Author
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Alberto Tessarolo, L. Branz, M. Bailoni, Claudio Bruzzese, IEEE, Tessarolo, Alberto, Bruzzese, C., Branz, Lorenzo, and Bailoni, Martino
- Subjects
electric machines ,round rotor machine ,Engineering ,geometry ,media_common.quotation_subject ,air-gap permeance function ,Rotor eccentricity ,Permeance ,Approximation methods ,permeance functions ,inductance ,law.invention ,modelling ,air gaps ,symbols.namesake ,Position (vector) ,law ,Taylor series ,mutual phase inductances ,Eccentricity (behavior) ,Fourier series ,media_common ,electric machine modeling ,Rotor (electric) ,business.industry ,Stators ,self phase inductances ,Mathematical analysis ,Control engineering ,Function (mathematics) ,winding functions ,Expression (mathematics) ,rotors ,Fourier series,air gaps,electric machines,geometry,inductance,modelling,rotors,Fourier-series expansion,air-gap permeance function,mutual phase inductances,permeance functions,rotor position,round rotor machine,round-rotor electric machine permeance function,self phase inductances,winding functions,Air gaps,Approximation methods,Fourier series,Rotors,Stators,Taylor series,Fourier series,Rotor eccentricity,electric machine modeling,permenance function ,symbols ,Fourier-series expansion ,rotor position ,business ,round-rotor electric machine permeance function ,permenance function - Abstract
One of the key tasks in the modeling of electric machines is the analytical expression of self and mutual phase inductances as a function of the rotor position. Winding and permeance functions are a powerful tool for this purpose. This paper investigates the expression of the air-gap permeance function for a round rotor machine subject to pronounced eccentricity. An expression is sought in the form of a Fourier series expansion in order to make it suitable for modeling purposes. Although derived through non trivial algebraic passages, the final expression proposed is proved to be accurate and computationally efficient as the theoretically infinite sums involved in it exhibit a very rapid convergence to their asymptotical values.
- Published
- 2014
42. Field oriented control of LCI-fed WFSM drives in stator flux reference frame
- Author
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Sobhan Mohamadian, Abbas Shoulaie, Alberto Tessarolo, IEEE, Mohamadian, Sobhan, Tessarolo, Alberto, and Shoulaie, Abbas
- Subjects
Engineering ,Electronic speed control ,LCI-fed WFSM drives ,independent flux control ,field oriented control (FOC) ,speed control ,Stator ,maximum torque to ampere ratio ,machine vector control ,stator flux coordinates ,Resistance ,load-commutated inverters ,invertors ,DC machine and WFSM drive analogy ,Decision support systems ,Network topology ,stators ,law.invention ,high-power medium-voltage applications ,Control theory ,law ,FOC ,Ampere ,LCI-fed WFSM drive ,PI control,angular velocity control,control system synthesis,invertors,machine vector control,stators,synchronous motor drives,FOC,LCI-fed WFSM drives,PI controller parameter design,drive topology,field oriented control,high-power medium-voltage applications,independent flux control,load-commutated inverters,maximum torque to ampere ratio,phase-controlled DC machine,rotor saliency,speed control,stator flux coordinates,stator flux reference frame,wound-field synchronous motors,Decision support systems,Educational institutions,Lead,Rectifiers,Resistance,Stators,Torque,DC machine and WFSM drive analogy,LCI-fed WFSM drive,field oriented control (FOC),stator flux reference frame ,synchronous motor drives ,Vector control ,field oriented control ,Rectifiers ,business.industry ,drive topology ,stator flux reference frame ,Control engineering ,PI controller parameter design ,rotor saliency ,PI control ,phase-controlled DC machine ,Lead ,Torque ,Direct torque control ,Educational institutions ,angular velocity control ,wound-field synchronous motors ,control system synthesis ,Synchronous motor ,business ,stator flUX reference frame ,Reference frame - Abstract
Load-commutated inverters (LCIs) in conjunction with the wound-field synchronous motors (WFSMs) are one of the most applicable drive topologies, and in some cases the only choice, in high-power medium-voltage applications. In this paper, a novel strategy is presented for field oriented control (FOC) of these drives in stator flux coordinates. Considering rotor saliency, independent flux and speed control is carried out to achieve maximum torque to ampere ratio. Furthermore, the proposed strategy provides a simple way to design the PI controllers' parameters according to the phase-controlled DC machine and WFSM drive analogy. Simulation studies are presented to verify the performance of the total proposed control scheme. Comparisons show the superiority of the proposed method over the conventional drive technologies for LCI-fed WFSM drives.
- Published
- 2014
43. The Photovoltaic Laboratory at the University of Trieste, Italy
- Author
-
Alberto Tessarolo, Alessandro Massi Pavan, Adel Mellit, Giorgio Sulligoi, Sergio Roitti, Vanni Lughi, IEEE, Pavan, Alessandro Massi, Lughi, Vanni, Mellit, Adel, Roitti, Sergio, Sulligoi, Giorgio, and Tessarolo, Alberto
- Subjects
Architectural engineering ,Engineering ,Test facility ,business.industry ,Photovoltaic system ,PV ,test facility ,PV, laboratory, photovoltaic, test facility ,photovoltaic ,Work (electrical) ,Systems engineering ,ComputerSystemsOrganization_SPECIAL-PURPOSEANDAPPLICATION-BASEDSYSTEMS ,Architecture ,business ,laboratory - Abstract
This work deals with the description of the Photovoltaic Laboratory at the Department of Engineering and Architecture of the University of Trieste. The description of the main facilities involved, such as three grid-connected photovoltaic plants and a test facility for the characterization of photovoltaic modules, is being proposed. Moreover, an overview of the recent and future research activities is given.
- Published
- 2014
44. Study of faulty scenarios for a fault-tolerant multi-inverter-fed linear permanent magnet motor with coil short-circuit or inverter trip
- Author
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L. Piva, D. Zito, Mario Mezzarobba, Mauro Bortolozzi, T. Mazzuca, Claudio Bruzzese, Alberto Tessarolo, IEEE, Bruzzese, C., Tessarolo, Alberto, Mezzarobba, Mario, Bortolozzi, Mauro, Zito, D., Mazzuca, T., and Piva, L.
- Subjects
Engineering ,partial machine fault ,rudder ,fin steering gear stability ,invertors ,board ships ,Force measurement ,reduced-performance operation ,service continuity ,machine fault ,Forging ,performance degradation ,rotary motors ,safety-critical tasks ,Permanent magnet motor ,linear actuator ,classical hydrostatic transmissions ,synchronous motor drives ,full-electric drives ,linear synchronous motors ,linear permanent-magnet direct drive ,Circuit faults ,Rudder ,Linear actuator ,fault diagnosis ,back-up systems ,multistage reduction gears ,short-circuit currents ,independently fed stator modules ,electrical safety,fault diagnosis,fault tolerance,invertors,linear synchronous motors,permanent magnet motors,short-circuit currents,stators,synchronous motor drives,back-up systems,board ships,classical hydrostatic transmissions,coil short-circuit,drive mechanical jam-stall avoidance,electrical failures,fault-tolerant machine,fault-tolerant multiinverter-fed linear permanent magnet motor,fin steering gear stability,full-electric drives,full-modular structure,independently fed stator modules,inverter trip,linear permanent-magnet direct drive,machine fault,machine winding,multistage reduction gears,partial machine fault,performance degradation,reduced-performance operation,rotary motors,rudder,safety-critical tasks,Circuit faults,Coils,Force,Force measurement,Forging,Inverters,Stators,Fault tolerance,inverter trip,linear actuator,permanent magnet motor,service continuity,short-circuit ,electrical safety ,Short circuit ,coil short-circuit ,permanent magnet motor ,short-circuit ,stators ,Control theory ,fault-tolerant multiinverter-fed linear permanent magnet motor ,full-modular structure ,Force ,business.industry ,Fault tolerance ,Coils ,Inverters ,fault-tolerant machine ,drive mechanical jam-stall avoidance ,Electromagnetic coil ,electrical failures ,machine winding ,inverter trip ,Inverter ,business ,permanent magnet motors - Abstract
A fault-tolerant machine used for safety-critical tasks must a) guarantee at least a reduced-performance operation in case of partial machine fault and b) guarantee avoidance of drive mechanical jam/stall in case of total machine fault, to allow for the intervention of the back-up systems. Classical hydrostatic transmissions used on board ships for critical tasks such as rudder and stabilizing fin steering gears fulfill both the requirements a), b) above, but recent proposals for substitution with full-electric drives (rotary motors coupled with multistage reduction gears) usually do not. Especially the requirement b) needs particular attention and increased complexity when dealing with geared drives. This paper proposes a linear permanent-magnet direct drive fulfilling both the requirements above, for (but not limited to) rudder/fin steering gears. The absence of gears grants the requirement b), whereas the full-modular structure satisfies a), with independently fed stator modules and multiple inverters. This paper addresses some fault scenarios including electrical failures, in the machine winding (short-circuited coils) and in the inverters (trip of one or more units). The performance degradation is studied and assessed for the cases considered by both simulations and measurements on a prototype.
- Published
- 2014
45. Analysis of asymmetrical short circuits downstream of 12 pulse diode rectifier fed by double three phase synchronous machines
- Author
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Alberto Tessarolo, Mario Mezzarobba, Simone Castellan, Mauro Bortolozzi, IET, Castellan, Simone, Mezzarobba, Mario, Tessarolo, Alberto, and Bortolozzi, Mauro
- Subjects
DC generators ,model validation ,Engineering ,12-pulse DC generator system ,MVDC grid ,Electric generator ,Hardware_PERFORMANCEANDRELIABILITY ,Permanent magnet synchronous generator ,Fault (power engineering) ,Precision rectifier ,law.invention ,law ,Electronic engineering ,asymmetrical short circuit downstream analysis ,DC power generation ,Diode ,business.industry ,rectifiers,smart power grids,synchronous generators,12 pulse diode rectifier,12-pulse DC generator system,DC power generation,MVDC grid,asymmetrical short circuit downstream analysis,double three phase synchronous machine,software simulation,synchronous generator,transient short circuit current,DC generators,asymmetrical short circuit,diode rectifiers,model validation,transient short circuit current ,Electrical engineering ,transient short circuit current ,smart power grids ,double three phase synchronous machine ,12 pulse diode rectifier ,Three-phase ,synchronous generator ,rectifiers ,software simulation ,diode rectifiers ,synchronous generators ,Transient (oscillation) ,asymmetrical short circuit ,business ,Short circuit - Abstract
DC power generation for MVDC grids is in the easiest way realized by a cascade connection of a synchronous generator and a diode rectifier. Due to large peak fault currents, including oscillating transient components, it is important to know in depth the short circuit behaviour of diode rectifiers, mainly during the first moments after the fault. This is helpful to be able to perform a suitable sizing of the system and its protections. In order to obtain an accurate estimation of the transient short circuit current, models for software simulation of 6-pulse and 12-pulse DC generator systems have been implemented. This paper shows the validation of such models by the comparison of simulation results with experimental tests.
- Published
- 2014
46. LCI-fed wound-field synchronous motors: A technology status review and new development trends
- Author
-
Sobhan Mohamadian, Simone Castellan, Alberto Tessarolo, M. H. Khanzade, IEEE, Mohamadian, Sobhan, Khanzade, Mohammad Hosein, Castellan, Simone, and Tessarolo, Alberto
- Subjects
LCI-fed WFSM drive ,Engineering ,Field oriented control (FOC) ,business.industry ,Field oriented control (FOC), high-power medium voltage applications, LCI-fed WFSM drive, stator flux reference frame, start up ,stator flux reference frame ,Field oriented control (FOC), LCI-fed WFSM drive, high-power mediumvoltage applications, start up, stator flux reference frame ,Insulated-gate bipolar transistor ,Network topology ,high-power mediumvoltage applications ,Automotive engineering ,start up ,Power (physics) ,Integrated gate-commutated thyristor ,High-definition video ,Electronic engineering ,business ,Synchronous motor ,high-power medium voltage applications ,Pulse-width modulation ,Strengths and weaknesses - Abstract
Load-Commutated Inverters (LCIs) are today one of the main converter topologies used for very-high-power drive applications, although new topologies, based on PWM technology and employing IGBT or IGCT as power switches instead of SCR's, have been recently gaining attractiveness also for increasing power ratings. The paper presents an overview of today's LCI technology and its applications, highlighting its strengths and weaknesses. Furthermore, the most promising lines of development are drawn along which LCI drive technology is being improved to overcome its major drawbacks and maintain competitiveness with Voltage-Source-Inverter (VSI) based counterparts.
- Published
- 2014
47. An innovative environmentally-friendly full-electric drive solution for the actuation of shipboard loads: Analysis based on prototype testing results
- Author
-
Alberto Tessarolo, Lucio Piva, Claudio Bruzzese, IEEE, Bruzzese, Claudio, Tessarolo, Alberto, and Piva, Lucio
- Subjects
Engineering ,linear machine ,electric drives,linear machines,permanent magnets,direct-drive full-electric application,force-transmission fluid,full electric drive solution,gear-less,hydrostatic transmissions,inverter feeding,limiting factors,linear drives,linear machine,oil-fed actuators,permanent magnets,prototype testing,rudders,shipboard loads,stabilizing fins,Direct drives,efficiency,environment,fins,hydraulics,linear drives,permanent magnets,rudders,ship ,ship ,linear machines ,hydraulics ,hydrostatic transmissions ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Thrust ,limiting factors ,oil-fed actuators ,fins ,prototype testing ,direct-drive full-electric application ,Torque ,linear drives ,business.industry ,permanent magnets ,Control engineering ,Rudder ,gear-less ,Direct drives ,stabilizing fins ,Environmentally friendly ,efficiency ,Obstacle ,Magnet ,rudders ,electric drives ,inverter feeding ,shipboard loads ,Inverter ,force-transmission fluid ,business ,Actuator ,environment ,full electric drive solution - Abstract
This paper analyzes a different approach for actuation of shipboard loads such as rudders, stabilizing fins, or other linear drives, which are usually powered by oil-fed actuators. Hydrostatic transmissions are classically used when the highest torques/forces with low speeds are demanded. However, the oil used as force-transmission fluid is troublesome due to environmental issues. Oil production, use, and final disposal is costly and presents environmental risks. Also the maintenance onboard ship is intensive and hazardous for the operators. A full electric solutions is ulteriorly studied in this paper, based on a prototyped linear machine using permanent magnets and inverter feeding. Copper, friction, and iron losses are the main limiting factors in developing the required thrust at low speed, which is, ultimately, the main obstacle to a gear-less or direct-drive full-electric application. This paper shows incremental work on the prototype, through a dedicated circuit model accounting for all the machine losses and providing an affordable model of machine overall efficiency. The model will be used in further works to asses the machine performances in typical onboard service duties.
- Published
- 2014
48. Challenging the hydraulics on its own ground: Ship steering through unconventionally-high thrust permanent-magnet direct motors with structural redundancy and fault-tolerance
- Author
-
Claudio Bruzzese, Alberto Tessarolo, IEEE, Bruzzese, C., and Tessarolo, Alberto
- Subjects
Direct drive ,Engineering ,ship ,mass 700 kg ,Hydraulics ,composite materials ,Thrust ,invertors ,linear permanent magnet direct motors ,Automotive engineering ,law.invention ,structural redundancy ,hydraulic technology ,Redundancy ,linear drive ,law ,Marine vehicles ,Redundancy (engineering) ,composite materials,fault tolerance,invertors,linear motors,permanent magnet motors,ships,steering systems,composite materials,fault tolerance,hydraulic technology,linear permanent magnet direct motors,low-frequency inverters,machine frame,mass 700 kg,permanent magnet actuators,ship steering,structural redundancy,Inverters,Marine vehicles,Prototypes,Redundancy,Stator windings,Valves,Direct drive,fault tolerance,full-electric drive,hydraulic drive,linear drive,low-speed high-force drive,permanent magnet,redundancy,ship,steering gear ,low-frequency inverters ,Prototypes ,machine frame ,business.industry ,full-electric drive ,permanent magnet actuators ,Fault tolerance ,Inverters ,hydraulic drive ,steering systems ,Valves ,steering gear ,Magnet ,ship steering ,permanent magnet ,fault tolerance ,business ,permanent magnet motors ,ships ,Stator windings ,linear motors ,low-speed high-force drive - Abstract
The ships have long been an easy play-ground for hydraulic technologies. When high torques and low speeds are demanded on board ship, both technical and traditional reasons usually lead to hydraulic solutions. In fact, the conventional electrical machines are better suited for low-torque, high-speed applications, and coupling gears must be used to reduce the speed. However, oil-free direct-drive alternatives can be conceived, by new concepts of low-speed permanent-magnet actuators fed by low-frequency inverters. This paper shows the experimental results obtained with a linear permanent-magnet motor designed for direct coupling to rudder stocks or stabilizing fins. The prototype weights 700kg and features a thrust-to-weight ratio of 5. Even better results can be obtained by using composite materials for the machine frame. The machine features a full structural redundancy and inherent fault tolerance, thanks to the modular construction. The present research has been carried out in the framework of the Italian Defence's Research National Program.
- Published
- 2014
49. Power electronics for all-electric ships with MVDC power distribution system: An overview
- Author
-
Alberto Tessarolo, Roberto Menis, Giorgio Sulligoi, Simone Castellan, IEEE, Castellan, Simone, Menis, Roberto, Tessarolo, Alberto, and Sulligoi, Giorgio
- Subjects
Employment ,Engineering ,Switched-mode power supply ,voltage levels ,DC/DC power converters ,medium voltage high power users ,air conditioning ,Power transformers ,Power factor ,AC distribution systems ,DC distribution systems ,Medium Voltage DC (MVDC) ,bow thrusters ,Solid State Transformer (SST) ,Electric power system ,marine power systems ,integrated power systems ,Power electronics ,AC adapter ,three-wire MVDC power systems ,Prototypes ,output voltage rectification ,electric vehicles ,Electric power distribution ,solid-state transformers ,Rectifiers ,energy storage ,business.industry ,Electrical engineering ,DC-DC power convertors ,MVDC power distribution system ,Integrated Power System (IPS) ,Voltage optimisation ,Generators ,propulsion drives ,DC distribution ,all-electric ships ,compressors ,Power module ,energy storage systems ,Power engineering ,business ,ships ,DC-DC power convertors,electric vehicles,energy storage,marine power systems,power transformers,ships,AC distribution systems,DC distribution systems,DC/DC power converters,MVDC power distribution system,air conditioning,all-electric ships,bow thrusters,compressors,energy storage systems,integrated power systems,medium voltage high power users,output voltage rectification,power electronics,power transformers,propulsion drives,solid-state transformers,three-wire MVDC power systems,voltage levels,Employment,Generators,Power electronics,Power transformers,Prototypes,Rectifiers,DC distribution,Integrated Power System (IPS),Medium Voltage DC (MVDC),Solid State Transformer (SST) - Abstract
Integrated Power Systems (IPS) with DC distribution require the massive use of power electronics for many tasks: 1) the output voltage rectification of generators and the connection of energy storage systems to the IPS, 2) the supply of medium voltage high power users (propulsion drives, bow thrusters, compressors for air conditioning), 3) the adjustment of voltage levels, which is performed by power transformers in AC distribution systems and by DC/DC power converters called Solid-State Transformers (SST) in DC distribution systems. In this paper, an overview is given of the power converters found in the literature and on the market that could be suitable for employment in the mentioned subsystems as parts of a future MVDC IPS. Finally authors propose a structure for an SST to be employed in three-wire MVDC power systems.
- Published
- 2014
50. A high-performance 640-kW 10.000-rpm Halbach-array PM slotless motor with active magnetic bearings. Part I: Preliminary and detailed design
- Author
-
Alberto Tessarolo, F. Agnolet, F. Luise, M. Scalabrin, Stefano Pieri, P. Raffin, IEEE, Luise, F., Tessarolo, Alberto, Agnolet, F., Pieri, S., Scalabrin, M., and Raffin, P.
- Subjects
Optimization ,Electric motor ,Engineering ,magnetic bearings,magnetic levitation,optimisation,permanent magnet motors,rotors,stators,Halbach-array PM slotless motor,Halbach-array magnetically-levitated PM rotor,active magnetic bearings,design optimization processes,highspeed electric motors,industrial R&D project,power 640 kW,production cost reduction,slotless stator,Optimization,Permanent magnet motors,Permanent magnets,Rotors,Stator cores,Stator windings,Design optimization,Halbach array,high efficiency,high speed,magnetic bearings,slotless stator ,active magnetic bearings ,business.product_category ,power 640 kW ,Permanent magnets ,optimisation ,Stator ,Halbach-array magnetically-levitated PM rotor ,Design optimization ,Permanent magnet motors ,Magnetic bearing ,stators ,Automotive engineering ,industrial R&D project ,law.invention ,design optimization processes ,Reliability (semiconductor) ,law ,Halbach array ,highspeed electric motors ,Halbach-array PM slotless motor ,Magnetic levitation ,production cost reduction ,Electric machine ,magnetic levitation ,Rotor (electric) ,business.industry ,slotless stator ,Control engineering ,magnetic bearings ,rotors ,high efficiency ,Stator cores ,high speed ,business ,Stator windings - Abstract
The ongoing gas industry expansion calls for quick and strong advances in turbomachinery-coupled highspeed electric motors. Very high efficiency, dynamic performance and reliability are among the main requirements to be met at competitive costs by electric machine suppliers. This paper reports on an industrial R&D project aimed at finding the best compromise between performance targets and production cost reduction. The development of a 640-kW 10.000-rpm PM motor prototype with slotless stator and Halbach-array magnetically-levitated PM rotor is discussed, including in particular the basic technology selection and design optimization processes. In a companion paper (Part II), prototype manufacturing and testing will be reported to assess the technology and design solutions adopted.
- Published
- 2014
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