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The aim of this paper is the low-cost experimental implementation of a field oriented control strategy for a Permanent Magnet Synchronous Motor (PMSM) by using an Atmel SAM3X8E microcontroller, mounted on an Arduino DUE board. In this electrical drive for PMSM, a resolver is used in order to measure the rotor position and speed: Therefore, the low-cost Arduino DUE performs not only FOC algorithm and phase currents data acquisition, but also a resolver-To-digital converter process, rotor position and speed data acquisition, and resolver signals management. The code has been implemented in the open source Arduino IDE, using C language, whereas the control and plot visualization interfaces have been developed by using an open source software. In order to make currents and resolver conditioning signals, a double-layer printed circuit board (PCB) has been created. The electrical drive has been experimentally tested and the main results reported in this work show high performance in terms of rotor speed response and compilation and execution speed of the code, validating the use of Arduino DUE for PMSM drives.

This paper presents a simple and effective procedure for the determination of the Gorges polygon, suitable for all possible winding configurations in electrical machines. This methodology takes into account the determination of a Winding Distribution Table (WDT), in which all the information about the distribution of the currents along the stator periphery is computed and from which the Görges polygon are easily derived. The proposed method can be applied to both symmetrical and asymmetrical multi-phase windings, including concentrated, fractional, reduced and dead-coil ones. The examples provided in this paper demonstrate the versatility of the proposed method.

This paper presents a feasibility study on the prototyping of a hybrid EPAC (Electric Pedal Assisted Cycle) through an FC-B-UC (Fuel Cell — Battery — Ultra-Capacitors) power system. Aim of this work is the characterization of a PEMFC (Proton Exchange Membrane Fuel Cell) in order to confirm its theoretical performances and to verify the possibility of its installation on an e-bike.

This paper presents an algorithm for the calculation of maximum slot filling factor in electrical machines. The determination of whole wire cross section that occupy the area of a stator slot is very important in order to estimate the copper losses: The greater is the filling factor the lower are copper losses. The main goal of this paper is to define a simple algorithm for the determination of slot filling factors suitable for all type of slot profiles. The algorithm can be considered as an additional useful tool for the fast design of electrical machine windings.

This paper presents a comparison of the performances between IPMSMs (Interior Permanent Magnet Synchronous Machine) with a symmetrical and with two different types of unsymmetrical windings. The aim is to demonstrate that the adoption of slightly unsymmetrical windings does not significantly affect the performances of the machines, both in terms of cogging torque and torque/load angle characteristics, providing also the advantage of a higher possibility of choice in terms of slot number/poles ratio. More in particular, an IPMSM model (named IPMSM-1) derived from a commercial geometry equipped with a symmetrical winding is analyzed by using a Finite Element Method (FEM) approach. The simulation results regarding the cogging torque trend, the static characteristics and the related harmonic analysis are shown and discussed. Afterwards, two other IPMSM models with unsymmetrical windings are obtained by modifying the IPMSM-1 stator structure, but maintaining the same rotor configuration. FEM analysis are carried out also for these geometries and the related simulation results are compared with those obtained for the IPMSM-1 model. From this comparison it can be stated that the equipment of slightly unsymmetrical windings can be a viable choice during the design process of rotating electrical machines.

This paper presents the comparison between the cogging torques produced by four IPMSGs (Interior Permanent Magnet Synchronous Generators) with different stator winding configurations. More in detail, an IPMSG model, which is derived from a commercial geometry, is analyzed through means of a FEM (Finite Element Method) approach. Then, three more structures are determined and analyzed by adequately changing the number of stator slots of the basic IPMSG stator structure and by maintaining the same rotor configuration. From the obtained simulation results, the cogging torque components for each structure are determined and compared. From this comparison, it can be stated that the use of dissymmetric windings does not affect significantly the generated cogging torque.

In this paper a wind electrical power generation system for Distributed on Site (DoS) applications is proposed. This system was developed and conceived in order to guarantee simple installation, use and service, obtaining a product that can be easily industrialized and put into the market with limited costs. The field of application of such an electrical generation system is addressed towards domestic or at the most toward condominium applications concerning moreover the opportunity of working in addition to combined photovoltaic and solar-thermal systems to enhance the renewable energy generation at house level (DoS). The proposed system has its hot spot in the blades shape, in the wind flux canalization system and in the permanent magnet synchronous generator (PMSG) optimized for this specific purpose. In fact with the proposed system intends to search the best aerodynamic profile and electrical generator to ensure the slightest encumbrance and the lowest weight. For this purpose the traditional and classical tangential wind turbine design, equipped with large blades, is overturned in favour of the use of numerous little blades. A further peculiarity of the system is the expected increase of its efficiency thanks to the presence of the wind flux channelling system with the elimination of the part opposing the wind and thanks to the adoption of a specifically designed PMSG.

This paper presents a possible minimization procedure of the cogging torque generated by an IPMSM (Interior Permanent Magnet Synchronous Machine) with a progressive modification of a basic geometrical structure of rotor laminates. More in detail, an IPMSM model is analyzed by using a Finite Element Method (FEM) approach. Then, other IPMSM models, which are obtained by modifying the geometry of the IPMSM rotor laminates and by maintaining the same stator configuration, are proposed and discussed. From the obtained simulation results, the cogging torque components for each structure are determined by means of FEM and compared to each other. From this comparison, it can be stated that the cogging torque is significantly related to the laminate geometry and it is demonstrated that the cogging torque components can be theoretically canceled by choosing a specified structure of the laminates.

In the scientific literature, various authors presented different control strategies aimed to increase the efficiency of the interior permanent magnet synchronous motors. These strategies, starting from a well-known mathematical model of the dynamic behaviour of the motor, are able to reduce the power losses acting on the magnetizing component of the stator current. However, none of the proposed approaches takes into account that, varying the working conditions of the motor, also the values of the parameters, which have an impact on the power losses, can vary. In this paper, therefore, starting from an accurate measurement of the motor characteristics for various values of speed and load, we present a new control strategy, which, by taking into account the variability of the motor parameters, allows a more efficient reduction of the motor power losses. In order to validate the model, the values of the power losses obtained by using the model are compared with the values obtained by experimentally measuring the power losses.

The topic of this paper is the discussion on the performance of a three-phase fault tolerant inverter with particular attention to the underrated aspect of current unbalances occurring due to the DC link voltage fluctuates after the inverter reconfiguration. Capacitor voltage unbalance affects not only the average output voltage of the inverter, but also its performance. In fact, the inverter performance depends on the fluctuating DC-link voltage components rather than on the average DC-link voltage. After a brief analysis of the voltage fluctuation phenomena resulting from fault tolerant configuration and their effect on load current unbalance, the Authors consider different compensating preventive or repressive strategies in different application scenarios. These strategies can operate both in open and closed loop control. The paper highlights their advantages, drawbacks and analyzes their different behavior.

This paper presents the analysis, characterization and comparison of the cogging torque components generated by five different IPMSM rotor structures. More in detail, an IPMSM model (named IPMSM1), which is derived from a commercial geometry, is analyzed by using a Finite Element Method (FEM) approach. Then, four other IPMSM models, which are obtained by modifying the IPMSM1 rotor structure and by maintaining the same stator configuration, are proposed and analyzed. From the obtained simulation results, the cogging torque components for each structure are determined and compared. From this comparison, a significant cogging torque decrease is occurring for the modified geometries, without affecting the values of the generated torque. Furthermore, a meaningful relationship between the peak values of the cogging torque and the gradients of the flux density around the neutral area is reported and discussed. Therefore, simple structure modifications applied to the rotor geometry can bring significant improvements in terms of motor performances and cogging torque reduction.

This paper investigates the detectability of rotor broken bars in double cage induction motors using current signature and vibration analysis techniques. Double cage induction motors are commonly used for applications where successive loaded starts-up are mandatory. Experimental results were performed under healthy and faulty cases, and for different load conditions using each technique. Rotor broken bars fault detection based on sideband current components may fails due to the presence of inter bar currents that reduce the degree of rotor asymmetry, yielding to a decrease of the magnitude of these spectral components. But inter bar currents produce core vibrations in the axial direction, which can be detected using vibration analysis, in order to overcomes the limits of the classical (MCSA) in this condition.

In this paper, a torque/weight and torque/moment of inertia ratio optimization procedure for interior permanent magnet syncronous motors (IPMSMs) is presented. More in detail, a performance comparison between several IPMSM rotor structures has been carried out in order to determine the optimum geometry that can maximize the torque/weight and torque/moment of inertia ratios. A commercial motor, with known electrical and mechanical characteristics, has been taken as reference. Its rotor structure has been modified several times, obtaining different rotor geometries and, therefore, many IPMSM models with different electrical and mechanical characteristics. The finite element method (FEM) analysis of each IPMSMs has been performed using the software FEMM, allowing to determine the related torque/load-angle characteristics. From the comparison between the torque/load-angle characteristics of the different IPMSM structures, it can be stated that significant performance improvements can be obtained in dependence not only of the type of permanent magnets and their direction of magnetization, but also of the PM displacement within the rotor.

This paper describes the realization of a two-degrees of freedom induction motor prototype with rotor helical motion, suitable for several industrial applications as grinders, augers, drilling and milling spindles, robotic arms and drives for medical tools and prostheses. This prototype was realized by combining a three-phase tubular linear induction motor (TLIM) with the stator of a three-phase rotary induction motor, resulting in a THMIM (Tubular Helical Motion Induction Motor). Moreover, a possible simple electrical drive, capable to control the helical motion, is proposed, simulated and analyzed. In particular, the mathematical model of the THMIM has been initially developed and, then, the complete drive has been simulated in MATLAB-Simulink. The simulation results demonstrate that, by acting separately on the control of rotary and tubular machine components, a very accurate controlled helical motion can be achieved.

This paper investigates the detectability of mechanical unbalance in double cage induction motor load using motor vibration signature analysis technique. Rotor imbalances induce specific harmonic components in electrical, electromagnetical, and mechanical quantities. Harmonic components characteristic of this category of rotor faults, issued from vibration signals analysis, are closely related to rotating speed of the rotor, which complicates its detection under non-stationary operating conditions of the motor. Firstly, experimental results were performed first under healthy and mechanical load unbalance cases, for different load levels under steady-state operating conditions to evaluate the sensitivity of motor axial vibration signature analysis (MAVSA) and motor radial vibration signature analysis (MRVSA) techniques. Secondly, and in order to overcome the limitations of the FFT analysis in time-varying conditions, a simple and effective method based on advanced use of wavelet analysis is proposed, that allows the diagnosis of mechanical load unbalance for a double cage induction machine operating under non-stationary conditions. Experimental tests were conducted for these purposes showing the effectiveness of the presented technique under time-varying operating conditions. © 2013 IEEE.

The paper investigates the diagnosis of rotor broken bars in field oriented controlled (FOC) double cage induction motor drives, using current and vibration signature analysis techniques. The Impact of the closed loop control system cannot be neglected when the detection of asymmetries in the machine are based on the signature analysis of electrical variables. The proposed diagnosis approach is based on optimized use of wavelet analysis by a pre-processing of phase current or axial/radial vibration signals. Thus, the time evolution of the tracked rotor fault components can be effectively analyzed. This paper shows also the relevance of the fault components computed from axial vibration signal in comparison to those coming from phase current and radial vibration signals. Cyclic fault quantification, issued from the wavelet analysis, has been introduced for accurate rotor fault detection. Experimental results show the validity of the proposed technique, leading to an effective diagnosis procedure for rotor broken bar in double cage induction motor.

In this paper a software developed for the determination of winding connections, the calculation of winding factors and the evaluation of their harmonic distribution of three and two phase windings is presented by using as input data simply the number of slots, pole pairs and phases. The software is implemented as a function in MATLAB environment. By means of some examples, covering the most relevant winding types, the capabilities of this software will be shown. Particularly, integer and fractional single and double layer winding can be treated. Some examples are presented and briefly discussed. The connections, the winding factor harmonic distribution, the electro-motive force (e.m.f) THD calculations results are shown together with an example on how is possible to determine the e.m.f. induced in a winding from the air gap flux distribution and to estimate the differential leakage inductance.

This paper investigates the detectability of rotor broken bars in indirect rotor flux oriented control (IRFOC) for variable speed double cage induction motor drives, using vibration signature analysis techniques. The Impact of the closed loop control system cannot be neglected when the detection of rotor asymmetries in the machine is based on the signature analysis of electrical or mechanical variables. Therefore, the investigation of rotor fault components for different bandwidths of closed-loop regulators is necessary to evaluate its relevance in the above listed variables. This paper investigates the impact of the control system on relevance of the fault components computed from axial and radial vibration signals. Experimental results show the validity of this impact, and more specifically, the bandwidth PI regulators. Due to its relevance, axial vibration analysis shows a more robust fault signature, under the control impact, in separating healthy from rotor bar breakage in double squirrel cage induction motors.

Advanced monitoring techniques leading to fault diagnosis and prediction of induction machine faults, operating under non-stationary conditions have gained strength because of its considerable influence on the operational continuation of many industrial processes. In case of rotor broken bars, fault detection based on sideband components issued from currents, flux, instantaneous control or power signals under different load conditions, may fail due to the presence of inter-bar currents that reduce the degree of rotor asymmetry, especially for double squirrel cage induction motors. But the produced core vibrations in the axial direction, can be investigated to overcome the limitation of the classical technique using appropriate time-frequency analysis for these purposes. Unlike previous approaches, the presented technique is based on optimized use of the Discrete wavelet transform to overcome the limitation of classical frequency approaches under non-stationary operating conditions. The developed approach is best suited for automotive or high power traction systems, in which safe-operating and availability are mandatory. Experimental results are provided, showing the validity of the investigated technique, leading to an effective diagnosis procedure for incipient rotor broken bars in double or single cage induction machines under dynamic operating conditions.

The single-phase induction motor (SPIM) is one of the electrical machines more used in the World, and can be found in several fractional and sub-fractional horsepower applications in houses, offices, shoppings, farms, and industries. The introduction of more sophisticated applications has required the use of variable speed drives for SPIM, where the adoption of sensorless techniques is the more reasonable option for speed control due to the low cost of this electrical machine. A proposal for sensorless variable speed SPIM drive based on direct rotor field orientation techniques is presented in this paper. None transformation is used in order to eliminate the asymmetry of the stator windings of the SPIM. The rotor speed is estimated from an flux observer, which is based on two independent linear feedback control systems. The speed and flux estimatives are used in two control loop based on PID regulators, which determine the voltages to be applied to the SPIM windings by a three-legs VSI inverter. Using computer simulations, two situations are considered in order to demonstrate the satisfactory performance of the proposed sensorless speed control for SPIM drives: variations on rotor speed reference and the application of mechanical load.

It is usual find single-phase induction motor (SPIM) in several house, office, shopping, farm, and industry applications, which are become each time more sophisticated and requiring variable speed drives. Considering the low cost of this machine, the adoption of sensorless speed control is the more reasonable option for SPIM drives. This paper presents a proposal for sensorless variable speed SPIM drive based on direct rotor field orientation techniques. An observer based on two independent linear close-loop control systems provides the estimation of the rotor flux and speed from the measurements of the stator currents and voltages. These estimatives are used by close-loop systems for speed control and flux regulation in order to determine the voltages to be applied in the main and auxiliary windings by a three-legs VSI inverter. None variable transformation is used in this proposal in order to eliminate the asymmetry of the stator windings of the SPIM. The performance of the proposed sensorless speed control is satisfactorily demonstrated from computer simulations considering two situations: variations on rotor speed reference and the application of mechanical load.

In this paper an IPMSM (Interior Permanent Magnet Synchronous Motor) rotor configuration optimization is proposed in order to increase the performances in terms of torque, limiting at the same time the rotor leakage flux. The final mixed radial and tangential rotor configuration here proposed and described determines a reduction in PM material quantity of about 25% compared to a tangential IPMSM one with the same dimension and weight, together with an increase of the motoring torque of about 50%. Some simulation carried out by using a FEM software and a comparative analysis with two traditional IPMSMs rotor configurations show that a significant improvement can be achieved with limited changes in the rotor geometry, without varying the stator iron core structure and windings.

In wind electrical energy generating systems, due to fast voltage and current fluctuations, the power converter represents a source of electromagnetic disturbances. EMI problems of stand alone wind generators are here analysed in order to take into account many different power quality problems which result in voltage fluctuations and harmonics in the net. This paper, moreover, presents a wind turbine experimental simulator (WTES) that moves a wind electrical energy generating system (WEEGS) to carry out EMI measurements and the relative experimental results. The WEEGS here taken into account comprises a wound rotor induction generator (WRIG) in which the frequency transformation from the rotor to the stator windings generate interharmonics and the direct connection between stator and grid increase the sensitivity to voltage sag. These two aspects are here discussed and the existing solutions are pointed out.

In this paper a control algorithm for the efficiency improvement of permanent magnet synchronous generators (PMSG), the relative simulations and their results are presented. The proposed algorithm reduces the losses of the generator without affecting its performances. In details, after a description of a dynamic model of the PMSG, which has been modified in order to take into account the iron losses, the basic methodologies to obtain the loss minimization are presented and discussed. Many simulations of a specific PMSG employing the proposed algorithm were carried out and are presented. The results of these simulations show that enhancement of the efficiency up to 3% and more can be reached in comparison to a PMSG using a traditional control strategy. The control algorithm has been tested through simulations in order to demonstrate its validity when the generator is coupled to wind turbines.

This paper deals with sensorless control of Interior Permanent Magnet Synchronous Motors (IPMS) based on the estimation of speed and rotor angular position. The above estimate is based on the injection of high frequency stator currents able to generate a signal similar to that generated by a resolver connected to the axis of the motor. A new digital algorithm has been designed to demodulate the above signal whose implementation can be carried out on the same DSP that processes the control algorithm. In this paper a new scheme of speed and angular position estimator is proposed and justified on the theoretic point of view. The experimental results here shown validate the effectiveness of the sensorless control algorithm in all the operating situations concerning the whole speed and load torque ranges.