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2. Quasi-Z-Source Indirect Matrix Converter Fed Induction Motor Drive for Flow Control of Dye in Paper Mill.
- Author
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Sri Vidhya, D. and Venkatesan, T.
- Subjects
- *
INDUCTION motors , *PAPER mills , *DYES & dyeing , *VOLTAGE control , *MATRIX converters , *PULSE width modulation - Abstract
This paper describes a flow control of the dye in the paper mill with the quasi-Z-source indirect matrix converter (QZSIMC) fed induction motor drive. More than a decade the voltage-source inverter (VSI) and current-source inverter (CSI) have been used to control the speed of the induction motor, which in turns controls the flow of dye. Recently, the matrix converter (MC) has been an excellent competitor for the VSI or CSI for its compactness. The voltage transfer ratio of the VSI, CSI, and MC has been limited to 0.866. Thus, the efficiency of these converters is less. To improve the voltage transfer ratio the quasi-Z-source network (QZSN) is to be used between voltage source and indirect MC (IMC). The modification in the shoot-through duty ratio of the QZSN varies the voltage transfer ratio greater than 0.866. Different voltage transfer ratios are needed for different voltage sag conditions. For a variation of the duty ratio of the QZSN, the fuzzy logic controller has been presented. To control the IMC vector control with space vector modulation has been presented. This paper proposes the implementation of QZSIMC adjustable speed drive for the flow control of dye in paper mill during different voltage sag conditions. A 4-kW prototype has been built and the effectiveness of the proposed system is verified with simulation results and experimental setup. Simulation is done in MATLAB, Simulink platform. Experimental setup is done with the aid of a TMS320F2812 (Texas Instrument) processor. The experimental results validate the maintenance of the speed of an induction motor at the set condition, thus controlling the perfect flow of dye in paper manufacturing technology. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
3. Modified unipolar SPWM inverter for solar PV applications using MATLAB/Simulink model interfaced with dSPACE DS1104
- Author
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L., Ashok Kumar and R., Kumaravel
- Published
- 2023
- Full Text
- View/download PDF
4. Quantitative Evaluation of DER Smart Inverters for the Mitigation of FIDVR in Distribution Systems.
- Author
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Wang, Wenbo and de Leon, Francisco
- Subjects
POWER resources ,INDUCTION motors ,ELECTRON tube grids ,CAPACITOR switching ,ELECTRONIC paper ,TEST systems ,ELECTRIC power distribution equipment - Abstract
This paper exploits smart inverters of distributed energy resources (DERs) for the mitigation of fault-induced delayed voltage recovery (FIDVR). According to the IEEE Standard 1547-2018, smart inverters with voltage ride-through and var injection capabilities are promising technologies for mitigating FIDVR. This paper quantitatively investigates the effectiveness of smart inverters for FIDVR from a system-wide perspective. It shows that the penetration of smart inverters and induction motors are important factors affecting mitigation success. In addition, the over-voltages at the end of FIDVR due to load disconnections can be prevented with coordinated control of DERs and automated switching capacitors. The control scheme of smart inverters used for FIDVR is extended from the distributed volt/var droop control to include low- and high-voltage ride-through capabilities. The IEEE 13-bus feeder, the 8500-node test feeder, and the IEEE 390-node low-voltage network test system are used to illustrate the impact of DER penetration. For example, one can determine the residential air conditioner penetration level (for a given system at certain DER penetration level) that makes a system susceptible to FIDVR. The effects of solar intermittency are also studied. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
5. A Current Limiting Strategy With Parallel Virtual Impedance for Three-Phase Three-Leg Inverter Under Asymmetrical Short-Circuit Fault to Improve the Controllable Capability of Fault Currents.
- Author
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Lin, Xinchun, Liang, Zhigang, Zheng, Yun, Lin, Yibin, and Kang, Yong
- Subjects
FAULT currents ,PULSE width modulation transformers ,SHORT-circuit currents ,IMPEDANCE control ,FILTER paper ,VOLTAGE control ,ELECTRIC potential - Abstract
Voltage-controlled three-phase three-leg inverters are widely applied in various occasions. The inverters are generally switched to the current-controlled mode to limit the fault currents when short-circuit faults happen. Under symmetrical fault, the inverter can be controlled as a symmetrical, three-phase current source. However, the voltage limiting will happen under asymmetrical fault. As a result, the fault phase currents will be distorted and cannot be completely controlled. Considering that the voltage limiting is mainly caused by large load impedance of healthy phase under asymmetrical fault, the voltage limiting is avoided by paralleling the virtual impedance with the output filter capacitor in this paper. As a result, the current limiting loop is not broken and the fault phase currents can be effectively controlled. The implementation of virtual impedance in control system and the influence of virtual impedance on the stability of system are also analyzed in detail in this paper. The theoretical results are validated by experiments. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
6. Effects of Transmission Belt Looseness on Electrical and Mechanical Measurements of an Induction Motor (best conference paper award)
- Author
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Fournier, Etienne, Picot, Antoine, Régnier, Jérémi, Andrieux, Christian, Saint-Michel, Jacques, Maussion, Pascal, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Leroy-Somer (FRANCE), and Institut National Polytechnique de Toulouse - INPT (FRANCE)
- Subjects
Belts ,Maintenance, Induction motors ,Variable speed drives ,Inverters ,Spectral analysis ,Mechanical variables measurement ,Current measurement ,Automatique ,Fault diagnosis ,Condition monitoring - Abstract
This article explores the impact of belt looseness on electrical and mechanical quantities of a system driven by an induction motor and a belt-pulley transmission. The effects of this defect, for example the belt slipping or the apparition of spectral signatures in some measurements, are first investigated under steady state operation. Transient state tests are then performed to analyse, in the time domain, the system response to a step of the speed reference. The behaviour of different variables (slip,speed, currents, etc.) is studied for different health conditions and the increase of the belt looseness clearly impact the electric and mechanical variables’ waveforms. The experimental tests carried out in this study, under steady or transient state, show promising results for the diagnosis of belt degradations. Perspectives of this work are therefore detailed at the end of this paper.
- Published
- 2015
7. Harmonic Resonance Mechanisms and Influencing Factors of Distributed Energy Grid-Connected Systems.
- Author
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Xu, Minrui, Li, Zhixin, Lu, Shufeng, Xu, Tianyang, Zhang, Zhanqi, and Quan, Xiangjun
- Subjects
GRIDS (Cartography) ,ENERGY development ,ELECTRIC vehicles ,RESONANCE - Abstract
With the rapid development of global energy transformation and new power system, ensuring the stability of distributed energy grid connections is the key to maintaining the reliable operation of the whole power system. This paper constructs detailed impedance models of grid-following (GFL) and grid-forming (GFM) inverters using a harmonic linearization method and thoroughly investigates the mechanisms of resonance when inverters are connected to the grid, as well as the impact of model parameters on the stability of the grid system. This paper also briefly analyzes the scenario where distributed energy and electric vehicles are integrated into the grid simultaneously, demonstrating that grid system stability can be ensured in complex grid situations through reasonable parameter design. Lastly, the accuracy of the proposed impedance models and analysis is verified through MATLAB/Simulink simulations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. A Novel Cooperative Controller for Inverters of Smart Hybrid AC/DC Microgrids.
- Author
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Alhasnawi, Bilal Naji, Jasim, Basil H., Issa, Walid, and Esteban, M. Dolores
- Subjects
MICROGRIDS ,STEADY-state responses ,FREQUENCY-domain analysis ,ELECTRONIC paper ,IDEAL sources (Electric circuits) - Abstract
This paper presents a novel cooperative control technique concerning fully-distributed AC/DC microgrids. Distributed generation based on inverters has two types, i.e., Current Source Inverter (CSI), also referred to as PQ inverter, and Voltage Source Inverter (VSI). Both inverter forms have a two-layer coordination mechanism. This paper proposes a design method for the digital Proportional-Resonant (PR) controller that regulates the current inside an inverter. The inverters will improve the voltage quality of the microgrid while maintaining the average voltage of buses at the same desired level. There is comprehensive detail on the computations specific to resonant and proportional gains and digital resonance path coefficients. The paper includes a digital PR controller design and its analysis in the frequency domain. The analysis is based on the w-domain. The main contribution of this paper is the proposed method, which not only focuses on the transient response but also improves the steady-state response which smoothens the voltage; furthermore, all inverters are effectively involved to increase the capacity of the microgrid for better power management. The suggested cooperative control technique is used on an IEEE 14-bus system having fully distributed communication. The convincing outcomes indicate that the suggested control technique is an effectual means of regulating the microgrid's voltage to obtain an evener and steady voltage profile. The microgrid comprises distributed resources and is used as the primary element to analyse power flow and quality indicators associated with a smart grid. Lastly, numerical simulation observations are utilised for substantiating the recommended algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
9. Impact of Sustained Supply Voltage Magnitude on Consumer Appliance Behaviour.
- Author
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Elphick, Sean, Robinson, Duane A., Perera, Sarath, Knott, Jonathan C., David, Jason, and Drury, Gerrard
- Subjects
CONSUMER behavior ,VOLTAGE ,DISTRIBUTED power generation ,HIGH voltages ,ENERGY consumption - Abstract
Voltage rise caused by high levels of distributed generation is manifesting as voltage regulation challenges for many electricity network service providers. In this environment it would be ideal to reduce supply voltage magnitudes, however, many network operators are hesitant to do so due to concerns related to consumer appliance performance at reduced supply voltage magnitudes. Voltage regulation requirements are defined by network standards and network service providers must ensure voltages remain within specified limits. Through an evaluation of domestic appliance performance when supplied at various voltage magnitudes, this paper examines the impact of varying voltage levels on residential appliances. Equipment energy demand, operation and actuation were monitored for each applied voltage magnitude. While no equipment failures were recorded, appliance behaviour varied significantly with applied voltage magnitude. Individual appliance conservation voltage reduction (CVR) factors have also been established. The results highlight the importance of good voltage regulation and provide substantiated appliance performance figures for future studies. The outcomes of this paper allow electricity network service providers to understand the implications of supply voltage magnitude on domestic appliance performance, whether it be understating of the impact of higher voltage magnitudes caused by distributed generation or implications of reducing voltage magnitudes to provide headroom for distributed generation integration. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
10. Algorithm for Assessment of the Switching Angles in the Unipolar SPWM Technique for Single-Phase Inverters.
- Author
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Ponce-Silva, Mario, Sánchez-Vargas, Óscar, Cortés-García, Claudia, Aguayo-Alquicira, Jesús, and De León-Aldaco, Susana Estefany
- Subjects
ELECTRIC inverters ,DC-AC converters ,MATHEMATICAL analysis ,ELECTRIC motors ,RENEWABLE energy sources - Abstract
The main contribution of this paper is to present a simple algorithm that theoretically and numerically assesses the switching angles of an inverter operated with the SPWM technique. This technique is the most widely used for eliminating harmonics in DC-AC converters for powering motors, renewable energy applications, household appliances, etc. Unlike conventional implementations of the SPWM technique based on the analog or digital comparison of a sinusoidal signal with a triangular signal, this paper mathematically performs this comparison. It proposes a simple solution to solve the transcendental equations arising from the mathematical analysis numerically. The technique is validated by calculating the total harmonic distortion (THD) of the generated signal theoretically and numerically, and the results indicate that the calculated angles produce the same distribution of harmonics calculated analytically and numerically. The algorithm is limited to single-phase inverters with unipolar SPWM. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. A Wireless DC Motor Drive Using LCCC-CCL Compensated Network With Bidirectional Motion Capability.
- Author
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Liu, Haitang, Zhou, Hong, Deng, Qijun, Hu, Wenshan, Gao, Xingran, and Fang, Li
- Subjects
MOTOR drives (Electric motors) ,ZERO voltage switching ,SERVOMECHANISMS ,RESONANT states ,WIRELESS power transmission ,MOTION - Abstract
This paper proposes an LCCC and CCL compensated wireless servo motor control circuitry utilizing the merits of fundamental and third harmonic. With this circuitry, the motor side needs no additional power supply and controller, which significantly reduces the difficulty of maintenance. Besides, benefiting from the proposing of CCL compensating topology and utilizing of the self-driven circuitry, the secondary operates in fully resonant state and the motor direction control H-bridge is self-driven by the LC frequency selecting circuitry (FSC). Moreover, compared with the conventional motor control circuitry, because of the use of fundamental and third harmonic, the power equalization becomes significantly easier, and zero voltage switch (ZVS) can be realized at the same time; Besides, motion direction control of the motor is simpler with only a single pole double throw (SPDT) at the transmitter side. In addition, system resource consumption is reduced compared with conventional motor drive topologies. In this paper, an 180W prototype is built for experimental verification, and the result shows a good power equalization capability and a transfer efficiency reaching up to 90% at the distance of 10cm. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
12. Considerations on Combining Unfolding Inverters with Partial Power Regulators in Battery–Grid Interface Converters.
- Author
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Galkin, Ilya A., Saltanovs, Rodions, Bubovich, Alexander, Blinov, Andrei, and Peftitsis, Dimosthenis
- Subjects
AC DC transformers ,ELECTRIC batteries ,ELECTRIC vehicle batteries ,RENEWABLE energy sources ,GRID energy storage ,POWER resources ,DC-to-DC converters ,ELECTRICAL energy - Abstract
The application of electrochemical cells as a source unit of electrical energy is rapidly growing—used in electric vehicles and other electric mobility devices, as well as in energy supply systems—as energy storage, often together with renewable energy sources. The key element of such systems is the power electronic converter used for DC energy storage and AC grid interfacing. It should be bidirectional to charge and discharge the battery when it is necessary. Two-stage battery interface converters are the most common; their DC-DC stage controls the battery current and adjusts voltage, but the DC-AC stage (inverter or frontend) controls the current in the grid. The use of unfolding inverters in two-stage battery interfaces can have some advantages. In this case, the DC-DC converter produces half-sinewave pulsating voltages and currents, but the unfolding circuit changes the polarity of the voltages and currents and produces no switching losses. Another trend of modern power electronics is the principle of partial power processing. In this case, power electronic converters deal only with a part of the total power; therefore, losses in such converters are reduced. This paper considers combining unfolding frontends with partial power DC-DC converters that enable the further reduction in losses. In this paper, it is shown that such implementation of the partial power conversion principle in semi-DC-AC systems is really possible based on the real-time matching of the voltage of the partial-power DC-DC converter, battery voltage (which depends on its state of charge) and the rectified instantaneous voltage of the AC grid. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. A new submodule‐based generalized multilevel inverter topology with reduced switches and DC sources.
- Author
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Seifi, Ali, Hosseini, Seyed Hossein, Tarafdar Hagh, Mehrdad, and Hosseinpour, Majid
- Subjects
- *
CONVERTERS (Electronics) , *POWER electronics , *IDEAL sources (Electric circuits) , *MATHEMATICAL analysis , *ELECTRONIC equipment , *ELECTRIC inverters - Abstract
Summary: Multilevel inverters are known as essential converters in renewable sources. First, in this paper, a new submodule is presented, and based on it, a new sub‐multilevel inverter is presented. The proposed sub‐multilevel inverter consists of several unidirectional and bidirectional switches and DC voltage sources. Then, the generalized topology, developed in two modular and cascaded modes, is presented to increase production levels. The proposed submodules are connected in series in the modular topology, increasing production levels. The proposed topology to produce the maximum output levels has the minimum number of IGBTs, drivers, DC voltage sources, etc. Mathematical analyses for conduction and switching losses are provided, and mathematical analyses for the number of devices and voltage across the switches are also presented. In addition to the mathematical analysis of losses, the simulation results are also presented. A general comparison of proposed topology components is presented to demonstrate their advantages. This comparison shows that the proposed topology has the minimum number of power electronic devices. In this paper, nearest level modulation is used to control the proposed topology. The simulation and experimental results of the proposed sub‐multilevel verify the performance of the proposed topology. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. A Hybrid Commutation Technique for Reducing Zero-Crossing Distortion in a Sliding Mode Controller for Single-Phase Grid-Tied Full-Bridge Inverters.
- Author
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Bolaños-Navarrete, Mario Andrés, Bastidas-Rodríguez, Juan David, and Osorio, Gustavo
- Subjects
SLIDING mode control ,SOLAR panels ,DESIGN techniques ,MICROCONTROLLERS ,SIMULATION methods & models - Abstract
This paper presents a single-phase Full-Bridge (FB) inverter with a hybrid commutation technique designed to reduce the harmonic distortion caused by the loss of the controller capability around the zero-crossing point in the unipolar commutation region. The hybrid modulation changes from unipolar to bipolar commutation under the loss of the reference control, improving the robustness and efficiency of the method. The commutation technique improves the switching performance and reduces the switching losses. Simulation models are developed in MATLAB/Simulink R2023b to evaluate their performance under different operating conditions. The results show that the proposed commutation technique can achieve high efficiency, low total harmonic distortion (THD), and fast dynamic response. The experimental implementation of sliding mode control (SMC) implemented in an STM32 microcontroller confirms that the hybrid commutation technique can reduce the THD by 0.96 percentage points for local (off-grid) loads and up to 2.45 in an industrial grid-tie network, compared with unipolar commutation. These findings highlight the potential of the proposed modulation technique for applications like solar panels and offer crucial insights for ongoing research and development in this field. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. Grid-Supportive Loads—A New Approach to Increasing Renewable Energy in Power Systems.
- Author
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Jain, Himanshu, Mather, Barry, Jain, Akshay Kumar, and Baldwin, Samuel F.
- Abstract
This paper demonstrates the potential of inverter-based loads to support grid reliability during power system transients thereby enabling reliable integration of renewable energy in power systems. Such loads are referred to in this paper as grid-supportive loads (GSLs). A new GSL model is developed that simulates the transient response capabilities that can be programmed in electronic loads. The model’s design enables it to be easily integrated in widely used commercial power system transient analysis software. Theoretical expressions are derived that explain the workings of the GSL model. The performance, numerical stability, and impact of the GSL model is validated on 9-bus and 2000-bus synthetic power system models using generator tripping and bus fault disturbances. Results on the 2000 bus system show that in the absence of frequency support from wind/solar generation resources, just 20% of loads with grid-supportive capabilities can improve frequency response by up to 2000 MW/0.1 Hz and reduce deviation in frequency at nadir by up to 60% compared to the situation when GSLs are absent. Power system reliability also improves under fault events. It is further shown that GSLs can aid in integrating more renewable generation without degrading the overall transient response of the power system. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
16. A Unified Method of Frequency Oscillation Characteristic Analysis for Multi-VSG Grid-Connected System.
- Author
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Qin, Benshuang, Xu, Yonghai, Yuan, Chang, and Jia, Jiaoxin
- Subjects
FREQUENCIES of oscillating systems ,CURRENT fluctuations ,TRANSFER functions - Abstract
This paper addresses the frequency oscillation problem in a parallel-inverter-based grid-connected system. Angular frequency interactions between inverters and the grid exhibit various numbers of complicated characteristics that seriously threaten the connected power system's stable operation. This paper proposes a unified frequency oscillation method analysis to investigate the oscillation problem in a multi-VSG grid-connected system. In this method, the power control model of each grid-connected inverter is equivalent to a two-terminal network by analogy method, which can be described as a “current source” connected in parallel with a reciprocal of “admittance” and then joined in series with a joint of “admittance.” Next, considering the influence of grid impedance, the model of the whole grid-connected system is established to reveal the mechanism of multi-VSG angular frequency oscillation. Subsequently, the influence factors of frequency oscillation and its variation law are analyzed through transfer functions, which provide an essential theoretical method for solving the frequency oscillation problem in the current multi-inverter grid-connected engineering application. Finally, we validate the effectiveness and correctness of the small-signal model and the frequency oscillation characteristics by building the MATLAB/Simulink simulation. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
17. Maximum Asymmetrical Support in Parallel-Operated Grid-Interactive Smart Inverters.
- Author
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Shabestary, Masoud M. and Mohamed, Yasser
- Abstract
Parallel operation of grid-interactive inverters has been continuously gaining attraction, and their contribution to sustaining the host grid stability has become strongly demanded. This paper investigates and discusses the trends in the most recent interconnection grid codes. Grid codes call for simultaneous requirements for the low-voltage ride-through capabilities of parallel operation of grid-interactive inverters as well as their effective asymmetrical voltage support by advanced active/reactive bi-sequence power provision under unbalanced grid faults. Addressing these demands in an optimized way becomes very challenging. This paper thus proposes a new methodology to simultaneously achieve three main objectives: (1) coordination of the asymmetrical ride-through and voltage support capabilities of parallel-operated inverters, (2) maximizing the utilization of each unit and their collective contribution in boosting the positive-sequence voltage and reduction of the negative sequence voltage subject to the constraints from the inverters and the grid, and (3) minimizing the impact of the support on the active power injections. Simulation and experimental results illustrate the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
18. Stanowiska dydaktyczne w laboratorium energoelektroniki ISEP/ZEP PW - opracowanie i implementacja w procesie dydaktycznym.
- Author
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ZDANOWSKI, Mariusz and GRZEJSZCZAK, Piotr
- Abstract
Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
19. A review of recent control techniques of drooped inverter‐based AC microgrids.
- Author
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Issa, Walid, Sharkh, Sulieman, and Abusara, Mohammad
- Subjects
MICROGRIDS ,RENEWABLE energy sources ,DISTRIBUTED power generation ,ALTERNATING currents ,GRIDS (Cartography) - Abstract
As the penetration of distributed generation (DG) systems in the grid is increasing, the challenge of combining large numbers of DGs in the power systems has to be carefully clarified and managed. The control strategy and management concept of the interconnected systems should be flexible and reliable to handle the various types of DGs. This can be suitably met by microgrids. This paper introduces the microgrid structure and elements and states the main objectives that should be achieved by the microgrid controllers and each DG controller in both operation modes (grid‐connected and island mode). It also presents the challenges of having multiple DG units in a microgrid in terms of accurate power control/sharing, voltage and frequency regulation, power management between DGs, different renewable energy sources integration and deployment, seamless mode transfer, and the modeling issues. The centralized and decentralized control techniques as potential solutions have been discussed and compared by highlighting the advantages and disadvantages of each. Furthermore, the recent control techniques for drooped alternating current microgrids and the main proposed solutions and contributions in the literature have been exposed to finally overcome the droop control limitations and obtain a flexible and smart distributed power system. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. Current Regulation in Parallel Combined Winding Bearingless Motors.
- Author
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Jiang, Yunlei, Torres, Renato Amorim, and Severson, Eric Loren
- Subjects
MAGNETIC suspension ,MAGNETIC torque ,ELECTROMAGNETS ,MOTOR drives (Electric motors) ,MOTORS ,TRANSFER functions ,POWER density ,HARDWARE - Abstract
To improve power density and motor performance, new bearingless motor topologies combine torque and magnetic suspension coils into a single winding. Of these topologies, the parallel dual-purpose no-voltage winding is advantageous from the bearingless drive perspective because it requires the least amount of hardware. However, this topology can result in undesirable current controller performance from cross-coupling effects between the suspension and torque operation. This paper investigates these cross-coupling effects using rotating reference frame theory to derive relevant system disturbance transfer functions. The nature of this coupling is explained in relation to the machine and control parameters (inductances, resistances, controller gains) to provide insights for bearingless machine and control designers. The paper proposes and simulates different compensation techniques to minimize or eliminate the cross-coupling. It is shown that with careful machine design or with proper feedback control compensation, the motor controller can be implemented as a conventional motor drive, without knowledge of the magnetic suspension system. Finally, experimental validation is provided via two prototype machines. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
21. Linear Amplifier-Based Power-Hardware-in-the-Loop Emulation of a Variable Flux Machine.
- Author
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Amitkumar, K. S., Thike, Rajendra, and Pillay, Pragasen
- Subjects
ELECTRIC inverters ,ELECTRIC controllers ,MACHINING ,POWER amplifiers ,FLUX (Energy) ,ELECTRIC drives - Abstract
Emulation of an electric machine allows the testing of a drive inverter and controller of an electric drive system, prior to the manufacture of a machine prototype. This paper presents the emulation of a variable flux machine (VFM). The VFM emulator system proposed in this paper uses a detailed look-up table-based machine model for the purpose of emulation. This allows the emulator to mimic all machine magnetic and geometric behaviors such as saturation and torque ripple. In addition, the machine emulator proposed in this paper uses high-performance high-bandwidth linear amplifiers as power amplifiers. This enables a high bandwidth; leading to a high accuracy machine emulation. A detailed control description for the proposed machine emulator system and a machine model look-up table data verification against a prototype machine is initially presented. Experimental results are then presented to validate the utility of the proposed VFM emulator system to emulate various machine transient behaviors at different magnetization levels. Experimental results obtained from the emulator are subsequently compared against the experimental results obtained from a prototype VFM drive to verify the emulation accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
22. A New Unbalanced Voltage Compensation Method Based on HOPF Oscillator for Three-Phase DC/AC Inverters With Unbalanced Loads.
- Author
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Luo, Siyi, Wu, Weimin, Koutroulis, Eftichios, Chung, Henry Shu-Hung, and Blaabjerg, Frede
- Abstract
In islanded microgrids, distributed generators (DGs) are employed as distributed compensators to improve the power quality on the load side. Due to the access of unbalanced loads, the low-voltage microgrid will naturally exhibit three-phase unbalance, which may cause additional power losses and deteriorate power quality. Therefore, this paper proposes a novel unbalanced-voltage compensation control method based on the Hopf oscillator, which introduces the negative-sequence voltage and current into the traditional Hopf oscillator to achieve the negative sequence voltage droop characteristics. It can not only realize the negative sequence droop control of a single inverter, but it is also capable to support the reactive power automatic distribution between multi-parallel grid-forming inverters. Compared with the traditional unbalanced voltage compensation method based on filtered negative sequence reactive power, the proposed unbalanced voltage compensation method can slightly improve the dynamic response. Experimental results verify the effectiveness of the proposed control strategy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
23. Present and Future Trends in Filters and Multiplexers.
- Author
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Snyder, Richard V., Mortazawi, Amir, Hunter, Ian, Bastioli, Simone, Macchiarella, Giuseppe, and Wu, Ke
- Subjects
ELECTRIC filters ,MULTIPLEXING equipment ,BARIUM strontium titanate ,ACOUSTIC resonators ,SUBSTRATE integrated waveguides - Abstract
In the last 10 or 15 years, exciting new developments have occurred in the field of filters and multiplexers. The two words that best explain this phenomenon are “topology” and “technology.” Thus, this paper will cover new connections, new materials, and new processes. This paper summarizes what is new, describes the new devices, and avoids simply surveying the entire field. It is not possible to cover everything, and regrettably, some new and possibly exciting areas are omitted (such as filters fabricated using liquid crystal polymers, active element inclusion, extreme power devices used in accelerators), and others,\ldots, because something has to be left for the next paper! The paper does cover bandstop filters, intrinsically switched film bulk acoustic resonator, and barium–strontium–titanate filters, brand new derivations of lossy filter synthesis and dual-band filter synthesis, multimode networks, new work on optimal multiplexer (multiport network) configurations, and substrate integrated waveguide filters. In each of these areas significant new work has been recently performed and is presented in a summary format suitable for those thinking that the area of filters and multiplexers has become mature (stagnant) with nothing interesting to learn. Nothing could be further from the truth! [ABSTRACT FROM PUBLISHER]
- Published
- 2015
- Full Text
- View/download PDF
24. SRAM-Based In-Memory Computing Macro Featuring Voltage-Mode Accumulator and Row-by-Row ADC for Processing Neural Networks.
- Author
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Mu, Junjie, Kim, Hyunjoon, and Kim, Bongjin
- Subjects
SUCCESSIVE approximation analog-to-digital converters ,ANALOG-to-digital converters ,STATIC random access memory ,RANDOM access memory ,DATA transmission systems - Abstract
This paper presents a mixed-signal SRAM-based in-memory computing (IMC) macro for processing binarized neural networks. The IMC macro consists of $128\times 128$ (16K) SRAM-based bitcells. Each bitcell consists of a standard 6T SRAM bitcell, an XNOR-based binary multiplier, and a pseudo-differential voltage-mode driver (i.e., an accumulator unit). Multiply-and-accumulate (MAC) operations between 64 pairs of inputs and weights (stored in the first 64 SRAM bitcells) are performed in 128 rows of the macro, all in parallel. A weight-stationary architecture, which minimizes off-chip memory accesses, effectively reduces energy-hungry data communications. A row-by-row analog-to-digital converter (ADC) based on 32 replica bitcells and a sense amplifier reduces the ADC area overhead and compensates for nonlinearity and variation. The ADC converts the MAC result from each row to an N-bit digital output taking 2N-1 cycles per conversion by sweeping the reference level of 32 replica bitcells. The remaining 32 replica bitcells in the row are utilized for offset calibration. In addition, this paper presents a pseudo-differential voltage-mode accumulator to address issues in the current-mode or single-ended voltage-mode accumulator. A test chip including a 16Kbit SRAM IMC bitcell array is fabricated using a 65nm CMOS technology. The measured energy- and area-efficiency is 741-87TOPS/W with 1-5bit ADC at 0.5V supply and 3.97TOPS/mm2, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
25. Cooperative Regulation of Imbalances in Three-Phase Four-Wire Microgrids Using Single-Phase Droop Control and Secondary Control Algorithms.
- Author
-
Espina, Enrique, Cardenas-Dobson, Roberto, Espinoza-B., Mauricio, Burgos-Mellado, Claudio, and Saez, Doris
- Subjects
MICROGRIDS ,SIGNAL generators ,PHASE-locked loops ,ELECTRIC power distribution equipment ,ALGORITHMS - Abstract
Collaborative control of power converters operating in microgrids with unbalanced single-phase loads is difficult to achieve, considering that the voltages and currents have positive-, negative-, and zero-sequence components. In this paper, a new control scheme for collaborative control of four-leg microgrids is proposed. The main advantage of the proposed methodology is simplicity, because the sharing of the powers produced by the positive-, negative-, and zero-sequence voltage and currents is simple to achieve using the easy to implement and well-known droop control algorithms, i.e., as those based on $P$ – $\omega$ and $Q$ – $v$ droop control. The proposed droop algorithms do not require high bandwidth communication channels and the application of virtual impedances, whose design usually demands extensive simulation work, is not required. Three secondary control systems are also analyzed, discussed, and implemented in this paper to regulate the frequency, voltage, and phase at the point of common coupling (PCC), to achieve a balanced 50-Hz three-phase voltage supply in the PCC during steady-state operation. For these secondary control systems, single-phase phase-locked loop based on quadrature signal generators are implemented. Small signal modeling and design are discussed in this paper. A microgrid prototype of $\approx$ 5 kW, implemented using two power converters of 3 kW (each), is used to experimentally validate the proposed algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
26. Resonant Switching Cell Model for High-Frequency Single-Ended Resonant Converters.
- Author
-
Lee, Kyung-Hwan and Ha, Jung-Ik
- Subjects
ZERO voltage switching ,ELECTRIC inductance ,CELLS ,DC-to-DC converters - Abstract
This paper proposes a resonant switching cell model to analyze and design the single-ended resonant dc–dc converters. The single-ended zero-voltage switching (ZVS) converters such as the Class E converter are efficient for megahertz switching because they feature low turn-on and turn-off switching losses. Also, they use only a ground-referenced switch, allowing a simple gate drive circuit. In this paper, we investigate the single-ended resonant converter with the small input inductance, whereas the conventional Class E converter has a large input inductance. The main contribution of this paper is to propose the resonant switching cell as an analytic model that simplifies the analysis and the design of the resonant dc–dc converters. Furthermore, this paper presents the design method of the resonant switching cell model for minimizing the resonant current magnitude and conduction loss while the converter maintains ZVS property. The experimental results from a 10-MHz GaN-based prototype demonstrate the feasibility and effectiveness of the analysis and design based on the proposed resonant switching cell model. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
27. Zero-Sequence Voltage Elimination for Dual-Fed Common DC-Link Open-End Winding PMSM High-Speed Starter-Generator—Part II: Deadtime Hysteresis Control of Zero-Sequence Current.
- Author
-
Rovere, Luca, Formentini, Andrea, Calzo, Giovanni Lo, Zanchetta, Pericle, and Cox, Tom
- Subjects
PERMANENT magnet motors ,HIGH-speed machining ,ELECTROMAGNETIC forces ,VOLTAGE-frequency converters ,ELECTRIC potential - Abstract
In a common dc-link dual-fed open-end winding permanent magnet synchronous motor (OEW-PMSM) topology, it is well known how the additional flow of a zero-sequence current (ZSC) is permitted. The low zero-sequence impedance characteristic of high-speed machines leads to high-intensity and high-frequency ripple of the ZSC. Therefore, there is a necessity to eliminate the zero-sequence-voltage (ZSV) produced by the two voltage source converters that feed the machine. Furthermore, the non-sinusoidal back electromagnetic force (back EMF) causes the circulation of a third harmonic ZSC. An OEW-PMSM high-speed starter-generator fed by a dual-inverter with a single dc-link is considered. Part I of this paper proposes a modulation for the considered topology able to eliminate instantaneously the ZSV produced. In this paper, a detailed analysis of the deadtime (DT) effect on the ZSV has been carried out and a novel hysteresis control for the ZSC using the DT as a control action is presented. The DT produces a ZSV distortion on the zero-axis that can be used to control the third harmonic ZSC flowing due to the non-sinusoidal machine back EMF. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
28. Performance and Stability Benchmarking of Monolithic 3-D Logic Circuits and SRAM Cells With Monolayer and Few-Layer Transition Metal Dichalcogenide MOSFETs.
- Author
-
Yu, Chang-Hung, Su, Pin, and Chuang, Ching-Te
- Subjects
MONOLITHIC microwave integrated circuits ,THREE-dimensional integrated circuits ,STATIC random access memory testing ,MONOMOLECULAR film testing ,TRANSITION metal compounds ,METAL oxide semiconductor field-effect transistor circuits - Abstract
For the first time, considering the architecture of monolithic 3-D integration, we evaluate and benchmark the performance of 3-D logic circuits and stability/performance of 3-D 6T SRAM cells with monolayer and few-layer transition metal dichalcogenide (TMD) devices based on ITRS 2028 (5.9 nm) technology node. The impact of random variations on the cell stability is also investigated. With the possibility of adopting monolayer or few-layer TMDs for nFET- and pFET-tiers enabled by monolithic 3-D integration, this paper indicates that the trilayer TMD device may substantially degrade the performance of 3-D logic circuits in spite of its higher mobility. This paper also reveals that stacking the monolayer pFET-tier over the bilayer nFET-tier may provide better nominal stability and read/write performance for 6T superthreshold SRAM compared with the planar technology, whereas the optimum 3-D configuration for near-/sub-threshold operations appears to be the monolayer pFET-tier over the monolayer nFET-tier. Besides the 6T cell structure, 8T SRAM cells are also investigated with monolithic 3-D integration for near-threshold/subthreshold operation. The monolayer nFET-tier over the bilayer pFET-tier configuration is shown to be the optimum 3-D 8T near-threshold/subthreshold cell design. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
29. Reactive Power Control Strategy for Inhibiting Transient Overvoltage Caused by Commutation Failure.
- Author
-
Yin, Chunya and Li, Fengting
- Subjects
REACTIVE power control ,OVERVOLTAGE ,ELECTRIC current rectifiers ,REACTIVE power ,SHORT circuits ,HIGH voltages ,WIND turbines - Abstract
The commutation failure (CF) is the most common fault in line-commutated high voltage direct current (LCC-HVDC) systems that may lead to the transient overvoltage in the sending-side system. In the worst condition, the CF may lead to large-scale wind turbine tripping. To resolve this problem, the mathematical relationship between the reactive power consumed by the rectifier and DC voltage, DC current is derived. Then, a transient overvoltage calculation method is proposed in this paper. Furthermore, the mechanism of transient overvoltage caused by the CF is analyzed; it is revealed that the reason for three times transient overvoltage is the rapid decrease of the reactive power consumed by the rectifier during the CF and the recovery period from the CF. This paper proposes a constant reactive power control (CRPC) to inhibit transient overvoltage of the sending-side AC system. The proposed CRPC can increase the reactive power consumed by the rectifier, reduce the exchange reactive power between AC and DC systems, and suppress the transient overvoltage. A simulation model in PSCAD serves to verify the proposed CRPC on the transient overvoltage suppression in the situation of different fault types, fault duration, fault severity and short circuit ratio (SCR). [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
30. Transmission Line Protection for Systems With Inverter-Based Resources – Part I: Problems.
- Author
-
Chowdhury, Ritwik and Fischer, Normann
- Subjects
PROTECTIVE relays ,ELECTRIC lines ,ELECTRIC transients ,POWER resources ,ELECTRIC relays ,OVERCURRENT protection ,GOVERNMENT laboratories - Abstract
Inverter-based resources respond differently than synchronous generation sources during power system faults, challenging line protection reliability. To understand the reliability challenges, Sandia National Laboratories and North American Electric Reliability Corporation (NERC) led a collaborative study with four inverter manufacturers (mix of Type 3 Wind, Type 4 Wind, and PV Solar) and two North American protective relay manufacturers. As part of this study, an electromagnetic transients program (EMTP) with “real-code” models representing inverter firmware was used to investigate the protective relay response to faults on the modeled power system with the different inverter types. The currents and voltages obtained from the study were then played back through line relay hardware with settings typical of systems with conventional generation. The protective relays exhibited the expected reliability challenges but provided insight into the behavior of inverter-based resources during power system faults. In this paper, we share some of the challenging cases with the responses of the different line protection schemes. Using insight from the various event records, Part II of this paper shows how relay settings can be modified to obtain a substantial improvement in reliability. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
31. Stability-Oriented Minimum Switching/Sampling Frequency for Cyber-Physical Systems: Grid-Connected Inverters Under Weak Grid.
- Author
-
Wang, Rui, Sun, Qiuye, Zhang, Huaguang, Liu, Lei, Gui, Yonghao, and Wang, Peng
- Subjects
CYBER physical systems ,DIGITAL control systems ,MICROGRIDS ,STABILITY criterion ,TELECOMMUNICATION systems - Abstract
Although the cyber-physical system stability is widely studied, scholars focus more on system stability with communication time delay. Therein, grid-connected inverters with the digital control system are regarded as one simplest and typical cyber-physical system. Meanwhile, the switching/sampling frequency of the inverter is always selected as low as possible from an efficiency viewpoint, resulting in unavoidable delay time. This delay time is apt to cause the system instability, which is more prone to severity under weak grid. To this end, this paper provides a minimum switching/sampling frequency for grid-connected inverters. Firstly, the system impedance model with equivalent delay time is constructed, which is based on padé approximate approach. This equivalent delay time consists of three parts, i.e., sampling delay time in cyber/physical level, calculation delay time in cyber level and pulsewidth modulation delay time in physical level, which reflects the cyber-physical interaction impact. Furthermore, the stability forbidden criterion is applied to make the switching/sampling frequency solving process become Hurwitz matrix identification problem through space mappings. Based on these space mappings, an adaptive step search approach is adopted to obtain the minimum switching/sampling frequency. Finally, the proposed approach can well evaluate the system stability under different frequencies through simulation and experiment. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
32. iRazor: Current-Based Error Detection and Correction Scheme for PVT Variation in 40-nm ARM Cortex-R4 Processor.
- Author
-
Zhang, Yiqun, Khayatzadeh, Mahmood, Yang, Kaiyuan, Saligane, Mehdi, Pinckney, Nathaniel, Alioto, Massimo, Blaauw, David, and Sylvester, Dennis
- Subjects
ERROR detection (Information theory) ,WIRELESS sensor networks ,COMPLEMENTARY metal oxide semiconductors - Abstract
This paper presents iRazor, a lightweight error detection and correction approach, to suppress the cycle time margin that is traditionally added to very large scale integration systems to tolerate process, voltage, and temperature variations. iRazor is based on a novel current-based detector, which is embedded in flip-flops on potentially critical paths. The proposed iRazor flip-flop requires only three additional transistors, yielding only 4.3% area penalty over a standard D flip-flop. The proposed scheme is implemented in an ARM Cortex-R4 microprocessor in 40 nm through an automated iRazor flip-flop insertion flow. To gain an insight into the effectiveness of the proposed scheme, iRazor is compared to other popular techniques that mitigate the impact of variations, through the analysis of the worst case margin in 40 silicon dies. To the best of the authors’ knowledge, this is the first paper that compares the measured cycle time margin and the power efficiency improvements offered by frequency binning and various canary approaches. Results show that iRazor achieves 26%–34% performance gain and 33%–41% energy reduction compared to a baseline design across the 0.6- to 1-V voltage range, at the cost of 13.6% area overhead. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
33. Exploiting Parallelism and Heterogeneity in a Radiation Effects Test Vehicle for Efficient Single-Event Characterization of Nanoscale Circuits.
- Author
-
Kauppila, J. S., Maharrey, J. A., Harrington, R. C., Haeffner, T. D., Nsengiyumva, P., Ball, D. R., Sternberg, A. L., Zhang, E. X., Bhuva, B. L., and Massengill, L. W.
- Subjects
COMPLEMENTARY metal oxide semiconductors ,INTEGRATED circuits ,WIRELESS communications ,TECHNOLOGICAL innovations ,DIGITAL electronics - Abstract
Novel design techniques for efficient testability are developed and have been implemented in a 14-/16-nm bulk FinFET node technology characterization vehicle. The result of this paper was the measurement of over 300 000 SETs across 12 combinational logic variants and 415 000 SEUs in three D-flip-flop designs over a large test matrix of heavy-ion linear energy transfer, angle of incidence, and supply voltage in only 319 test runs with a total test time of 108 h. A similar-sized data set with equivalent technology coverage, using the traditional serial testing approach as used in previous work, would typically require thousands of test runs and a significant number of additional hours of testing. The methodologies developed in this paper are technology agnostic and have provided the capability to efficiently characterize the radiation-induced response of the 14-/16-nm FinFET technology generation and yielded insights for assessing the feasibility for incorporation in systems requiring radiation resiliency. [ABSTRACT FROM PUBLISHER]
- Published
- 2018
- Full Text
- View/download PDF
34. Comprehensive analysis of offshore wind-photovoltaic hybrid systems: unveiling state-of-the-art autonomous components for maritime applications.
- Author
-
Popa, C., Popa, N.-S., Isac, H., Deliu, A.-D., and Andronic, C.
- Subjects
OFFSHORE wind power plants ,INTELLIGENT agents ,STORAGE batteries ,RENEWABLE energy sources ,HYBRID systems - Abstract
This paper conducts a comprehensive analysis of offshore wind-photovoltaic hybrid systems, presenting autonomous components tailored for maritime applications. Focusing on the critical role of these systems in supplying electricity to regions with limited infrastructure, particularly maritime zones, the study explores economic advantages over traditional power line installations, emphasizing remote areas. Key components, including battery storage, autonomy, battery selection (with a spotlight on lead-acid batteries), charge controllers, inverters, and the integration of Automatic Identification System (A.I.S.) for maritime safety, are discussed. The article concludes by underscoring the significance of power supply buoys for ship safety and efficient refueling near hybrid systems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Overcurrent Suppression Control for Hybrid LCC/VSC Cascaded HVDC System Based on Fuzzy Clustering and Identification Approach.
- Author
-
Guo, Chunyi, Wu, Zhangxi, Yang, Shuo, and Hu, Jingxuan
- Subjects
FUZZY systems ,CONSTRUCTION projects ,TRANSIENT analysis ,FUZZY neural networks ,VOLTAGE control - Abstract
The hybrid LCC/VSC cascaded HVDC (HC-HVDC) scheme, in which the LCC is adopted as rectifier, and one LCC in series with multiple paralleled VSC based MMCs is adopted as inverter, combines the advantages of both LCC and VSC-MMC technologies. Presently, a HC-HVDC project is planned to deliver the hydro power from Baihetan to Jiangsu in China. One of the major challenges is to suppress the DC overcurrent issue of VSC-MMCs especially under commutation failure condition of LCC at inverter side. Based on Baihetan-Jiangsu project under construction, the model of HC-HVDC system is developed in PSCAD/EMTDC. In the system, the rectifier employs a dual 12-pulse LCC, while the inverter adopts a hybrid scheme, i.e., one LCC converter in series with three paralleled VSC-MMC converters. This paper addresses the main cause and feature of the DC overcurrent, then proposes an overcurrent suppression control method for HC-HVDC system based on fuzzy clustering and identification approach. And the system transient performances with the proposed control approach are evaluated under AC fault conditions. The results show that the proposed approach can not only suppress the DC overcurrent following the commutation failure to a certain extent, but also improve the post-fault recovery performance of the overall system. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
36. Robustness of Model-Predictive and Passivity-Based Control in the Three-Phase DC/AC Converter Application.
- Author
-
Dyga, Łukasz, Alhasheem, Mohammed, Davari, Pooya, and Rymarski, Zbigniew
- Subjects
PASSIVITY-based control ,AC DC transformers ,PULSE width modulation ,QUALITY factor ,UNINTERRUPTIBLE power supply - Abstract
In modern controller design, various solutions for controlling power converter systems can be found depending on their applications, speed of working, pulse width modulation (PWM) techniques, switching frequencies— f c , and different load types. The need to manipulate control parameters can be often observed in classical structures, e.g., well-known PID, repetitive, or deadbeat control particularly sensitive to distinct parameters uncertainties. The purpose of this paper is to present an improved version of controllers designated for a UPS that will be considerably resistant to model changes. Proposed control techniques are independent of unexpected output filter changes: L f —filter coil inductance and C f —filter capacitor conductance. The second aspect of this paper is to compare effectiveness of modified predictive MPC (model-predictive control) and feedback PBC (passivity-based control) controllers in reducing output voltage total harmonic distortion (THD) for various load values. The biggest distortions of output voltage were observed during experiments with nonlinear RC load. Both simulation and experimental verification of mismatching parameters were performed and examined. Thanks to the proposed solution, the output voltage T H D v quality factor was reduced below 8% in an efficient way for all the applied loads and stayed at the level of 1% when well-matched filter parameters were provided. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
37. A Grid Impedance Estimation Method Robust Against Grid Voltages Unbalance and Harmonic Distortions.
- Author
-
Gomes, Hugo M. T. C., Carralero, Leandro L. O., Suárez, José H., Tahim, André N., Pinheiro, José R., and Costa, Fabiano F.
- Subjects
NEWTON-Raphson method ,VOLTAGE ,HARDWARE-in-the-loop simulation ,REACTIVE power ,ELECTRIC inverters ,ADAPTIVE control systems ,HARMONIC distortion (Physics) - Abstract
In this paper, a grid impedance estimation procedure based on the injection of active and reactive powers through a grid-tied inverter is proposed. The estimation is based on Newton–Raphson algorithm acting on the phasors of the voltages and currents at the point of common coupling between the inverter and the grid. Unlike, similar procedures, based on power injections, the method is implemented in the α β frame, avoiding Park transformations. This is an advantage because dq quantities are prone to be too noisy, or oscillating in unbalance grid conditions or in the presence of voltage harmonics. Moreover, the proposed method allows variations of active and reactive to be imposed simultaneously, differently of methods relying on dq voltages and currents. This feature speeds up the estimation. The voltages and current phasors used to estimate the impedance are determined with the aid of a positive sequence extractor and Fourier algorithm providing the method robustness against unbalance grid conditions and harmonic distortions. Besides the impedance estimation, this paper proposes a technique in which the impedance information is applied to enhance the inverter's control. Here, the impedance value is used with a Routh criterion to assure the system's stability. The propositions are verified with PSIM simulations and with a Hardware-in-the-Loop real-time platform. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
38. Advances in Converter Control and Innovative Exploitation of Additional Degrees of Freedom for Multiphase Machines.
- Author
-
Levi, Emil
- Subjects
HYBRID electric vehicles ,CASCADE converters ,TRACTION (Engineering) ,ELECTRIC power ,DEGREES of freedom ,WINDING machines - Abstract
Multiphase variable-speed drives and generation systems (systems with more than three phases) have become one of the mainstream research areas during the last decade. The main driving forces are the specific applications, predominantly related to the green agenda, such as electric and hybrid electric vehicles (EVs), locomotive traction, ship propulsion, “more-electric” aircraft, remote offshore wind farms for electric energy generation, and general high-power industrial applications. As a result, produced body of significant work is substantial, making it impossible to review all the major developments in a single paper. This paper therefore surveys the recent progress in two specific areas associated with multiphase systems, namely power electronic supply control and innovative ways of using the additional degrees of freedom in multiphase machines for various nontraditional purposes. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
39. Control of a Three-Phase Grid-Connected Inverter Under Non-Ideal Grid Conditions With Online Parameter Update.
- Author
-
Chowdhury, Vikram Roy and Kimball, Jonathan W.
- Subjects
ELECTRIC inverters ,PHYSICAL constants ,SYSTEM dynamics ,ELECTRIC inductance ,MICROCONTROLLERS ,COMPUTER architecture ,ARCHITECTURE - Abstract
Three-phase grid-connected inverter modeling depends on the equivalent resistance and inductance between the inverter and the grid. However, these parameters are not fixed during the operation of the inverter and vary with the operating conditions. In this paper, a new globally stable adaptive controller is proposed to estimate these values online and update the controller during its operation. A model reference adaptive system (MRAS) based on two fictitious quantities with no physical significance is utilized, namely $M = v \cdot i^*$ and $N = v^* \times i$ , where $v$ and $i$ are the steady-state values of voltage and current in synchronously rotating frame of reference. Detailed stability analysis of the proposed estimation technique has been presented using a Lyapunov energy function-based approach proving the global stability of the technique. Small-signal modeling and analysis of the proposed scheme has also been presented so as to understand the local dynamics of the system. The guidelines to select the parameter of the proposed MRAS system along with updating the controller are elaborated in this paper. Detailed simulation based on MATLAB/Simulink and PLECS, along with experimental studies through a Texas Instruments TMS320F28377S microcontroller, validates the feasibility of the proposed control architecture. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
40. Hybrid SVM-SOPWM Modulation of Current-Fed Three-level Inverter for High Power Application.
- Author
-
Kulothungan, Gnana Sambandam, Edpuganti, Amarendra, Rathore, Akshay Kumar, Rodriguez, Jose, and Srinivasan, Dipti
- Subjects
VECTOR spaces ,ELECTRON tube grids ,HYBRID power systems - Abstract
The goal of the paper is to develop a hybrid modulation technique to combine space vector modulation (SVM) scheme and synchronous optimal pulsewidth modulation (SOPWM) technique for current source inverter (CSI). SVM provides better dynamic performance, but is unable to produce less total harmonic distortion (THD) on inverter current at low device switching frequency ($< $ 1 kHz). SOPWM provides less THD even at low device switching frequency, however it needs a conversion technique to operate CSI and it needs an additional control technique to improve dynamic performance. Hence to overcome these limitations, this paper develops a single modulation technique called optimal SVM technique that can achieve less THD as well as better dynamic performance. To develop optimal SVM technique, three methods have been proposed in this paper. These three methods do not require an additional conversion technique to operate CSI and they provide less THD even under low device switching frequency of 450 Hz. Experimental results prove that the proposed modulation technique can provide better steady-state performance as well as dynamic performance. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
41. A Design and Optimization Tool for Inverter-Based Microgrids Using Large-Signal Nonlinear Analysis.
- Author
-
Kabalan, Mahmoud, Singh, Pritpal, and Niebur, Dagmar
- Abstract
In this paper, large-signal Lyapunov-based stability analysis is performed on an inverter-based microgrid. Most microgrid stability studies have been based on small-signal stability by using linearization techniques. This paper produces the large-signal nonlinear mathematical model of an inverter-based microgrid. The inverter models include the dc-side circuits associated with dc sources. The mathematical model is then used to estimated the domain of asymptotic stability of the microgrid. A three bus microgrid system is used as a case study to highlight the design and optimization capability of such an approach. This paper explores the effect of system component sizing, load transient, and dc-side voltage source variations on the asymptotic stability of the ac microgrid. Thus, this approach quantifies the effect of dc-side variations on the transient stability of the ac-side microgrid. Time domain simulations were used to illustrate the mathematical nonlinear analysis results. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
42. A Novel Vernier Reluctance Machine Excited by Slot PMs and Zero-Sequence Current for Electric Vehicle.
- Author
-
Zhao, Xing, Niu, Shuangxia, and Fu, Weinong
- Subjects
ELECTRIC currents ,ELECTRIC vehicles ,VERNIERS ,SLOT machines ,PERMANENT magnets ,PERMANENT magnet generators - Abstract
This paper proposes a new Vernier reluctance machine (VRM) drive for electric vehicle. The key is to incorporate both stator-slot permanent magnets (PMs) and zero-sequence current as the excitation source to establish a parallel magnetic field and interact with armature winding. In this way, two different machines, namely, slot-PM-excited VRM and dc-excited doubly salient machine, are artificially integrated into a single structure, which contributes to enhance the torque density. Moreover, flexible flux control can be realized by regulating zero-sequence current. In this paper, the machine structure and operation principle are introduced, with its feasibility verified by both finite-element analysis and prototype experiments. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
43. Efficiently Mapping VLSI Circuits With Simple Cells.
- Author
-
Matos, Jody Maick, Carrabina, Jordi, and Reis, Andre
- Subjects
VERY large scale circuit integration ,BUFFER storage (Computer science) ,ALGORITHMS ,INTEGRATED circuits ,ENERGY dissipation ,TRANSISTORS - Abstract
This paper presents two main contributions toward efficient very large scale integration circuits mapped with simple cells: 1) a complete synthesis flow to provide good-quality circuits mapped only with simple cells; and 2) an area-oriented, level-aware buffering algorithm based on inverter trees to fix cell fanout violations. An effective pattern-based algorithm to identify XORs/XNORs on and-inverter graphs is also presented. We show that efficient implementations in terms of inverter count, transistor count, area, power, and delay can be generated from circuits with a reduced number of both simple cells and inverters, combined with XOR/XNOR-based optimizations. The proposed buffering algorithm can handle all unfeasible fanout occurrences, while: 1) optimizing the number of added inverters and 2) assigning cells to the inverter tree based on their level criticality. When comparing with academic and commercial approaches, we are able to simultaneously reduce the average number of inverters, transistors, area, power dissipation, and delay up to 48%, 4%, 8%, 14%, and 16%, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
44. Enhancement of Grid Connected PV Arrays Fault Ride Through and Post Fault Recovery Performance.
- Author
-
Mojallal, Aslan and Lotfifard, Saeed
- Abstract
In this paper, a novel nonlinear control system for enhancing the low-voltage ride through capability and post-fault recovery performance of two-stage grid connected PV arrays (GCPAs) is proposed. The proposed control scheme is composed of two controllers: 1) finite-time sliding mode control (FTSMC) and 2) proxy-based sliding mode control (PBSMC). The FTSMC, which assures the finite time convergence of the tracking error, controls the dc/dc converter of GCPA during voltage sags to assure the dc-link capacitor voltage does not exceed its limits. PBSMC controls the dc/ac inverter. PBSMC provides accurate and fast tracking feature during normal condition (similar to PID controller) and is capable of very smooth resuming to the desired reference value/trajectory after large disturbances that may lead the control signal to exceed the limits. Therefore, during post-fault voltage recovery period, PBSMC exits saturation faster and smoother which significantly enhances the recovery performance of GCPA. The advantages of the proposed control schemes are demonstrated using simulation results. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
45. Complementary Black Phosphorus Nanoribbons Field-Effect Transistors and Circuits.
- Author
-
Feng, Xuewei, Wang, Lin, Huang, Xin, Chen, Li, and Ang, Kah Wee
- Subjects
NANORIBBONS ,FIELD-effect transistors ,ANISOTROPY ,GATE control theory ,NANOELECTRONICS - Abstract
This paper demonstrates a high-performance black phosphorus nanoribbons field-effect transistor (BPNR-FET) and systematically investigates methods for enhancing its anisotropic carrier transport. The BPNR-FET shows a strong dependence on crystal orientation in which the best mobility performance is achieved in armchair-oriented nanoribbons. A downscaling of nanoribbon width is shown to improve the short-channel effect owing to a better electrostatic gate control. Furthermore, hydrogenation is employed to effectively passivate the dangling bonds and heal the nanoribbon edge defects, leading to nearly hysteresis-free transfer properties. By virtue of bandgap and contact-metal workfunction engineering, n-type BPNR-FET is successfully demonstrated, which enables complementary inverter circuits to be simultaneously realized. This paper unravels the superior performance underscores a conceptually new BPNR-FET, paving the way toward the development of non-planar devices and integrated circuits based on 2-D materials platform. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
46. A 0.4-V, 0.138-fJ/Cycle Single-Phase-Clocking Redundant-Transition-Free 24T Flip-Flop With Change-Sensing Scheme in 40-nm CMOS.
- Author
-
Le, Van Loi, Li, Juhui, Chang, Alan, and Kim, Tony Tae-Hyoung
- Subjects
FLIP-flop circuits ,LOW voltage integrated circuits ,SINGLE-phase alternating currents - Abstract
This paper presents an extremely low-voltage and low-power single-phase-clocking redundant-transition-free flip-flop (FF), named change-sensing FF (CSFF). By utilizing a local change-sensing scheme for eliminating redundant transitions of internal clocked nodes, CSFF does not consume any dynamic power when there is no data activity. Measurement results from a test chip fabricated in 40-nm CMOS technology show that CSFF saves up to 90% power dissipation at 5% data activity without additional transistors compared to the conventional transmission-gate FF (TGFF). CSFF consumes only 0.138 fJ/cycle, which is 84% lower than that of TGFF, at 0.4 V and 10% activity. In addition to the significant improvement in power and energy efficiencies, CSFF also enhances performance and minimum operating voltage. The test chip measurement demonstrates successful operations of CSFF down to 0.19 V and the delay improvement of 37% compared to TGFF in the supply voltage range of 0.4–1 V. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
47. An Improved Predictive Current Control of Eight Switch Three-Level Post-Fault Inverter With Common Mode Voltage Reduction.
- Author
-
Xiang, Chaoqun, Ouyang, Zekeng, Zhang, Xinan, Iu, Herbert Ho Ching, and Cheng, Shu
- Subjects
VOLTAGE ,ELECTRIC inverters ,PROBLEM solving ,PULSE width modulation transformers ,TORQUE control ,VOLTAGE control ,TOPOLOGY - Abstract
Eight-switch three-phase post-fault inverter (ESTPI) is widely used as the reconfigured topology of three-phase three-level neutral point clamped DC/AC inverter when open-circuit fault occurs. A key technical challenge for the ESTPI is the post-fault controller design. The existing post-fault control approaches for the ESTPI suffer from the difficulty in trading off the current tracking performance, neutral point voltage (NPV) balancing and common mode voltage (CMV) levels. To solve this problem, this paper proposes an improved predictive current control algorithm. The proposed algorithm contributes to achieve accurate output current tracking while greatly reducing the CMV with a balanced NPV. Simulation and experimental results are presented to validate the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
48. DAB Converter With Q Capability for BESS/EV Applications to Allow V2H/V2G Services.
- Author
-
Haque, Md. Mejbaul, Wolfs, Peter, Alahakoon, Sanath, Sturmberg, Bjorn C. P., Nadarajah, Mithulananthan, and Zare, Firuz
- Subjects
ZERO voltage switching ,REACTIVE power control ,GALVANIC isolation ,ANALYTICAL solutions ,TIME-domain analysis ,HARMONIC analysis (Mathematics) ,CATALYTIC converters for automobiles - Abstract
This paper presents a dual active bridge (DAB) converter with reactive power control capability (Q-capability) for a battery energy storage system (BESS) or an electric vehicle (EV) to deliver vehicle-to-home (V2H) and vehicle-to-grid (V2G) services. The DAB topology is preferable for EV charging systems due to its galvanic isolation and bidirectional power flow capabilities. However, this topology increases reactive current peak and loses zero voltage switching (ZVS) operation at light loads if it is not controlled with improved modulation strategies and proper Q control. This paper proposes a mixed modulation method and a reactive power optimization (RPO) algorithm based on power system load flow concepts. Due to the complexities associated with the analytical solution using time domain analysis, this paper develops detailed universal expressions of a DAB converter using the harmonic analysis method. Analytical identification of ZVS boundaries and DSP implementation of the RPO algorithm become easier with these universal expressions. Multiple modes analysis for different operational states is no longer required. Simulation results have been shown for different modulation strategies of the DAB converters. The theoretical analysis of modulation strategies, RPO algorithm and ZVS operation are validated by experimental results on a DAB prototype. Results show that the proposed control strategy reduces the reactive power and provide ZVS operation over a wide ranges of voltages. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
49. Research of Varying Frequency Driving Scheme for Asynchronous Induction Coil Launcher.
- Author
-
Liu, Kaipei, Xiao, Zhenren, Niu, Xiaobo, and Zhang, Yadong
- Subjects
INDUCTION coils ,ASYNCHRONOUS circuits ,SIMULATION methods & models ,MATHEMATICAL models - Abstract
There are few of transient control models are adapted to asynchronous induction coil launcher (AICL) with air core coil. Thus, many papers about AICL were written with the goal of increasing muzzle velocity of projectile. This paper concentrate on how to control the projectile speed and thrust accurately by using improved current filament (CF) method and variable voltage variable frequency (VVVF) scheme. The improved CF method contains mathematical model of three-phase inverter based on switch function, including conventional two level converter and cascaded multilevel converter models. The whole launch process is programmed with MATLAB. Simulation results show that this scheme have a smoother thrust fluctuation on projectile than other driving models. The motor parameters are changing with the temperature and frequency in launching process. Hence, the constant voltage frequency ratio (V/f) in this paper is more simple and reliable than vector control. To verify the control model and simulation results, a nine stages coil launcher prototype is constructed. The measured force and muzzle velocity are basically consistent with simulation results. It is proved that the improved CF method and VVVF strategy is feasible, and it is characterized by its small calculating amount that make it a valuable tool for design of AICL. The simple and excellent control of the thrust during launch process avoids load peaks, which means that the payload is handled more carefully compared to the classical launchers. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
50. Can a Shaft Brush be Safely Applied on a Motor in a Class I Hazardous Location?
- Author
-
Melfi, Michael J., Ladonne, Francis G., and Ankele, Donald W.
- Subjects
HAZARDOUS geographic environments ,ELECTRIC inverters ,ELECTRIC motor design & construction ,MACHINERY equipment ,SAFETY - Abstract
Some inverter-fed motors, particularly at higher power ratings, are supplied with a shaft brush in order to help mitigate bearing currents. As more inverters are applied to motors in Class I Division 1/Zone 1 and Class I Division 2/Zone 2 locations, there is a need to understand whether a shaft brush can be safely applied in such an environment. This paper addresses the physics of why this is a concern and a methodology to evaluate the relative safety of two example cases. These issues are considered from the perspective of users, manufacturers of inverters and motors, and certifying bodies. The question posed in the title of this paper is answered by considering whether the addition of a shaft brush to an inverter-fed motor in a Class I hazardous location makes the system more safe or less safe. [ABSTRACT FROM PUBLISHER]
- Published
- 2015
- Full Text
- View/download PDF
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