Design of five-phase permanent magnet assisted synchronous reluctance motor for low output torque ripple applications

Baek, Jeihoon,Bonthu, Sai Sudheer Reddy,Choi, Seungdeog IET 2016 IET electric power applications Vol.10 No.5

<P>This paper presents the design of five-phase permanent magnet assisted synchronous reluctance motor (PMa-SynRM) for integrated starter and generator (ISG) of hybrid electric vehicle with low torque ripple. When ISG works as starter in order to operate engine, PMa-SynRM produces 3 kW power at the rated speed of 1800 rpm with reduced vibration by multi-phase structure. PMa-SynRMs are similar to interior permanent magnet motors in structure but are more economical due to reduced permanent magnets. In this study, lumped parameter model (LPM) using magnetic circuit design is used in the approach to initially design the five-phase PMa-SynRM. Numerical equations are integrated with the LPM to design the machine with its given range of design parameter values. Thousands of designs are generated by LPM, which are then converged to optimised model using differential evolution strategy. In this study, optimisation is done with maximum efficiency and minimum torque ripple as objective. The optimised 3 kW five-phase PMa-SynRM is then analysed by finite element method for fine tuning. Simulation results for back electromotive force, flux linkage, developed torque, torque ripple, cogging torque, torque speed characteristics and d and q-axis inductances variation over respective axis currents are verified by fabricated prototype.</P>

Direct Power Control of PMa-SynRG with Back-to-back PWM Voltage-fed Drive

Jeihoon Baek,Sangshin Kwak 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

In this paper, the performance analysis of a control topology based on the direct output power control (DPC) for robust and inexpensive permanent magnet-assisted synchronous reluctance generator (PMa-SynRG) system is presented. The PMa-SynRG might be coupled to an internal combustion engine running at variable speed. A three-phase PWM rectifier rectifies the generator output and supplies the dc link. A single-phase PWM inverter supplies constant ac voltage at constant frequency to the grid. The overall control algorithm is implemented on a TMS320F2812 digital signal processor board. Simulations results and experimental results verify the operation of the proposed system.

Direct Power Control of PMa-SynRG with Back-to-back PWM Voltage-fed Drive

Baek, Jeihoon,Kwak, Sangshin The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

In this paper, the performance analysis of a control topology based on the direct output power control (DPC) for robust and inexpensive permanent magnet-assisted synchronous reluctance generator (PMa-SynRG) system is presented. The PMa-SynRG might be coupled to an internal combustion engine running at variable speed. A three-phase PWM rectifier rectifies the generator output and supplies the dc link. A single-phase PWM inverter supplies constant ac voltage at constant frequency to the grid. The overall control algorithm is implemented on a TMS320F2812 digital signal processor board. Simulations results and experimental results verify the operation of the proposed system.

Optimal Design and Performance Analysis of Permanent Magnet Assisted Synchronous Reluctance Portable Generators

Jeihoon Baek,Sangshin Kwak,Hamid A. Toliyat 한국자기학회 2013 Journal of Magnetics Vol.18 No.1

In this paper, design and performance analysis of robust and inexpensive permanent magnet-assisted synchronous reluctance generators (PMa-SynRG) for tactical and commercial generator sets is studied. More specifically, the optimal design approach is investigated for minimizing volume and maximizing performance for the portable generator. In order to find optimized PMa-SynRG, stator winding configurations and rotor structures are analyzed using the lumped parameter model (LPM). After comparisons of stator windings and rotor structure by LPM, the selected stator winding and rotor structure are optimized using a differential evolution strategy (DES). Finally, output performances are verified by finite element analysis (FEA) and experimental tests. This design process is developed for the optimized design of PMa-SynRG to achieve minimum magnet and machine volume as well as maximum efficiency simultaneously.

이동형 전원장치용 3㎾ PMa-SynRG 설계에 대한 연구

백제훈(Jeihoon Baek),김남훈(Namhun Kim) 한국정보기술학회 2009 한국정보기술학회논문지 Vol.7 No.3

In this paper, an analytical model using equivalent magnetic circuits for the PMa-SynRG is presented. The lumped parameter model (LPM) is developed from machine geometry, stator winding and machine operating specifications. By the LPM, magnetic saturation of rotor bridges is incorporated into model and it provides effective means of predicting machine performance for a given machine geometry. The LPM is not as accurate as finite element analysis but the equivalent magnetic circuits provide fast means of analyzing electromagnetic characteristics of PMa-SynRG. It is the main advantage to find the initial design and optimum design. The LPM model in an efficient numerical optimization routine is using to identify optimum designs. The linear LPM and the nonlinear LPM are programmed using MATLAB and all of machine parameters are calculated very quickly. To verify justification of the proposed design of PMa-SynRG, FEM analysis is used and this results shows machine parameters are well established.

고속철도 추진용 5상 영구자석 저감형 동기전동기의 최적설계

백제훈(Jeihoon Baek),김명룡(Myung Yong Kim),이경표(Kyung-Pyo Yi) 한국철도학회 2017 한국철도학회논문집 Vol.20 No.5

Soft-Switching AC-Link Three-Phase AC–AC Buck–Boost Converter

Amirabadi, Mahshid,Jeihoon Baek,Toliyat, Hamid A.,Alexander, William C. Institute of Electrical and Electronics Engineers 2015 IEEE transactions on industrial electronics Vol. No.

<P>In this paper, the soft-switching ac-link ac-ac buck-boost converter will be studied in more detail. This single-stage converter, which is, in essence, an extension of the dc-dc buck-boost converter, can be an excellent alternative to dc-link converters. Being a buck-boost converter, this converter is capable of both stepping-up and stepping-down the voltage. The link current and voltage are both alternating, and their frequency can be as high as permitted by the switches and the sampling time of the microcontroller. This eliminates the need for dc inductors or dc electrolytic capacitors, and the main energy storage element is an ac inductor (L). Moreover, in this converter, galvanic isolation can be provided by adding a single-phase high-frequency transformer to the link. Therefore, the proposed converter is expected to be more compact compared to the conventional dc-link converter. The other advantage of this converter is the soft switching of the switches, which is feasible by adding a small capacitor (C) to the link. In this paper, the design and analysis of this converter will be studied in detail. In order to accurately analyze this converter, the effect of the LC link resonance on the performance of the converter will be studied. This analysis helps in evaluating the performance of the converter at low power levels when the resonating time of the LC link is not negligible. Using this analysis, the link peak current and the link frequency may be calculated at any point of operation. The accuracy of this method is verified through simulations and experiments. Detailed comparison of the proposed converter with the dc-link converter will be also presented in this paper. It will be shown that, despite having more switches, the current rating of the switches is lower in this converter. Moreover, the efficiencies of the two converters will be compared. Finally, the performance of the soft-switching ac-link ac-ac buck-boost converter is experimentally evaluated in this paper. It will be shown that the converter has the possibility of changing both the frequency and the voltage. Both step-up and step-down operations will be verified through experiments.</P>

Bidirectional Soft-Switching Series AC-Link Inverter

Amirabadi, Mahshid,Baek, Jeihoon,Toliyat, Hamid A. IEEE 2015 IEEE transactions on industry applications Vol.51 No.3

<P>This paper proposes a novel bidirectional inverter, named series ac-link inverter. This three-phase inverter belongs to a new class of partial resonant ac-link converters in which the link is formed by a series ac inductor/capacitor (LC) pair having low reactive ratings. The input and output of this converter can be either dc, ac, single-phase, or multiphase. Therefore, they can appear as dc-dc, dc-ac, ac-dc, and ac-ac configurations. In all of these configurations, the ac capacitor is the main energy-storage element, and the inductor is merely added to facilitate the zero-current turnoff of the switches and their soft turn-on. Due to the zero-current turnoff of the switches in the proposed converter, the use of SCRs with natural commutation is possible as well. Since the current and voltage of the link are both alternating, no bulky dc-electrolytic capacitors are required in this converter. This paper mainly focuses on bidirectional dc to three-phase ac conversion. This single-stage inverter can step up or step down the voltage in a wide range. If galvanic isolation is required a single-phase high-frequency transformer can be added to the link. In the proposed inverter, the power can flow in both directions, and therefore, it is an excellent candidate for battery-utility interface and electric vehicle applications. In this paper, the principles of the operation of the proposed inverter, along with its design and analysis, are studied. Moreover, the performance of the proposed configuration is evaluated in this paper. Both simulation and experimental results are included.</P>

Ultrasparse AC-Link Converters

Amirabadi, Mahshid,Jeihoon Baek,Toliyat, Hamid A. IEEE 2015 IEEE transactions on industry applications Vol.51 No.1

<P>Soft-switching ac-link universal power converters, also called partial resonant converters and ac-link buck-boost converters, have received noticeable attention during the last few years. In these converters, each of the inputs and outputs can be dc, single-phase ac, or multiphase ac; therefore, they can be used for dc-dc, dc-ac, ac-dc, or ac-ac power conversion systems. The soft-switching ac-link universal power converters are compact, reliable, and expected to offer longer lifetime compared with the other types of converters. However, they require more switches, which make the control process more involved. The sparse ac-link buck-boost converters were proposed to partially solve this problem. The sparse configuration reduces the number of switches from 24 to 20 in a three-phase ac-ac configuration. This paper proposes a modified configuration, which further reduces the number of switches without changing the principles of operation. This converter, which is named ultrasparse ac-link buck-boost converter, reduces the number of switches from 24 to 16, in a three-phase ac-to-ac case, and from 20 to 10, in a dc-to-three-phase-ac configuration. The proposed converter is applicable to systems with unidirectional flow of power, such as PV and wind power generation systems. This converter is expected to offer higher reliability compared with the original converter and higher reliability and efficiency compared with the sparse configuration. Another important feature of this configuration is that it can be fabricated by insulated-gate bipolar transistor modules, which are more compact and more cost effective compared with discrete devices. This paper presents the principles of the operation of this configuration and compares the efficiency, the failure rate, and the current rating of the switches in the ultrasparse, sparse, and original configurations. Moreover, it evaluates the performance of the proposed converter through simulation and experiment.</P>

Sparse AC-Link Buck–Boost Inverter

Amirabadi, Mahshid,Jeihoon Baek,Toliyat, Hamid A. IEEE 2014 IEEE transactions on power electronics Vol.29 No.8

<P>Due to their remarkable merits, the soft-switching ac-link universal power converters have received noticeable attention during the last few years. These converters, which can be configured as dc-dc, dc-ac, ac-dc, or ac-ac, are compact, reliable, and offer longer life time compared to the other types of converters. However, they require more switches, which make the control process more complicated. This paper proposes a modified configuration for the dc-ac power conversion, which reduces the number of switches without changing the principles of operation. This converter, which is named sparse ac-link buck-boost inverter, reduces the number of switches from 20 to 18. Despite reducing the number of switches, the partial resonant time, during which no power is transferred, is as short as the original configuration. An important feature of this inverter is that it can be fabricated by IGBT modules, which are more compact and more cost-effective compared to the discrete devices. This paper presents the principles of the operation of this configuration, and compares the efficiency, the failure rate, and the current rating of the switches in the proposed and original inverters. It is shown that the failure rates of the sparse configuration are lower than the original configuration. Therefore, they have longer lifetime. The efficiency of the sparse configuration is slightly lower than that of the original configuration. However, by using reverse blocking IGBTs in the sparse configuration, the efficiency of the proposed inverter will be improved significantly. This paper evaluates the performance of the proposed inverter through simulation and experiment.</P>