Flux Linkage Estimation in a Switched Reluctance Motor Using a Simple Reluctance Circuit

Cheewoo Lee 한국자기학회 2013 Journal of Magnetics Vol.18 No.1

Flux linkage of phase windings is a key parameter in determining the behavior of a switched reluctance motor (SRM) [1-8]. Therefore, the accurate prediction of flux linkage at aligned and unaligned rotor positions makes a significant contribution to the design of an SRM and its analytical approach is not straightforward due to nonlinear saturation in flux. Although several different approaches using a finite element analysis (FEA) or a curve-fitting tool have been employed to compute phase flux linkage [2-5], they are not suitable for a simple design procedure because the FEA necessitates a large amount of time in both modeling and solving with complexity for every motor design, and the curve-fitting requires the data of flux linkage from either an experimental test or an FEA simulation. In this paper, phase flux linkage at aligned and unaligned rotor positions is estimated by means of a reluctance network, and the proposed approach is analytically verified in terms of accuracy compared to FEA.

Characteristic Analysis for IPMSM Considering Flux-Linkage Ripple

Woo, Dong-Kyun,Kwak, Sang-Yeop,Seo, Jang-Ho,Jung, Hyun-Kyo The Korean Institute of Electrical Engineers 2010 Journal of Electrical Engineering & Technology Vol.5 No.4

In a multi-layer interior permanent magnet synchronous motor, the d- and q-axis parameters vary nonlinearly according to different load conditions, consequently changing the level of saturation. The flux-linkage of d- and q-axis conveys ripple characteristics resulting from mechanical structure and degree of magnetic saturation. If the calculated flux-linkage is correct, the torque using the Maxwell stress tensor method is the same torque calculated by the flux-linkage. However, discrepancy between results exists. In this paper, the d- and q-axis flux-linkage, in consideration of the ripple characteristic, is calculated. Simulation results are then compared with experimental results.

Characteristic Analysis for IPMSM Considering Flux-Linkage Ripple

Dong-Kyun Woo,Sang-Yeop Kwak,Jang-Ho Seo,Hyun-Kyo Jung 대한전기학회 2010 Journal of Electrical Engineering & Technology Vol.5 No.4

In a multi-layer interior permanent magnet synchronous motor, the d- and q-axis parameters vary nonlinearly according to different load conditions, consequently changing the level of saturation. The flux-linkage of d- and q-axis conveys ripple characteristics resulting from mechanical structure and degree of magnetic saturation. If the calculated flux-linkage is correct, the torque using the Maxwell stress tensor method is the same torque calculated by the flux-linkage. However, discrepancy between results exists. In this paper, the d- and q-axis flux-linkage, in consideration of the ripple characteristic, is calculated. Simulation results are then compared with experimental results.

영구자석 쇄교 자속 변화를 고려한 매입형 영구자석동기전동기의 MTPA 제어 알고리즘 개발

최성민,류성호,이재석 한국전기전자학회 2022 전기전자학회논문지 Vol.26 No.4

This paper presents a Maximum Torque per Ampere (MTPA) control algorithm for an interior permanent magnetsynchronous motor (IPMSM) drive considering the permanent magnet (PM) flux linkage variations due to PMtemperature variation. PM flux linkage are estimated in real time via a Gopinath style stator flux linkage observerand a torque error correction factor is calculated from the estimated PM flux linkage. A 2-dimensional (2D) MTPAlook-up table (LUT) is developed to achieve the MTPA trajectory reflecting PM flux linkage variation for compensatingtorque error occurred by parameter variation. The proposed IPMSM control algorithm is verified throughsimulations. 본 논문에서는 온도 변화로 인한 영구자석 쇄교 자속 변화를 고려한 PMSM 드라이브의 MTPA(Maximum Torque perAmpere) 제어 알고리즘을 제시한다. 영구자석 쇄교 자속은 고정자 쇄교 관측기를 통해 실시간으로 추정되고, 추정된 영구자석 쇄교 자속으로부터 토크 오차 보정 계수가 계산된다. 2차원 MTPA look-up table(LUT)은 토크 오차를 보상하기 위해 영구자석 쇄교자속 변화를 반영하는 MTPA 전류 궤적을 달성하기 위해 개발되었다. 제안된 PMSM의 MTPA 제어 알고리즘은 시뮬레이션을 통해검증된다.

Optimization of Energy Conversion Loop in Switched Reluctance Motor for Efficiency Improvement

Jian Li,Ronghai Qu,Zhichu Chen,Yun-Hyun Cho 대한전기학회 2013 Journal of Electrical Engineering & Technology Vol.8 No.3

This paper presents an effective method to improve efficiency of switched reluctance motor by optimizing energy conversion loop. A nonlinear analytical model which takes saturation account is developed to calculate inductance and flux-linkage. The flux-linkage curve is studied to calculate the co-energy increment to obtain the optimum exciting current. For a given cross-section, the exciting current at which co-energy increment is maximum was found to be constant while stack length varies. Then the energy conversion loop was optimized by varying the stack length and turns of windings. The constraints during optimization were that motor was excited by the maximum increment co-energy current and the energy in the loop was determined by rated power of motor. Dynamic finite element analysis was used to evaluate the efficiency of various models and the comparison of results shows promising effects of the proposed method. Experiment was also conducted to validate the simulation result.

Analysis on Magnetizing Characteristics Due to Peak Fault Current Limiting Operation of a Modified Flux-Lock-Type SFCL With Two Magnetic Paths

Seok-Cheol Ko,Sung-Hun Lim IEEE 2016 IEEE transactions on applied superconductivity Vol.26 No.4

<P>The advantage of the flux-lock-type superconducting fault current limiter (SFCL) is that the operational current of the SFCL can be easily adjusted by the winding ratio and the winding direction between two windings. Furthermore, the peak fault current limiting operation according to the transient initial fault current was reported to be performed by adding the third winding and another superconducting element into the flux-lock-type SFCL with either one or two magnetic paths. In this paper, the magnetizing characteristics of the modified flux-lock-type SFCL, due to its peak fault current limiting operation, which another superconducting element and the third winding were added into the E-I iron core structure with two magnetic paths, were analyzed. To analyze the dependence of its magnetizing characteristics on the peak fault current limiting operation of the SFCL, the peak fault current limiting tests of the SFCL due to the fault angle were carried out. With the measured voltage and the current values, the flux linkage and the magnetization current derived from the equivalent magnetization circuit were calculated and compared, at each fault angle, together with the magnetizing power related with the accumulated magnetic energy in the iron core during the fault period.</P>

Magnetizing Characteristics of a Flux-Coupling Type Superconducting Fault Current Limiter Connected in Parallel between Two Coils Using an E–I Iron Core

고석철,한태희,임성훈 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.4

In power systems, there are short-circuit faults due to various causes. One way to reduce this fault current is the superconducting fault current limiter (SFCL). Since the current limiter model using a winding includes an iron core, the magnetizing current generated in the iron core when the fault current is limited should not be as large as possible. That is, when saturation of the iron core occurs, suffi cient magnetic fl ux is not generated and the fault current limiting characteristics are degraded. Therefore, in this paper, a fl ux-coupling type SFCL using an E–I iron core was fabricated to eff ectively reduce the saturation of the iron core and limit the fault current to twice. The two major windings N1 and N2 were connected in parallel, and the peak current limiting characteristics and voltage waveforms were compared based on the winding directions of the two coils. The two main coils were also connected in parallel to analyze the fl ux linkage and instantaneous power characteristics. The magnetization power area and operating range of the fl ux linkage based on the magnetic fl ux energy accumulated in the E–I iron core were compared and analyzed in relation to the increase or decrease of the magnetizing current.

Vector Control of Stator-Permanent Magnet Memory Machine Based on Three Magnetization State Manipulations

Gong-De Yang,Ming-Yao Lin,Nian Li,Li Hao 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.1

Owing to the estimated permanent magnet (PM) flux linkage fluctuation, the stator-PM memory machine employing the continuous magnetization state (MS) manipulation may suffer from frequent MS manipulations and the accidental inverter damage in its extended speed range. In order to deal with this issue, in this paper, a novel vector control based on three MS manipulations is proposed and implemented on the existing hybrid PM axial field flux-switching memory machine. After a brief analysis of the researched machine configuration, the principle of the three MS manipulations, the remedial sliding mode speed regulator and the current distribution strategy are discussed. The simulated results show that the proposed scheme reduces the speed and electromagnetic torque overshoot and improves the dynamic performance. Meanwhile, compared with the flux-weakening control, the wide speed range can be obtained. Finally, the experiment is carried out to verify the validity of the theory.

Optimization of Energy Conversion Loop in Switched Reluctance Motor for Efficiency Improvement

Li, Jian,Qu, Ronghai,Chen, Zhichu,Cho, Yun-Hyun The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.3

This paper presents an effective method to improve efficiency of switched reluctance motor by optimizing energy conversion loop. A nonlinear analytical model which takes saturation account is developed to calculate inductance and flux-linkage. The flux-linkage curve is studied to calculate the co-energy increment to obtain the optimum exciting current. For a given cross-section, the exciting current at which co-energy increment is maximum was found to be constant while stack length varies. Then the energy conversion loop was optimized by varying the stack length and turns of windings. The constraints during optimization were that motor was excited by the maximum increment co-energy current and the energy in the loop was determined by rated power of motor. Dynamic finite element analysis was used to evaluate the efficiency of various models and the comparison of results shows promising effects of the proposed method. Experiment was also conducted to validate the simulation result.

IPMSM의 쇄교자속 계산을 통한 릴럭턴스 토크 산정

조규원(Gyu-Won Cho),김철민(Cheol-Min Kim),김규탁(Gyu-Tak Kim) 대한전기학회 2013 전기학회논문지 Vol.62 No.2

Classically, reluctance torque of IPMSM(Interior Permanent Magnet Synchronous Motor) by using inductance according to current phase angle generates an error. This error is affected by total torque. From current phase angle 0° to large errors will occur, because reluctance torque include current phase angle. But, reluctance torque from steady-state voltage equation of IPMSM is represented by linkage flux. So, reluctance torque is unrelated to the current phase angle formula can be derived. In this paper, operating torque was analyzed by d, q-axis linkage flux of IPMSM and reluctance torque to perform calculations reduced the error of the total torque calculation.