Investigation on the Performance of N-S Consequent Pole Permanent Magnet Synchronous Machines with Different Slot/Pole Combinations

Wang Xu,Fan Ying 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.4

The consequent pole permanent magnet synchronous machine with N-S-iron–S-N arrangement (NSCP-PMSM) adopted 1/3 of the iron core instead of permanent magnet (PM) to ensure high torque density and improve the utilization rate of PMs. The diff erent unit machines with 3-slot/2-pole, 9-slot/2-pole, 15-slot/4-pole, 21-slot/4-pole as slot/pole combinations are established for comparative analysis, including back electromotive force (EMF), airgap density, output torque, cogging torque and unbalanced magnetic pull. The reason for absence of even harmonic back EMF and airgap density in NSCP-PMSM is analyzed, the output torque with diff erent slot/pole combinations are compared, the cycle number of cogging torque are derived, and the condition for eliminating unbalanced magnetic pull is given. The eff ect of diff erent slot/pole combinations on the performance of NSCP-PMSM was obtained with fi nite element analysis. Finally, a prototype of NSCP-PMSM with 54-slot/12-pole was manufactured to verify the correctness of the above analysis.

극수/슬롯수 조합에 따른 Radial Vibration Force 고려한 매입자석 동기모터 특성 연구

방량(Liang Fang),이수진(Su-Jin Lee),이병화(Byeong-Hwa Lee),홍정표(Jung-Pyo Hong) 대한전기학회 2011 전기학회논문지 Vol.60 No.5

This paper presents a comparative study on motor characteristics with specific consideration of radial vibration force in interior permanent magnet synchronous motors (IPMSM) according to pole/slot combinations. Three IPMSM models, 16-pole/15-slot design, 16-pole/18-slot design and 16-pole/24-slot design are built, in which 16-pole/15-slot and 16-pole/18-slot designs provide high winding factor and 16-pole/24-slot design is known as a general pole/slot combination. By coupling finite element analysis (FEA) with equivalent circuit method, motor characteristics, back electro-motive force (Back-EMF), inductances, cogging torque, etc. as well as machine output performances are analyzed and compared. The radial vibration force (RVF) distribution in air gap causing stator vibration and noise is interested. It is expected that this study help with appropriate choice of pole/slot combination in IPMSM design.

슬롯수 조합에 따른 유도전동기의 진동 특성

추용하,윤경환,김창환,이치우 한국조명.전기설비학회 2022 조명·전기설비학회논문지 Vol.36 No.3

In this paper, two four-pole induction motors having 36 and 24 stator slots are analyzed in terms of vibration performance with respect to the number of rotor slots. Radial and tangential flux densities in air gap are obtained by finite element analysis, and by using the flux densities, radial force density is calculated and separated into its temporal and spatial harmonic orders through Fast Fourier Transform (FFT). The variation of radial force density regarding a slot combination is investigated, and vibration acceleration is estimated by radial force density from FFT. The relation of vibration acceleration with a rotor slot number is scrutinized in terms of temporal and/or spatial harmonic orders. Main and diagonal orders among harmonics are defined, and it is found that vibration performance deteriorates in a rotor slot number creating the 2nd diagonal orders. In this paper, it is claimed that the existence of the 2nd diagonal orders is determined by several simple equations, and a slot combination is easily evaluated in terms of vibration performance by the equations obtained from this research.

계자권선형 동기전동기의 극 슬롯 조합에 따른 전자계 특성 비교

정상용,조재훈,윤한준,전성배 대한전기학회 2023 전기학회논문지 Vol.72 No.1

This paper analyzes the electromagnetic characteristics of wound field synchronous motor (WFSM) for home appliances according to pole slot combination. The analyzed factors are output torque, total harmonic distortion (THD) of back-EMF, cogging torque, efficiency and power factor (PF) which should be considered when designing motors. The pole slot combinations are selected with same number of slots per pole per phase (NSPP) of prototype interior permanent magnet synchronous motor (IPMSM). Because the electromagnetic performances show specific tendencies depending on the number of poles and each performance tends to be different, this study can be a reference in determining pole slot combinations of WFSM.

Variation Regularity of Key Performance Indexes Against the Slot Number of Tooth-Coil PMSMs

Zhu Zichong,Ge Wenjie,Mei Lei,Huang Yunkai 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.4

Tooth-coil permanent magnet synchronous machines (TC-PMSMs) are commonly used in wind power generation and wheelhub propulsion applications. These machines operate at low speeds and have a large number of poles and slots, providing various pole/slot combinations as options. Typically, these combinations have similar performances, making it challenging to choose the best one from diff erent perspectives. This study focuses on 32-pole TC-PMSMs with diff erent slot numbers to understand how key electromagnetic and thermal performance indicators vary with slot numbers. Using the fi nite element method, parameters such as torque density, cogging torque, inductance, fl ux-weakening capability, losses, and temperature rise are evaluated and compared. Prototypes of the wheel-hub TC-PMSM are manufactured and tested on a back-to-back test rig, to validate the analysis results. The fi ndings and conclusions derived from this research can assist in determining the optimal slot number or narrowing down the selection range of competitive pole/slot combinations during the scheme comparison stage.

SPM 모터의 극과 슬롯수 변화에 따른 전자기 가진력 특성 연구

송정용(Jeongyong Song),김도연(Doyeon Kim),장건희(Gunhee Jang) 한국소음진동공학회 2013 한국소음진동공학회 학술대회논문집 Vol.2013 No.4

This paper investigates the magnetic excitation force of a surface-mounted permanent magnet (SPM) motor according to the change of pole/slot combination. The characteristics of magnetic flux and radial magnetic force (RFM) due to pole/slot combination were analyzed by using magnetic circuit analysis. Also, the RMF of motors with the variable pole/slot combination was numerically simulated by using the finite element analysis to verify the result of the magnetic circuit analysis. This research shows that RMF ripple is reduced when the number of pole is smaller than the number of slot.

전기자동차 압축기용 표면부착형 영구자석 전동기의 극/슬롯수 조합에 따른 특성해석 및 설계

최장영(Jang-Young Choi),박형일(Hyung-Il Park),장석명(Seok-Myeong Jang),이성호(Sung-Ho Lee) 대한전기학회 2011 전기학회논문지 Vol.60 No.10

This paper deals with design and analysis of surface-mounted PM (SPM) motor for compressor of air-conditioning system for electric vehicle applications according to slot/pole combination. First, required torque-speed curve characteristics are determined from operating conditions of the compressor. Restricted conditions such as motor size limit and current density are also determined. And then, under same rated and restricted conditions, twelve models which have different slot/pole combinations each other are designed for various pole arc/pitch ratio using simple equations and 2-d finite element (FE) analyses. Designed models are analyzed and compared in terms of back-emf THD, cogging torque, torque ripple, power losses, efficiency, etc. On the basis of analysis results, it is found that the motor with a 6-pole PM rotor and a 27-slot stator has most outstanding performances in electromagnetic aspects. Finally, through the mechanical modal analysis and demagnetization analysis, it is concluded that the determined motor is most suitable for the compressor of air-conditioning system for electric vehicles

돌극성 기반의 센서리스 제어가 가능한 EV 구동용 집중권 IPMSM의 극 수-슬롯 수 조합에 대한 연구

임명섭(Myung-Seop Lim),채승희(Seung-Hee Chai),홍정표(Jung-Pyo Hong) 한국자동차공학회 2013 한국자동차공학회 부문종합 학술대회 Vol.2013 No.5

This paper presents the decision process of pole-slot number combination for a saliency-based sensorless controlled interior permanent magnet synchronous motor(IPMSM) with concentrated winding for EV traction. To figure out the machine characteristics of noise and vibration, the equation about the force order(noise and vibration order) and the simulation results of the radial force are shown. Furthermore, it is suggested that calculating procedure for the changing pattern of d, q-axis inductance profiles varied with rotor position converted from the 3-phase inductances including harmonics to evaluate sensorless drive feasibility. Lastly, 115Nm-14kW 16-pole/24slot sensorless-oriented IPMSM model which is designed based on the decision process is proposed. The validity of the sensorless controlled prototype and the decision process are verified showing the d, q-axis inductance profiles of the machine under the maximum load condition.

전기자동차 견인용 전동기의 극 수 슬롯 수 조합에 따른 전기적 특성 및 진동 특성 분석

박권일(Kwon-Il Park),차경수(Kyoung-Soo Cha),윤명환(Myung-Hwan Yoon),홍정표(Jung-Pyo Hong) 한국자동차공학회 2017 한국자동차공학회 부문종합 학술대회 Vol.2017 No.5

The greenhouse effect is getting worse in these days. To reduce this environmental problem, emission regulation in the automotive industries became strict. Accordingly, the automotive makers stared to develop the environmental friendly vehicles such as the hybrid electric vehicle(HEV) and the electric vehicle(EV). EV is an excellent alternative for conventional combustion engine vehicle. As high torque and wide operation range are essential for EV traction motor. Recently, it is necessary to design an electric motor having excellent vibration characteristics as well as electrical characteristics in accordance with the desire of the consumer who demands a comfortable riding condition. This paper deals with electrical and vibration characteristic of a traction motor for EV depending on pole-slot combination. First, four motors having the same output and different number of slots were selected. Second, the electrical characteristics such as average torque and torque ripple induced voltage of each motor were compared using finite element analysis. Third, the vibration order of the four models is calculated numerically and the vibration characteristics of each motor are compared. Finally number of pole slot combinations suitable for traction motor using the results of electrical and vibration characteristics.

Spoke-type PM Vernier as a Promising Candidate for MW-Scale Direct Drive Wind Turbine Applications

Abdur Rehman,Byungtaek Kim 전력전자학회 2023 ICPE(ISPE)논문집 Vol.2023 No.-

This paper presents the design and analysis of an outer rotor spoke-type PM vernier (ST-PMV) generator as a potential candidate for MW-scale direct drive (DD) wind turbine applications. ST-PMV despite of its magnetic potential oscillations issue still has certain advantages over the general surface PM vernier machine especially in terms of the power factor. At power ratings of MW-Scale, there are serious concerns of having worse power factor, magnetic saturation of cores and PM demagnetization issues. In this regard, in order to obtain the optimum performance, various design aspects are discussed such as the proper selection of the PM dimensions that is interlinked with the choice of slot geometry, specific electric loading and the slot-pole combination. For the proper selection of the various entailed design parameters of ST-PMV a design criteria based on certain design assumptions is developed. Moreover, it is pointed that for the proper sizing of the core parts it is important to accurately consider the magnetic potential oscillations issue. Finally, by using the developed design procedure five 15-MW ST-PMV generators are designed and their electromagnetic performances are comparatively analyzed against a 15-MW conventional DD PM generator.