• Journal of Power Electronics
• /
• v.12 no.1
• /
• pp.10-18
• /
• 2012

This paper proposes a finite element method (FEM)-based model of an interior permanent magnet (IPM)-type BLDC motor having stator inter-turn faults. We also propose impedance modeling of the magnetic characteristics. By integrating the developed model with a current-controlled voltage source inverter (CCVSI) model, the distributed characteristics of an inter-turn fault operated by a six-switch inverter are investigated considering speed control. Moreover, this paper presents the flux density distribution and torque characteristics for analyzing the inter-turn fault of an IPM-type BLDC motor. Additionally, fault impedance is required to calculate the circulating current that causes magnetic distortion. Thus, this paper proposes a method for estimating the circulating current taking into account the voltage at the shorted turn and the rotating speed. The analysis data were verified experimentally.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.2
• /
• pp.279-285
• /
• 2016

In this paper, a cogging torque of IPM(Interior Permanent Magnet)-type BLDC motor is analyzed by FE program and the optimized notch on the rotor surface is designed to minimize the torque ripple. A differential evolution strategy algorithm and a response surface method are employed to optimize the rotor notch. In order to verify the proposed algorithm, an IPM BLDC motor is used, which is 50 kW, 8 poles, 48 slots and 1200 rpm at the rated speed. Its characteristics of the motor is calculated by FE program and 4 design variables are set on the rotor notch. The initial shape of the notch is like a non-symmetric half-elliptic and it is optimized by the developed algorithm. The cogging torque of the final model is reduced to $1.5[N{\cdot}m]$ from $5.2[N{\cdot}m]$ of the initial, which is about 71 % reduction. Consequently, the proposed algorithm for the cogging torque reduction of IPM-type BLDC motor using the rotor notch design seems to be very useful to a mechanical design for reducing noise and vibration.

• Proceedings of the KIEE Conference
• /
• 1997.07f
• /
• pp.2095-2097
• /
• 1997

This paper describes a indirect sensing method for the rotor flux position of interior permanent magnet (IPM) brushless DC motors. The phase inductance of an IPM motor varies appreciably according to the rotor position. The waveform characteristics of the terminal voltage of IPM brushless DC motors is analysed and a simple and practical method for indirect sensing of the rotor position is proposed. A compact sensorless drive is implemented and tested using a 87c196mc 16-bit microcomputer. The experimental results show the validity of the proposed method and the drive works well from 500 to 7,200rpm.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.891_892
• /
• 2009

This paper presents the rotor study on the deal with the shape design with a flux barrier to minimize the cogging torque of Interior Permanent Magnet Synchronous Motor(IPMSM). In order to consider the notch effect, the torque characteristics according to the shape of notch is performed and analyzed. From the this results, we found that an optimal location and radius of the notch effectively suppresses the torque pulsation of the IPM drive. The rotor shape design also shows improvement in the average torque

• Proceedings of the KIPE Conference
• /
• 2006.06a
• /
• pp.98-100
• /
• 2006

본 논문은 매입자석형 동기전동기 (Interior Permanent Magnet Motor, 이하 IPM)의 Sensorless 제어에 관한 것이다. IPM에서 벡터제어를 수행하기 위해서는 계자분 전류와 토크분 전류로 나누어서 제어를 해줘야 한다. 이때, 토크는 영구자석과 직교하는 방향으로 토크분 전류를 인가해줘야 하기 때문에, 영구자속에 의해 발생하는 자속의 정확한 위치를 알아야 하고, 그로 인하여 엔코더 등의 자극위치센서를 사용해야 한다. 따라서, IPM은 일반적으로 Sensored제어를 하게 된다. 그러나, 고가의 장치인 엔코더 등의 자극위치센서를 사용하지 않고 적절한 제어를 수행해주기 위하여 여러 sensorless 기법들이 개발되어 발전되었다. 본 논문에서는 자속추정기를 이용하여 자속을 추정하고, 이를 이용하여 모터의 회전속도 및 회전각을 추정함으로써 Sensorless제어가 가능하였다. 본 제어 알고리즘은 자사 벡터제어 인버터인 iV5를 통해 실험하여 확인하였다.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.6
• /
• pp.959-965
• /
• 2008

This paper presents a novel method for cogging torque reduction of interior type permanent magnet motor. For calculation position and width of notch, energy formulation and cogging torque function in air gap are analyzed by analytical method(space harmonics method) and numerical method. The optimal shape of notchs is decided by using finite element method. The validity of the proposed method is confirmed with experiments.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.12 no.1
• /
• pp.9-18
• /
• 2007

This paper proposes the modeling of sensorless drive system using 120 degree conduction method for IPM (Interior Permanent Magnet) BLDC motors and analyzes characteristics of the terminal voltage that is used to detect the rotor position. This paper shows that the ZCP (Zero-Crossing Point) of the measured terminal voltage used In sensorless control is ahead of that of the back EMF of IPM motors because they have a saliency. This research also analyzes that the amount of position detection error is related to saliency, rotor speed, and load condition. In addition, this paper shows that motors have bigger advance angles than we have expected because the ZCP of terminal voltage precedes the actual ZCP, and under operation conditions such as heavy load and high speed it may generate abnormal currents that flow toward opposite direction after phase current becomes zero.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.2 no.2
• /
• pp.134-140
• /
• 2013

This paper proposes a new design of rotor shape of Interior Permanent Magnet Synchronous Motor (IPMSM) used for agricultural electric vehicle (AEV). The distribution of the residual magnetic flux density at the air gap is modified by rotor surface shape and V-type magnet angle. As a result, cogging torque and physical characteristic have been improved, and back electromotive force (back-EMF) of the suggested model has been improved to be closest to sine wave form compared to initial model. The validity of the proposed rotor shape optimization is confirmed by the manufactured IPM rotor core and measured the performance of the cogging torque.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.3
• /
• pp.519-523
• /
• 2007

In this paper, we propose a precise parameter extraction of interior permanent magnet (IPM) motors based on finite element analysis. For the calculation of the two-axis inductances Ld and Lq, the slotting effect and cross magnetization due to torque angle are considered. It is examined that back electro-motive force (BEMF) constant is affected by the magnetic saturation in different ways dependent on motor types. Numerical analyses and some measurements are performed for a spoke type and a flux barrier type IPM motors

• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.783-784
• /
• 2006

In case of a difference exist between the experimental value and estimated value of back-emf, there can be a difference of turn number or residual flux density of permanent maget of the motor. In order to presume the turn number, the average length for each coil is used to calculate the resistance. However in producing the motor, doc to the tension of coil, the outer diameter of coil becomes smaller, and then the resistance estimated by average length for each coil is not correct. Therefore in this paper, through the comparison of experiment value and estimated value of inductance, a method of presuming the turn number and PM's residual flux density of an IPM motor is presented. The inductance of IPM motor changes with the rotor position, therefore the rotor part is taken out and then the inductance in open circuit condition is measured. In the analytical calculation, 3D FEM(Finite Element Method) is used, which can consider the leakage flux of end turns in frinzing effect.