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An interior permanent magnet synchronous motor (IPMSM) with "VV—" shape rotor topology structure is proposed, and its performances are compared with "V" shape and "V—" shape rotor topology structure. The results show that the performances including output average torque, reluctance torque, torque ripple, cogging torque, iron loss of the IPMSM with "VV—" shape is better than the other two rotors. Firstly, the parameters which have great influence on the torque and the efficiency of the IPMSM are analyzed and optimized. The no‐load back electromotive force (EMF) of three different optimized rotor topology structures are analyzed and compared, the results show that the no‐load back EMF of the IPMSM with "VV—" shape topology structure has the lowest total harmonic distortion rate (THD). Secondly, the torque of the IPMSM with "VV—" shape under different current angles, current densities and speeds are analyzed and compared with the other two rotors. The results show that the torque performance of the IPMSM with "VV—" shape rotor topology structure is better than that of the other two. Finally, aiming at the problems that the torque ripple and cogging torque of the IPMSM with "VV—" shape rotor topology structure are greatly increased when the iron loss is reduced, This paper proposes to add a set of circular flux isolation holes between the second layer and the third layer of permanent magnets, and the position and diameter of this set of circular flux isolation holes are optimized and adjusted. The results show that the torque ripple and cogging torque of the IPMSM with the further optimized "VV—" shape rotor topology structure are greatly reduced, and the THD of no‐load back EMF is also further reduced, which has great significance to reduce vibration and noise, improve the control accuracy of the IPMSM. [ABSTRACT FROM AUTHOR]

An interior permanent magnet synchronous motor (IPMSM) with 'VV—' shape rotor topology structure is proposed. The established two‐dimensional (2D) parameterized finite element analysis (FEA) models are used to analyze and compare the output average torque, torque density, air‐gap flux density and back electromotive force (EMF) of the IPMSM with 'V' shape, 'V—' shape, 'VV—' shape for electric vehicle (EV) applications. The rotor topology structure has a great influence on the performance of the IPMSM, especially the first layer of permanent magnet of the multi‐layers permanent magnet structure has the greatest influence on the performance of the IPMSM. Therefore, firstly, this paper mainly analyzes and optimizes the opening angle of permanent magnet and the pole arc angle of the first layer, which have a great influence on the electromagnetic performance of the IPMSM. Secondly, the d‐axis and q‐axis inductance, saliency ratio, output average torque, reluctance torque under different current angles are analyzed and compared. The results show that the output average torque and reluctance torque of the IPMSM for EV applications with 'VV—' shape rotor topology structure proposed in this paper are larger than that of the other two rotor topology structures as the amount of permanent magnet with 'VV—' shape rotor topology structure is slightly reduced. Finally, the torque density versus current density of the IPMSM with three different rotor topology structures is analyzed and compared. The results show that the torque density of the IPMSM with 'VV—' shape proposed in this paper is higher than that of the other two rotor topology structures under different current densities. [ABSTRACT FROM AUTHOR]

In the speed control of an interior permanent magnet synchronous motor (IPMSM), for stability reasons, the closed-loop pole positions should be on the left-hand side of the S-plane, and for fast response requirements these poles should have a small time constant. Unfortunately, the motor poles have a very long time constant, which makes the system response very slow. To solve this problem, the zeros of PI controllers are used to compensate the motor poles. As the motor operates, the temperature increases, which changes the parameters of the motor and, accordingly, the motor poles change their position so the PI controller cannot compensate these poles. To solve this problem, many parameter estimation algorithms have been used to detect new parameter values and adapt the PI controller gains so that to compensate the motor poles continually. These parameter estimation algorithms complicate and add cost to the system. This paper demonstrates that, for a temperature up to 70 °C, the system is capable of giving fast response and stable operation by using a good design of the PI controller regardless of the parameter changes. [ABSTRACT FROM AUTHOR]

SUMMARY This paper proposes a new current control method for an interior permanent magnet synchronous motor (IPMSM). In the case of ac motor control, two-axis current feedback control is performed to control the voltage amplitude and phase. When the inverter voltage is saturated, current control is achieved by controlling the voltage phase. Conventional techniques require switching the mode of the control system from variable voltage mode to voltage saturation mode. However, in the conventional techniques, transient voltage saturation occurs due to switching the control system. The proposed method achieves current control in the variable voltage mode and voltage saturation mode without switching the control system. Moreover, the current response is not affected by the rotor speed. Numerical simulation results and experimental results confirm the effectiveness of the proposed current control method. [ABSTRACT FROM AUTHOR]

This paper presents a position-sensorless interior permanent magnet synchronous motor (IPMSM) control system at low and zero speed based on a multi-space-vector pulse-width modulation (MSVPWM) pattern with the elimination of nonlinear inverter effects. In conventional sensorless methods based on the MSVPWM pattern, the high-frequency (HF) components of voltage and current are used to estimate the rotor position information. However, the inverter nonlinear effects, such as forward voltage drops and deadtime, distort the HF components of the voltage and current so that an error occurs in the position estimation. Therefore, an improved position estimation scheme is developed in this paper. The compensated HF components of the voltage taking account of the inverter nonlinear effects can be used to decrease the estimation error. The proposed method can be implemented without increasing any hardware cost. Experimental results confirm the effectiveness of the proposed method. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]