Design and control of variable field permanent magnet motors

Abstract

This is a survey paper focusing on permanent magnet motors with variable field capability. The synchronous motors, which have been applied to somewhat limited fields, have garnered attention as attractive electric drives. Due to a connection with rare‐earth magnet and power electronics‐based flexible control, current permanent magnet synchronous motors have achieved the best position in terms of high power and torque densities, high efficiency and flexible control capability. In order to satisfy the diverse demands of users, a motor is requested to ensure high‐efficiency operation at multiple operating points on the speed–torque plane. It is well recognized that maximum efficiency is attained under the condition that the copper loss is equal to the fixed loss, mainly composed of iron loss, at a given operating point. This is why permanent magnet synchronous motors should have the capability of adjusting the field excitation, similar to the direct current shunt motors. In this paper, recent trends of research and development of variable field permanent magnet motors are overviewed from the standpoint of design and control. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Optimization design of a new hybrid magnetic circuit motor

“…The flux bridge is placed in the middle of the rotor to change the direction of magnetic flux distribution. Dr. Nakai proposed a new type of variable magnetic field circular wound permanent magnet motor [12]. The rotor of the motor is composed of a permanent magnet and a salient pole iron core, forming a clockwise pole structure.…”

Expansion of Motor High-Efficiency Area by Inserting Magnetic Composite Material into Rotor

“…Variable magnetic flux motors have been proposed to realize high-efficiency operation in a wide drive range from high torque to high-speed range [16]- [21]. The variable torque constant is achieved by controlling the amount of field magnetic flux from the outside.…”

Design and implementation of adaptive fuzzy‐RST digital speed control of PMSM drive

“…In recent decades, permanent magnet synchronous motors (PMSMs) are widely used in many industrial applications (e.g., robot industry, petroleum industry, electric and hybrid vehicles, wind energy, and air conditioning applications) [1,2]. The main advantages of PMSM compared to other electrical machines are due to the high torque density, high efficiency, simple mathematical modeling, easy maintenance, and reliability.…”

“…Despite the advantages of this machine, high precision control of the PMSM drive system is rather difficult because its dynamic is complicated and intrinsically nonlinear. In addition, the drive performances are generally deteriorated in practice, influenced by various sources of disturbances and uncertainties, such as nonmodeled dynamics, parameter variation, and external disturbances [1][2][3][4].…”