A multi-phase permanent magnet motor speed control system and its speed control method based on phase switching

Abstract

The invention discloses a multi-phase permanent magnet motor speed regulating system and a speed regulating method based on phase switching. The system includes first and second inverters, switching circuits, first and second circuit breakers, and multi-phase permanent magnet motors; the multi-phase permanent magnet motors have two sets of three-phase winding structures; the three-phase winding structures of the first inverter The phase output ends are respectively connected to the three-phase positive ends of the first set of windings of the motor, and the three-phase negative ends of the first set of windings are respectively connected to the three-phase positive ends of the second set of windings of the motor through a switching circuit. The three-phase negative terminals of the two inverters are respectively connected to the three-phase output terminals of the second inverter; the first and second inverters are respectively powered by two independent DC power sources, and the first and second circuit breakers are respectively set at the first and second inverters. The low potential end of the DC bus of the second inverter; the switching circuit is used to adjust the connection mode of the first and second sets of windings, thereby adjusting the opposite potential of the motor. The invention can improve the speed regulation range, the speed regulation flexibility and the fault tolerance rate of the speed regulation system of the permanent magnet motor.

Description

technical field [0001] The invention belongs to the technical field of motors, and more specifically relates to a multi-phase permanent magnet motor speed control system based on phase switching and a speed control method thereof. Background technique [0002] At present, in low-voltage, high-power, high-performance, and high-reliability applications such as ship propulsion, electric locomotives, and industrial traction, motor drive systems with high torque density and quality, high efficiency, wide speed ratio, and strong fault tolerance are the research topics of people. hotspots. [0003] Research at home and abroad shows that the permanent magnet motor system has the characteristics of high torque density and high efficiency, making it gradually become the best choice for modern industrial drive systems, especially in the electric vehicle industry. However, in electric drive systems such as electric vehicles and direct-drive CNC machine tools, the operating speed range ...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the above defects or improvement needs of the prior art, the present invention provides a multi-phase permanent magnet motor speed regulation system and its speed regulation method based on phase switching, the purpose of which is to improve the speed regulation range and flexible speed regulation of the permanent magnet motor The performance and the fault tolerance rate of the speed control system, thereby solving the technical problems of the permanent magnet motor with short life and poor stability caused by the irreversible demagnetization of the permanent magnet

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