Torque characteristic improvement method under short-circuit fault of five-phase permanent magnet motor

Abstract

The invention discloses a torque characteristic improvement method for a five-phase permanent magnet motor under a short-circuit fault, belongs to the field of multi-phase permanent magnet motors, and aims to improve the torque performance of the five-phase permanent magnet motor under the short-circuit fault and enable the motor to have the capability of stable operation under the short-circuit fault. According to the method, when the short-circuit fault occurs, the non-short-circuit phase current is adjusted, and 2-time and 4-time torque ripple components in the torque after the fault are suppressed, so that the low-torque ripple characteristic is maintained, and stable fault-tolerant operation is further realized. The short-circuit fault is divided into a one-phase winding end part short-circuit fault, a one-phase winding turn-to-turn short-circuit fault and an inverter switching tube short-circuit fault, and the limitation condition is that zero sequence current is not restrained. And the torque fluctuation of fault-tolerant operation when the five-phase motor has a one-phase winding end part short-circuit fault, a one-phase winding turn-to-turn short-circuit fault and an inverter switching tube short-circuit fault is effectively reduced.

Description

technical field [0001] The invention belongs to the field of multiphase permanent magnet motors, and relates to a fault-tolerant control technology under short-circuit faults. Background technique [0002] Permanent magnet synchronous motors are widely used in modern vehicles, aerospace, high-end industrial equipment and other fields due to their significant advantages in efficiency and power density. At present, three-phase permanent magnet synchronous motors are widely used, and their related supporting technologies are very mature. However, the fault tolerance of traditional three-phase permanent magnet synchronous motors is poor, especially when open-circuit or short-circuit faults occur in the windings, the output torque characteristics of the motor become worse, or even fail to work, making it difficult to meet the reliability requirements of the motor system for pure electric vehicles, aerospace, etc. stringent requirements for reliability and fault tolerance. Compa...

AI Technical Summary

Problems solved by technology

Under normal circumstances, there are third, fifth and other high-order harmonics in the rotor magnetic field of multi-phase permanent magnet motors, and the rotor magnetic field harmonics will generate harmonic back EMF and harmonic short-circuit current in the winding back EMF and short-circuit current, thereby affecting Operation characteristics of multi-phase permanent magnet motor under short-circuit fault

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