Open-circuit fault-tolerant position-free control method for five-phase permanent magnet synchronous motor based on rotor flux observer

Abstract

The invention discloses a five-phase permanent magnet synchronous motor open-circuit fault-tolerant position-free control method based on a rotor flux observer. According to the strategy, on the basis of a fault-tolerant model, a sliding-mode observer based on an exponential reaching law is constructed to obtain a counter electromotive force signal; secondly, in order to suppress the influence of direct current bias and low-frequency and high-frequency harmonic waves in the observed counter electromotive force on the rotor position observation precision, an improved second-order generalized integrator is designed, and the improved second-order generalized integrator and a sliding-mode observer are cascaded to form a rotor flux linkage observer; thirdly, rotor position information is extracted from a rotor flux linkage by adopting a phase-locked loop technology; and finally, combining the rotor flux observer with a fault-tolerant control strategy. The strategy effectively suppresses direct current bias and low-frequency and high-frequency disturbance in observation of the counter electromotive force, improves the rotor position estimation precision of the five-phase permanent magnet synchronous motor under the open-circuit fault, and realizes position-free high-performance operation of the motor under the open-circuit fault.

Description

technical field [0001] The invention relates to a position sensorless control method, in particular to a positionless control method for a five-phase permanent magnet synchronous motor based on an open circuit fault of a rotor flux observer. It is suitable for new energy vehicles, aerospace and other occasions that have high requirements on the reliability and dynamic performance of the motor. Background technique [0002] The five-phase permanent magnet synchronous motor has the advantages of high power density, low torque ripple, and strong fault tolerance. By adding a fault tolerance strategy without adding additional hardware, it can achieve smooth operation after a fault. Therefore, five-phase permanent magnet motors have received widespread attention in high-reliability fields such as new energy vehicles and aerospace. [0003] After the motor has an open-circuit fault, an appropriate fault-tolerant control strategy based on a mechanical position sensor can be used to...

AI Technical Summary

Problems solved by technology

Although the second-order generalized integrator suppresses high-frequency signals in the back EMF, it is less capable of suppressing DC bias and low-frequency signals

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