Fault tolerance control method and device of multiphase motor

Abstract

The invention discloses a fault tolerance control method and device of a multiphase motor. The fault tolerance control method comprises the following steps: when at least one phase of the multiphase motor is subjected to a phase loss fault, obtaining a phase voltage and phase current of a normal phase that is not subjected the phase loss fault; transforming the phase voltage and the phase currentof the normal phase to obtain stator current and a stator voltage in a two-phase stationary coordinate system; obtaining an amplitude and a phase of a rotor flux linkage and a rotating speed parameterof the multiphase motor according to the stator current and the stator voltage in the two-phase stationary coordinate system; transforming the stator current in the two-phase stationary coordinate system according to the phase of the rotor flux linkage to obtain the stator current in a two-phase rotating coordinate system; obtaining a reference phase voltage of the normal phase according to a setvalue of the amplitude of the rotor flux linkage, a set value of the rotating speed parameter, the amplitude of the rotor flux linkage, the rotating speed parameter, the phase of the rotor flux linkage and the stator current in the two-phase rotating coordinate system, and controlling the multiphase motor according to the reference phase voltage of the normal phase.

Description

technical field [0001] The invention relates to the technical field of multi-phase motor control, in particular to a fault-tolerant control method for a multi-phase motor and a fault-tolerant control device for a multi-phase motor. Background technique [0002] In a multi-phase motor (number of phases > 3) drive system, because the increase in the number of phases improves the redundancy of the motor system, when one or more phase windings fail, the remaining phase currents can be balanced through the corresponding fault-tolerant control strategy , keep the air gap flux linkage unchanged, ensure the motor continues to run smoothly, and greatly increase the reliability of the system operation. Therefore, it has been widely used in electric vehicles, rail transit, ship propulsion and other occasions. [0003] When a multi-phase induction motor has a phase winding fault, the torque and speed inevitably fluctuate. In order to maintain the smooth operation of the motor, it i...

AI Technical Summary

Problems solved by technology

Since the amplitude of the back EMF is proportional to the speed, the signal-to-noise ratio of the back EMF is small when the speed is very low or even zero speed, plus other disturbance factors, it is difficult to accurately estimate the rotor speed and flux linkage, so this method is suitable For the identification of medium and high speed motors, the models of these methods are based on accurate motor mathematical models, which are convenient for digital realization. However, the identification of motor parameters is difficult and easily affected by ambient temperature, which reduces the accuracy and robustness of speed estimation.

And when the multi-phase induction motor is in a phase open-circuit fault, due to the change of electromagnetic parameters, this traditional closed-loop observer-based speed sensorless algorithm cannot accurately observe the speed and flux linkage under fault conditions. To achieve fault tolerance running, the control method without speed sensor must be improved

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