A fault-tolerant direct torque control method for five-phase permanent magnet synchronous motor

Abstract

The invention discloses a fault-tolerant direct torque control method for a five-phase permanent magnet synchronous motor. Firstly, a mathematical model of the motor under a fault state is established, and the stator flux linkage ψ of the motor is calculated through the corrected flux equation and torque equation. s and torque T e The estimated value of , compare it with the given stator flux linkage ψ s * and torque T e * As a difference, combined with the sector where the stator flux vector is located, the corresponding space voltage vector in the fault-tolerant switch table is selected according to the control requirements to realize direct control of the motor torque and stator flux. Then the fault-tolerant switch table is applied to the five-phase permanent magnet synchronous motor under the condition of no fault, and the same dynamic and steady-state performance as that of the traditional switch table is obtained for the fault-free motor. The invention ensures that under the condition that the same switch table is used for the motor, the output torque and dynamic performance of the motor are consistent before and after the single-phase open circuit fault, and can effectively restrain the torque ripple of the motor, greatly simplifying the design of the switch table.

Description

technical field [0001] The invention relates to a fault-tolerant direct torque control method for an open-circuit fault of a motor, in particular to a fault-tolerant direct torque control method for a five-phase permanent magnet synchronous motor. It is suitable for occasions that have high requirements on the reliability of the motor, such as aerospace and electric vehicles. Background technique [0002] After the motor drive system fails, the motor will run asymmetrically, the output torque will fluctuate significantly, the noise will increase significantly, the overall performance of the system will deteriorate, and even fail to work, seriously endangering production safety. Therefore, the fault tolerance of the motor system is very important. [0003] Direct torque control (DTC) technology is a control method with simple structure, less parameter dependence and fast torque response. Existing DTC strategies cannot suppress the influence of motor system faults on the moto...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a fault-tolerant direct torque control method for a five-phase permanent magnet synchronous motor, which is used to solve the problem of large torque ripple and poor dynamic performance of the five-phase permanent magnet synchronous motor when a single-phase open circuit fault occurs

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