Direct torque control strategy of five-bridge-arm inverter driving type dual-three-phase motor system

Abstract

The invention discloses a direct torque control strategy of a five-bridge-arm inverter driving type dual-three-phase motor system. During the normal six-bridge-arm inverter driving dual-three-phase motor direct torque control operation, a voltage vector needs to be corrected and harmonic currents can be suppressed when direct torque controlling is carried out by using a corrected virtual vector; and when a five-bridge-arm inverter driving type dual-three-phase motor fault-tolerant system is used for direct torque control after one phase of bridge arm of the six-bridge-arm inverter has a fault,the voltage vector needs to be corrected again. When the traditional dual-three-phase motor is in phase-deficient operation, the direct torque control needs to carry out stator flux linkage area division and switch table designing again; however, with the disclosed direct torque control strategy, the stator flux linkage area division and switch table selection rule is consistent with one in normal operation of the dual-three-phase motor; and the only difference is that amplitudes of six virtual vectors are reduced when five bridge arms works. The direct torque control strategy is easy to realize.

Description

technical field [0001] The invention belongs to the technical field of motor control, and in particular relates to a direct torque control strategy for a dual three-phase motor system driven by a five-bridge arm inverter. Background technique [0002] With the rapid development of power electronic conversion technology and control theory, multi-phase (phase number > 3) motor drive systems have been widely studied by domestic and foreign scholars due to their advantages such as low-voltage high-power output, low torque ripple, and suitable for fault-tolerant operation; Among many different types of multi-phase motors, six-phase motors have received more attention due to their close relationship with traditional three-phase motors. The asymmetrical six-phase motor (double three-phase motor with 30° phase shift) obtained by splitting the phases of the three-phase motor with a phase belt angle of 60° has greater application advantages due to smaller torque ripple. The double...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a direct torque control strategy for a five-leg inverter driving a dual three-phase motor system, which solves the need to re-execute the stator magnetization when one phase of the six-phase voltage type inverter fails in the prior art. Problems with chain partition and switch table design

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