One-phase-failure fault-tolerant torque control method of 60-degree offset six-phase permanent magnet synchronous motor

Abstract

The invention relates to a one-phase-failure fault-tolerant torque control method of a 60-degree offset six-phase permanent magnet synchronous motor. The method includes the steps that currents from ib to if of the remaining healthy phases and the position angle of a rotor are acquired; the currents ib to if of the remaining five healthy phases are transformed into i5alpha, i5beta, i5z1, i5z2 and i5z3; the virtual stator currents iz5alpha and iz5beta are calculated; the virtual stator flux linkages psiz5alpha and psiz5beta are worked out; the serial number thetai of the virtual stator flux linkages psiz5alpha and psiz5beta on the alpha and beta plane sector is judged; the variable phi for controlling the virtual stator flux linkage amplitudes is output; the electromagnetic torque (please see the symbol in the specification) is calculated; the electromagnetic torque control variable tau is output; the zero-sequence current error vector (please see the symbol in the specification) is output; the zero-sequence current error vector, the tau, the phi and the thetai are sent to an optimum switch vector table to obtain an optimum switch combination, the optimum switch combination further acts on windings of the remaining five healthy phases to achieve the control target that the zero-sequence current, the virtual stator flux linkage amplitudes and the electromagnetic torque error are zero. Through the control method, a direct torque control driving system of the 60-degree offset six-phase permanent magnet synchronous motor can continue running after one phase of the motor fails or one phase of an inverter bridge fails.

Description

technical field [0001] The invention relates to a six-phase permanent-magnet synchronous motor with an offset of 60 degrees and a fault-tolerant torque control method with one phase missing. Background technique [0002] At present, the direct torque control strategy has been studied in detail in the case of symmetrically balanced windings of multi-phase motors, and rich research results have been obtained. Literature research shows that after adopting direct torque control, the multiphase motor drive system has strong torque control ability. [0003] Although the literature has done some research on the direct torque control strategy of multi-phase motors with symmetrical balanced windings without faults, there are few researches on direct torque control fault-tolerant strategies when the windings or inverters are faulty, especially in the case of multi-phase permanent magnet synchronous There are no research results on the electric motor. [0004] For the multi-phase mo...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a 60-degree biased six-phase permanent magnet synchronous motor torque control method with one phase missing and fault tolerance, which can solve the problem of the direct torque control drive system of a 60-degree six-phase permanent magnet synchronous motor. Difficulties in continuing to operate after one phase is broken or one phase of the inverter bridge is faulty

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