One-phase short-circuit fault-tolerant direct torque control method for five-phase permanent magnet motor

Abstract

The invention discloses a one-phase short-circuit fault-tolerant direct torque control method for a five-phase permanent magnet motor. The one-phase short-circuit fault-tolerant direct torque controlmethod comprises the steps of: when an open-circuit fault of an A phase occurs, deducing a healthy-phase open-circuit fault-tolerant current, a fault-tolerant transformation matrix T4 / 2 and an inversematrix thereof T2 / 4 according to constraint conditions that a stator flux linkage vector is unchanged before and after the fault, a sum of healthy-phase currents is zero and the copper consumption isminimum; when a short-circuit fault of the A phase occurs, deducing a residual healthy-phase compensation flux linkage according to the principles that the stator flux linkage vector is unchanged before and after the fault and the copper consumption is minimum, or according to the constraint conditions that the healthy-phase compensation current amplitudes are equal and a sum of healthy-phase compensation currents is zero; and acquiring a stator phase voltage command through combining a stator flux linkage with a torque observer, setting torque and stator flux linkage amplitude and carrying out coordinate transformation, and combining the voltage with a pulse width modulation technology based on zero-sequence voltage injection to achieve consistent steady-state performance and dynamic performance before and after the motor short-circuit fault. The one-phase short-circuit fault-tolerant direct torque control method has the advantages of constant switching frequency of an inverter and small CPU overhead.

Description

technical field [0001] The invention relates to a direct torque fault-tolerant control method for a one-phase short-circuit fault of a permanent magnet motor, in particular to a fault-tolerant direct torque control method for a five-phase permanent magnet motor, which can be applied in aerospace, electric vehicles, etc., and has important effects on motor reliability and dynamic performance occasions with strict requirements. Background technique [0002] With the improvement of the level of social development, the means of transportation are also undergoing tremendous changes. For example, the emergence of electric vehicles can greatly reduce energy consumption and reduce environmental pollution. At the same time, the technical standards of electric vehicles are becoming more and more stringent. As one of the most important components of an electric vehicle, its steady-state performance and dynamic performance under fault conditions directly determine the reliability of the...

AI Technical Summary

Problems solved by technology

So far, no literature has proposed a fault-tolerant control method based on direct torque for one-phase short-circuit faults of five-phase permanent magnet motors.

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