Fault-tolerant control method for short-circuit fault of power converter in switched reluctance motor

Abstract

The invention discloses a fault-tolerant control method for the short-circuit fault of a power converter in a switched reluctance motor. For the short-circuit fault of a power switch tube in a three-phase asymmetric half-bridge structure, current soft chopper control is used as a basic control algorithm, and the de-rating factor is selected according to different fault conditions. The current overshoot of a faulty phase is restrained by shortening the conduction angle, and the waveform and amplitude of the phase current of a healthy phase are changed in real time to compensate for the adverseeffect of the current of the faulty phase on the output torque. Finally, the voltage across the two ends of the circuit of the conducting phase is locally adjusted by adjusting the duty cycle of the power switch tube in the three-phase circuit, so that the fault torque ripple of the switched reluctance motor system under service in de-rated capacity can be further optimized. The hardware cost is not increased. The control algorithm is simple and feasible, achieves a good fault torque ripple suppressing effect and has good engineering application value.

Description

technical field [0001] The invention belongs to the technical field of switched reluctance motors, and in particular relates to a fault-tolerant control method for a short-circuit fault of a power converter of a switched reluctance motor. Background technique [0002] Switched Reluctance Motor (SRM) is a new type of motor developed in the 1980s. The motor has the advantages of simple structure, solid body, high reliability, many controllable parameters, wide speed range, etc. It is favored in industrial applications and has been used in electric vehicles, household appliances, general industry, aviation and other fields. Different degrees of application and development. [0003] The power converter used in the switched reluctance motor drive (Switched Reluctance Motor Drive, SRD) is generally an asymmetrical half-bridge power converter structure, and its phase circuits are independent of each other, with strong stability and good fault tolerance, which makes the SRM phase ...

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Problems solved by technology

[0007] 1. The use of complex algorithm control can obtain better fault-tolerant effects, but the implementation is complex, which cannot meet the real-time requirements of the system, and the program is prone to crash

[0008] 2. Using a simple control algorithm, the effect of fault-tolerant control is poor

[0009] 3. Using hardware topology fault-tolerant control, adding more power devices can achieve better fault-tolerant control effect, and the system cost will increase significantly. At the same time, the increase of power devices will also increase the system failure rate

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