Double salient-pole motor drive power tube fault diagnosis method

Abstract

The invention relates to a diagnosis method for power transistor of doubly salient motor driver, belonging to the fault diagnosis method for power device in motor driving system. In the method three-phase current sensor is set on three-phase bridge arm; while three-phase current is measured the measurement for current signal of current reflowing is added; after current reflowing signal is treated digitally and driving signal of power transistor is combined on-line fault measurement and diagnosis for main power circuit are realized. The invention is provided with simple realization and good rapidity. Not only open fault of power transistor can be diagnosed quickly but also it can play a better protecting effect for bridge-arm direct phenomenon maybe generated by short circuit of power transistor. At the same time it provides a feasible method for fault diagnosis of motor driving system based on full-bridge converter.

Description

1. Technical field [0001] The invention relates to a fault diagnosis method for a power tube of a double salient motor driver. 2. Background technology [0002] The doubly salient pole motor is composed of permanent magnets or field windings embedded in the stator of the switched reluctance motor. It has the advantages of simple structure, flexible control, high power density and good high-speed performance. In the entire motor drive system, the power device of the main power converter is the weak link most prone to failure. After the failure, the motor will work in an unbalanced state, which will not only have a certain impact on the stability of the entire system, but also may burn the motor. series of serious consequences. Therefore, the real-time online fault detection and diagnosis of the main power converter becomes the key to improve the reliability of the whole system. [0003] The main power circuit of the doubly salient motor is similar to other brushless machine...

AI Technical Summary

Problems solved by technology

In many literatures, there have been researches on the fault diagnosis of power tubes of full-bridge converters, which can be roughly divided into two types. One is to realize fault diagnosis by detecting the voltage change of the lower tube of the bridge arm. This method is simple and fast, but it needs Adding three additional voltage sensors increases hardware cost and complexity; the other is to compare the sampled operating current value with the fault current reference value in the program to implement fault diagnosis. This method does not require any additional hardware, but it needs to be delayed. The judgment method is implemented, and the speed is not as good as the first type

Moreover, the above two methods focus on the open-circuit fault of the power tube, and only briefly mention the severe short-circuit fault that may cause the bridge arm to pass through, without research

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