Method for detecting open-circuit fault of inverter circuit

Abstract

The invention discloses a method for detecting the open-circuit fault of an inverter circuit. The method comprises the following steps of: (1) defining fault characteristic quantities, wherein the three fault characteristic quantities are available in the method and respectively represent different meanings; (2) computing a three-phase voltage fundamental current amplitude, carrying out the phase shift and the Park conversion on the obtained three-phase voltage in a sampling way respectively, obtaining the size of the fundamental current amplitude by a conversion result, and filtering by a digital filter in the process; (3) detecting the fault of a neural network, and outputting the former two characteristic quantities through the BP (pressure transducer) neural network by the computation result in the step (2); and (4) positioning a fault power tube, testing the maximum value and the minimum value of the obtained three-phase voltage in a sampling way respectively, obtaining the specific position of the fault power tube through simple logical judgment, and outputting the third fault characteristic quantity. According to the method disclosed by the invention, the fault information of the power tube of the inverter circuit can be quickly and exactly obtained only by analyzing the output three-phase voltage, and the method can be realized only by a software algorithm without adding other outer hardware circuits, so that the cost can be reduced, the efficiency can be improved, the method is higher in application ability, and the method has the application value for researching the real-time fault detecting aspect of a power electronic circuit.

Description

Technical field [0001] The invention relates to a method for detecting an inverter circuit open circuit fault, belonging to the field of inverters. Background technique [0002] With the increasing development of power electronics technology, pulse width modulation (PWM) inverters have developed rapidly due to their simple main circuit structure, flexible control and many other advantages. Especially voltage source pulse width modulation inverters have been developed in many ways. widely used. However, the power semiconductor device and its control circuit in the inverter are the weakest link that is most prone to failure, which will directly affect its further promotion in the industrial field. Therefore, the fault detection of the power tube in the inverter circuit is particularly important. [0003] So far, many papers and patents have proposed methods for detecting open circuit faults of inverter circuit power tubes. Among these methods, there are mainly two types. The first...

AI Technical Summary

Problems solved by technology

The first method detects the open-circuit fault of the power tube with the hardware circuit and the corresponding algorithm. This method generally detects the voltage at both ends of each power tube, and analyzes the difference between the voltage at both ends of the power tube and the normal voltage. To judge the fault, the main disadvantage of this method is that it needs to add multiple voltage sensors and other hardware circuits, which increases the cost accordingly

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