Real-time diagnostic method for open circuit fault of phase-shifted full bridge converter

Abstract

The invention discloses a real-time diagnostic method for an open circuit fault of a phase-shifted full bridge converter, comprising the steps of sampling by a current sensor to measure the current of a direct current bus of the phase-shifted full bridge converter, acquiring the ratio of the current peak of the direct current bus and the integral value thereof, comparing the acquired ratio with historical data of the ratio of the current peak of the direct current bus of the phase-shifted full bridge converter under a normal condition, determining whether the phase-shifted full bridge converter is in the open circuit fault or not; meanwhile, acquiring a follow current signal when the converter is in the open circuit fault by virtue of current sensors arranged on two bridge arms, and locating a power switching tube in the open circuit fault according to a power tube antiparallel diode follow current signal logical relation when in the open circuit fault. The real-time diagnostic methodcan be used for rapidly and accurately locating the fault and determining the type of the fault to realize fault prediction.

Description

Technical field [0001] The invention relates to the field of system fault diagnosis, in particular to a real-time diagnosis method for the open circuit fault of a phase-shifted full-bridge converter. Background technique [0002] In power electronic devices, the main power converter power device is the weakest link that is most prone to failure. In recent years, the reliability of power device operation has improved, but it has failed to meet the requirements of power converters. Statistics show that open circuit is one of the most common faults of power devices. Phase-shifted full-bridge converters (such as figure 1 ) The open circuit fault of the power tube can be divided into two types: single tube open circuit and double tube open circuit. At present, the technologies used for fault diagnosis of power converters can be divided into two categories: based on mathematical models and independent of mathematical models. The fault diagnosis method based on the mathematical model c...

AI Technical Summary

Problems solved by technology

The direct measurement method can be divided into two categories: detection of power device variables and detection of other related variables of the circuit. This method is simple and intuitive, and has strong real-time performance, but it cannot accurately locate circuit faults.

Signal processing method, pattern recognition, expert system, neural network and other methods involve complex algorithms, and the program processing time is long, so it is difficult to meet the requirements of power electronic converters with higher and higher operating frequencies

[0003] In general, fault diagnosis methods for power electronic converters that do not rely on mathematical models have the following deficiencies: (1) direct measurement methods cannot accurately locate faults; (2) signal processing methods, pattern recognition and other fault diagnosis involving artificial intelligence The algorithm of the method is complex and difficult to apply in engineering

Images