Open-circuit fault diagnosis method for dual-active-bridge DC-DC converter

Abstract

The invention discloses an open-circuit fault diagnosis method for a dual-active-bridge DCDC converter. The method specifically comprises the following steps of: calculating the switching function of two H bridges of the dual-active-bridge DC-DC converter according to a system driving pulse signal and the polarity of primary side inductive current; calculating an inductive current state estimation model of the dual-active-bridge DC-DC converter according to the circuit topology and the working principle of the dual-active-bridge DC-DC converter; and designing a fault diagnosis algorithm according to inter-bridge-arm voltage characteristics and current residual characteristics under the fault. According to the method of the invention, monitoring of the working state of the dual-active-bridge DC-DC converter and rapid and accurate diagnosis under different switching tube faults are realized, and a new diagnosis idea is provided for the fault diagnosis technology of the dual-active-bridge DC-DC converter.

Description

technical field [0001] The invention belongs to the technical field of fault diagnosis of power electronic systems, and in particular relates to an open circuit fault diagnosis method of a dual active bridge DC-DC converter. Background technique [0002] As a general power conversion topology, the dual active bridge DC-DC converter has been applied to various important power conversion systems due to its advantages of high power density, strong control flexibility, and modular design, such as electric vehicles, storage energy systems and power electronic transformers. With the increasing reliability requirements of power electronic converters, the problem of fault diagnosis in dual active bridge DC-DC converters has attracted more and more attention. [0003] Power modules are the most fragile semiconductor devices, and their faults can be roughly divided into open circuit faults and short circuit faults. Short circuit faults mainly include switch short circuit, antiparall...

AI Technical Summary

Problems solved by technology

However, the dual active bridge DC-DC converter control system generally only collects the input and output voltages, and cannot complete the fault switch location without adding hardware equipment.

At present, most of the diagnostic algorithms used for full-bridge DC-DC converters will design a hardware detection circuit to obtain the internal operating status information of the converter, mainly including bridge arm voltage and inductor current. The detection information is relatively large and cannot be popularized and applied. into a dual active bridge DC-DC converter

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