LLC resonant converter fault diagnosis method based on resonant capacitor voltage

Abstract

The invention discloses an LLC resonant converter open-circuit fault diagnosis method based on resonant capacitor voltage, and the method comprises the steps: setting a reasonable threshold value according to the amplitude of the resonant capacitor voltage of an LLC resonant converter under a normal working condition, sampling the resonant capacitor voltage after a fault, and comparing the sampledresonant capacitor voltage with the set threshold value, thereby achieving the fault diagnosis; then, through phase shift control between bridge arms, realizing the fault positioning. The LLC resonant converter open-circuit fault diagnosis method provided by the invention is high in diagnosis speed, low in error diagnosis rate and high in robustness, and has important significance for ensuring the uninterrupted operation of the LLC resonant converter under the condition of an open-circuit fault.

Description

technical field [0001] The invention relates to the technical field of power electronics, and more specifically, to a fault diagnosis method for an LLC resonant converter based on a resonant capacitor voltage. Background technique [0002] With the rapid development of power electronics technology, it has been widely used in new energy development and energy saving. As a DC-DC converter with transformer isolation, the LLC resonant converter is widely used in various fields of modern industry because of its simple control and zero-voltage turn-on, such as as an intermediate isolation stage, for solid-state transformers , to achieve voltage amplitude adjustment and electrical isolation of the primary and secondary sides. In the power supply system of multi-electric aircraft, the LLC resonant converter is used as the core power electronic converter to realize the conversion of electric energy. [0003] As the core part of power conversion, the LLC resonant converter will have...

AI Technical Summary

Problems solved by technology

At present, most researches on fault diagnosis of DC-DC converters focus on the bidirectional active bridge (DAB), and most of the diagnosis methods are complicated and not suitable for LLC resonant converters.

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