Fault detection method and device for four-quadrant rectifier

Abstract

The embodiment of the invention provides a fault detection method and device for a four-quadrant rectifier, and the efficiency, accuracy and reliability of fault judgment are improved. The fault detection method comprises the steps of collecting a first current signal of a first half period and a second current signal of a second half period; carrying out wavelet decomposition and single reconstruction on the first current signal and the second current signal to obtain a first reconstruction coefficient and a second reconstruction coefficient; calculating a first wavelet energy value and a first wavelet singular value according to the first reconstruction coefficient, and calculating a second wavelet energy value and a second wavelet singular value according to the second reconstruction coefficient; performing evidence fusion on the first wavelet energy value and the first wavelet singular value to obtain a first fusion value, and performing evidence fusion on the second wavelet energyvalue and the second wavelet singular value to obtain a second fusion value; and comparing the difference between the first fusion value and the second fusion value with a diagnosis threshold, and determining whether the four-quadrant rectifier has a fault according to a comparison result.

Description

technical field [0001] The present application relates to the field of traction drive systems, in particular to a fault detection device for a four-quadrant rectifier. Background technique [0002] As the executive tool of high-speed railway, the reliability of high-speed EMU is directly related to the driving safety of high-speed railway. The electric traction drive system is the source of forward power for high-speed EMUs, and its reliability requirements are particularly strict. As one of the core components in the electric traction system of the EMU, the traction converter is mainly responsible for converting the electric energy between the traction transformer and the traction motor. [0003] The four-quadrant rectifier in the traction converter of high-speed EMUs plays a role of rectification during train traction, converting single-phase alternating current into direct current; during regenerative braking of trains, the four-quadrant rectifier converts direct current...

AI Technical Summary

Problems solved by technology

Therefore, the failure of the four-quadrant rectifier in the traction converter will have a serious impact on the safe operation of the train

[0004] However, during the operation of the high-speed EMU, when the four-quadrant rectifier in the traction converter of the EMU fails, it will directly cause the intermediate DC side voltage to fluctuate sharply, and the harmonics on the grid side will increase, which will cause the traction converter unit to fail. And seriously endanger the safety and stable operation of other equipment in the traction drive system

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