Direct-current charging pile rectifier power tube open-circuit fault diagnosis and fault point positioning method

Abstract

The invention provides a direct-current charging pile rectifier power tube open-circuit fault diagnosis and fault point positioning method. The method comprises the following steps: S1, collecting alternating current side phase current data of a direct current charging pile rectifier; s2, determining a time sequence of instantaneous frequency of the phase current data window; s3, determining the fault characteristic quantity Flj of the bridge arm of the rectifier, if the fault characteristic quantity Flj of the bridge arm of the rectifier is 1, determining that a fault exists and entering the next step, and if the fault characteristic quantity Flj of the bridge arm of the rectifier is 0, determining that no fault exists and ending; S4, determining a phase current mean value iave-l when the open-circuit fault occurs; and S5, determining the positioning characteristic quantity R1 of the open-circuit fault power tube, if the positioning characteristic quantity R1 of the open-circuit fault power tube is equal to 1, indicating that the upper tube of the power tube has a fault, if the positioning characteristic quantity R1 of the open-circuit fault power tube is equal to 0, indicating that the double tubes of the power tube have a fault, and if the positioning characteristic quantity R1 of the open-circuit fault power tube is equal to -1, indicating that the lower tube of the power tube has a fault. According to the invention, the open-circuit fault power tube in the fault bridge arm of the rectifier is positioned.

Description

technical field [0001] The invention relates to the technical field of fault diagnosis of charging piles, in particular to a method for diagnosing an open circuit fault of a rectifier power tube of a DC charging pile and a method for locating a fault point. Background technique [0002] Electric vehicle charging piles have become an important infrastructure. DC charging piles are an important direction for future construction and development. Due to the fragility of their converter power devices and the complexity of control, they have a high proportion of failures and are the weak link of charging piles. Among them, when an open-circuit fault occurs in a power device, the fault feature is not obvious and difficult to find. If the open-circuit fault of the power device is not discovered and repaired in time, it will have a harmonic impact on the power grid, and induce accelerated damage to the normal power device, which will eventually lead to a sudden failure of the chargin...

AI Technical Summary

Problems solved by technology

If the open-circuit fault of the power device is not discovered and repaired in time, it will have a harmonic impact on the power grid, and induce accelerated damage to the normal power device, which will eventually lead to a sudden failure of the charging pile.

However, there is no effective and easy fault diagnosis technology

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