Valve short circuit fault classification and positioning method of high-voltage direct current transmission converter

Abstract

A valve short circuit fault classification and positioning method of a high-voltage direct current transmission converter comprises the steps: a, if a high-voltage direct current transmission protection system determines that a converter has valve short circuit faults, the processor of a protection system reads current magnitude information collected by a current measurement device in a sampling window; b, the processor performs integration calculation of section electric charge quantity and branch electric charge quantity differences; c, the processor distinguishes the alternating current side short of the converter, the bridge arm short circuit and the direct current outgoing line short circuit according to the size relation of each section electric charge quantity; and d, if the bridge arm short circuit happens, the processor further locates a fault bridge arm according the sizes of the branch electric charge quantity differences and the direction of the alternating current branch current. The method provided by the invention can rapidly classify positioning valve short circuit faults to facilitate rapidly and effectively processing faults and prevent accidents from being enlarged; and the method provided by the invention is not influenced by fault moments, noise and the length of the sampling window, and is low in sampling rate requirement and good in adaptability.

Description

technical field [0001] The invention relates to a valve short-circuit fault classification and location method of a high-voltage direct current transmission converter. Background technique [0002] The high-voltage direct current transmission system has large transmission capacity, long transmission distance and low transmission loss, so it occupies an increasingly important position in my country's power structure. By the end of 2015, the installed capacity of my country's power grid was 1.5 billion kilowatts, and the inter-regional transmission power reached 210 million kilowatts, of which 23 high-voltage direct current transmission lines assumed one-third of the transmission power. The basic principle of HVDC transmission is: at the transmission end of the HVDC transmission system, a converter is used for rectification, and the three-phase AC power is converted into DC power. The inverter is used for inversion, and the direct current is converted into three-phase alterna...

AI Technical Summary

Problems solved by technology

As a result, after the valve short-circuit fault occurs, the protection system cannot automatically and accurately judge the type of fault (including three types of phase-to-phase short circuit on the AC side, bridge arm short circuit, and DC outgoing line short circuit) and location (the specific bridge arm and phase difference under the bridge arm short-circuit fault ), so that the fault cannot be dealt with quickly and effectively, reducing the operating efficiency and reliability of the system

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