Adaptive reclosing method of mmc-hvdc DC line using circuit breaker injection pulse signal

Abstract

The invention discloses an adaptive reclosing method of MMC-HVDC DC line through injecting pulse signal by utilizing circuit breaker. The method comprises that follow steps of: when the MMC-HVDC linefails, Hybrid circuit breakers at both ends of the faulty line tripped off, Within the interval between fault isolation of the fault DC line and reclosing, controlling the on-off of the hybrid circuitbreaker transfer branch sub-module to inject characteristic signals into the fault line, There are differences in the propagation characteristics of the characteristic signals when the faults exist or disappear, which can be used to distinguish the fault characteristics of the faulty HVDC lines, and then to control whether the faulty HVDC lines coincide with the circuit breakers, so as to realizethe fault protection of HVDC lines. The method of the invention realizes adaptive reclosing in the DC system of the overhead transmission line, shortens the power outage time, ensures the safe and reliable operation of the DC system, and has very significant direct and indirect benefits.

Description

technical field [0001] The invention belongs to the field of DC line fault protection, in particular to an MMC-HVDC DC line adaptive reclosing method using a circuit breaker to inject pulse signals. Background technique [0002] The line fault has the characteristics of single-phase (pole) and instantaneous. After the line fault is removed, the probability of successful reclosing within a fixed time limit is 60% to 90%. The higher the voltage level, the higher the recombination power. It is very important to improve the stability and continuity of power supply of the power system dominated by overhead lines. Automatic reclosing is widely used in AC lines. Single-phase automatic reclosing for single-hop single-closing not only meets the actual characteristics of line faults but also meets the needs of my country's national conditions, and has huge social and economic benefits. When the traditional automatic recloser blindly recloses on a permanent fault, the power system wil...

AI Technical Summary

Problems solved by technology

When the traditional automatic recloser blindly recloses on a permanent fault, the power system will suffer two consecutive fault impacts in a short period of time, resulting in an increase in the swing of the power system after reclosure, reducing the insulation of electrical equipment such as circuit breakers and reducing their service life

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