高压断路器电流零点延迟开断回路计算及试验  

Calculation and Experiment of Current Zero Delay Breaking of High-voltage Circuit Breakers

作　　者：张高潮 翟小社[1] ZHANG Gaochao;ZHAI Xiaoshe(State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]电力设备电气绝缘国家重点实验室(西安交通大学),西安710049

出　　处：《高电压技术》2023年第11期4775-4781,共7页High Voltage Engineering

基　　金：国家自然科学基金(51937009)。

摘　　要：高压断路器利用交流电弧过零熄灭这一机理来完成电流开断,但随着特高压工程和直流电网的建设,系统中会出现电流零点延迟现象,对高压断路器的开断造成影响。采用非同步三相短路故障回路,分析了电流零点延迟现象产生的原因,并采用PSCAD软件对回路进行了仿真计算。计算表明:发生B、C两相短路时,当A相电流源电压的初始相位角α为90°或270°时,回路具有最大的直流分量,此时当两相短路经过5 ms发展成三相短路时,在B相中产生正向电流延迟零点现象;当两相短路经过15 ms发展成三相短路时,在C相中产生负向电流延迟零点现象。利用此现象,研究开发了一种电流延迟零点合成试验回路,并实现了高压断路器的电流延迟零点开断试验验证,结果表明断路器在开断过程中产生的电弧电阻会使回路中直流分量减小,从而导致电流延迟零点时间减小。High-voltage circuit breakers use the mechanism of AC arc zero-crossing extinguishing to complete current breaking,however,with the construction of UHV project and DC power grid,the phenomenon of current zero delay will appear in power systems,which will affect the interruption of high-voltage circuit breakers.In this paper,the cause of current zero delay is analyzed by using the fault circuit of asynchronous three-phase short-circuit,and the circuit is simulated by the PSCAD software.The calculation results show that when B and C two-phase short-circuit occurs,and the initial phase angle of A-phase current source voltage is 90°or 270°,the circuit has the largest DC component;when two-phase short-circuit develops into three-phase short-circuit after 5 ms,positive current zero delay phenomenon occurs in phase B,and negative current zero delay phenomenon occurs in phase C when two-phase short-circuit develops into three-phase short-circuit after 15 ms.Based on this phenomenon,a synthetic test circuit of current zero delay is developed,and the current zero delay interruption test of high-voltage circuit breaker is realized.The results show that the arc resistance produced by the circuit breaker during the interruption process will reduce the DC component in the circuit,resulting in the decrease of the current zero delay time.

关 键 词：高压断路器 零点延迟开断 直流分量 电流开断 暂态恢复电压 合成试验 

分 类 号：TM561[电气工程—电器]