母线系统变化对10kV并联电容器分闸操作影响机理的研究  

Study on Influencing Mechanism of Bus System Change Impacting on Switching Operation of 10 kV Shunt Capacitors

作　　者：郑飞扬 席世友[1] 欧阳沙[2] 扬庆 

机构地区：[1]重庆市电力公司,重庆401420 [2]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400030

出　　处：《高压电器》2016年第3期165-170,共6页High Voltage Apparatus

摘　　要：近年来,变电站投切10 kV并联电容器时发生断路器炸裂事故率连年上升,笔者发现类似故障具有普遍性,而事故本身又表现出一种特殊性,都伴随有明显的母线系统变化。文中对此提出了母线系统变化影响10 kV并联电容器的分闸操作的观点,并对其影响作用机理进行理论和仿真计算研究。研究表明:母线对地电容与电缆对地电容通过断路器形成电容冲放电回路,母线对地电容变化会产生高频电流分量。此时分闸操作,断路器触头电流"高频过零"并出现"等效截流"现象,断路器负载侧、断口都将产生极高幅值的高频过电压(4.5 p.u.),极有可能引发断路器重燃甚至电容器、断路器等设备的绝缘击穿。In recent years, the accident ratio of circuit breaker explosion when a substation switches on/off10 k V shunt capacitors has been rising. Through the authors＇ analysis, it is found that the similar explosion accidents are of universality and particularity and with apparent change of the bus system. This paper presented that the change of bus system will impact on the switching operation of 10 k V shunt capacitors. And the theoretical analysis and simulations of effect mechanism are made. The results proved that the capacitance to ground of bus and cable forms a capacitor charging and discharging circuit and the change of bus capacitance to ground produces a high frequency circuit component, and that if the switching operation is performed in this case the circuit of the circuit breaker between contacts will be with high frequency over zero and equivalent closure, and a high-frequency overvoltage of very high amplitude（4.5 p.u.） will be produced on the load side and across the break of the circuit breaker, which would be possible to cause the reignition of the circuit breaker and the insulation breakdown of the equipment such as the circuit breaker and the shunt capacitor.

关 键 词：并联电容器 母线系统变化 过电压 对地电容 ATP-EMTP仿真 

分 类 号：TM53[电气工程—电器] TM645.11