摘要
通过对一起500 kV变电站高压并联电抗器保护误跳闸事故的调查分析,说明了控制电缆对地分布电容对继电保护的影响。根据对误跳闸事故的理论分析作了模拟直流正电源接地、模拟直流正母线和负母线对地之间迭加交流电源3个试验,结果表明:在发生直流系统接地或误将交流串入直流系统时,就会通过控制电缆的分布电容构成回路,产生电容电流,引起一些动作值较低的灵敏继电器发生误动作。误动作取决于3个因素,即电缆对地分布电容值的大小、继电器的动作值大小及外界干扰因素,并据此提出了防范措施。
The influence of the distributing capacitance of control cables on relay protection is explained by analyzing a faulty tripping of high voltage shunt reactor protection in a 500 kV substation. Based on the theoretical analysis,three simulative experiments are carried out：DC positive bus grounding fauh,AC current exerted between DC positive bus and ground,and AC current exerted between DC negative bus and ground. The results show that,in above experimental conditions,the capacitance current introduced by the distributing capacitance of control cables leads to the misoperations of sensitive relay with low action threshold. The decisive factors are the level of distributing capacitance,the action threshold,and the environmental interference. The countermeasures are proposed.
出处
《电力自动化设备》
EI
CSCD
北大核心
2007年第11期115-118,121,共5页
Electric Power Automation Equipment
关键词
控制电缆
分布电容
继电保护
防范措施
control cable
distributing capacitance
relay protection
preventive measures
