一起弧光保护装置误动导致电气事故扩大的事件分析

Analysis of an Electrical Accident Caused by the Malfunction of the Arc Light Protection Device

近年来为了有效抑制发电厂或变电站中、低压母线开关设备损坏及母线、断路器故障引起主变压器损坏的发生,越来越多发电厂或变电站中、低压开关柜配置“弧光保护”(主要用于110 kV以下电压等级的母线和开关设备保护)。通过“弧光保护”可以快速地切除故障点,保证系统的安全稳定运行。但其配套的弧光/压力传感器若安装位置不当,将会影响保护动作准确性。通过一起发电厂中压配电柜电气事故,分析“弧光保护”的动作性能,针对存在的问题制订防范措施,防止保护误动导致事故扩大。

In order to control the damage of the main transformer in a power plant or substation caused by the damage of the medium and low voltage busbar switch apparatus as well as the faults of the busbar and the circuit breaker,medium and low voltage switch cubicles are equipped with arc light protection in more and more power plants or substations(mainly used in the protection of the busbar and the switch apparatus below 110 kV).The fault point can be quickly removed by means of arc light protection to ensure secure and stable operation of the system.However,if the supporting arc/pressure sensor is not installed properly,it will affect the accuracy of the protection action.Based on an electrical accident of the medium voltage power distribution cabinet in a power plant,this paper analyzes the action performance of the arc light protection as well as formulating preventive measures for existing problems to prevent the deterioration of the accident caused by the protection malfunction.