考虑燃弧区间的断路器非对称开断能力校核方法研究

Study on Calibration Method of Asymmetric Breaking Ability of Circuit Breaker Considering Arcing Interval

电网X/R比值增大会导致短路电流直流分量衰减时间常数超出在运断路器标准时间常数或特殊工况时间常数,在电力系统短路电流高直流分量影响下,断路器开断性能受限且无法达到标称的额定开断能力。文中综合考虑非对称短路电流开断过程中断路器燃弧窗口、电弧能量、电流变化率和电压变化率等因素对开断性能的影响,比对不同类型的断路器短路电流开断性能等效折算方法,提出考虑断路器修正系数的基于燃弧区间的非对称短路电流开断能力校核方法,并以电网实际系统的变电站短路电流情况进行实例校核验证,为校核高压断路器非对称短路电流开断性能提供了指导,对提升电网运行的可靠性和经济性具有重要的理论和工程价值。

The increase of the X/R ratio of the power grid can cause the decay time constant of DC component of short-circuit current to exceed the standard time constant or special time constant of the circuit breaker(CB)in operation.Under the influence of high DC component for the short-circuit current in the power system,the breaking performance of the CB is limited and cannot reach its nominal breaking ability.In this paper,the influence factors such as arcing window,arc energy,current and voltage variation rate of CB during the asymmetric short-circuit current breaking period are comprehensively considered.The equivalent conversion methods of short circuit current breaking performance of different types of circuit breakers are compared,and the calibration method of asymmetrical short circuit current breaking performance with consideration of correction coefficient of the circuit breaker and also on the basis of arcing window is proposed.The actual calibration and verification are performed in accordance with the short circuit situation of the substation of the real system of the the power grid,which provides guidance for calibrating asymmetrical short circuit current breaking performance of high voltage circuit breaker and has important theoretical and engineering value for improving reliability and economy performance of operation of the power grid.