利用线路两端电压差的输电线路相位纵联保护

Phase Pilot Protection of Transmission Line Based on Voltage Difference Between Both Terminals

提出了一种基于线路两端电压差的输电线路相位纵联保护.根据分相阻抗的相角特性,相位值是由线路各相两个等效电压故障分量差的比值计算而来的,利用这个比值的相位判断故障是否发生在保护区内.当比值的相位等于0°时表明为区外故障,当比值的相位等于180°时表明为区内故障.该保护动作灵敏、适应性强,具备较强的抵御线路电容的特性,可不经过补偿,直接运用于绝大多数输电线路的纵联保护中,同时可有效抵御区外故障时电流互感器(TA)饱和的影响.EMTP数字仿真和动模仿真结果验证了该保护的有效性.

A phase pilot protection of transmission line based on the voltage difference between both terminals is proposed.According to the angle characteristics of the individual phase impedance,the phase value is evaluated by the ratio of the two equivalent differences of the fault-superimposed components of voltage at each phase of the line,then whether the fault occurred in the protected region is judged.When the phase values just equal to 0°,the fault appears outside of the protected zone,and the fault is inside of the protected zone when they equal to 180°.The proposed protection with identity of sensitive operation and adaptation is capable of resisting the line capacitors,and can be directly used in pilot protections of most transmission lines without com-pensation.The EMTP simulation and the dynamic simulation show the effectiveness.