距离继电器作为变压器低压侧故障远后备保护时的性能

对Y,d接线变压器低压侧故障时高压侧线路保护距离继电器的测量阻抗进行了分析,得出装设在Y,d接线变压器高压侧线路上的距离保护对变压器低压侧的各种短路故障可以起到远后备作用.在此基础上提出圆阻抗结合四边形阻抗作为线路末端变压器后故障的远后备保护,并给出了负荷校验公式.动模试验验证了理论分析结果.

Performance of Distance Relay when Used as Remote Backup Transformer Protection

Based on the analysis of measured impedances of distance relay on high voltage level transmission line when fault occurs behind Y, d transformer, it is concluded that phase-to-ground distance relay can evaluate the exact impedance. The round impedance characteristics combined with quadrangle impedance characteristics is designed as remote backup transformer protection. Load checking formulae are also proposed. These conclusions are verified by dynamic simulation.