特高压配套750kV线路重合闸过程的短路电流直流分量对系统稳定性影响分析

Study on Influence of DC Component of Short-Circuit Current of UHV 750kV line in Reclosing Process on System Stability

针对特高压直流外送型电网直流分量对系统稳定性的影响问题,分析了特高压配套线路短路故障后,在不同重合闸方式下断路器重合于永久故障后,短路电流直流分量对其开断能力的影响。利用电力系统分析综合程序PSASP,计算特高压系统中重合闸过程短路电流直流分量衰减时间常数,校核直流输送功率与火电开机不同方式下系统稳定性及短路电流因子。最后校验了短路电流是否满足遮断容量,提出重合闸方式及时间整定的推荐值,并建议典型电网需通过专题研究校核断路器重合闸方式和时间。

Aiming at the influence of DC component of UHV DC external transmission network on the system stability,and the influence of DC component of short-circuit on the breaking capacity of the circuit breaker is analyzed after it recloses to a permanent fault in different reclosing modes after the short-circuit fault of the UHV supporting line.By using power system analysis software package(PSASP),the decay time constant of DC component of short circuit current during the reclosing process of UHV system is calculated,and the stability of the system and short-circuit current factor under different working conditions of DC transmission power and thermal power startup is checked.Finally,the short-circuit current is verified to meet the interrupting capacity,and reclosing mode and time setting are put forward.It is suggested that the reclosing mode and time of circuit breaker should be checked by special research in typical power grid.