计及换流站闭锁的多端直流系统限流电抗器优化配置策略

多端直流系统故障电流上升速度快,仅靠直流断路器无法可靠隔离故障,需要配置故障限流器降低故障电流上升速度.目前,多端直流系统故障限流器配置方法大多未考虑故障后换流站闭锁的情形.文中提出了一种计及换流站闭锁的多端直流系统限流电抗器(CLR)优化配置策略,给出了换流站闭锁方案,以减小换流站闭锁对交流电压的影响.提出用于优化配置分析的故障位置选取方法,可以获得最严重故障场景,从而保证了最终的CLR配置方案最优.基于柔性四端直流系统,详细分析了2种不同场景下CLR的优化配置.结果表明,所提策略能够得到不同换流站闭锁情形的CLR优化配置方案,可为实际直流电网工程的CLR配置提供参考.

Optimization Placement Strategy of Current Limiting Reactors in Multi-terminal DC System Considering Converter Station Blocking

The fault current of multi-terminal direct current (MTDC) systems rises rapidly, and the fault can not be isolated reliably only by DC circuit breakers. So it is necessary to configure fault current limiters to reduce the rising speed of fault current. At present, most fault current limiter configuration methods for MTDC systems do not consider the situation of converter station blocking after the fault. In this paper, an optimization placement strategy of current limiting reactor (CLR) for MTDC systems considering converter station blocking is proposed, and the converter station blocking scheme is given to reduce the impact of converter station blocking on AC voltage. A fault location selection method for optimization placement analysis is proposed, which can obtain the most serious fault scenario and ensure the optimal configuration of the final CLR scheme. Based on the four-terminal DC system, the optimization placement of CLR in two different scenarios is analyzed in detail. The results show that the proposed strategy can obtain the CLR optimization placement schemes for different converter station blocking situations, which can provide reference for the actual CLR placement of DC power grid projects