摘要
直流电网故障快速清除是保证电网持续可靠运行的关键。平波电抗器、故障限流器和混合式断路器等设备可使故障电流发展速度得以削弱,同时,他们对故障电流发展特性也有一定影响,需要进一步研究使平波电抗和故障限流器配置更合理。首先研究了多种限流设备的共同限流下,综合考虑故障限流器的能量吸收及断路器的动作时序,给出了直流电网故障电流计算方法。其次,将减小断路器开断电流和限流设备吸收能量作为优化目标,得到了直流电抗参数配置的优化方法。最后在PSCAD/EMTDC进行仿真验证,结果表明所提优化方法比之前优化方法降低故障开断电流15%。
The rapid clearing of DC faults is the key to ensuring the continuous operation of the grid. Equipments such as Current Limited Reactor (CLR), Fault-Current-Limiter (FCL) and hybrid DCCB can weaken the development speed of fault current. At the same time, they also have influence on the development characteristics of fault current. Further research is needed to make the configuration of CLR and FCL more reasonable. Firstly, the current calculation method of DC grid is given considering the energy absorption of FCL and the action sequence of DCCB. Secondly, taking the breaking current of DCCB and the energy absorbed by current limiting equipment as optimization targets, the optimization method of the DC reactance is obtained. Finally, PSCAD/EMTDC simulation verified that the proposed optimization method reduces the fault breaking current by 15% compared with the previous optimization method.
