基于MIESCR的多馈入直流协调恢复策略

Coordinated Recovery Strategy for Multi-infeed HVDC System Based on MIESCR

针对直流同时恢复造成的换流器消耗动态无功过大及直流有功恢复缓慢的问题,提出基于多馈入有效短路比协调直流恢复的策略。首先推导论证了2种定义多馈入有效短路比的一致性,完善了其物理意义;其次,阐述了MIESCR在MIDC系统中对电压稳定和功角稳定所起的作用;然后从减小换流器消耗的动态无功峰值及避免后续换相失败的角度,提出基于MIESCR指标数值大小设计的各回路直流子系统先后恢复顺序的方案;然后,协调直流PI环节比例增益参数,控制直流电流恢复的速度,实现直流子系统的有序恢复。最后通过南方电网某两回直流构建的双馈入直流模型,在PSCAD/EMTDC电磁暂态仿真验证了本文所提方法的有效性。

In the light of converters with excessive dynamic reactive power demand and power transmission low speed recovery in recovering HVDC simultaneously,the paper proposes a MIESCR-based coordinated recovery strategy.Firstly,the article deduces the consistency of the MIESCR with two definitions,and uses the respective advantages of the definition to improve the physical meaning of the MIESCR.Secondly,the paper elaborates the role of the MIESCR played in regulating voltage and power-angle in MIDC system.Thirdly,the paper puts forward a MIESCR based scheme to distinguish the strength of AC system,and uses the MIESCR index value to arrange the recovery order of DC system.Furthermore,the parameter of PI controller is used to realize the control of each DC system current.Finally,this paper establishes a double infeed HVDC system simulation model by PSCAD/EMTDC,which bases on two actual DC systems in China Southern Power Grid,to confirm the validity of this method proposed.