A novel dynamic reactive power planning methodology to enhance transient voltage stability

Summary Transient voltage stability (TVS) is an important issue for security operation with the development of power system topology and loads. Lots of research on reactive power planning mainly focus on static voltage stability. But the research on the dynamic reactive power planning considering TVS is very lacking so far. And most of them are only analyzed on some serious buses without covering all the weak faults. And some research considering TVS are limited under some conditions and not general enough for large-scale applications. Therefore, it is an urgent task to propose a feasible dynamic reactive power planning methodology to enhance TVS. So a novel dynamic reactive power planning methodology is proposed in this paper. In addition, although some TVS assessment indices have been proposed, they may not be suitable to be used in dynamic reactive power planning in the iteration calculation. To evaluate voltage stability after contingencies, a TVS assessment index is presented. Then an approach based on compensation sensitivity analysis is discussed for the best dynamic volt ampere reactive planning candidate locations. And a dynamic reactive power planning optimization methodology based on the memetic immune algorithm for multiobjective optimization is proposed to enhance TVS with the least static volt ampere reactive compensator investment cost and power loss cost. The methodology can cover all faults through random faults selection in the optimization. Afterwards, IEEE 39 power system and Zhejiang power grid in China are illustrated and analyzed for the improvement of TVS. It is proved that the proposed dynamic reactive power planning methodology is effective and beneficial to the security operation for power system.