Partitioning voltage stability critical injection regions via electrical network response and dynamic relative gain

In this paper, a new approach based on dynamic relative gain is proposed for partitioning voltage control areas in bulk power systems. The critical nodes of voltage stability are determined using voltage stability index, “L index”. The cross relative gain between the critical nodes and other nodes are calculated based on the concept of dynamic transfer function (DTF) and dynamic cross relative gain (DRG). The principle of identifying the strong coupling load nodes and generator nodes are proposed according to the characteristics of DTF and DRG. Then the voltage control regions are constructed based on the critical node and its strong coupled nodes. Furthermore, the practical voltage control regions are obtained through merging different control areas according to the voltage coupling relationships of the critical node. Finally, the effectiveness of the proposed method is demonstrated in the New England 39-bus system with multi-scenario and comparison study. Besides, the method is applied in the Polish power grid, which verifies its feasibility and practicality in bulk power system.