Network partitioning in coherent areas of static voltage stability applied to security region enhancement

•Improvement of the system criticality index determination by WAMS using PMU.•New network partitioning method based on the energy function criticality index.•Novel adaptive definition of generators groups for SSR based on network partitioning.•Improvement of power systems operational region with large penetration of RESs. The increasing penetration of variable renewable energy sources (RESs) is introducing critical challenges to the power system operation. In this perspective, this paper proposes a novel method for the improvement of the static security region (SSR) based on a new network partitioning algorithm. The proposed algorithm focuses on modern power systems with high penetration of variable RESs generation. It divides the power system in coherence areas according to its criticality mapping. To this end, each bus is assigned a criticality index from the potential energy function, whereas this calculation is based on the data of the wide-area measurement system (WAMS) using phasor measurement unit (PMU). Afterwards, the obtained coherence areas are employed to adaptively determine the generators groups applied to the system SSR assessment in the short-term horizon. To validate the proposed approach, several cases studies are conducted on the IEEE 118-bus system. The results demonstrate the potential of the proposed methodology in the SSR improvement.