Optimizing Hierarchical Site Selection for Grid-Forming Energy Storage System: A Case Study of Power System in Western China

Abstract

As the power system shifts from conventional synchronous generation (SG) to converter-interfaced generation (CIG), the reliance on CIG for maintaining frequency and voltage stability has increased. Grid-forming energy storage systems (GFM-ESSs), with control response characteristics similar to SG, are considered essential for improving the stability and performance of power systems. This article introduces a strategic approach for optimizing GFM-ESS site selection, addressing both plant-level and system-level stability statically and dynamically. First, a hierarchical siting index system is established, taking into account the impact of energy storage systems on static voltage stability and power losses, small-signal stability conditions at grid-forming stations, and the transient support capabilities of GFM-ESS devices. The K-means clustering method and an improved GRA-VIKOR evaluation algorithm are then applied to address the hierarchical siting problem and determine optimal installation locations for GFM-ESS within a large power grid. A case study of the Western China power system demonstrates that the proposed site selection strategy effectively identifies optimal locations, enhancing performance and support capabilities.