Deep analysis of the influence of the different power system structures on the performance of the energy storage systems

Abstract

With an increasing need to install variable renewable energy sources to the grid, energy storage (ES) has become a key component for electrical grids to maintain stability. Various methods have been developed to optimize siting of ES systems to benefit a certain actor in the power grid, such as consumers, system operators, or power generators, or to optimize a particular variable, such as frequency, voltage, investment profits, or operator costs. In this paper, a new method has been developed to maximize the grid's efficiency by determining optimal ES siting and evaluating the impact of grid structure on ES performance. The method can decouple the grid structure's impact on grid performance from other factors to show which grid structure is best for ES performance. Inspired by a centrality concept known as a net ability that determines the importance of transmission lines, the net ability equation was modified to include ES within the grid. This paper introduces a weighted topological method called ES net ability that considers capacity, impedance, power transfer distribution factor (PTDF), and node type. ES net ability was also compared to another centrality concept known as betweenness. Using a linear programming method based on direct current (DC) power flow, a MATLAB program was written to determine ES optimal siting for bus test systems IEEE 30, IEEE 118, and IEEE 300. The ES net ability and betweenness of each bus were calculated and compared to determine which bus has the greatest impact on ES performance and efficiency. The buses' rankings could be used to compare buses within a network to determine which node provides the greatest benefit to ES performance and the grid. The average ES net ability of each IEEE test system was calculated to determine which grid structure is best suited for ES grid structure was further broken down into different factors, such as line impedance, line capacity, number of lines per node, number of connections per node, and node location.