Optimization of ESS Based Damping Control Using Electric Torque Method

As smart-grid technology develops, the energy storage system (ESS) is widely used. By controlling exchange of either active or reactive power between ESS and power system, power system's damping and dynamic performance can be improved. Aiming at meeting the requirements of online applications of Wide-Area damping control, this paper adopts Electric torque analysis (ETA) to realize the analysis of small signal stability of power system. Based on the two-machine equivalent system, this paper explores the definition of the ETA method, as well as its mathematic relationship with the MA method, and the condition of stability. An online optimization scheme of ESS is presented, which is based on damping control, to maximize the damping torque coefficient with the synchronizing torque restraint. Finally, the paper uses a 4-machine-2-area benchmark to verify the effectiveness and superiority of the proposed optimization method.