Utilization of Electrochemical Energy Storage System with External Characteristics of Voltage Source for Independent Voltage Support in Power Systems

The increasing penetration of renewable energies poses a threat to the voltage stability of power system. Energy storage technology can be utilized for voltage support in the power system with high proportion of renewables. The external characteristic of traditional energy storage system (ESS) performs as a current source, which only passively responds to the variations in power system after disturbance. In this paper, the model of electrochemical energy storage system with external characteristics of the voltage source is proposed. The control strategies of ESS are established based on the virtual synchronous generator (VSG) algorithm, in order to emulate the electromotive force and inertia of traditional synchronous generator. Application results of a practical power system in Northwest China show that the proposed model can provide independently voltage support, and effectively improve the consumption and delivery capacity of renewable energies.