Application of User Side Energy Storage System for Power Quality Enhancement of Premium Power Park

Abstract

User-side battery energy storage systems (UESSs) are a rapidly developing form of energy storage system; however, very little attention is being paid to their application in the power quality enhancement of premium power parks, and their coordination with existing voltage sag mitigation devices. The potential of UESSs has not been fully exploited. Given the above, this paper proposes a hierarchical power supply strategy for premium power parks (PPPs) based on the coordination of UESSs and dynamic voltage restorers (DVR). Firstly, the topology and control strategy of the UESS for voltage sag mitigation are devised. Further, we construct a prototype device, and experimental tests are conducted to verify its effectiveness in voltage sag mitigation. To avoid the negative effects caused by the UESS control mode switching between the voltage sag mitigation mode and the peak-shaving and valley-filling modes—namely, the long control mode switching time and low state of charge (SOC)—a hierarchical power supply strategy is proposed. The basic idea is to supply three levels of power quality service for loads with different sensitivities in PPPs by coordinating UESS with DVR. Several cases are explored to demonstrate the feasibility of the proposed strategy.