Centralized control of step voltage regulators and energy storage system under high photovoltaic penetration

Abstract

The penetration level of distributed energy resources (DERs) especially photovoltaic (PV) system is envisioned to keep on increasing in future distribution grid. Current step voltage regulators (SVRs) equipped with local controls such as line drop compensation (LDC) will experience the increased tap operation in the presence of PV system particularly on a cloudy day. This operational stress will increase the annual maintenance cost and reduce the lifespan of SVRs. To cope with this issue, current volt/VAR control (VVC) schemes need to integrate additional control equipment and adopt different coordinated control schemes. This paper proposes a centralized coordinated control scheme to reduce the SVRs' operational burden by contributing towards voltage support. The centralized coordinated control is ensured by integrating SVRs and battery energy storage system (BESS) into the smart distribution management system (DMS). Particle swarm optimization (PSO) has reduced the tap operation and optimized the charging and discharging operations of BESS. Simulation studies are conducted using modified quasi-static time-series IEEE 34-bus test feeder. The PSO is implemented in MATLAB while DigSILENT PowerFactory is used for quasi-dynamic simulations. Results indicate the effectiveness of BESS in voltage support and considerable decline in operational cost.