Overvoltage mitigation using coordinated control of demand response and grid-tied photovoltaics

Overvoltages in low voltage distribution grids with high solar photovoltaic (PV) integration are usually alleviated by implementing various active/reactive power control techniques. As those methods create revenue loss or inverter cost increase to PV owners, a coordinated control of load demand and the PVs, considering electric vehicles (EVs) as potential demand response resource, is proposed in this study to alleviate the overvoltages. A two-stage control is designed to comprehend the proposed coordinated control such that a centralized stage periodically determines optimum operating set-points for PVs/EVs and a decentralized stage adaptively control the PVs/EVs in real-time. To demonstrate effectiveness of the proposed approach, simulations are performed in a typical 0.4 kV/400 kVA Danish distribution network containing 45 detached residential consumers. The presented method demonstrates better technical performance by effectively mitigating the overvoltages and improved economic performance by efficiently utilizing the PV power. For the given configuration and market structure, the presented method demonstrated 19.23% increment on PV power revenue and 25.73% decrement on EV charging cost.