Applying Control Scheme Function of PV Inverter for Minimizing Voltage Fluctuation and Imbalance with Consideration of Maximum PV Generation

At present, connections of photovoltaic (PV) systems to low-voltage (LV) distribution systems are growing rapidly because of the compliance with government policies, drop in the prices of PV technologies, and environmental awareness. Unfortunately, the high penetration of solar PV systems, which suffers from the intermittence of sunlight, leads to voltage fluctuation and voltage imbalance, thereby deteriorating the power quality. To cope with this problem, this paper proposes a control strategy of the PV inverter to improve the limiting and balancing of voltage profiles in an unbalanced, three-phase, four-wire LV distribution system. The control strategy is based on the real power limitation and the reactive power adjustment through a control scheme function that is embedded in all PV inverters for supporting high penetration of PV systems. However, real power limitation leads to less utilization of solar energy. Then, the concern on PV generation (real power) regarding voltage fluctuation and imbalance is optimally analyzed by multi-objective particle swarm optimization. The optimal solution of the control scheme function is numerically demonstrated in a modified 29-node LV distribution system. (C) 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.