Cooperative Control for Mitigation of Voltage Fluctuations in Power Distribution Systems

Distributed generators (DGs), especially inverter based renewable generation sources, are becoming prevalent in power distribution grids to meet increasing demand and harness renewable energy. However, DGs of intermittent nature such as solar power can lead to significant voltage fluctuations. Traditional mechanical voltage regulating equipment such as on-load tap changers (OLTCs) and capacitor banks (CBs) are unable to handle these fast-changing fluctuations. This paper proposes a new optimal cooperative control-based method for controlling DG inverters to adjust reactive power generation or consumption of DGs. The optimization is based on local information and the information received from other nodes with or without reactive power sources. The objective function is to minimize voltage fluctuation and reactive power output since additional reactive power output could cause accelerated aging of inverters. Results based on simulation studies have shown that the proposed method can achieve smoother voltage profiles.