Voltage imbalance compensation by injecting active and reactive power using demand side inverter

In recent years, the increased use of renewable energy sources (especially photovoltaic (PV) systems) has been remarkable, and use is growing because of considerations for environmental problems. However, renewable energy sources dependent on weather conditions, such as PV systems, cause output power fluctuations. In an electric distribution system, many PV systems are connected with distribution lines, and PV systems generate unstable power and inject unbalanced power to each line. Therefore, it is possible for voltage imbalance to occur in three-phase distribution systems. In this paper, we propose a method of voltage imbalance compensation by injecting active and reactive power using inverters in Power Conditioning Systems connected to smart houses. If voltage imbalance compensation is executed considering only the distribution voltage, there is a concern that the voltage at the power receiving end will deviate. Therefore, the optimum quantity of power injection is decided depending on the proper rate of both the distribution voltage and the receiving voltage. The effectiveness of the proposed method is verified by simulation results in the MATLAB /SimPowerSystems environment.