Analysis of voltage unbalance due to rooftop PV in low voltage residential distribution system

Due to crisis shortage of electric power, global warming issues and pressure on changing energy production from coal-fired power to renewable energy, the solar energy is becoming increasingly attractive. In Thailand, the government has approved energy department plan to increase its renewable energy target, which will include three and single phase PV installations. This paper presents a study on voltage unbalance due to the increased rooftop PV installations on low-voltage residential distribution system. The single-phase rooftop PV model is developed by Matlab/Simulink and is used in the study for analyzing the voltage unbalance under different installation ratings and locations. The obtaining results can be used as guidelines for electric distribution utilities to determine the maximum PVs installations in low-voltage residential distribution systems without affecting the power quality issues.