Three-Phase Probabilistic Power Flow in Distribution System with Grid-Connected Photovoltaic Systems

This paper analyzes a method of three-phase probabilistic power flow in unbalanced radial distribution system with single-phase and three-phase grid-connected photovoltaic (PV) systems using sequential Monte Carlo techniques. The output power of grid-connected PV system is simulated for each hour, considering the solar irradiance with random variation of weather, the effect of shadow, the conversion efficiency´s change of the photovoltaic arrays with time, the efficiency of PV inverter and the reliability of the overall photovoltaic system. Then the time-varying load model with randomness is incorporated in the probabilistic power flow and a program has been developed based on the method. At last, two cases have been implemented to verify the applicability of the method by giving the probability of voltages beyond limit for each hour in one day.