Sensitivity analysis of radially distributed power system under random penetration of photovoltaic generation

In this paper, we aim to analyze the characteristics of voltage variation in power systems with random integration of Photovoltaic(PV) systems, investigate the dangerous PV placement pattern along a specific power system, and search for the optimal control scheme for voltage regulation in such system. We conducted the investigation of voltage variation on a radial distribution circuit with a random integration of certain amount of PV systems. The results of voltage variation showed that severe variation of voltage due to PV penetration mostly occurs around the tail part of circuit lines, and the root part of the lateral circuit lines tend to rise near to or exceed voltage permitted range easily. Since several previous studies have regarded local inverter reactive power control as important to regulate voltage deviation of PV interconnected power systems, to begin with the study about the optimal voltage control problem, we compared the effectiveness of several proposed inverter reactive power control schemes for voltage variation. The smoothed switching mode of reactive power control method maintained voltage within permitted range, although the results of voltage deviation were still higher than the voltage of non-PV integrated power system.