Study of photovoltaic integration impact on system stability using custom model of PV arrays integrated with PSS/E

This paper focuses on the impact of large solar plants on power systems due to rapid variation in power injection caused by various factors such as the intermittency of solar radiation, changes in temperature and tripping out of power electronic based converters connected to the system. In the first step of this research, incorporating the Maximum Power Point Tracking (MPPT) algorithm, a mathematical model of PV (Photovoltaic) array based solar plant has been developed. The model produces changes in DC power output for changes in its two inputs; (1) solar irradiance and (2) temperature. In the next step, the mathematical model is integrated with the dynamic simulation software PSS/E through user written model integration technique. The dynamic model for the inverter and the electrical controller are used from the PSS/E library. The PV plants are added to the 39-bus New England test system at three different locations. To demonstrate a high penetration of PV, the power generation from PV has been increased up to 20% and was randomly distributed between three plants. The dynamic behavior of the system was studied by changing the solar irradiance, tripping of the PV plant and by simulating a three phase fault at PV connected buses. The responses obtained from these studies indicate that vulnerability of the system increases with the increase in penetration of PV power.