Analytical Determination of the Control Parameters for a Large Photovoltaic Generator Embedded in a Grid System

It appears that, until now, no work has been reported on evaluating the operational impacts of large photovoltaic generators (PVGs) embedded in a high-voltage grid system. To meet this goal, the authors have proposed in this paper that the pulsewidth-modulated inverter that interfaces a PVG with a grid Bus be modelled in terms of its control parameters in the load flow analysis. This will then provide a direct answer as how to control a PVG and what will be the real and reactive power, and voltage at the interfacing and other grid Buses. For this it is necessary to predetermine the PVG inverter control parameters for a given steady state, i.e., given insolation (incoming solar radiation) and system load. So an analytical method for this predetermination has been proposed considering the available insolation and the boundary conditions of the interfacing grid Bus. Also the way the impact evaluation using the control parameters incorporated load flow analysis is made has been shown for two test systems having different characteristics. The proposed method being very fast can be applied for setting in real-time the control parameters for inverters of large PVGs embedded in a conventional power system.