Power balance theory based control of grid interfaced solar photovoltaic power generating system with improved power quality

This paper proposes a grid interfaced solar photovoltaic (SPV) power generating system consisting of a SPV, DC-DC boost converter, voltage source converter (VSC), interfacing inductors, ripple filter and a three phase grid feeding variety of linear and nonlinear loads. The reference grid currents are estimated by using power balance theory (PBT) to control the three-leg voltage source converter (VSC). The proposed SPV power generating system provides unity power factor, reactive power compensation for voltage regulation in a three phase distribution system. In this two stage SPV power generating system, the DC link voltage of VSC is regulated through a DC voltage PI (Proportional integral) controller and the maximum power point tracking (MPPT) is achieved using a DC-DC boost converter. The grid interfaced SPV power generating system is modeled and simulated in the MATLAB using the Simulink and the sim power system (SPS) toolboxes.