Optimal coordination control for stand-alone PV system with nonlinear load

This paper presents a stand-alone photovoltaic system with Ni-Mh battery serving as its energy storage element. The proposed system is composed of a boost converter, a bidirectional DC/DC converter and a single-phase DC/AC inverter. The boost converter is used to track the maximum power point of the solar panel whereas the bidirectional DC/DC converter is applied to maintain the DC-link voltage stable through battery charging or discharging, and the inverter is to provide high quality AC voltage for local load. Nonlinear load is considered to verify the universality and robustness of the control scheme. Optimal coordination control schemes for these three converters are proposed to harness maximum energy and guarantee both DC and AC voltages. Using MATLAB SIMULINK, the simulation model of the isolated PV system with the proposed control schemes is created, and the performance of the coordinated control strategies is confirmed.