Design method of input voltage robust PI controller for PV interface converter

The robust stability of interface converter input voltage control is crucial for the effective implementation of MPPT control strategy under the actual working condition. A simplified design method of input voltage robust PI controller for the interface converter is proposed in this paper. Firstly, the boost converter with an input capacitor is taken as an example, and its small signal model including the dynamic equivalent circuit of PV cells is built up. Then, the relations between the stability condition of input voltage control and PV cells output resistance are analyzed. Finally, the design method of input voltage PI controller is deduced to maintain the input voltage stability within the entire operation range of input voltage and PV panel temperature. The validity of the theoretical analysis has been verified by the experiment results of a 150W/100kHz prototype.