Compensation Loop Design of a Photovoltaic System Based on Constant Voltage MPPT

This paper presents an approach to design a high performance compensation loop for a photovoltaic system based on constant voltage (CV) maximum power point tracking (MPPT) method, which is quite different from that of common DC/DC converter. The dynamic model of the power module, which is implemented by a Buck converter, is established using switch average model. Based on the analysis of the dynamic model, a PID controller is designed to compensate the loop. Wide phase margin, amplitude margin and bandwidth are achieved by introducing the compensation stage. Finally, the performance of the photovoltaic system with and without compensation is simulated and compared using Cadence Spectre.