MPPT scheme applicable to photovoltaic single peak curve
WANG Yi meng1, LI Yu ling1, WU Jian er2, WANG Guan jian1
(1.College of Electrical Engineering, Zhejiang University, Hangzhou 310058, China;
2.Hangzhou Municipal Electric Power Bureau, Hangzhou 310009, China)

Abstract: Aiming at the problem that traditional single peak PV curve MPPT method has low tracking speed and low precision, a para curve predictive power close loop maximum power point tracking (MPPT) method was proposed. By quadratic fitting, the actual power value at the stationary point of the fitting function was considered to predict and revise the position of maximum power point, making PV system work on the maximum power point. Initial points were chosen reasonably to speed up MPPT. Schematics of photovoltaic control system with MPPT were presented, and the hardware platform of DC photovoltaic system based on Buck Boost circuit was built. The algorithm proposed was implemented in experimental prototype and compared with variable step perturbation and observation method, which proved the feasibility and effectiveness of the scheme. The results indicate that the single peak MPPT scheme proposed has good performance with high tracking speed and favorable stability.

Key words: photovotaic system; maximum power point tracking (MPPT); para curve predictive; power closed loop