Abstract:

According to the optimized characteristics of solar cells, we  get the engineering equation model, and the MATLAB/SIMULINK simulation model is established. The simulation results are analyzed simply, mostly the VI characteristics and VP characteristics of solar cells under standard parameters, and the characteristics of change under different temperature and light intensity conditions. The paper introduces the principle of the maximum power point tracking(MPPT), and uses the perturbation and observation(P&O) to perform fixedstep simulations and analyses the results. We propose a variablestep algorithm based on fuzzy control, and design a fuzzy controller by the fuzzy toolbox of the MATLAB software. The simulation results show that, the maximum power point can be stabilized and can avoid the maximum power point shock in fixed perturbation and observation(P&O) . It is able to find a new maximum power point quickly when the environmental parameters change and the results demonstrate its excellent tracking performance.

Key words: maximum power point tracking (MPPT);fuzzy control;variablestep