Abstract:For the current MPPT control strategy that adopts single step size tracking, there is a problem that the difference in step size selection cannot obtain the system dynamic performance and steady-state accuracy simultaneously. In this paper, an improved MPPT control strategy combining constant voltage startup method and double exponential function step size algorithm is proposed. When starting up, the constant voltage method is used to locate the maximum power point (MPP) quickly, and then the double exponential function is used to change the step size and accurately track the PV maximum power point. The function characteristics of the two exponential functions are used to adjust the step size superposition on both sides of MPP in real time, so as to further optimize the tracking effect of variable step size. Finally, a comparative analysis is carried out in MATLAB/Simulink, and the results verify that the proposed algorithm is effective in improving the speediness of photovoltaic MPPT and reducing the steady-state fluctuation.