An improved MPPT control strategy based on incremental conductance method

Abstract

Photovoltaic cells efficiency can be effectively improved by maximum power point tracking (MPPT) technology. An improved MPPT control strategy is proposed to solve the current problems of poor convergence speed and accuracy of incremental conductance method. In this method, the P–U characteristic curve is divided into three sections: non-MPP sections, MPP-like section and MPP sections. In the non-MPP section, the constant voltage method is adopted to reduce the tracking time. In the MPP-like section, the incremental conductance method is adopted and its step size is improved, which effectively reduces the tracking time. In MPP section, particle swarm algorithm is adopted to improve tracking accuracy. Taking light intensity and temperature variation as examples, the proposed method and the traditional method are simulated respectively. Simulation results show that compared with the constant voltage method, the accuracy can be improved by more than 4% when the temperature or light intensity is changed, while maintaining the tracking speed. Compared with the traditional incremental conductivity method, the method can reduce the tracking time by 33% and improve the tracking accuracy by 1% when the light intensity or temperature changes.