Max Power Point Tracking Using Discrete-Time Ripple Correlation Control For Photovoltaic Charging System

Along with the rapid development of human civilization, resource shortages and environmental pollution becomes progressively sever, and our planet has been overwhelmed. Renewable energy is the only solution, and has been widely used. This paper extends the previous analog Ripple Correlation Control (RCC) technique to the digital domain. With a few simplications, the RCC method is reduced to a sampling problem. If the appropriate variables are sampled at the correct times, the discrete-time RCC (DRCC) algorithm can find the optimal operating point quickly. The proposed digital implementation is less expensive, more flexible, and more robust. First, a Simulink model of the Solar Maximum Power Point Tracking (MPPT) system was built. The proposed algorithm was realized and testified in Simulink system, and results verify the high tracking accuracy and reliability of this method. Then the algorithm was applied to a photovoltaic maximum power point tracking problem. The circuit is based on a microcontroller and a Buck converter. The algorithm was implemented on an AVR MEGA32microcontroller with low power consumption, which enables an effective MPPT for a relatively small panel. Results show that the proposed digital implementation is less expensive, more flexible and more robust.