A Maximum Power Point Tracking Strategy Based on Self Tuning Adaptive Control for Solar Energy Harvesting Application

Abstract

According to the increasing global energy requirements and the competitions exist among the energy investors, the renewable energy sources ought to harvest maximum available energy. Thus, the control of renewable energy sources must be fulfilled such that maximum available power is extracted in various environmental conditions. Indeed, it is essential that their control system be able to transfer the operating point to the maximum power point with appropriate dynamic response and free of chattering. In this paper a two-step control strategy is proposed for solar energy harvesting. In the first step of the proposed control strategy, the maximum power point is estimated according to the voltage and the current of the cell with an acceptable accuracy. After that, the converter's duty cycle is calculated through a Sliding Mode Controller (SMC). The second step is a Self-tuning adaptive controller which applies the calculated duty cycle to the converter such that the overall control system have a proper response. As the control system operation is different in various operating points and the controller gains are dependent on the system parameters, the control gains are instantaneously tuned after the parameters identification. The proposed system simulation results confirm that this strategy is able to track the maximum power point with an acceptable accuracy. In addition, the control system has an admirable dynamic and steady-state response.