Combined Tracking of the Maximum Power and Maximum Efficiency Operating Points for Real-Time Maximization of the Energy Production of PV Systems

Abstract

The power production of a photovoltaic (PV) system can be maximized by applying a global maximum power point tracking (MPPT) method for ensuring that the PV array operates at the global MPP where its power production is maximized and, simultaneously, by dynamically maximizing the efficiency of the power converter that interfaces the PV-generated energy to the energy storage devices or the electric grid. In this paper, a new control method has been presented for the real-time maximization of the power production of PV systems by modifying in real time the duty cycle and switching frequency of the power converter PWM control signal. The proposed method has the advantage that it can be applied in PV systems operating under partial shading conditions. Also, knowledge of either the operational characteristics and configuration of the PV modules within the PV array or the power converter operational characteristics, is not required for its application. The experimental results validated that by using the proposed method, the power production of the PV system is increased significantly compared to the case that only the power production of the PV array is maximized by using a global MPPT technique without tracking the optimal value of the power converter efficiency.