New effective PV battery charging algorithms

Abstract

Energy security and independence is one of the most growing concerns around the globe, combined with the environmental impact of traditional energy sources, renewable energy systems have become of great importance. Photovoltaic (PV) systems are the most popular form of renewable energy, as price have become reasonable, and deployment is scalable. However, in many schemes, PV systems require rechargeable batteries for energy storage, and increased system dependability. In this paper a numerical solution and two new control methodologies are proposed for effective battery charging from PV systems.The first method is a modified single stage charge controller with a new maximum power point tracking (MPPT) algorithm. This method uses the battery voltage as a feed-forward term while optimizing the duty cycle of the converter to maximize the output power harvested from the PV cell.The second method is a modified two stage charge controller. The proposed approach optimizes the duty cycle of the second converter, which includes maximum power passage and maximum current into the battery.The main contribution of the proposed methods, is that the dynamic models of both the battery and the PV cell are taken into consideration, this greatly increases overall system efficiency.