Design and implementation of a 140W charge regulator

Different kind of devices have been developed for matching photovoltaic generators to their loads. They range from simple and less efficient linear regulators, to more complex power electronic based converters. Therefore, based on the requirements of the system, more efforts should be focused on the design of the converter that links the PV generator to the load, in addition new and more sophisticated control strategies must be added into the system. Undoubtedly, energy storage system is one of the systems that require more efficiency at the conversion stage as well as adequate algorithms and control strategies, for ensuring long lasting at the energy storage device. In particular, the process of charging a battery requires a determinate number of stages, for ensuring long-life for the battery. At this paper, is exposed the design process of a 140W regulator for a battery based energy storage system. The regulator designed is a SEPIC converter that guarantees high efficiency under a wide range of operation. Additionally, the power converter is governed by a maximum power point tracking algorithm (MPPT) and control strategies that ensure an adequate process of charge for the batteries. Besides, a software tool was proposed for supervising the different stages of the charge as well as the complete energy storage system. The system was implemented and tested experimentally in order to verify the behavior under each stage of the battery charging process.