Design and Development of a Low-Cost Malaysian Charge Controller for Commercial Standalone Photovoltaic Power Systems

A photovoltaic system consists of an array of solar cells in addition to a number of other system components. Since the PV modules do not generate electricity during the night time, the most obvious solution is to store the daytime energy generation so that it can be tapped whenever needed. This can be achieved by using storage batteries that are often integrated into the system. However a management system/unit is needed to achieve an optimum balance between the three, vis-à-vis the solar generator, the battery and the load. This management unit often comes in the form of a charge controller: which acts like a brain of the system. Besides controlling the charging and discharging of the battery, which also protects them, the functions of the controller include switching loads, monitoring system performance and give warnings when the system is not working properly. This paper presents a charge controller that is indigenously designed, fabricated and tested under Malaysian climate. The paper presents and discusses the principles, circuit design and results from field testing of the controller. The controller presented in this paper is based on a simple ON-OFF concept, while offers monitoring capabilities, often absent in many commercial controllers.