Testing Maximum Power Point Tracking Controller for PV System

Abstract

Recently, the demand for renewable energy sources, in particular solar, has been increasing. This is due to declining demand for other fuels due to the poor reputation, waste of nuclear energy and limited fossil resources such as coal. The growing popularity of silicon significantly reduces the cost and increases the availability of solar energy. The main technique of increasing efficiency of the converter is to find maximum power point tracking (MPPT) that addressing problem of efficiency of power transfer from the solar cell depends on both the amount of sunlight falling on the solar panels and the electrical characteristics of the load. As the amount of sunlight varies, the load characteristic that gives the highest power transfer efficiency changes, so that the efficiency of the system is optimized when the load characteristic changes to keep the power transfer at highest efficiency. This load characteristic is called the maximum power point and MPPT is the process of finding this point and keeping the load characteristic there. Electrical circuits can be designed to present arbitrary loads to the photovoltaic cells and then convert the voltage, current, or frequency to suit other devices or systems, and MPPT solves the problem of choosing the best load to be presented to the cells in order to get the most usable power out.This article considers the construction of MPPT controller of solar panel, which must operate at up to 60W power of solar panel and up to 30V of output battery voltage. Given the structure of the system and the necessary operating parameters, for its construction it is necessary to take into account various circuit solutions for the power unit, as well as methods for finding the point of maximum power for the control circuit.The design and construction of the MPPT controller of the photovoltaic system and testing for different irradiation values is considered. Various circuit design solutions and algorithms for the operation of the MPPT controller were analyzed and a two-switch buck-boost circuit and a perturb and observe algorithm were selected. After making the system task is at general checking of possible operating in a given range of current and voltage, as well as the ability to respond to changes in current and voltage values and some external conditions that directly affect the work of a solar panel. The algorithm of work, formulas for emulation and an example of system work were given. The algorithm of work, formulas for emulation and an example of system work were given. The time diagrams of the control signals of the transistors at the time of switching from buck mode to boost mode are shown. A step-by-step description of the changes that occur in the system during the change of parameters and how the feedback stabilizes the operation of the device to maintain the maximum power of the system.After the developed experiment, the workability of the layout was checked and various variants of operation of the device for different lighting conditions were simulated. A conclusion was drawn on the potential for further development of the proposed solution. The circuit used operates at a given power and the proposed idea has the potential for further development and experimenting.