A DC-DC converter suitable for controlling a photovoltaic powered pumping system

A photovoltaic powered pumping system offers an attractive means of supplying fresh water in remote areas not serviced by a utility grid. In order to extract the maximum amount of energy from the solar panels, it is necessary to match the characteristics of the photovoltaic array to the DC motor which drives a pump. A one quadrant DC-DC converter is capable of adjusting the effective load impedance for maximum power transfer under most lighting conditions. Three styles of DC-DC converters used to control the pumping system are described and compared. The voltage tracking style of converter fixes the array voltage at a level considered optimum. The power tracking converter measures, and attempts to maximize, the output power of the photovoltaic array. The microprocessor based power tracking, voltage tracking converter toggles between the two methods of control. Experimental results are included.Applied Science, Faculty ofElectrical and Computer Engineering, Department ofGraduat