DC converter design for a DC direct use. Case study solar powered irrigation system at Kabuga, Rwanda

Abstract

A DC-DC booster converter for PV DC direct use was designed within research. A desired voltage of 48V as output from the converter is needed to drive a 0.5hp,10 A Dc water pump for irrigation. The converter input supply is from the PV system, which was designed and calculated dependent on the Rwandan atmosphere and sun oriented conditions. The chosen site for the contextual analysis is found at Kabuga, Gasabo, Kigali where a minimum solar insolation at this site is 4.54kwh/m2. Selection of component used in this design by looking at the type of the materials was taken into the consideration as a way of ensuring that the converter is providing the maximum efficiency. Polypropylene film capacitor was used at the output to increase the lifetime of the converter due to its good properties like self-healing, diode selection was based on the reverse recovery time in the spirit of avoiding and reducing the reverse conduction losses. The type of switch used is IGBT because of its lower state voltage drop, easy control and the range of frequency the converter is switching on which is 30KHZ in this work. Voltage control was applied to adjust the voltage output from the DC to DC converter, where PID was the technique employed. Simulation and analysis proved that the output voltage was following the controlled reference given to it despite the fluctuation of the input voltage due to the solar insolation level hence providing a required output voltage to the load