Development of two stage buck-boost converter for solar PV based rural domestic water purifier

Renewable or sustainable energy sources such as photovoltaic (PV) cells usually generate variable power. The dc voltage obtained from PV system is boosted/bucked double times and used for renewable energy applications. This work proposes the design and development of a DC-DC Converter for a double buck-boost operation. This converter is suitable for low power application such as a solar water purifier system. The advantage of this converter is that instead of using two controlled switches as in case of a conventional converter, this circuit uses only one MOSFET as a switch. The circuit posses two inductors and two capacitors as energy transferring elements that are able to provide a good quality, high efficiency power supply to the load. In this paper the design of DBB converter is analyzed with closed loop control using a PI controller circuit. A simulation model of the DBB converter with results is presented. And the output of the DBB converter is given to the power supply unit of an electric water purifier and water is purified.