A Two Stage DC-DC Converter with Isolation for Renewable Energy Applications

In this work, the design and development of a DC-DC Converter using a two stage buck-boost operation is discussed. This converter is suitable for low power application such as a matrix LED lighting system. The advantage of this converter is that instead of using two controlled switches as in case of a conventional converter, this circuit uses one MOSFET as a switch. The circuit uses two inductors and two capacitors as energy transferring elements that are able to provide a good quality, high efficiency power supply to the load. The design of TSBB converter is analyzed with closed loop control using a PI controller circuit. Even with smaller values of inductor and capacitor a highly efficient power supply can be made. The main feature of this circuit compared to the other circuits proposed previously is that have a galvanic isolation between the load and the source is provided. Thus, by a suitable controller and galvanic isolation, the ripple magnitude in the output is reduced considerably. A simulation model of the TSBB converter with results is presented.