Investigation of Power Converter Topologies for Standalone DC System

Abstract

The power distribution system, mainly powered by the utility grid, is under more strain due to constant rise in load demand. This conventional distribution system will cater to DC load at the end of the power chain. However, there are several power conversion stages involved before generating a DC output.Consequently, there will be power loss at various conversion points. Therefore,to address this situation, a standalone DC system using solar and wind energysources together is suitable solution to cater for the DC load demand.The solar and wind energy are known to be complementary in nature. However,combining these sources together necessitates use of appropriate power converters. In recent years, many researchers have put forth the numerous power conversion methods with these sources. These conversion stages comprises with the qualities of reliability and simplicity in operation. Therefore, various efforts have been laid in these directions to reduce the intermediateconversion stages and to ensure the reliability of hybrid input energy supply at the load side. In pursuance of overcoming the redundancy involved in the conversion stages, a PV-wind sources based single stage hybrid power converter has been proposed that takes into consideration the concurrent conversion processes of wind sources and solar sources power together to the supply load demand simultaneously. In this work, primary focus is laid down on the design and development of this hybrid input based power converter. The converter aspects of operating principle and operational modes have been discussed to bring out the operational merit over the other existing hybrid system structures in standalone system. The comprehensive control strategies and appropriate PWM scheme for performing simultaneous conversion processes has been discussed. Further, the operational aspects of the proposed converter is verified through simulation case studies. In addition, a laboratory prototype power converter is developed and operational aspects are validated through experimental case studies. Lastly, with regard to the simulation and experimental results, it canbe stated that the proposed hybrid power converter offering the single stage circuitry is suitable for PV-wind sources based standalone DC system.