Design approach for Supercapacitor Assisted LED lighting (SCALED) technique for DC-microgrids

Energy efficiency is a main requirement in power converters used in domestic electrical goods including lighting. Using DC at home and DC-microgrids are relatively new concepts proposed to overcome the problems with energy efficiency. DC-microgrids are local energy networks which consist of renewable energy sources and storage systems. In many modern white goods, typically advertised as inverter driven, there is an AC-DC converter in the power drive train starting from AC 230V, 50Hz. Most domestic white goods, including energy efficient lighting are internally DC-driven and based on multiple DC-DC converters. Overall efficiency of a domestic appliance is determined by the multiplication of the efficiencies in each conversion stage. If the first stage of AC-DC conversion is not used, by feeding it from a DC source such as solar energy, end-to-end efficiency (ETEE) will be increased. Energy engineers are now getting ready to use DC-microgrid techniques. In this project where LED lighting loads are to be fed by solar or other renewable energy DC sources, 12V LED lighting is an excellent starting point, since LED lamps operate from plus or minus DC sources of widely varying DC values. We are developing a new technique, Supercapacitor Assisted LED (SCALED) lighting system powered by DC bus fed directly from solar panels, in which a supercapacitor (SC) bank is to be used to buffer short-term energy supply interruptions. This project derives from the patented SCALDO technique.