Renewable energy-powered DC-converted refrigerator based on a supercapacitor-assisted technique

In six ICDCM conferences, the value of future DC systems, and DC homes for reducing losses in our electrical systems was discussed indicating the need for a DC-based future. DC outputs from renewable sources contribute to reducing CO2 emissions and lowering electrical energy consumption. In modern white goods, internal circuits are based on DC power rails derived from AC mains followed by a rectifier. Powering AC households from renewable requires maximum power point tracking based on battery chargers and inverters. End-to-end efficiency is related to the number of individual converters inside an equipment. Here we describe a low-frequency supercapacitor-assisted converter system coupled with an "inverter-driven" refrigerator converted to DC operation by eliminating the rectifiers. With this modification, whiteware becomes more tolerant of variable DC sources, allowing continuous operation without battery buffers in solar or wind energy systems. A modified 230 V, 50 Hz refrigerator for DC operation was connected with a supercapacitor module rated at 110 V DC, allowing it to run directly from a renewable source and eliminating the need for battery buffering. This is another supercapacitor-assisted technique based on the relatively new supercapacitor-assisted loss management concept and it eliminates the requirement for electromagnetic compatibility filtering.