Light Load Efficiency Improvement in Variable DC-link Voltage Inverter Systems for Home Appliances

This paper describes an efficiency improvement scheme in variable dc-link voltage inverter systems for home appliances and especially focuses on the light load operating area. Although, variable dc-link voltage according to the load could improve the efficiency of inverter, it can cause complex operation and low efficiency of PFC circuit. Therefore, in this paper buck boost selective control scheme is proposed to increase the efficiency of PFC circuit under low dc-link voltage. The validity of the proposed scheme is verified by 2.2kW dynamo system and maximum 6.5% system efficiency improvement could be achieved. KCI Citation Count: 1