The Application of FRD with Avalanche Capability for Improvement of Power Conversion Efficiency in Output Rectifier and PFC

This paper shows that power efficiency in the power supply with PFC is improved drastically by using the new FRD with high avalanche capability. Firstly the new FRD is applied to the output rectifier of 3 kW output power in order to reduce the loss of it. High frequency switching loss decreases because the new FRD has faster trr. Secondly, we apply the new FRD to the PFC circuit. In the PFC circuit, we will show that turn-on loss of switching device such as MOSFET is dominant. The new FRD enables -di/dt condition to be high, then the total loss is reduced. For PFC loss reduction, it is important that MOSFET turn-on loss and FRD recovery loss have the adequate balance so as to make the total loss minimum. As the result of the above application, we achieve a great improvement of total power efficiency in the power supply from 86.5% to about 90%. We propose that this technology is one of the efficiency improvement methods and is effective in prevention of global warming.