Investigation on Impact of Transformer Parasitic Capacitance on Standby Power Consumption in Power Converters

The significance of reducing no-load or standby power dissipation is increasingly vital in various isolated power converter applications to save energy and meet stringent energy efficiency standards. While multiple factors contribute to this dissipation, the transformer stands out as a key contributor. But unlike transformer leakage inductance, parasitic capacitance plays a pivotal role, especially in scenarios involving high input voltage and light or no loads. This study delves into the impact of parasitic capacitance on standby power consumption through an analysis of two iterations of a custom-designed planar transformer for 400V to 15V/65W DC-DC converter employing a fly-back converter topology. The findings provide valuable insights for optimizing transformer design to reduce energy loss during standby and lightly loaded operations. This optimization not only enhances energy efficiency but also ensures adherence to stringent no-load energy conservation regulations.