Design and Performance Analysis of a Two-Switch Forward Converter with RC Snubber for Battery Charging Applications

Two-switch forward converter (2SWFC) is widely used in power electronics, especially for battery charging applications, due to its straightforward design and high efficiency. However, hard switching in 2SWFCs can lead to large voltage spikes across the freewheeling diode (FWD) due to the transformer leakage inductance, and reverse recovery of the FWD. The spikes degrade efficiency, increase electromagnetic interference (EMI), and even cause damage to the diode. This paper presents the incorporation of an RC snubber circuit to mitigate over-voltage spikes and reduce the ringing effects caused by the reverse recovery phenomenon. As a result, the performance of the 2SWFC is improved. Further, a 30 W prototype has been designed and tested as a proof of concept, showing a 48% reduction in voltage spikes with overall improvement of the 2SWFC in battery charging applications.