Novel bidirectional snubberless naturally clamped ZCS current-fed full-bridge voltage doubler: Analysis, design, and experimental results

This paper presents a novel soft-switching bidirectional snubberless current-fed full-bridge voltage doubler. A novel secondary modulation technique is proposed to clamp the voltage across the primary side switches naturally with zero current commutation (ZCC). It, therefore, eliminates the necessity for active-clamping or passive snubbers to absorb the switch turn-off voltage spike, a major challenge in current-fed converters. Zero-current switching (ZCS) of primary side devices and zero-voltage switching (ZVS) of secondary side devices are achieved, which significantly reduce switching losses. Primary device voltage is clamped at low voltage, which enables the use of low voltage devices with low on-state resistance. Soft-switching and voltage-clamping is inherent and load independent. Analysis and design of proposed topology are presented. Simulation results using PSIM 9.0.4 are shown to verify the accuracy of the proposed analysis and design. A 250 W prototype has been tested to validate its performance.