Suppression of Voltage Spikes in Full-Bridge Push-Pull Bidirectional DC/DC Converters Using Active Clamp Circuits

This paper investigates the mechanisms for generating low-side voltage spikes in a full-bridge push-pull bidirectional DC/DC converter in both the buck and boost modes, as well as their suppression methods. Simulation analysis reveals that voltage spikes increase the voltage stress on the low-side switch, reduce efficiency, and cause severe electromagnetic interference. To effectively suppress voltage spikes, this paper proposes an active clamp circuit. By comparing the simulation results of various suppression schemes, the superiority of the active clamp circuit in mitigating voltage spikes is demonstrated. Experimental results show that a well-designed closed-loop control parameter enables the active clamp circuit to significantly reduce voltage spikes in both operating modes without introducing additional energy loss, thereby enhancing the system’s operational stability and efficiency.