Detailed Simulation Model of an Asymmetrical Half-Bridge PWM Converter with Synchronous Rectification including Parasitic Elements

The asymmetrical half-bridge converter implemented with GaN-switches represents a great candidate for achieving high power density and high efficiency. These requirements call for the implementation of a synchronous rectifier on the secondary side to push the efficiency. Furthermore, higher switching frequencies lead to smaller passive components needed for compact power supplies. In order to gain accurate and reliable simulation results for these high switching frequencies, this paper presents a detailed simulation model featuring parasitics of all semiconductors and transformer capacitances. Besides current and voltage waveforms of one switching cycle, this model allows for studying ZVS transitions as well. Measurements on a practical test setup deliver waveforms very close to the simulation results and thus prove the validity of the simulation model.