A Novel Family of Class EFnm and E/Fnm Inverter for Improved Efficiency

Abstract

The enhanced class E configurations (EF n and E/F n ) are proposed to counter the high peak switch voltage issue in conventional class E inverter along with an improved stability and augmented load regulation feature. Despite these advantages, the class EF n and E/F n inverters demonstrate a lowered efficiency particularly at higher duty ratios and light loading conditions. The later also affect the stability of the inverter in the entire operating range. To counter the aforementioned issues, this paper proposes a novel family of class EF nm and E/F nm inverters. Two auxiliary resonant networks tuned at nth and mth harmonics of the primary resonant frequency are implemented. The auxiliary networks, configured across the switch and the primary resonant network, delivers the power to the secondary through a multiwinding transformer built in a single core to reduce power loss, space and cost. Consequently, the inverter becomes capable of providing lowered switch voltage and higher efficiency simultaneously. The designed converter is simulated in LTSPICE. A prototype is also built and tested to verify the theoretical design and simulation results. It is observed that the simulation results concur with the theoretical design. Also, the performance parameters are recorded for the designed inverter family.