DCM Forward-Flyback converter with Cockcroft-Walton Voltage Multiplier: steady-state analysis considering the influence of the parasitic capacitances at very low power and very high voltage gain

Abstract

Electrohydrodynamic (EHD) cooling systems are becoming a feasible solution to replace rotary fans from electronic products, leading to more robust solutions with lower weight. High voltage power supplies are an essential part of the system. In general, EHD loads require very low current to produce the corona discharge and the air flow [1]. The Forward-Flyback converter with Cockcroft-Walton Voltage Multiplier (FF-CWVM) is presented in this paper as a suitable candidate to supply an EHD load. Under very low power (1.5W) and high voltage gain (1:250) conditions, the FF-CWVM is very sensitive to the influence of the parasitic capacitances, leading to new operation stages. Then, the steady-state operation of the converter is analyzed and the most representative equivalent circuits and waveforms are presented. Finally, the theoretical analysis is validated with simulation and experimental results and the importance of achieving ZVS is highlighted.