ZVT-ZCT PWM DC-DC Boost Converter With Improved Efficiency With Low Current Stress
An improved active snubber cell is proposed for ZVT-ZCT PWM DC-DC boost converter. Zero voltage transition
(ZVT) turn on and zero current transition (ZCT) turn off is provided by this active snubber cell. There is no extra current or
voltage stresses on the main switch. Also, zero current switching (ZCS) turn on ZCT turn off is provided for the auxiliary
switch. Although there is no extra voltage stress on the auxiliary switch, a current stress is present. However, auxiliary
switch current stress is decreased by coupling inductance. The coupling inductance transfers the part of the current stress to
the output load according to the transform ratio. So, the converter efficiency is improved. Experimental application is proved
by 300 W prototype with 100 Khz switching frequency. As a result, improved ZVT-ZCT PWM boost converter is reached
98,8% total efficiency at full load with decreased current stress.
Key words- active snubber, ZCS, ZCT, ZVS and ZVT.