PEREE ZVT PWM converter Circuit VD VLr Equivalent circuit during t, -t2 L VD to t,Power Electron cs i 20 ZVT PWM converter ZVT PWM converter Circuit Circuit L S Cr S1 Lr VD1 VD Ui C + Uo IL iLr iVD VDS R Equivalent circuit during t1 ~ t2 S S1 uS iLr iS1 uS1 i D i S IL t 0 t 1 t 2 t 3 t 4 t 5 t t t t t t t t O O O O O O O O L S1 Lr iLr Ui IL C VD r S