The scheme of realizing soft - switching can be found , at the same tune , the concepts of the leading switches and the lagging switches are presented . two kinds of soft - switching methods , zero - voltage - switching ( zvs ) and zero - voltage and zero - current - switching ( zvzcs ) , can be classified on the base of realizing soft - switching of the lagging switches 在对其控制策略的研究中,找出了可以实现软开关的方案;同时提出了超前管和滞后管的概念,根据滞后管实现软开关的方式,将变换器的软开关方式分为两类:零电压开关方式和零电压零电流开关方式。