采用次级辅助网络的零压零流PWM三电平变换器

该文提出一种新型的ZVZCSPWMTL直流变换器，在变压器的次级侧增加一个辅助绕组，其辅助电压为滞后管创造零电流条件，较好地解决了滞后管轻载下软开关难的问题。新的主电路拓扑减小了功率器件的电压应力。辅助电路没有使用有源开关和有损元件，具有简单高效低成本的优点，特别适用于高电压大功率的场合。该文分析了该变换器各时段的工作原理，并提供了设计参考和实验结果(4kw实验样机)。

A ZVZCS PWM TL CONVERTER USING AUXILIARY NETWORK IN TRANSFORMER SECONDARY SIDE

A novel zero-voltage and zero-current-switching (ZVZCS) PWM three-level converter is proposed, which introduces an auxiliary Winding in transformer secondary side. The voltage of auxiliary Winding provides ZCS condition for lagging switches. The problem that soft switching of lagging switches is difficult to be achieved at light load is resolved very well in the new circuit topology and voltage stress of power devices is reduced when input voltage is high. An auxiliary circuit includes neither loss component nor active switches . This new converter has many advantages such as simple circuit topology , high efficiency and low cost make it attractivefor high capacity power and high voltage applications. The operation principle during each periodof time is analyzed, design considerations and experi-mental results are presented 4kW prototype of converter).