软开关PWM三电平直流变换器的控制策略

系统地提出PWM三电平直流变换器的一族共九种控制方式，根据一对开关管中两只开关管的关断情况，将这九种控制方式归纳出两类开关切换方式。引入超前管和滞后管的概念，提出它们实现软开关的方式，然后将软开关PWM三电平直流变换器归纳为零电压开关和零电压/零电流开关两类，并分别指出适合它们的控制策略。提出在零状态电流复位的方法，并提出几种零电压/零电流开关的电路拓扑。

Control Strategies of Soft-Switching PWM Three-Level Converters

A family of control strategies including nine control strategies for PWM three-level (TL) converters is proposed. The control strategies can be classified into two kinds according to the turn-off sequence of the two switches of the pair switches. The concept of leading and lagging switches is introduced to realize soft-switching for PWM TL converters. The realization on soft-switching for both leading and lagging switches is proposed, soft-switching PWM TL converters can be classified into two kinds: zero-voltage-switching (ZVS) and zero-voltage and zero-current-switching (ZVZCS), The suitable control strategies are pointed out from the family of control strategies respectively. The current reset strategy is proposed based on several ZVZCS TL converters proposed.