桥式直接交交斩波变换器及换流策略研究

为解决交流斩波功率变换器中双向全控电力电子开关结构复杂、换流过程繁琐的问题,研究了一种新颖的桥式直接交交斩波变换器,并提出了与之相适应的非互补控制换流策略。首先通过改进变换器结构和功率流向,取代了单管组合式双向全控开关的设计方案,简化了多路驱动电路间的隔离设计,使线路分布参数的影响较小,开关器件与驱动电路的一致性好,成本降低。换流策略设计了有源、续流和死区3种工作模式以及多种性质负载条件下的换流路径,消除了输出电压失控区间,且不使用电流极性检测环节。最后设计了功能样机,在多种负载条件下进行了性能测试。实验结果验证了方案的有效性。

Research on Bridge Type Direct AC/AC Chopper Converter and Its Commutation Strategy

In order to simplify the design of bidirectional power switches, a new design of direct AC/AC chopper power converter which adopts intelligent power module to do power conversion is proposed. Through the improvement of the circuit design, electrical isolation unit is not necessary in driver circuits of the chopper switches. A novel type non-complementary control commutation strategy is designed. The proposed commutation strategy adopts power source voltage polarity control method and do not need current polarity detection unit which must be used in the traditional commutation strategy. The commutation process and output voltage control method are disscussed. In experiment, different load are used to test the validity of the proposed plan. The power converter efficiency with different duty ratio is also analyzed. Compared with traditional AC chopper design, the proposed converter has simplified driver circuits design, high system reliability, low cost and provide favorable conditions for wide application.