有源钳位正激二次侧谐振PWM Buck-Boost型变换器

Active Clamp Forward Secondary Side Resonant Buck-Boost PWM Converter

针对传统有源钳位正激(ACF)变换器存在输出二极管反向恢复损耗,以及轻载时不能实现软开关的问题,提出了ACF二次侧谐振(SSR)PWM(ACF-SSR-PWM)Buck-Boost型变换器,分析了ACF-SSR-PWM Buck-Boost型变换器的工作模式及其稳态特性。分析结果表明:ACF-SSR-PWM Buck-Boost型变换器可以在全负载范围内实现主开关管、辅助开关管的零电压开通(ZVS)和输出二极管的零电流关断(ZCS),其电压传输比与负载、开关频率和占空比无关,呈现出DC-DC变压器(DCX)的工作特性。与二次侧谐振ACF变换器相比,ACF-SSR-PWM Buck-Boost型变换器减小了辅助开关管的电流应力和主开关管的关断电流。最后,搭建了一台200V输入、50V/1.6A输出的实验装置,验证了理论分析的正确性。

Due to the reverse recovery loss of output diode and the difficulty to satisfy soft switching condition of traditional active-clamp forward(ACF) converter under light load condition, a secondary side resonant(SSR) PWM ACF converter is proposed in this paper. Its operation modes and steady state characteristics are analyzed. The analysis results show that ACF-RPWM Buck-Boost-type converter exhibits the characteristics of DC-DC transformer(DCX) with its DC voltage conversion ratio independent of load, switching frequency and duty ratios. The proposed ACF-SSR-PWM Buck-Boost-type converter can realize zero-voltage turn-on switching(ZVS) of switches in the full load range and zero-current turn-off switching(ZCS) of the diode. Compared with traditional secondary resonant ACF converter, ACF-SSR-PWM Buck-Boost type converter has reduced switch current stress and turn-off current of the main switch. Finally, a 200V input, 50V/1.6A output experimental prototype is established to verify the correctness of the theoretical analysis.