ZVS PWM全桥三电平直流变换器

Three-Level ZVS PWM Full-Bridge Converter

提出了一种新型的 ZVSPWM全桥三电平直流变换器。该变换器使用了以能量传输最大、滤波电感电流纹波最小、开关管实现 ZVS等为条件寻找到的最佳开关方式 ,克服了传统 ZVS全桥直流变换器中开关管电压应力高、滤波电感电流纹波大等缺点 ,所以其变换效率更高 ,响应速度更快 ,进一步拓宽了它的应用范围。本文分析了变换器的工作原理 ,给出了一个周期内的所有开关模态。本文还论述了谐振电感的设计和占空比的丢失 ,最后通过一个 3 k W,5 0 k Hz的实验样机加以验证分析结果。

A three level ZVS PWM full bridge converter is presented. With the best modulation strategy under condition it must have the largest energy transfer ratio, the smallest current ripple of the filter inductor, and realizing ZVS of each switches. The converter overcomes the drawbacks presented by the conventional ZVS full bridge converter, such as high voltage stress of each switch, and large current ripple of the filter inductor, so it can get higher efficiency, faster respond speed, and wider application area. In this paper, the operating principle of the new converter is analyzed, and each switching mode in one period is given. Based on the analysis, the design principle of the resonant inductor is discussed, and the duty loss is calculated. The new converter is verified on a 3kW, 50kHz experimental prototype.