基于SiC MOSFET的移相全桥ZVS变换器

Phase-shift Full-bridge ZVS Converter Based on SiC MOSFET

移相全桥ZVS变换器通过软开关技术,显著地减小了开关损耗,并进一步提高装置的效率,得到了广泛应用,但传统移相全桥ZVS变换器在低压大电流情况下整流二极管导通损耗较大。首先采用同步整流技术,降低了次级整流管的导通损耗;然后采用在原边加箝位二极管的方法抑制了副边整流管两端的电压尖峰;并且采用在原边串联隔直电容的方法抑制直流分量;最后用Saber搭建SiC MOSFET半桥模块的仿真模型,通过MATLAB和Saber协同仿真来验证高频下SiC MOSFET的工作特性。

With the soft-switching technology, phase-shift full-bridge ZVS converter significantly reduces the switching loss, and further improves the efficiency of the device. Therefore, it has been widely applied. However, the rectifier diode conduction loss is relatively larger when a traditional phase-shift full-bridge ZVS converter is operating under the condition of low voltage and large current. In this paper, synchronous rectifier technology was adopted to reduce the secondary rectifier conduction loss at first. Then, clamp diode was added in the primary side to suppress the rectifier voltage spike in the secondary side, and the DC component was suppressed by connecting a blocking capacitor in series to the primary side. At last, a simulation model of SiC MOSFET half-bridge module was established using Saber. The high-frequency operation characteristics of SiC MOSFET were verified through the collaborative simulation of MATLAB and Saber.