交错控制高频隔离的整流侧过电压箝位研究

Research on Overvoltage Clamp in the Rectifier Output of a High Frequency Isolating Converter

正弦脉宽调制(SPWM)交错控制高频隔离后的整流电路,高频变压器漏感和整流二极管寄生结电容会发生谐振,在整流二极管两端产生过电压。过电压的存在不仅对整流二极管提出了更高的耐压要求,而且增加了功耗和电磁噪声。这里分析了过电压产生的原理和过程,并提出一种通过在整流桥输出端加RCD箝位电路来抑制过电压的方法。详细分析了RCD箝位电路的工作原理、电路波形、参数计算方法和功率损耗。最后,给出一个详细的工程设计实例及其实验结果,证明了分析的正确性。

Rectifying circuit of interleaving control high frequency isolation of sinusoidal pulse width modulation（SPWM）, two ends of rectifier diode generates high frequency overvoltage because of high frequency leakage inductance of transformer and rectifier diode parasitic junction capacitance effect.The existence of overvohage not only puts forward a higher pressure requirement on rectifier diode, but also increases power consumption, and causes electromagnetic noise.This article analyses the principles and processes of overvoltage and advances a kind of overvohage suppression method that adds a RCD clamping circuit at the output of rectifier bridge.Operating principles of RCD clamping circuit and circuit waveforms are analyzed in detail and circuit parameter calculation method and power losses are given.Finally, a detailed engineering design and experimental results are given to demonstrate the correctness of the design.