大功率变流技术与应用(二)——软开关变流器

High Power Converter Technology and Application (2)——Soft-switching Converter

传统的硬开关逆变器在转换状态期间存在一些严重问题。高开关频率使电力电子器件遭受高的开关应力和高的开关损耗。此外,很大的du/dt和di/dt引起严重的电磁干扰(EMI),而寄生电容和杂散电感可能在开关过程中产生高的电压和电流尖峰及振荡。采用软开关技术,可以克服这些缺点,消除开关损耗,提高效率;减少开关du/dt,消除相关的EMI和轴承电流。文章着重介绍用于PWM电压源逆变器的两类软开关技术,即谐振中间环节和谐振吸收回路。

It is exist serious problems of traditional hard-switching inverter in case of conversion. Power electronic devices fall into nigh switching stress and nigh switching loss by nigh switching frequency. Otherwise, large du/dt and di/dt brings serious electromagnetic interference （EMI）, while parasitic capacitance and stray inductance produce nigh voltage, current spike and oscillation. The defects can be overcome by soft-switcning technology with eliminating switch loss, proving efficiency, reducing switch du/dt and removing the relevant EMI and bearing current. Two soft-switcning technologies for PWM voltage inverters are emphasized, including resonant medium link and resonant absorbing circuit.