大功率H桥逆变器损耗的精确计算方法及其应用

Refinded Loss Calculation Method and the Applications of High Power H-bridge Inverter

大功率H桥逆变器中广泛采用IGBT作为开关器件,传统的IGBT开关损耗计算是基于供应商提供的开关能量曲线,而该曲线上所提供的开关能量与逆变器实际运行时的数据有较大出入。为此,提出了一套完整的大功率H桥逆变器的损耗分析与精确计算方法。逆变器损耗主要包括IGBT损耗和电解电容损耗,而IGBT损耗又包括导通损耗、开通损耗、关断损耗和反向恢复损耗。给出了各类损耗的定量计算方法,并且采用了双脉冲测试方法获得实际开关能量曲线,因此计算结果更加精确。搭建了一台3.45kVA的实验样机,1kHz开关频率下满载运行时,计算损耗为218W,实测损耗为210W。实验结果验证了所提出的分析与计算方法的准确性。

IGBT is widely used in high power H-bridge inverter. Traditional IGBT switching loss calculation method is mainly based on the switching energy curves provided by the suppliers, which is quite different from the real switching energy. Therefore, a refined calculation method of high power H-bridge inverter has been proposed in this paper. The power losses of inverter always include IGBT power loss and capacitor power loss, while the IGBT power losses always include conduction power loss, turn-on power loss, turn-off power loss and reverse recovery power loss. The quantitative calculation methods for different power losses are presented and the real switching energy curves are obtained using double pulse test way, which will provide a more precise calculation result. Finally, a 3.45kVA prototype has been built, and the calculated power loss is 218W with the measured power loss as 210W under 1kHz switching frequency at full load. The experimental results verify the accuracy of the proposed method.