单相全桥逆变器共模等效电路研究 common-mode equivalent circuit of single-phase full-bridge inverters.pdfVIP

2007 年 2 月 电 工 技 术 学 报 Vol.22 No. 2 第22 卷第2 期 TRANSACTIONS OF CHINA ELECTROTECHNICAL SOCIETY Feb. 200 7 单相全桥逆变器共模等效电路研究 张 凯 方华松 周运斌 章勇高 华中科技大学电气与电子工程学院 武汉 430074 摘要 提出了一种新型单相全桥逆变器共摸等效电路 与现有电路相比 该电路适用叠加原 理 而且它更好地反映了共模电流的传播机理 考虑叠加原理的需要 分别针对以下三种情况进 行了仿真和实验 两桥臂中的某一个从装置中完全拆离 被拆离的桥臂恢复原位但不进行开 关动作 两桥臂按单极倍频PWM 调制方式同时进行开关动作 根据所提出的等效电路和从实 验装置上测量得的电路参数 用Matlab 软件进行了仿真 仿真结果与实测的共模电流时域波形和 频谱吻合得较好 关键词 逆变器 电磁干扰 共模电流 等效电路 中图分类号 TM464 Common-Mode Equivalent Circuit of Single-Phase Full-Bridge Inverters Zhang Kai Fang Huasong Zhou Yunbin Zhang Yonggao Huazhong University of Science and Technology Wuhan 430074 China Abstract A modified equivalent circuit for common-mode current of single-phase full -bridge inverters is proposed. The circuit allows application of superposition theorem, and it provides more insights into the propagation mechanism of the CM noise. Taking the needs of applying the theorem of superposition into account, simulations and experiments are conducted on an inverter test-setup to validate the proposed equivalent circuit. Three operation conditions are studied, which is with one of the two legs detached from the DC bus, with that leg installed back in place but not switching and with normal unipolar PWM switching of both the two legs. Based on the proposed equivalent circuit and measured parameters from the test-setup, simulations with Matlab software predicted the CM current both in time and frequency domains with reasonable precision. Keywords Inverter, EMI, common mode c