准Z源逆变器共模电磁干扰抑制的改进

Improvement of the Common Mode Electromagnetic Interference Suppression of the Quasi-Z-Source Inverter

在准Z源逆变器中,正常运行时绝缘栅双极型开关管的高速开关动作,会产生很大的电压变化率、电流变化率,产生严重的共模电磁干扰,且现有的抑制方法效果不理想.针对此问题,首先对准Z源逆变器拓扑结构和工作原理进行分析;其次对逆变器共模电磁干扰产生的主要原因进行理论分析;然后研究了抑制共模电磁干扰的方法,从干扰源和耦合路径方面考虑,设计一种改进的无源滤波器进行抑制;最后通过仿真对抑制前后的准Z源逆变电路进行验证.仿真结果表明:该滤波器在传导干扰频率范围内能有效抑制产生的共模电磁干扰,证明了该方法的正确性,使准Z源逆变器的电磁兼容性有明显提高.

In the Quasi-Z-source inverter system,the high dv/dt and di/dtin normal operation due to the fast switching of IGBT can bring about serious common mode electromagnetic interference,and the effect of the existing suppression method is not ideal.In order to solve the problem,the structure and working principle of the Quasi-Z-source inverter system were firstly analysed.Theoretical analysis was conducted on the main reasons leading to the common mode electromagnetic interference of the inverter.The method to suppress common mode electromagnetic interference was studied.Considering the interference source and coupling path,an improved passive filter was designed to suppress the common mode electromagnetic interference.Finally,the Quasi-Z-source inverter circuit before and after the suppression was verified by simulation.The simulation results show that the filter can effectively suppress common mode electromagnetic interference within the range of conduction interference frequency,which verifies the effectiveness of the proposed method and dramatically improves the electromagnetic compatibility of the Quasi-Z-source inverter system.