高压变频调速系统仿真研究

Simulation of high-voltage adjustable speed drive system

详细地分析了两电平高压变频器共模电压产生机理。为有效抑制共模电压对高压变频器的不良影响,提出了两种措施和一种新型拓扑结构:在24脉波整流输出的直流电路中设置共模电抗器,在三电平逆变器和电动机之间设置输出滤波器,并将滤波器中性点、直流侧中间点和三电平逆变器中性点相连。利用MATLAB的Simulink环境,基于该拓扑结构对6kV/2250kW的电机进行了仿真研究。从仿真结果可以明显看出,所提出的有关减小高压变频器的共模电压的措施有利于减小电磁干扰,提高变频器运行的可靠性。

The principle of the common-mode voltage (CMV) in a two-level high-voltage adjustable speed drive (ASD) system has been discussed. In order to effectively eliminating the impact of CMV on ASD's, some measures based on a new topology is presented, including appending a common-mode reactor (CMR) to 24-pulse rectifier and an output LC filter between the three-level inverter and the motor. In this topology, the star point of the output filter, the neutral point of the de-link and the neutral clamped point of the three-level inverter are got together. The presented measures and the topology of ASD'S system are simulated by means of simulink tools in MATLAB environment. Based on the simulation results of a 2 250 kW motor, it is concluded that the proposed measures are reasonable, effective and can give some valuable references in designing a high-voltage ASD'S with elimination of Electro Magnetic Interference (EMI).