用于抑制多相异步电动机定子谐波电流的电抗滤波器

电压型逆变器驱动多相异步电动机运行时,虽然降低了转矩脉动和转子谐波损耗,却在定子绕组出现了明显的低次谐波电流.在总结现有的方法基础上,提出一种新型的电抗滤波方法.电抗器采用和多相交流电机定子类似的电磁结构,适当调整绕组的分布,使在多相电机中不产生旋转磁场的谐波电流在滤波电抗器中产生旋转磁场.这些谐波电流在多相异步电动机中仅遇到漏电抗,在滤波电抗器中却遇到高值的耦合电抗,因而有选择地对定子中的显著谐波电流进行滤波.以六相移30°的绕组结构为例,对包括滤波器的多相异步电动机建立了数学模型并进行了仿真分析,仿真结果验证了电抗器的有效性.

Study of Novel Filter for Reducing Harmonic Currents of Stator Windings in Multi-Phase Induction Motor

Multi-phase induction motors have smaller torque pulsation and lower rotor loss due to harmonics than three-phase motors. However, when fed by voltage source inverter (VSI), they generally have low-order stator harmonic currents. On summarizing various methods of reducing these harmonic currents put forward previously, a novel scheme of reactance filter is proposed. Construction of the reactance is resembled the stator of multi-phase motor. By properly adjusting distribution of multi-winding, we can make those harmonic currents that do not produce revolving magnetic field in induction motor nevertheless generate such field in the reactance filter. Therefore the filter is able to produce reactance to the low-order harmonic currents selectively but transparent to fundamental and other harmonic currents. The inductance motor being studied is of six-phase. Mathematical model of the motor comprising the reactance filter has been set up and analyzed by simulation. The simulation result shows the validity of the method.