一种多谐波联合起动的新型无刷双馈电动机

A New-type Brushless Doubly-fed Machine Started by Combined Multi-harmonic Fields

由于无刷双馈电动机在起动过程中存在起动转矩小、起动电流大,以及对电网和电机造成冲击大等问题,使得电机起动性能达不到工业要求。将复合线圈结构引入到无刷双馈电机的转子绕组,并与定子磁动势谐波理论相结合,提出一种多谐波联合起动的方法,以改善电机的起动性能。介绍定子两套绕组的接线方式及其不同状态时的通电方式,分析转子结构在起动状态和运行状态下的工作原理。利用时步有限元法对电机在不同负载下的起动转矩、起动电流进行仿真分析,对比无刷双馈电机多谐波联合起动和异步起动的起动性能。通过仿真与试验验证绕组设计的正确性,其结果表明,该方法提高了起动转矩,减小了起动电流和对电网的冲击,具有一定的理论研究和实际应用价值。

With the problems of small starting torque,large starting current and large impact on the power grid during the starting process, the starting performance of the brushless doubly-fed machine(BDFM) can’t meet the requirements of industrial application. With the composite coil structure adopted by the rotor winding of BDFM and based on the magnetic motive force(MMF) harmonic theory of stator winding, this paper presented a kind of multiharmonic combined starting method to improve the starting performance of the BDFM. The connection mode of two sets of stator windings and their on-off state in different working conditions were introduced in the paper, the function principle of the rotor structure in both starting condition and operating condition were analyzed. The starting torque and starting current of the machine under different loads were analyzed based on the simulations established by the finite element and the starting performance of multi-harmonic combined starting and asynchronous starting of BDFM was compared. The correctness of the winding design was verified by simulations and experiments. The results show that the method has significant theoretical and practical values to improve the starting torque and reduce both starting current and the impact on the power grid.