多极少槽永磁电机绕组并联支路间环流分析

Analysis on Ring Current Between Stator Shunt Circuits of Multiple-pole& Few-slot Permanent Magnet Motors

多极少槽永磁同步电机在各领域的应用越来越广泛,其绕组往往设计成多支路并联形式。在电机制造和运行过程中,绕组各并联支路易受制造公差和运行磨损的影响,在并联支路间易产生环流,造成电机损耗增加,运行状况恶劣。文章首先分析了多极少槽永磁同步电机并联支路间环流产生的机理,并重点分析了转子偏心情况下定子绕组两条支路并联反电动势和电压方程;推导出环流数学模型,为降低环流提供了理论依据。然后利用Ansoft软件建立了不同并联路数、不同偏心类型及不同偏心量的电机模型,并对顺槽相连、隔槽相连、对槽相连三种连接方式电机各支路反电动势进行仿真,对比各支路反电动势不平衡度,得到环流最低的绕组连接规律。最后制作了三种连接方式的样机,通过样机测试验证了理论分析的正确性和降低环流措施的有效性。

Multiple-pole ＆ few-slot permanent magnet motors are widely used in various fields, and their wind- ings are usually designed in multi-branch form. In the process of manufacturing and running of the motor, the winding is easily affected by manufacturing tolerance and running wear, thus ring current is generated in the parallel branches, causing loss increases, harsh operating conditions. The mechanism of PMSM ring current and the back electromotive force（back-EMF） and voltage equation of two parallel branches under rotor eccentricity were firstly analyzed in the paper . And the ring current mathematical model was derived, which provided theoretical basis to reduce it. Then, using Ansoft software to establish motor models in different parallel branches, different types of eccentricity and different eccentricity. Simulating each branch back- EMF under the three connections which are order-slots connection, apart-slots connection, opposite-slots connection; and comparing all branches back-EMF imbalance degree to find the rule of connections which can largely reduce the ring current. Finally, prototypes were developed with three connections, and the correctness of the theoretical analysis and the effec- tiveness of the reduction of the ring current were verified by the prototype tests.