THE SYNCHRONOUS MOMENTS IN ASYNCHRONOUS ENGINES WITH NONCONVENTIONAL WINDINGS

Abstract

The synchronous moments result from interaction of harmonics of a magnetic field статора
and a rotor, having an identical order, but created independently from each other. The technique of stock- taking of the synchronous moments in asynchronous engines with nonconventional windings is offered. In such windings the maintenance of harmonics of direct and return rotation increases. It creates preconditions for occurrence of the synchronous moments, both at a motionless rotor, and at rotation. The greatest harm is brought by the synchronous moments at a motionless rotor. They interfere with start-up of engines. The syn- chronous moments arising at rotation of a rotor, not always lead to negative consequences. The expressions allowing on harmonious structure MDS of a winding to define recommended numbers of grooves of a rotor from a condition of absence of the synchronous moments at start-up and at rotation are resulted. As an ex- ample the two-high-speed winding with 2р1:2р2=6:4 in 48 grooves статора is considered. Model samples of two-high-speed engines with different numbers of grooves on a rotor are executed. Experimental re- searches of model samples of two-high-speed asynchronous engines with different numbers of grooves on a rotor are spent. Mechanical characteristics of the tested engines are shown. In the engine with 30 grooves on a rotor there are no synchronous moments. Experimental researches have proved calculations. Techniques of definition of numbers of grooves of a rotor and статора in the asynchronous engine it is recommended for any windings.