Development of a pole-changing winding for close pole ratio

Development and research of new pole-changing windings with close pole ratios for two-speed motors used in ventilation units. When developing a new pole-changing winding with a pole ratio of 3/4 with 54 stator slots, the method of "Discrete-specified spatial functions" was used; when analyzing the electromagnetic properties of the resulting winding, the "Graphoanalytical method of Fourier series expansion", "Method of vector and harmonic analysis", "Methods of vector algebra". Using the "Discrete-Specified Spatial Functions" method, a new pole-changing winding has been developed based on the basic "YYY/YYY with additional branches" circuit for a 3/4 pole ratio with 54 stator slots. From a technological point of view, the developed pole-changing winding is a conventional two-layer winding consisting of equal-turn coils of the same pitch evenly distributed along the slots, which allows for the industrial applicability of the proposed winding, since two-speed motors with such a winding can be used on numerous centrifugal pumps and fans, where it is necessary to adjust the rotation speed according to the technological process or for energy saving purposes.