Construction methodology and analysis of electromagnetic properties of pole-changing winding

The article presents a method for constructing pole-changing windings for two-speed asynchronous motors with a close pole ratio of 3/4 with 36 stator slots, which is widely used in the electric drive of turbo mechanisms.The necessity of using two-speed asynchronous motors on electric drives of turbo mechanisms in order to save electrical energy in less loaded operating modes of the mechanism is justified.Currently used two-speed motors have two separate windings, which worsens their weight and size characteristics.The use of one pole-changing winding in two-speed motors makes it possible to save winding copper and insulating materials.A method for constructing pole-changing windings with a ratio of pole pairs of 3/4 with 36 stator slots is described based on the basic circuit "three three-phase stars" and "three three-phase stars with additional branches", where m-zone windings with numbers of pole pairs p1 are taken as the initial winding 1=3 and 2=4, in steps y=1-7 and y=1-5.An analysis of the electromagnetic properties of the developed pole-changing windings showed that they have improved patterns of magnetomotive forces, which lead to a decrease in the presence of higher harmonics and an improvement in vibroacoustic characteristics from both poles.Using the developed circuit of a field-switchable winding based on the basic YYY/YYY circuit with additional branches at the Gebze Institute of High Technologies (Turkey), a prototype of a new two-speed asynchronous motor assembled on the basis of a magnetic core of a single-speed AGM100L6 engine was manufactured and tested in the laboratory of Electromechanics of the Archelik company (Turkey).According to the results of experimental studies, it was revealed that the new two-speed AGM100L6/8 motor on the p1=3 side develops power P2=1200 W at =76.9%, cos=0.722,I1=3.7 A, n=958 rpm , and from the side 2=4 -2=1000 W at =72.8%, os=0.71,I1=3.74A, n=708 rpm.