Three-phase unequal-turns fractional slot concentrated winding

Abstract

The invention relates to a three-phase unequal-turns fractional slot concentrated winding, wherein each phase of winding is formed by serially connecting 12 coils with pitch of 1; each coil of four coils in the 12 coils has the turns of n, wherein n is a natural number, and each coil of the rest 8 coils has the turns of 2n; the turns ratio of two kinds of unequal-turns coils is 2:1; three phases of windings are in difference of 1200 electric angles and are of three-phase symmetrical windings; the slot fullness of each slot is balanced; a stator iron core is inclined to 1/7 slot pitch; and thethree phases of windings can be in r connection or Y connection. The unequal-turns fractional slot concentrated winding not only preserves the advantages, such as coil pitch of 1, capability of beingdirectly wound on one tooth and short winding end part of a concentrated winding with slot number q=1/2 of each phase and each pole, but also overcomes the serious defects that the q=1/2 equal-turns concentrated winding has the potential harmonic content up to 27.3 percent in the induction phase and poor performance, and a multipole permanent magnet servo motor cannot be used in a servo system with strict requirements on position precision. The three-phase unequal-turns fractional slot concentrated windings has the potential harmonic content less than 2 percent in the induction phase, reachesan ideal sinusoidal wave state, ensures that the permanent magnet servo motor reaches high performance, can be used for the fields, such as numerical control laths having strict requirement on position precision, and the like and has the advantages of traditional process, easiness in implementation and excellent performance, thereby having an actual popularization meaning.

Description

technical field [0001] The invention relates to a winding of an AC motor, in particular to a concentrated winding of three-phase slots with unequal turns and fractions. Background technique [0002] As we all know, multi-pole permanent magnet synchronous servo motors have been widely used in the field of CNC machine tools, and have gradually replaced DC servo motors. However, the control performance of the multi-pole permanent magnet synchronous servo motor in the servo system with strict position accuracy requirements does not have obvious advantages. This is mainly because the induced potential of the multi-pole permanent magnet synchronous motor is not an ideal sine wave and contains large harmonics. Multi-pole permanent magnet synchronous servo motors often use the number of slots per pole and phase q =1 / 2, the coil pitch is 1, and each coil is a concentrated winding with equal turns. The main advantage of this kind of winding is that the coil is wound on one tooth, and...

AI Technical Summary

Problems solved by technology

This is mainly because the induced potential of the multi-pole permanent magnet synchronous motor is not an ideal sine wave and contains large harmonics. Multi-pole permanent magnet synchronous servo motors often use the number of slots per pole and phase q =1/2, the coil pitch is 1, and each coil is a concentrated winding with equal turns. The main advanta...

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