Pre-formed Stator Windings for Electric Machine Copper Reduction
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Solution Overview
Problem
In large electrical machines with a high number of poles and small pole pitch, traditional double-layer windings are difficult to mount due to the need to temporarily lift coils, and single-layer windings result in large copper-consuming winding overhangs.
Innovation Solution
A group of three stator windings with pre-formed closed loops, where each winding has two segments embedded in adjacent slots, and winding heads that combine rotation and translation, reducing the length and axial extent of the windings, thereby minimizing copper usage and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional double-layer windings are used, then all coils are identical and easy to manufacture, but insertion of the last coil requires temporarily lifting the first coil out of the slots
Solution Approach 1:
The stator windings are divided into multiple independent single-layer windings, each forming a complete closed loop. This segmentation allows each winding to be inserted independently into its designated slots without interfering with other windings, eliminating the need to lift previously inserted coils during the insertion process.
2Ease of operation
If single-layer windings are used to avoid coil removal during insertion, then mounting is simplified, but winding overhangs become large consuming excessive copper
Solution Approach 1:
The winding heads are configured to extend primarily in the radial direction rather than the axial direction. By changing the dimensional orientation of the winding overhangs from axial to radial, the patent achieves compact axial dimensions while significantly reducing copper consumption in the winding heads.
Solution Approach 2:
The patent optimizes the geometric parameters of the winding heads, specifically configuring them to have minimal axial extent and to follow the radial contour of the stator. This parameter optimization reduces the length of winding overhangs and consequently reduces copper consumption while maintaining electrical performance.
3Ease of manufacture
If winding heads extend in axial direction, then connection between slots is achieved, but axial extent and copper consumption increase
Solution Approach 1:
Instead of extending winding heads axially to connect between slots, the patent configures them to extend radially outward from the slot openings. This dimensional change allows electrical connection while minimizing axial dimension, achieving compact stator design.
Data Source
AI summary
In one aspect, a stator is provided having a first cylindrical surface with a plurality circumferentially spaced winding slots, each winding slot extending along an axial length of the first cylindrical surface and formed to embed a segment of a single stator winding, Each stator winding is pre-formed as a closed loop and two substantially parallel segments of each stator winding formed to be embedded in a first and a second winding slot of the stator, with the second winding slot being the third adjacent winding slot to the first winding slot. Each of the three stator windings has a first winding head segment leaving the winding slots in axial direction of the stator, the first winding head segment of a first winding of the three stator windings describing in space in parts a combination of a rotation about an axis and a translation along that axis.