Stator Phase Winding Asymmetric Wire Length for Slot Insertion
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Solution Overview
Problem
In stators with a greater number of slots, such as those with sixteen poles or six phase windings, the reduced size of slots and increased number of coil ends make it difficult to insert phase windings without interference from other windings, leading to space constraints and insertion challenges.
Innovation Solution
The stator design features inner and outer half-phases with the length of wire for each turn of the inner half-phase being greater than that of the outer half-phase, allowing the inner coil ends to protrude more axially, enabling them to be folded radially and freeing up intermediate slots, while the turns are oppositely corrugated and the half-phases are wound in opposite directions to optimize space usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of slots is increased to accommodate more poles or phase windings, then the stator can handle higher power requirements, but the slot size is reduced and insertion of phase windings becomes difficult
Solution Approach 1:
The phase winding is divided into two distinct half-phases (inner and outer), each with different wire lengths and axial heights. This segmentation allows the outer half-phase to have reduced axial height for easier insertion, while the inner half-phase maintains sufficient height for electrical performance, resolving the contradiction between power capacity and insertion ease.
Solution Approach 2:
Different parts of the phase winding (inner vs. outer half-phase) are given different local qualities in terms of wire length and axial height. The outer half-phase has shorter wire and reduced axial height to facilitate insertion, while the inner half-phase has longer wire and greater axial height to ensure proper electrical function, allowing the system to simultaneously achieve ease of manufacture and power handling capacity.
2Power
If the number of coil ends is increased to accommodate more phase windings, then the stator can support higher power requirements, but interference between coil ends increases
Solution Approach 1:
The phase winding is segmented into inner and outer half-phases with different axial heights. This segmentation reduces the axial height of outer coil ends, minimizing their protrusion and reducing interference with adjacent windings, while maintaining sufficient height for inner coil ends to ensure proper electrical function and power handling capacity.
Solution Approach 2:
The inner and outer half-phases are designed with asymmetric wire lengths and axial heights. The outer half-phase has shorter wire and reduced axial height to minimize interference, while the inner half-phase has longer wire and greater axial height to ensure proper electrical function, allowing the system to simultaneously achieve reduced interference and power handling capacity.
3Reliability
If the axial height of coil ends is increased to ensure proper electrical function, then the electrical performance is improved, but space constraints and insertion difficulties increase
Solution Approach 1:
The phase winding is divided into inner and outer half-phases with different axial heights. The outer half-phase has reduced axial height for easier insertion and less interference, while the inner half-phase maintains sufficient axial height to ensure proper electrical function, resolving the contradiction between electrical reliability and ease of operation.
Solution Approach 2:
Different local qualities are assigned to inner and outer half-phases regarding axial height. The outer half-phase has shorter axial height to facilitate insertion and reduce interference, while the inner half-phase has sufficient axial height to ensure proper electrical function, allowing the system to simultaneously achieve ease of operation and electrical reliability.
Data Source
AI summary
A rotating electrical machine stator comprising an annular cylindrical body including axial grooves, and at least one phase winding including corrugated turns of wire, the phase winding comprising a first outer half-phase and a second inner half-phase which are radially superimposed, the first outer half-phase including outer leading-out wires projecting from the radial walls of the body and the second inner half-phase including outer leading-out wires projecting from the radial walls of the body. The invention is characterized in that for each phase winding, the wire length of each turn of the inner half-phase is greater than the wire length of each turn of the outer half-phase. The invention also concerns a phase winding designed to be mounted in such a rotor.