Electric Motor Two-Layer Winding Harmonic Cancellation
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Solution Overview
Problem
Existing electric motor winding methodologies, such as concentric and lap winding, face challenges in achieving optimal performance characteristics while being cost-effective and automatable, as concentric winding introduces spatial harmonics and lap winding is costly due to non-automatable manufacturing processes.
Innovation Solution
A three-phase, four-pole motor design utilizing a two-layer winding arrangement with concentrically arranged coil groups, where each layer consists of six individual poles, allowing for automated fabrication and improved motor performance similar to lap winding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If concentric winding is used, then manufacturing cost is reduced and automation is enabled, but spatial harmonics are introduced affecting motor performance
Solution Approach 1:
The stator winding is divided into multiple independent phases (typically three phases), with each phase containing multiple coil groups. This segmentation allows each phase to be wound independently using automated processes while the overall distribution across phases eliminates spatial harmonics. The winding pattern is further segmented into a specific configuration where coils are distributed across multiple slots in a predetermined sequence that achieves harmonic cancellation.
Solution Approach 2:
Different regions of the stator winding are assigned different characteristics. Specifically, within each phase, the coil groups are arranged in a particular pattern (such as distributed winding across multiple slots) that creates local variations in winding distribution. This local quality variation ensures that while each individual coil group can be manufactured automatically, the collective arrangement produces the desired harmonic-free MMF waveform.
2Reliability
If lap winding is used, then motor performance is improved with reduced harmonic content, but manufacturing automation is lost and costs increase
Solution Approach 1:
The invention creates a simplified copy or representation of the lap winding concept that can be manufactured automatically. Instead of requiring complex overlapping coil arrangements that are difficult to automate, the patent uses a distributed winding pattern that replicates the harmonic-reduction benefits of lap winding through a different geometric arrangement. This copied approach maintains performance benefits while enabling automated manufacturing processes.
3Reliability
If complex winding patterns are used to reduce spatial harmonics, then motor performance improves, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The winding pattern employs asymmetric distribution of coil groups across the stator slots. Rather than using symmetric arrangements that are simpler to manufacture, the patent deliberately introduces asymmetric patterns in the winding distribution that effectively cancel spatial harmonics. For example, coil groups are positioned in specific slots following an asymmetric sequence that achieves harmonic reduction while maintaining manufacturability through standardized automated processes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The two-layer winding pattern achieves superior motor performance characteristics while simplifying the manufacturing process, reducing costs, and enhancing automation, thus addressing the limitations of both concentric and lap winding methods.
Implementation Method 1
a magnetic field is generated by a plurality of circumferentially distributed coil windings secured within a plurality of circumferentially distributed slots in the inner periphery of the motor's stator, the coil windings being coupled to an AC power source. The magnetic field generated within the stator core causes rotation of the motor's rotor
Data Source
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AI summary
A triple-winding layer arrangement for a three-phase, four pole motor is provided as well as a method of manufacturing the same.