Armature Winding Layout for Lower Circulating Current in Slotless Motors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rotary electric machines with tooth-less and slot-less stator cores face issues such as increased circulating current due to increased magnetic flux through the stator winding, leading to losses and torque ripple.
Innovation Solution
The rotary electric machine incorporates an armature winding with multiple winding segments having different coil resistances, connected in series and parallel configurations, along with a winding support member, to equalize coil resistance and reduce circulating current, while allowing for field-weakening control and minimizing eddy-current loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a tooth-less and slot-less stator core is used, then the structure is simplified and manufacturing is easier, but circulating current increases due to increased magnetic flux through the stator winding
Solution Approach 1:
The stator winding is divided into multiple winding segments with different coil resistances. These segments are connected in series and parallel configurations to equalize the total coil resistance across different phases, thereby reducing circulating current while maintaining the simplified tooth-less and slot-less stator core structure.
2Loss of energy
If winding segments with different coil resistances are used, then circulating current is reduced, but winding assembly complexity increases
Solution Approach 1:
Different winding segments are designed with locally differentiated coil resistances achieved by varying the number of turns in each segment. This local variation in resistance compensates for the increased magnetic flux distribution in the tooth-less and slot-less stator core, reducing circulating current while maintaining manageable assembly complexity through systematic design.
3Power
If multiple winding segments with different resistances are connected in series and parallel, then torque performance is enhanced, but device complexity increases
Solution Approach 1:
The winding segments are connected in dynamically configurable series and parallel arrangements that can be optimized for different operating conditions. This dynamic connection structure enables enhanced torque performance across varying load conditions while managing device complexity through modular design principles.
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
This configuration reduces circulating current and eddy-current loss, enhances torque performance, and allows for easier assembly and design flexibility by providing increased freedom in winding segment arrangement and connection.
Implementation Method 1
a rotary electric machine includes a field element having a plurality of magnetic poles; and an armature including an armature winding
Data Source
AI summary
An armature winding of a rotary electric machine includes multi-phase windings. The phase winding of each phase includes a plurality of series-connected parts of the winding segments, and the series-connected parts are connected in parallel to form the phase winding. The winding segments include a first winding segment and a second winding segment, both having coil resistance different from each other. Each of the series-connected parts is formed by connecting the first winding segment and the second winding segment in series.