Segmented Fractional-Slot Stator Layout for Balanced Multi-Phase Windings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fractional-slot electrical machines face issues such as inferior electromagnetic performance, high self-inductance, high rotor loss, torque ripple, and manufacturing challenges due to redundant teeth and unbalanced phases, particularly in multi-phase machines.
Innovation Solution
A fractional slot topology arrangement with stator segments having balanced conductor distribution and integrated coils, where each phase in a segment has the same number of coils, and the segments are connected at their ends to form a unified stator, ensuring balanced electrical performance and protecting conductors during transport and assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional fractional-slot electrical machines use redundant teeth for stator segmentation, then manufacturing and transport become easier, but electromagnetic performance deteriorates with high self-inductance, high rotor loss, and torque ripple
Solution Approach 1:
The stator is divided into multiple stator segments with each segment having a specific number of slots and teeth. The segmentation is designed such that Ns/(Np*m) equals a fraction where the denominator is not an integer, allowing easier manufacturing and transport while maintaining balanced electromagnetic performance across all phases.
Solution Approach 2:
The patent changes the slot/pole/phase ratio parameter to a specific fractional form where the denominator is not an integer. This parameter modification enables the stator to be divided into segments with balanced conductor distribution, reducing rotor losses while maintaining manufacturing feasibility.
2Ease of manufacture
If redundant teeth are used to isolate stator segments, then manufacturing becomes simpler, but electromagnetic performance worsens with abundant back-EMF harmonics and high torque ripple
Solution Approach 1:
The stator is segmented into multiple sections with each segment containing a balanced number of coils for all phases. The segmentation ratio Ns/(Np*m) with non-integer denominator ensures that harmonic distribution is optimized, reducing back-EMF harmonics while maintaining manufacturing simplicity.
Solution Approach 2:
Each stator segment is designed with specific local characteristics including balanced conductor distribution and optimized slot/teeth arrangement. This local optimization ensures that each segment contributes uniformly to the overall electromagnetic performance, minimizing harmful harmonics.
3Reliability
If alternative teeth wound winding is used for segmented stator, then manufacturing stability improves, but electromagnetic performance deteriorates with low power factor and high self-inductance
Solution Approach 1:
The stator is divided into segments with each segment having balanced conductor distribution for all phases. This segmentation approach provides manufacturing stability through standardized segment production while maintaining optimized electromagnetic characteristics by carefully designing the slot/pole/phase ratio.
Solution Approach 2:
The patent optimizes the electromagnetic parameters by setting Ns/(Np*m) to a specific fraction with non-integer denominator. This parameter change reduces self-inductance and improves power factor while maintaining the segmentation benefits for manufacturing stability.
4Ease of manufacture
If mixed layer winding is used for single three-phase machines, then segmented stator application becomes effective, but space is wasted due to redundant teeth and unbalanced performance occurs in multi-phase machines
Solution Approach 1:
The stator is segmented into multiple sections with each segment containing a balanced number of coils for all phases. This segmentation enables effective application in multi-phase machines while optimizing space utilization by eliminating the need for excessive redundant teeth through careful design of the slot/pole/phase ratio.
Solution Approach 2:
The segmented stator design with balanced conductor distribution is made universal for multi-phase machines. The design principles can be applied to various phase configurations (three-phase, six-phase, etc.) while maintaining balanced performance and efficient space utilization across different machine types.
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 solution enhances manufacturing efficiency, reduces conductor damage, and maintains balanced electrical performance, while minimizing torque ripple and rotor loss, making it suitable for large generators like wind turbines.
Implementation Method 1
a conductor wound in coils around teeth of the plural teeth
Data Source
Figure 1
Figure 2
Figure 3
AI summary
It is described an arrangement (100, 200, 500, 600, 1900, 2000) for an electrical machine having fractional slot topology, comprising: plural stator segments (103a, 103b, 103c), each stator segment having plural teeth (105) alternating with plural slots (107) in a circumferential 10 direction (109), each stator segment having at both circumferential ends a tooth portion (111, 113); for each phase of plural phases (A, B, C) a conductor (115) wound in coils around teeth (105) of the plural teeth, wherein the number of coils of any phase (A, B, C) in any stator segment (103a, 103b, 103c) is the same as the number of coils of any other phase in this stator segment (103a, 103b, 103c).