Segmented Stator Coil Layout for Higher Slot Space Factor
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Solution Overview
Problem
Existing rotating electrical machines with concentrated winding face challenges in improving efficiency and output without increasing size, due to dead spaces between conductors in slots, which limit the space factor of the coil and result in reduced magnetic characteristics and increased copper loss.
Innovation Solution
The rotating electrical machine employs a configuration with segment coils disposed in multiple layers in a radial direction, where each segment coil has a linear portion within the slot and a projection outside the slot, with adjacent segment coils connected at their ends to form a wavy pattern, eliminating crossover wires and optimizing the space factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If concentrated winding is used with square wire, then coil end is reduced, but dead space is formed between conductors in slot reducing space factor
Solution Approach 1:
The coil is divided into multiple segment coils (first segment coil and second segment coil) that are disposed in different layers within the slot. This segmentation allows the conductors to be arranged more efficiently in the radial direction, eliminating dead spaces between conductors while maintaining the concentrated winding structure.
Solution Approach 2:
The invention transitions from a single-layer conductor arrangement to a multi-layer arrangement in the radial direction. By stacking segment coils in multiple layers (first layer, second layer, etc.), the space factor is improved without increasing the coil end volume, as the additional dimension utilized is the radial depth of the slot.
2Reliability
If distributed winding is used, then winding coefficient and torque pulsation are improved, but coil end increases
Solution Approach 1:
The distributed winding structure is segmented into multiple discrete layer units, each containing segment coils arranged in specific patterns. This segmentation allows optimization of both the winding coefficient through proper phase distribution and the space factor through efficient radial stacking, without requiring large coil ends.
Solution Approach 2:
The invention utilizes the radial dimension (stacking layers in the radial direction) to accommodate distributed winding structures more compactly. By arranging segment coils in multiple radial layers rather than extending coil ends axially, the winding coefficient is maintained while coil end volume is reduced.
3Ease of manufacture
If conventional concentrated winding is used, then manufacturing is simplified, but copper loss increases due to reduced space factor
Solution Approach 1:
The coil is segmented into multiple layer units with standardized segment coils, which simplifies the winding process while maximizing space utilization. The segmented structure allows for systematic assembly and reduces manufacturing complexity compared to traditional single-layer arrangements, while the improved space factor reduces copper loss.
4Loss of energy
If coil cross-sectional area is increased to reduce copper loss, then efficiency improves, but machine size increases
Solution Approach 1:
Instead of increasing the cross-sectional area of conductors in the traditional planar direction, the invention utilizes the radial dimension by stacking multiple layer units. This allows the effective conductor area to be increased within the existing slot boundaries, reducing copper loss without increasing the overall machine size.
Solution Approach 2:
Multiple segment coils are nested within each other in the radial direction, with each layer unit containing conductors arranged in specific patterns. This nested arrangement maximizes the utilization of slot space, effectively increasing the conductor cross-sectional area without expanding the machine's external dimensions.
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 enhances the efficiency and output of the rotating electrical machine without increasing its size, by increasing the space factor of the coils and reducing torque pulsation and copper loss.
Implementation Method 1
a rotating electrical machine includes a stator including a stator core having a plurality of slots and a plurality of segment coils respectively disposed in the plurality of slots of the stator core
Implementation Method 2
it is important to suppress a Joule loss (hereinafter, copper loss) generated in a coil by increasing a cross-sectional area of the coil
Data Source
AI summary
A rotating electrical machine includes segmented coils respectively disposed in layers aligned in a row in a radial direction inside a slot of a stator core. The segmented coils include first regions having a straight line section disposed inside the slot and a protrusion protruding to the outside of the slot from one end of the straight line section, and second regions extending toward one side in the circumferential direction from the other end of the respective straight line section, such that the position in the radial direction changes. The tip end section of the second region of a first segmented coil disposed in a prescribed layer within a prescribed slot is disposed and connected to be adjacent, in the radial direction, to the tip end section of the first region of a second segmented coil disposed in the prescribed layer within a slot adjacent to the prescribed slot.