Integrated Oriented Silicon Steel Stator for Lower Iron Loss
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Solution Overview
Problem
The processing technology for stators in electric vehicles is complex and costly due to the need to form and splice separate parts from oriented and non-oriented silicon steel, leading to high energy losses and reduced power density.
Innovation Solution
Integrally forming stator tooth and yoke parts from oriented silicon steel with a grain direction aligned radially, using a fractional slot winding structure to minimize the angle between magnetic field lines and grain direction, thereby reducing iron loss and improving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oriented silicon steel and non-oriented silicon steel are used separately for stator tooth and stator yoke parts, then magnetic performance is improved, but processing complexity and cost increase due to separate forming and splicing
Solution Approach 1:
The patent merges the stator tooth part and stator yoke part into a single integrated component formed from oriented silicon steel sheet. The oriented silicon steel sheet is bent and folded to simultaneously form both the tooth portions and yoke portions, eliminating the need for separate forming and splicing operations while maintaining the magnetic performance benefits of oriented silicon steel in both regions.
Solution Approach 2:
The oriented silicon steel sheet serves multiple functions: it forms both the stator tooth parts and stator yoke parts, providing magnetic flux paths in both regions. The grain direction of the oriented silicon steel is oriented radially in both the tooth and yoke portions, ensuring optimal magnetic performance throughout the entire stator structure.
2Ease of manufacture
If oriented silicon steel sheet is bent and folded to form stator tooth and yoke parts, then manufacturing process is simplified and cost is reduced, but magnetic field alignment must be precisely controlled
Solution Approach 1:
The patent applies local quality by orienting the grain direction of the oriented silicon steel radially at different locations within the stator. In the stator tooth parts, the grain direction is radial to optimize magnetic flux in the teeth. In the stator yoke parts, the grain direction is also oriented radially to optimize magnetic flux in the yoke, ensuring optimal magnetic performance at each specific location.
Solution Approach 2:
The oriented silicon steel sheet is bent and folded into a curved, three-dimensional structure where the grain direction follows radial lines from the center of the stator. This curved configuration allows the flat oriented silicon steel sheet to be transformed into a cylindrical stator structure with proper radial grain orientation throughout, simplifying manufacturing while maintaining precision.
3Power
If fractional slot winding with winding pitch 1 is used, then magnetic circuit length is reduced and power density increases, but winding structure becomes more complex
Solution Approach 1:
The patent uses fractional slot winding with winding pitch 1, where the number of slots per pole per phase is less than 1. This partial winding approach reduces the magnetic circuit length and improves power density by creating a more compact magnetic path, while accepting a more complex winding structure as a necessary trade-off for achieving higher power density.
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 approach simplifies the manufacturing process, reduces costs, and enhances the power density and performance of the motor by aligning the grain direction of oriented silicon steel with the magnetic field, resulting in improved magnetic permeability and reduced iron loss.
Implementation Method 1
Performance is relatively good along a magnetic domain direction of the oriented silicon steel... a grain direction of the formed oriented silicon steel sheet points to the central axis of the stator along a radial direction
Implementation Method 2
a closing path of a magnetic circuit of the stator is relatively short (that is, a short magnetic circuit structure), and a magnetic field line forms a corner at a position of the stator yoke part
Data Source
AI summary
Embodiments of this application disclose a stator, a stator manufacturing method, a motor, and an electric vehicle. The stator includes: a stator tooth part, where a plurality of stator tooth parts are arranged at intervals along a circumferential direction; and a stator yoke part, where the stator yoke part is disposed along a circumferential direction of the stator tooth part, and the circumferential direction is a circumferential direction around a central axis of the stator; where the stator tooth part and the stator yoke part are integrally formed by an oriented silicon steel sheet, and a grain direction of the formed oriented silicon steel sheet points to the central axis of the stator along a radial direction. Therefore, the stator tooth part and the stator yoke part are formed by using one material, and there is no need to splice two materials, thereby reducing process costs.