Variable-Flux Rotor Layout With Mixed-Coercivity Magnets
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Solution Overview
Problem
Existing variable flux machines (VFMs) without rare-earth permanent magnets suffer from loading de-magnetization, lower reluctance torque utilization, and inefficiency due to low coercivity of magnets, often using a single type of magnet.
Innovation Solution
A rotor configuration with a first set of high coercivity magnets arranged in a V-shape and a second set of lower coercivity magnets connected in parallel, forming a magnetic circuit, using materials like Iron-Nitride (FeN) and different grades of AlNiCo magnets to enhance flux regulation and reluctance torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single type of low coercivity magnet is used in rare-earth-free VFMs, then the machine is free of rare-earth materials, but loading de-magnetization occurs leading to degradation or abrupt ceasing of operations
Solution Approach 1:
The patent applies local quality by using different magnet grades in different regions of the rotor. Specifically, higher grade magnets with higher coercivity are placed in regions more susceptible to de-magnetization, while lower grade magnets are used in other regions. This spatial differentiation of magnet properties resolves the contradiction by providing enhanced de-magnetization resistance where needed while maintaining rare-earth-free construction overall.
Solution Approach 2:
The patent employs composite materials by combining multiple magnet grades (e.g., AlNiCo 5, AlNiCo 9, and FeN) within the same rotor structure. This composite approach creates a hybrid magnetic system where different material properties complement each other, providing both rare-earth-free construction and improved de-magnetization resistance through the higher coercivity components.
2Quantity of substance
If low coercivity magnets are used to avoid rare-earth materials, then the machine is rare-earth-free, but reluctance torque utilization is reduced
Solution Approach 1:
The patent uses local quality by strategically placing higher grade magnets with superior magnetic properties in specific rotor regions where maximum torque production is required. This localized enhancement of magnetic strength in critical areas compensates for the lower coercivity of standard rare-earth-free magnets, thereby maintaining high reluctance torque utilization while preserving the rare-earth-free construction.
3Reliability
If hybrid magnet VFMs with high and low coercivity magnets are constructed, then de-magnetization resistance improves, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the rotor into distinct magnetic zones or segments, each containing specific magnet grades arranged in particular patterns. This segmented approach to magnet placement systematically manages the complexity of hybrid magnet configurations while achieving improved de-magnetization resistance through the strategic distribution of high and low coercivity magnets throughout the rotor structure.
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 proposed rotor design improves de-magnetization resistance and efficiency by utilizing high reluctance torque, achieving stable operation and enhanced performance without rare-earth materials.
Implementation Method 1
a first set of magnets with higher coercivity integrated in at least a slot of the rotor to be arranged in a V-shape; and a second set of magnets with a lower coercivity... the first set of magnets forms a first magnetic layer and the second set of magnets forms a second magnetic layer
Implementation Method 2
Variable flux machines (VFM) are electric machines, such as electric motors and/or generators, that may dynamically change the intensity of magnetization, via increasing or decreasing magnetic current
Implementation Method 3
therein subject to volatile availability and costs for procurement. Additionally, there may be a specific desire to reduce environmental degradation that come with the procurement of rare-earths... may have lower utilization of reluctance torque
Data Source
AI summary
Systems are provided a rotor and magnets of a system of an electric machine that is a variable flux machine (VFM), such as a memory machine or memory motor (MM). The rotor of the system, comprising: a first set of magnets with higher coercivity integrated in at least a slot of the rotor to be arranged in a V-shape; and a second set of magnets with a lower coercivity, compared to the first set of magnets, the second set of magnets comprising at least a pair of magnets of different grades arranged in parallel in a radial slot of the rotor, where the first set of magnets forms a first magnetic layer and the second set of magnets forms a second magnetic layer of the rotor.