Interior permanent magnet motor
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Solution Overview
Problem
Conventional interior permanent magnet motors require a large number of permanent magnets to achieve high performance, which increases material costs and complexity, necessitating a solution to reduce the number of magnets while maintaining performance.
Innovation Solution
The interior permanent magnet motor design incorporates a stator with a specific ratio of slots to magnetic poles and a rotor with permanent magnets of equal polarity, along with flux barriers to maximize magnetic flux and reduce leakage, allowing for half the number of permanent magnets while maintaining performance equivalent to conventional designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of permanent magnets is increased to improve motor performance, then magnetic flux amount increases, but material cost increases
Solution Approach 1:
The rotor is divided into multiple magnetic pole regions, each containing permanent magnets. By segmenting the rotor into P/2 magnetic pole regions with alternating polarity, the design achieves P magnetic poles effect using fewer permanent magnets, resolving the contradiction between performance and material quantity
Solution Approach 2:
The invention changes the polarity arrangement parameter from traditional alternating magnets to same-polarity magnets in each region with flux barriers creating the alternating pole effect. This parameter change reduces permanent magnet quantity while maintaining magnetic flux amount and motor performance
2Power
If the thickness of permanent magnets is increased to increase magnetic flux amount, then motor performance improves, but material cost increases
Solution Approach 1:
Instead of increasing magnet thickness, the invention changes the magnetic circuit structure by introducing flux barriers and alternating polarity regions. This structural parameter change optimizes magnetic flux distribution and increases effective magnetic flux amount without increasing material quantity
Solution Approach 2:
Flux barriers are introduced as intermediary elements between permanent magnets to redirect and concentrate magnetic flux. These flux barriers act as mediators that enhance magnetic flux amount without requiring additional permanent magnet material
3Power
If rare earth permanent magnets are used to increase residual magnetic flux density, then motor performance improves, but material cost increases
Solution Approach 1:
The invention changes the magnetic circuit configuration parameters (flux barrier placement, polarity arrangement, magnetic pole region division) to optimize flux distribution. This allows conventional magnets to achieve performance levels previously requiring rare earth materials, reducing material cost
4Quantity of substance
If the number of permanent magnets is reduced to decrease material cost, then material cost decreases, but motor performance deteriorates
Solution Approach 1:
The rotor is segmented into P/2 magnetic pole regions with flux barriers, creating P magnetic poles effect. This segmentation allows using half the number of permanent magnets while maintaining the magnetic flux amount and motor performance through optimized flux distribution
Solution Approach 2:
Flux barriers serve as intermediaries that redirect magnetic flux to ensure adequate flux linkage with stator windings. This intermediary structure compensates for the reduced number of permanent magnets, maintaining motor performance despite using fewer magnets
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 design effectively maximizes magnetic flux and minimizes magnetic flux leakage, achieving performance comparable to conventional motors with half the number of permanent magnets, thus reducing material costs and complexity.
Implementation Method 1
When the current is applied to the plurality of coils of the conventional interior permanent magnet motor 1000 having such a structure, the rotor 1120 is rotated by the attractive force and the repulsive force generated between the plurality of coils of the stator 1110 and the plurality of permanent magnets 1130 and 1131 of the rotor 1120
Implementation Method 2
a plurality of flux barriers provided on left and right sides of one end of each of the plurality of permanent magnets adjacent to an outer circumferential surface of the rotor
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
An interior permanent magnet motor includes a stator provided with a plurality of slots and a rotor rotatably disposed inside the stator. A plurality of permanent magnets of the same polarity are disposed at equal intervals in a circumferential direction inside the rotor. A plurality of flux barriers are provided on left and right sides of one end of each of the plurality of permanent magnets adjacent to an outer circumferential surface of the rotor. A ratio of a number of slots of the stator to a number of magnetic poles of the rotor is 3:2 or 3:4. The number of permanent magnets provided in the rotor is 1/2 of the number of magnetic poles of the rotor.