IPM Rotor Hole Layout for Higher Interlinkage Magnetic Flux
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Solution Overview
Problem
Conventional interior permanent magnet (IPM) motors experience a decrease in interlinkage magnetic flux due to interference between the magnetic flux of first permanent magnets and second permanent magnets, resulting in reduced efficiency.
Innovation Solution
The rotor design includes an iron core with first and second holes arranged radially around a rotating shaft, where the second holes have a shorter radial length and include protrusions towards adjacent first holes, optimizing the magnetic flux interlinkage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If second permanent magnets are arranged in second magnet arrangement holes adjacent to first permanent magnets, then the rotor can generate both magnet torque and reluctance torque, but the magnetic flux of the first permanent magnet is interfered with and interlinkage magnetic flux decreases
Solution Approach 1:
The rotor divides magnet arrangement holes into two types: first magnet arrangement holes for permanent magnets and second magnet arrangement holes for flux barriers. This segmentation allows the magnetic flux from permanent magnets to pass through dedicated barrier regions without interference, resolving the contradiction between torque generation and flux interlinkage
Solution Approach 2:
The patent extracts the flux barrier function from the permanent magnet arrangement structure by creating separate second magnet arrangement holes that serve exclusively as flux barriers. This extraction prevents the interference between adjacent permanent magnets and maintains magnetic flux interlinkage
2Shape
If second magnet arrangement holes are provided adjacent to first permanent magnets, then structural symmetry is achieved, but magnetic flux leakage increases and motor efficiency decreases
Solution Approach 1:
The patent applies different properties to different regions: first magnet arrangement holes contain permanent magnets for torque generation, while second magnet arrangement holes contain flux barriers with specific magnetic resistance characteristics. This local differentiation optimizes both structural symmetry and motor efficiency by preventing flux leakage in critical regions
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 interlinkage magnetic flux, reducing leakage and increasing the magnetic flux linked with the stator, thereby improving motor efficiency.
Implementation Method 1
a plurality of first permanent magnets arranged in the plurality of first holes, respectively... in addition to magnet torque by the permanent magnet embedded in the iron core, reluctance torque due to the unevenness of a magnitude of magnetic resistance generated in the iron core can be obtained
Implementation Method 2
reluctance torque due to the unevenness of a magnitude of magnetic resistance generated in the iron core... the iron core in each of the plurality of second holes has a radial length smaller than a radial length of the iron core in each of the plurality of first holes
Data Source
AI summary
A rotor includes: a rotor core including a plurality of first holes and a plurality of second holes; and a plurality of first permanent magnets arranged in the plurality of first holes, wherein the first holes and the second holes are provided radially around a rotating shaft, the rotor core in each of the plurality of second holes has a radial length smaller than a radial length of the rotor core in each of the plurality of first holes, each of the plurality of second holes is located closer to an inner side in the radial direction of the rotor core with respect to a first hole adjacent to the second hole in a circumferential direction of the rotor core among the plurality of first holes, and includes a protrusion protruding toward the first hole adjacent to the second hole in the circumferential direction of the rotor core.