Reluctance Motor Rotor With Movable Magnetic Element
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Solution Overview
Problem
The existing multilayered flux-barrier-type reluctance motors with permanent magnets inserted in the rotor suffer from inefficient energy usage due to magnetic flux leakage and armature reaction, which reduces torque generation and increases energy consumption.
Innovation Solution
A rotor design with slits arranged in a radial direction, where a permanent magnet is inserted orthogonally, and a movable magnetic element is placed within a cavity, allowing it to move and increase the magnetic path width, thereby enhancing the field magnetic flux and reducing magnetic flux leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If permanent magnets are inserted in the slits to cancel magnetic flux leakage, then magnetic flux leakage is reduced, but torque generation efficiency decreases due to armature reaction
Solution Approach 1:
The movable element is introduced to dynamically adjust the magnetic path width in response to rotor position and load conditions. This dynamic adjustment optimizes the balance between reducing magnetic flux leakage and maintaining torque generation efficiency, resolving the contradiction between these two parameters.
Solution Approach 2:
The magnetic path width is changed as a variable parameter through the movable element's position adjustments. By varying this parameter according to operating conditions, the system optimizes both magnetic flux leakage reduction and torque generation efficiency simultaneously.
2Productivity
If field current is increased to compensate for armature reaction, then torque generation is maintained, but energy consumption increases
Solution Approach 1:
The movable element converts the harmful effect of armature reaction into a beneficial mechanism by automatically adjusting the magnetic path width to counteract armature reaction effects. This reduces the need for additional field current, thereby maintaining torque generation while reducing energy consumption.
3Loss of energy
If the magnetic path width is increased to reduce magnetic flux leakage, then magnetic flux distribution is optimized, but the device complexity increases
Solution Approach 1:
The movable element is nested within the existing rotor structure, utilizing the available space in the magnetic path. This nested design minimizes additional structural complexity while achieving the goal of optimizing magnetic flux distribution and reducing leakage.
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 increases torque generation, minimizes the field current required, and enhances the power factor of the electric motor by optimizing the magnetic flux distribution, leading to a higher torque constant and reduced total current usage.
Implementation Method 1
permanent magnets are inserted in the slits 2. Specifically, the permanent magnet 3 is inserted into a portion of the slits 2 away from the outer periphery of the slits 2 and closer to the inner periphery of the slits 2. Magnetic poles of the permanent magnet 3 are directed perpendicular to the magnetic paths to allow cancellation of magnetic flux leakage.
Implementation Method 2
a movable element made of a magnetic material and inserted into the cavity, the movable element being capable of moving in the cavity in the circumferential direction while being in contact with both sides of the cavity in the radial direction
Implementation Method 3
the magnetic flux is formed around the windings at Id1 and Id2 in a direction indicated by arrows shaded by hatched lines in the drawing around the positions of the windings in accordance with the right-hand screw rule. At the winding at Iq, a clockwise force is generated in accordance with Fleming's left-hand rule. Thus, the rotary torque is generated in an anticlockwise direction in the rotor 1 in accordance with the law of action and reaction.
Data Source
AI summary
A rotor for a flux-barrier-type reluctance motor having a plurality of poles formed in a circumferential direction includes a plurality of slits provided for each pole, a permanent magnet partially inserted into the slits in such a manner that magnetic poles of the permanent magnet are directed substantially orthogonal to the slit, a slit for a movable element disposed radially inside the permanent magnet disposed at an innermost position in a radial direction, and a movable element made of a magnetic material and inserted into the cavity, the movable element being capable of moving in the slit for the movable element in the circumferential direction. A radially inner side of the innermost slit into which the permanent magnet is inserted and radially outer and inner sides of both the slit for the movable element and the movable element are in a concentric circular-arc shape.