FSCW Permanent Magnet Motor Structure for Electromagnetic Vibration Reduction
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Solution Overview
Problem
The electromagnetic vibration issue in fractional slot concentrated winding (FSCW) permanent magnet (PM) motors restricts their application in various fields due to abundant magnetic field and electromagnetic force harmonic components, with existing methods either not applicable or increasing manufacturing complexity and affecting torque performance.
Innovation Solution
A method based on the Nyquist Shannon sampling theorem to derive mathematical expressions for electromagnetic force modulation, evaluate contributing components, establish equivalent flux density models, and design a new magnet structure to reduce electromagnetic vibration by injecting flux density harmonics, verified through multi-physical field simulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a damping layer is added between the motor base and stator core to block vibration transmission, then vibration transmission is reduced, but the vibration source of the PM motor is not suppressed and processing complexity increases
Solution Approach 1:
The patent utilizes the abundant electromagnetic force harmonic components inherent in FSCW PM motors to generate counteracting electromagnetic forces that suppress vibration at its source. Instead of treating vibration as a separate problem to be blocked, the invention converts the motor's own electromagnetic characteristics into a beneficial vibration suppression mechanism through flux density harmonic injection.
2Object-affected harmful factors
If additional stator teeth are added to reduce noise performance, then vibration and noise are reduced, but manufacturing difficulty increases and output torque performance is greatly affected
Solution Approach 1:
The patent changes the magnetic field parameters by injecting specific flux density harmonics through modified magnet structures. This alters the electromagnetic force characteristics to suppress vibration and noise without changing the fundamental stator geometry or slot-pole combination, thereby avoiding manufacturing complexity and torque performance degradation.
Solution Approach 2:
The patent applies local quality modification to the magnet structure by creating different remanence regions within the magnets. This localized modification of magnetic properties enables precise control over flux density harmonics to counteract vibration while maintaining overall motor performance and simple manufacturing.
3Object-affected harmful factors
If flux density harmonic injection is used to reduce electromagnetic force amplitude, then electromagnetic vibration is reduced, but magnet structure complexity increases
Solution Approach 1:
The patent applies local quality modification to the magnet structure by creating different remanence regions within the magnets. This localized modification of magnetic properties enables precise control over flux density harmonics to counteract vibration while maintaining overall motor performance and simple manufacturing.
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
Effectively reduces electromagnetic vibration without increasing processing difficulty or cost, providing a universal solution applicable to FSCW PM motors by modulating high-order electromagnetic forces into lower order components and counteracting electromagnetic forces with injected flux density harmonics.
Implementation Method 1
according to Maxwell stress equation, getting the relationship between magnetic flux density harmonics and main electromagnetic force harmonics
Implementation Method 2
according to Maxwell stress equation, getting the relationship between magnetic flux density harmonics and main electromagnetic force harmonics
Implementation Method 3
designing a new magnet structure of the PM motor, and the magnetic flux density harmonic content in the PM motor is used to effectively reduce the electromagnetic force amplitude
Data Source
AI summary
The present disclosure provides a method for reducing the electromagnetic vibration of a fractional slot concentrated winding (FSCW) permanent magnet (PM) motor, which provides a guidance for the low vibration design of FSCW PM motor. The implementation of the method includes: Based on Nyquist Shannon sampling theorem, the modulation effect of electromagnetic force in the air gap is obtained, and the electromagnetic force component that contributes the most to the electromagnetic vibration of the FSCW PM motor is determined. The equivalent analytical model of PM flux density is established to obtain the phase relationship between different flux density harmonics. According to Maxwell stress equation, the internal relationship between each order of flux density harmonics and electromagnetic force harmonics is obtained. A new magnet structure of the PM motor is designed, and specific flux density harmonics are injected to reduce the electromagnetic force and electromagnetic vibration of the FSCW PM motor.