Vibration In Switched Reluctance Motor Research Articles

A Multi-Physics Modeling-Based Vibration Prediction Method for Switched Reluctance Motors

Currently, vibration has been one crucial factor hindering the application of switched reluctance motor (SRM). Hence, it is of crucial importance to predict and suppress this undesirable vibration. This paper proposes a multi-physics analysis-based vibration prediction approach for SRM. It consists of three modules: digital controller and drive circuit module, electromagnetic field module, and mechanical module. In the mechanical module, it not only includes the influence of the stator, but also fully considers the influence of rotor, end cover, bearing, and other components of the motor on the system modal. Moreover, the vibration data under different control strategies areis obtained in real time, and data dynamic interaction between the three segments can be also be achieved. By combining the electromagnetic forces and the system structure modal, the vibration of SRM can be predicted. Finally, the effectiveness of the proposed method was verified on a 12/8 poles, 1.5KW SRM drive system test bench. The results demonstrate that the modal simulation method based on static pre-calculation achieves high accuracy, and the vibration spectrums predicted by the proposed method shows good agreement with the experimental results.

Methods of Torque Ripple Minimization Techniques on Switched Reluctance Motor

In recent decades, Switched Reluctance Motor (SRM) drive has proved to be an attractive alternate for the conventional industrial drives. Many published research works have proved that SRM drives finds significant application in almost all industrial sectors. This paper presents a comprehensive review on various control strategies of SRM drive implemented in literatures. The objective of this review is to identify the accurate control strategies for controlling the SRM speed and torque. This paper also reviews the various strategies for minimization of the torque ripples, acoustic noise and vibration in SRM

Coupling effect between road excitation and an in-wheel switched reluctance motor on vehicle ride comfort and active suspension control

The coupling effect between road excitation and an in-wheel switched reluctance motor (SRM) on vehicle ride comfort is numerically analysed. A hybrid control system consisting of fault tolerant H∞ suspension controller and SRM controller for an in-wheel SRM driven electric vehicle is proposed to improve the vehicle ride comfort and motor operation performance. By conducting numerical simulations based on the developed quarter-car active suspension model and switched reluctance motor model, it is observed that the road roughness is highly coupled with SRM airgap eccentricity and unbalanced residual vertical force. The SRM airgap eccentricity is influenced by the road excitation and becomes time-varying such that a residual unbalanced radial force is induced; which is one of the major causes of SRM vibration. To suppress SRM vibration and to prolong the SRM lifespan, while at the same time improving vehicle ride comfort, a fault tolerant controller based on output feedback H∞ control method is designed to reduce the sprung mass acceleration. Moreover, an SRM controller is adapted by using the combined Current Chopping Control (CCC) and Pulse Width Modulation control (PWM) to further improve the SRM performance. A comparison of passive suspension and suspensions with hybrid control method on the vehicle and SRM dynamic response under stochastic road excitation and bump road excitation is illustrated. The results indicate that the proposed hybrid control method can effectively reduce the SRM airgap eccentricity, residual unbalanced radial force and achieve better vehicle ride comfort.

Suppression of Switched Reluctance Motor Vibration of In-Wheel Motor Electric Vehicle

Switched reluctance motor (SRM) has got great attention in in-wheel motor electric vehicle (IWM-EV), but SRM vertical force, the vertical component of SRM unbalanced radial force, yields SRM vertical vibration and does harm to dynamic performance of IWM-EV. In order to reduce the SRM vertical vibration, electromagnetic active suspension and a linear quadratic Gaussian (LQG) controller were used to suppress the unbalanced radial force in this paper. All the models and the controller were constructed in Matlab/Simulink R2015b. The controller considers five performance indexes: vehicle body acceleration, SRM airgap eccentricity, SRM stator acceleration, suspension dynamic deflections, and tyre deformation. Analytic Hierarchy Process (AHP) was used to calculate the weighted coefficients of performance indexes. Simulations indicate that this electromagnetic active suspension can reduce SRM vertical vibration obviously and improve dynamic performance of IWM-EV.

Review of Switched Reluctance Motor Control for Acoustic Noise and Vibration Reduction

Switched Reluctance Motor (SRM) is one of the candidates for substituting permanent magnet motor in Hybrid Electric Vehicle (HEV) application. Compared to permanent magnet motor, SRM is relatively low cost, robust, high reliability, and possible for high-temperature operation because of the absence of permanent magnet. One significant problem in SRM is the high acoustic noise and vibration. The vibration in SRM is caused by the radial forces acting at the stator teeth. Because of the saliency pole configuration in SRM, vibration is prominent. Many studies tried to reduce acoustic noise and vibration in SRM. In this paper, several controls for acoustic noise and vibration reduction are shown. The acoustic noise and vibration reduction from the experiment are also compared in each method.

Study on Commutation Control Method for Reducing Noise and Vibration in SRM

Many kinds of commutation methods have been proposed to reduce the noise and vibration in a switched reluctance motor (SRM). One of these is well known as the two-stage commutation method. However, it has a defect that is principally revealed when an SRM is operated at high speed and under a high-load condition. This study investigated why vibration reduction based on two-stage commutation does not work through an electromagnetic-structural coupled analysis using a finite element method and mathematical analysis of the exciting force in a 0.4 kW four-phase 8/6 SRM. Based on the investigations, a modified method is proposed to reduce the vibration and noise independent of the operating condition. Experimental studies using the tested SRM demonstrated that the proposed modified control method could reduce the noise and vibration at high speed and under a high-load condition.

Semi-Active Vibration Control for in-Wheel Switched Reluctance Motor Driven Electric Vehicle With Dynamic Vibration Absorbing Structures: Concept and Validation

This paper presents novel algorithms for vibration control of the in-wheel motor (IWM) driven electric vehicles to improve its ride comfort and reduce IWM vibration. A quarter vehicle model is first developed based on a dynamic vibration absorbing structure (DVAS) driven by a switched reluctance motor (SRM). This model considers the coupled longitudinal-vertical dynamics and the unknown road profile as well as the unbalanced electromagnetic force induced by the SRM are treated as the excitation. The dynamics and boundary models of two commercially available semi-active dampers are then presented, which are used as the actuators of both the suspension and the DVAS structure. Based on the developed model, a hybrid controller with a hybrid acceleration driven damping algorithms is proposed to reduce the vibration of the sprung mass and the SRM. The controller parameters are subsequently determined by solving the multi-objective optimization problem with a multi-objective evolutionary optimization method. Numerical simulation results for random road and bumpy excitations are analyzed, and multi-body simulation is finally performed to validate the feasibility of the proposed controllers. Results indicate that the proposed hybrid controllers can effectively improve ride comfort and reduce the SRM vibration compared with the traditional suspension system with IWM.

Torque Ripple Reduction of Switched Reluctance Motor by Optimizing Stator Pole Type

The torque ripple is the important restriction affecting the promotion and application of switched reluctance motor, the analytic expressions to calculate switched reluctance motors tangential force and radial force are derived in this paper, based on analyzing the cause of switched reluctance motor vibration and torque ripple. By improving the stator poles structure, the torque near the commutation points is compensated, which smooth the wave of air gap magnetic field to reduce torque ripple when the stators and the rotors salient poles coincide. In this paper, three structures that puts wedge angle on both sides of the stator poles is presented, and analysis of torque ripple is made. Studies shows that the right size of wedge angle can effectively inhibit the switched reluctance motor torque fluctuations.

Development of a Switched-Reluctance Motor Drive With PFC Front End

In this paper, the development and control for a switched-reluctance motor (SRM) drive with front-end switch-mode rectifier (SMR) are presented, and good motor driving performance and line drawn power quality are obtained. In the SMR, the dc-link voltage spikes caused by periodic pulse-type motor currents are eliminated using high-frequency small capacitor. And the bulky capacitor is designed according to the specified double-frequency voltage ripple. Then, the robust voltage and current schemes are developed to yield excellent and robust SMR control performance. Having well-regulated and adjustable dc-link voltage source, the performance enhancements of the SRM in vibration as well as current and speed dynamic responses are performed and evaluated. The robust current and speed control schemes are designed to yield improved driving performance. In addition to voltage boosting, the commutation advanced shift is proposed to further the improve current and speed dynamic responses, the torque-generating capability, and the vibration of SRM.

Prediction of Electromagnetic Forces and Vibrations in SRMs Operating at Steady-State and Transient Speeds

Although some research has been conducted on vibrations in switched reluctance motors (SRMs), the response during transients, which may occur during sudden load changes or braking, has not received much investigation. In this paper, a simulation model to predict the transient vibration of SRMs is developed. The vibration prediction model is built based on the detailed normal force versus phase current and rotor position lookup table using finite-element calculations. The model is then verified by a running motor test, which shows acceptable accuracy. The results reveal that there are abundant harmonics of transient force during transients and, thus, resonance may be excited. This model allows the possibility of improved design of SRMs from a vibration and acoustic noise point of view.

Analysis and characterization of switched reluctance motors: Part II. Flow, thermal, and vibration analyses

This paper presents new approaches for certain mechanical characterizations, such as thermal and vibration analyses, of switched reluctance motors (SRMs). The paper presents, in three parts, the modeling and simulation procedure for three-dimensional (3-D) finite-element analysis (FEA)-based flow analysis, flow-analysis-based thermal analysis, and a realistic vibration analysis. Section I documents a computational fluid dynamics (CFD) flow analysis procedure for the evaluation of the air velocity distribution inside the SRM at any speed. Section II presents a prediction method for steady-state and transient thermal characteristics of an SRM, using 3-D FEA. The convection coefficient at various heat-dissipating surfaces inside SRM, which is not a material property, but a quantity that solely depends on the air velocity at the respective surfaces, is the major parameter to be evaluated for an accurate simulation of heat distribution. The results of CFD analysis are used, for the first time on SRM, for this purpose. Windage loss calculation, one of the other applications of CFD, is introduced. Vibration in electric motors is an inevitable, at the same time undesirable, property that originates from four major sources: mechanical, magnetic, applied loads and, to a smaller extent, the associated electronic devices. Section III presents: 1) a thorough numerical study of vibration analysis in SRMs, using 3-D FEA methodology, covering all the above vibration sources except the electronics; 2) a 3-D modal analysis of SRMs including stator and rotor structures, shaft, end shields, bearings, and housing; 3) an unbalanced rotor dynamics analysis; 4) associated harmonic analysis; and 5) a stress analysis under various loading conditions. The 3-D vibration analyses presented in this paper to examine the vibration in SRM as a whole are new additions to SRM vibration analysis. Section IV concludes the paper. Future work in every section is highlighted.

Static and Dynamic Vibration Analyses of Switched Reluctance Motors Including Bearings, Housing, Rotor Dynamics, and Applied Loads

This paper presents a thorough numerical study of vibration analysis in electric motors, with particular application to switched reluctance motors (SRMs), using three-dimensional finite-element analysis (3-D FEA) methodology. It covers the major vibration sources: mechanical, magnetic, and applied load. The following analyses are presented. 1) A 3-D modal analysis including stator and rotor structures, shaft, end shields, bearings, and housing. 2) An unbalanced rotor dynamics analysis of the rotor, which is important for deciding on the eccentricity of the rotor mass to ensure that the vibration of rotor and housing is within acceptable limits. 3) A harmonic analysis to identify the range of speeds producing high vibration and noise that should be skipped over quickly during acceleration. 4) A stress analysis under different loading conditions (a simulation of load testing) to predict the deformation of the shaft and rotor. Apart from frequently reported modal analysis on the stator of SRMs in two dimensions, these 3-D vibration analyses are essential to examine the vibration in SRMs as a whole.

Orbital analysis of rotor due to electromagnetic force for switched reluctance motor

The purpose of this paper is to analyze the orbital response of rotor due to unbalanced electromagnetic force for switched reluctance motor (SRM). In order to reduce vibration of SRM, it is necessary to predict the mechanical dynamic behavior of the rotor-bearing system. So the orbit of the rotor according to rotation speed is analyzed by using the finite element method (FEM), and unbalanced electromagnetic force induced by dynamic eccentricity is calculated by the Maxwell stress tensor. From the results, the stability behavior of the rotor caused by unbalanced electromagnetic force is evaluated.