Eddy Current Braking System Research Articles

Thermal network model of rotary eddy current braking system for transient thermal process analysis

Thermal network model of rotary eddy current braking system for transient thermal process analysis

Analysis of linear eddy current brakes for maglev train using an equivalent circuit method

An equivalent circuit method (ECM) is developed to analyse the linear eddy current braking system (ECBS) of the maglev train. The distribution of eddy current in the rail is represented by dividing the rail into a series of small segments in which the current is assumed to be uniform. Each segment is described as an equivalent circuit with parameters of resistance and inductance. The circuit parameters, such as self-inductance and mutual inductance, are evaluated from the geometry parameters using an analytic method. The state equation derived from the circuit equations and the Newton's equations is solved using the Runge–Kutta method, from which the dynamic performance of the linear ECBS can be obtained. The accuracy and efficiency of the proposed ECM are verified by comparing the results with the one obtained from the finite element method. By adopting the developed ECM, the influence of parameters, such as speed, the exciting current and air gap of the linear ECBS, are analysed. The variation law of the linear ECBS with parameters is roughly grasped.

Drag-based aerodynamic braking system for the Hyperloop: a numerical study

The Hyperloop promises to revolutionize the transport infrastructure of the 21st century by reducing travel time and allowing people to reach transonic speed on land. It carries with it the hope of a sustainable transportation system during an era of global energy crisis. Overall passenger safety in a high-speed pod necessitates a reliable braking system. This paper introduces the possibility of utilizing aerodynamic drag in the Hyperloop, anticipated to operate at high Mach and low Reynolds flow regime, to attenuate the speed of the pod. Numerical analysis was conducted to investigate the effect of incorporating an aerodynamic brake at different pod velocities (100, 135, and 150 m/s) and deployment angles (30°, 45°, 60°, and 90°). A detailed comparison between the proposed aerodynamic braking system (AeBS) and existing braking systems for the Hyperloop has been presented in this paper. The results demonstrate an increase in drag value of the pod by 3.4 times using a single 0.15 m2brake plate. When the brake plate was fully deployed at a pod velocity in excess of 112 m/s, the aerodynamic drag-based braking systems was shown to be more effective than the contemporary eddy current braking system.

Material Selection and Optimisation of an Eddy Current Braking System with Regeneration

With the urge in increase in speed of locomotives in Indian Railways, there is increased urge in safety of railway is increased speed will automatically needs in increased effectiveness in a braking system. With the braking system in Indian railways relies on regenerative pneumatic braking it does have a time – lapse on braking from the front to the end of the locomotive. Thus,this work is on material selection for eddy current braking with regeneration for faster braking, and power regeneration from braking

Identification and Analysis of different parameters for Eddy Current Braking System along with its applications

Identification and Analysis of different parameters for Eddy Current Braking System along with its applications

Characteristic Analysis of the Peak Braking Force and the Critical Speed of Eddy Current Braking in a High-Speed Maglev

In the eddy current braking system of high-speed maglev, the peak braking force and the critical speed are key factors determining the performance of eddy current braking force. In this paper, the analytical formula of eddy current braking force is derived by a subdomain method considering the skin effect of the induction plate, and, subsequently, the characteristics of peak braking force and critical speed are analyzed. The analytical model is set up in a 2D Cartesian coordinate system. The Poisson equations in each subdomain are listed by treating the vector magnetic potential as a variable. By combining the boundary conditions between two adjacent subdomains, the expressions of eddy current density and magnetic density in the induction plate are obtained. Then, the analytical formula of the eddy current braking force is obtained by the Ampere force formula. The results of finite-element analysis confirm the validity of the analytical calculation. The methods of improving the performance of eddy current braking force under high speed are proposed by parametric analysis of peak braking force and critical speed, which provides guidance for the design of the eddy current braking system in high-speed maglev.

Modelling, analysis and control of an eddy current braking system using intelligent controllers

Combination of conventional brakes with Eddy Current Brake is the current trend in many applications where superior braking performance at high speed is desired. Eddy Current Brakes being frictionless and contactless offer numerous advantages over conventional brakes. This paper gives detailed insi ght into the hardware model development, analysis and control of a multi disc Eddy Current Braking System using different intelligent controllers. Firstly, Fuzzy Logic Controller has been developed which can give the feasible value of the electromagnet current required which leads to improved braking performance. Further, Artificial Neural Network Controller has been designed for existing hardware system which gives better, reliable, efficient results in comparison to the Fuzzy Logic Controller and hardware reference model for the sample period of time.

Implicit control of eddy current braking system using fuzzy logic controller (FLC) and particle swarm optimisation (PSO)

This paper shows the novel design of Eddy Current Braking System (ECBS) using soft computing techniques mainly FLC and PSO for the validation of experimental results of ECBS. Eddy Current Brakes are used in many applications where superior braking performance at high speed is desired. Eddy current brakes being frictionless and contactless offer numerous advantages over conventional mechanical brakes. The ECBS can be implemented in aircraft arreter barrier system as energy absorber for optimum braking. The hardware model of ECBS has been developed, simulated, and analysed. Performance of ECBS was optimized using soft computing techniques such as FLC and PSO on the MATLAB platform and the control dynamics of the system was analysed. It was observed that PSO based ECBS gives better result in comparison to FLC based ECBS in terms of settling time and peak overshoot.

Experimental Investigation of Influence of Various Parameters on Permanent Magnet Eddy Current Braking System

Investigations on permanent magnet eddy current braking system were carried out with Neodymium – Iron – Boron (NdFeB) magnets of 12.5 mm thickness and 50 mm diameter. Investigations were carried out with Copper, Aluminium, Brass discs of 4 mm, 6 mm and 8 mm thickness at 2000 rpm, 3000 rpm and 4000 rpm totalling to 27 experiments. It is observed that Copper disc 6 mm thickness has 84.8%, 86.3%, 81.8% speed reduction. Time taken for speed reductions are 16 seconds, 15 seconds and 22.5 seconds respectively. Aluminium disc of 8 mm thickness was observed to have 70.6%, 86% and 85.1% speed reduction. Time taken for speed reductions are 3.3 seconds, 10 seconds and 18 seconds respectively. Brass disc of 4 mm thickness was observed to have speed reduction of 61.8%, 60% and 57.4%. The time taken for speed reductions are 25.2 seconds, 20 seconds and 24.5 seconds respectively. Considering that the density of Aluminium is less, cost effective and time taken for higher percentage of speed reduction is less compared to Copper and Brass, Aluminium disc of 8 mm thickness is the best material for transportation and other applications.

DESIGN OF DOUBLE-SIDED LINEAR PERMANENT MAGNET EDDY CURRENT BRAKING SYSTEM

This work tries to design an Eddy current braking system that can brake at a very high speed within a short time or a short distance. In order to maximize the braking force and reduce lateral forces that can cause track deformation or damage, a double-sided linear permanent magnet Halbach array is proposed in this paper. Two possible designs (Type I and Type II) have been investigated. By using mathematic models, Finite Element Method (FEM) and experimental results, Type I design of a double-sided linear permanent magnet Halbach array is selected. Compared with the other design, Type I design can provide a much larger braking force. Moreover, the analysis also shows that the mathematic models can well capture the characteristic of Type I design. Thus these models are used to design a set of optimal design parameters such as the length and thickness of permanent magnet block to maximize flux density and braking force per unit mass of permanent magnets. The optimal performance is validated by using FEM.

English

Eddy Current braking technique is a classical example of how effective and efficient braking be obtained from application of magnetic field. Eddy current braking is based on the principle of relative motion between a magnetic source and a metal. In this paper, eddy current braking system is modeled in SIMULINK and effects of various parameters are observed over the overall braking. This would provide a comparative study between the various parameters involved and understand the braking system.

Investigation on Eddy Current Braking Systems – A Review

The changing magnetic field will induce eddy currents in the conductor. These currents will dissipate energy in the conductor and generate drag force. It is found that Aluminium is the best material as conductor compared to Copper and Zinc. Also, it is found that the larger thickness of disc, more number of turns of electromagnet and higher electrical conductivity of conductor influences the generation of greater braking torque. Conventional braking system relies on adhesion force between rail and wheel. It is found that a brake built up from permanent magnet pieces that combine both magnetic rail brake and eddy current brake permits the most profitable braking action through the whole range of acceptable speeds. Permanent magnet eddy current brake uses Neodymium - Iron - Boron (NdFeB) magnets. The analysis of permanent magnet eddy current shows that the parallel magnetised eddy current topology has the superior braking torque capability. In electrically controlled eddy current braking system subjected to time varying fields in different wave forms, the triangular wave field application resulted in highest braking torque. Electromagnetic brakes were found to interfere with the signalling and train control system. Permanent magnet eddy current brakes are a simple and reliable alternative to mechanical or electromagnetic brakes in transportation applications. Greater the speed greater is the eddy current braking efficiency. Hence, author intends to work on the development and investigation of permanent magnet eddy current braking system.

A linear eddy current braking system defined by finite element method

The authors propose in this paper the modelling and computing of a linear eddy current braking system by the finite element method. This braking system will be used in a high speed train. They study this device in 2D and 3D taking into account nonlinearities such as saturation and the displacement of the train. The authors present many results detailing the induction, the eddy currents in the rail and the braking force versus train speed.

A study of the design for touch free linear eddy current brake

This paper describes the performances of eddy current brake according to the design parameters. The characteristics are analyzed by using 2-dimensional Finite Element Method (2-D FEM) in order to predict the effect of the design parameters. The magnet stack width is determined from equivalent stack width that is calculated by solution of the field with scalar potential. The validity of available calculation program with FEM is achieved by comparing with experimental value. From the results, the optimized magnet configuration of the eddy current braking system is designed to obtain not only the maximum braking force but also the minimum attraction force.

Calculation of the 3D nonlinear eddy current field in moving conductors and its application to braking systems

This paper presents a complete FE formulation for the calculation of 3D nonlinear eddy current fields with ferromagnetic moving conductors. The formulation is realized by using the A/spl I.oarr/, V-A/spl I.oarr/ formulation in combination with the Coulomb gauge. To consider nonrectangular shapes of geometries tetrahedral elements were employed. The computation procedure is applied to an eddy current braking system of a high velocity train and the resulting braking forces are compared to measurements.