BRADLEY UNIVERSITYDepartment of Electrical and .ppt

1、BRADLEY UNIVERSITY Department of Electrical and Computer Engineering Sr. Capstone ProjectAdvisor: Dr. AnakwaStudent: Paul Friend,Overview:Background Information Halbach Array Inductrack Sensors Propulsion Methods,Controls Physical Design Theories Parts and Equipment Schedule Resources,Background Inf

2、ormation Inductrack: Created by Richard F. Post in the late 1990s at Lawrence Livermore National Laboratory 20 meter test track Burst Propulsion,Background Information Inductrack: Contracted by NASA for Satellite Launcher Low-Speed Urban Maglev Program,Halbach Array Created by Klaus Halbach Creates

3、a strong, nearly one-sided magnet with a sinusoidal field by directing the magnetic fields.,Halbach Array Standard FormationExpanded WavlengthDoubled Method,Halbach ArrayB0 = Br (1 e-2d/)(sin(/M)/( /M) Tesla B0 = 0.82843 (1/2” Gr. 38 NdFeB Cube Magnets)Bx = B0 sin(2/)x) e-(2/) (y1 y) TeslaBy = B0 co

4、s(2/)x) e-(2/) (y1 y) Tesla,Inductrack Basic Methods: Array of InductorsLaminated CopperLaminated Aluminum,Inductrack Array of Inductors Used in 1st Inductrack Insulated Litz-wire Ferrite Loading,Inductrack Laminated Copper Square Litz-wire bulks Used for Low-Speed Urban Maglev Program,Inductrack La

5、minated Copper & Aluminum Thin Sheets Slots cut to guide eddy currents Slots terminated at ends for “shorts”,Inductrack PhysicsLenzs Law Discovered in 1834 Eddy currents created due to moving magnetic field (Not guided),Inductrack Physics Circuit Equation: V = L dI/dT + RI = 0 cos(t) VLift/Drag Rati

6、o: Lift/Drag = / = L/R = (2v/) (L/R)Power Efficiency: K = / = (2/) (L/R) Newtons/Watt,Inductrack Physics optimum = 4 y1 m Magnet thickness of /5 Only valid for max. load for min magnet weightand for original Inductrack50:1 levitated weight/magnet weight ratio,Inductrack Inductrack II,Sensors Types:

7、Velocity Sensor Optical Sensor Magnetic Sensor,Propulsion Types: Linear Synchronous Motor (LSM)Linear Induction Motor (LIM),Propulsion Linear Synchronous Motor (LSM) Used for Low-Speed Urban Maglev Program Allows for large air gap 25 mm Varied 3-phase frequency and current for contols Solid copper c

8、ables and laminated iron rails Works with Halbach array,Propulsion Linear Induction Motor (LIM) Typically electromagnets in train Aluminum ladder as track Levitation and propulsion aquired,Propulsion Modified Linear Induction Motor (LIM) Synchronized electromagnets Precision sensing required Control

9、ed via the currentPWMCurrent Level,Controls Properties to Control (80515 Microcontroller Based)Levitation HieghtDirectionVelocity,Controls Levitation Height Control Theory of current Low-Speed Urban Maglev Program Height by causing a phase shift Compromises the structure,Controls Direction and Veloc

10、ity Control Modified Induction Motor (LIM) Sensing and Electromagnets,Controls Direction and Velocity Control Inputs:Mode of OperationVelocity or Current Outputs:Train LevitationTrain PropulsionLCD Display,Controls Direction and Velocity Control Modes of Operation: 0.) Open Loop Backwards Current In

11、put 1.) Closed Loop Backwards Velocity Input with Control 2.) Backwards Coast with No Propulsion 3.) Stop 4.) Forwards Coast with No Propulsion 5.) Closed Loop Forwards Velocity Input with Control 6.) Open Loop Forwards Current Input,Controls Free Running Position Detector Inputs:CurrentDirectionAdd

12、ressed Sensor Outputs:Addresses SenosrAddresses ElectromagnetsVelocity,Controls Open Loop Modes 0 & 6 Inputs:Current LevelDirection Outputs:Current,Controls Closed Loop Modes 1 & 5 Inputs:VelocityDirection,Controls Coast Modes 2 & 4 Direction is indicated for sensor prediction Utilizes free running

13、position detector with no current Velocity still displayedStop Mode 3 Pulse electromagnets in front of train Position detector can not be used Details have not been worked out,Controls High Power DC Switching Current Control Power MOSFETInsulated -gate bipolar transistor (IGBT)Gate-turn-off thyristo

14、r (GTO),Controls Current Converted Converts current levels 0 - 256 (0-FF hex) to increasing current levels using PWM and resistor paths,Controls Magnet Addresser Directs current to each individual electromagnet using an array of switches for each section, and corresponding placement in each section.

15、,Physical Design Materials Wood and 1/16” Aluminum,Testing Inductrack Testing Use of a horizontal or lateral wheel Utilized by Post,Theories Disk Method Wheel Method Tractor Tread Method Paddle Wheel Method,Standards Table of standards used by the Low-Speed Urban Maglev ProgramWill be used for conce

16、pts to keep in mind,PatentsRichard F. Post Magnetic Levitation System for Moving Objects U.S. Patent 5,722,326 March 3, 1998 Richard F. Post Inductrack Magnet Configuration U.S. Patent 6,633,217 B2 October 14, 2003Richard F. Post Inductrack Configuration U.S. Patent 629,503 B2 October 7, 2003Richard

17、 F. Post Laminated Track Design for Inductrack Maglev System U.S. Patent Pending US 2003/0112105 A1 June 19, 2003Coffey; Howard T. Propulsion and stabilization for magnetically levitated vehicles U.S. Patent 5,222,436 June 29, 2003,Coffey; Howard T. Magnetic Levitation configuration incorperating le

18、vitation, guidance and linear synchronous motor U.S. Patent 5,253,592 October 19, 1993Levi;Enrico; Zabar;Zivan; Air cored, linear induction motor for magnetically levitated systems U.S. Patent 5,270,593 November 10, 1992Lamb; Karl J. ; Merrill; Toby ; Gossage; Scott D. ; Sparks; Michael T. ;Barrett;

19、 Michael S. U.S. Patent 6,510,799 January 28, 2003,Schedule Tentative schedule:Weeks 1 4 Development and testing of tracks Weeks 5 8 Development of a propulsion method Weeks 9 10 Integration of the propulsion and the Inductrack Weeks 11 13 Propulsion Controls Week 14 Finish Loose EndsBased on progre

20、ss, meetings with Dr. Anakwa will determine the direction the project will take after each step,Parts and Equipment40 - 1/2” NdFeB, Grade 38 Cubes $90.00 40 - 1/4” NdFeB, Grade 38 Cubes $14.40 Litz-wire Bulks, Copper Sheets, Aluminum Sheets, Wheels, Conductive balls, and Electromangets Cart/Train no

21、n inductive materials and CNC router machine time provided by Midwestern Wood Products Co.,ResourcesMany Documents by Richard F. Post (LLNL) General Conversation with Richard F. Post (LLNL) General Conversation with Phil Jeter (General Atomics) General Conversation with Hal Marker (Litz-wire) General Converastion with Dr. Irwin (Bradley University),