MAGNETIC LEVITATION TRAIN TECHNOLOGY II

Transcription

1 MAGNETIC LEVITATION TRAIN TECHNOLOGY II SENIOR PROJECT PROPOSAL Department of Electrical and Computer Engineering Bradley University December 10, 2003 Students: Tony Pederson and Toby Miller Advisor: Winfred Anakwa

2 PROJECT SUMMARY: The main idea of this project is to make a magnetic levitation train. The train car will be made of aluminum and have rare earth magnets attached to it. By arranging the magnets in a Halbach Array, they will provide levitation when moving at a minimum speed over the track and will help provide propulsion. The track will be made of two aluminum rails with copper wire coils around it and a linear synchronous motor attached to the inside of the two rails. This motor will interact with the Halbach Array to provide propulsion. Figure 1 below shows the block diagram of the system. FREQUENCY REFERENCE SIGNAL FOR SPEED CONTROL CONTROLLER TRAIN WITH SPEED SENSOR THREE- PHASE POWER INPUT TRACK FIGURE 1 BLOCK DIAGRAM OF SYSTEM SUBSYSTEMS: Train The train will have one sensor on it to measure speed. This sensor may or may not be attached to the train. This will be determined later. (See figure 4) Changes in the frequency of the signal in the track will change the speed of the train and will in turn determine the levitation height. Four Halbach Arrays will be on the train to provide levitation and to keep it centered on the track. (See FIGURE 2)

3 FIGURE 2 Drawing of Track and Train Track The track will consist of levitation coils and a propulsion motor. Different types of motors are being researched and are discussed later. The levitation will either be laminated sheets of aluminum or copper or wire wrapped around the track. The track will be made out of aluminum. The dimensions and shape of track are still being determined Controller Consists of an analog or digital system with one speed sensor. The system will consist of varying the frequency of the signal sent to the linear synchronous motor. The variable frequency will change the speed of the train and levitation height. The input to the controller will be the speed sensor. FIGURE 3 DIAGRAM OF THE CONTROLLER

4 TECHNOLOGY FOR LEVITATION: Electrodynamic suspension (EDS) The magnets on the train produce currents while traveling in the guide way. This uses repulsion to guide and support the train, but will need a support for landing and takeoff since EDS does not work below 25 mph on a full size train. The minimum speed for levitation will be determined later once the train is built. It has been determined to be a function of magnet size, speed, and weight. Halbach Array This special type of magnet array will levitate train. Interaction between the linear synchronous motor and the Halbach Array will provide the propulsion. Figure 4 shows an example of the Halbach Array. Halbach Array s are a special arrangement that cancels the magnetic field above the magnets, but allows the combination of fields below. The permanent magnets that will be using are made out of a rare earth metal, Neodymium Iron Boron (NdFeB). FIGURE 4 HALBACH ARRAY TECHNOLOGY BEING RESEARCHED FOR PROPULSION: "Long-stator" propulsion An electrically powered linear motor winding in the guide way is used instead of a passive system like the short-stator. A type of linear synchronous motor will be used. POWER REQUIREMENTS: Three-phase power will be required to run the MAGLEV system. The coils used for propulsion could draw large amounts of current, so the power requirements could be substantial. The size of the train will determine how much current the coils draw. In an actual train, the power required to run the train is less than to run the air conditioner for a full size train.

5 SPRING SEMESTER SCHEDULE: WEEK 1 Build the Train and Make Track Calculations WEEK 2-3 Build the Track and Design Motor WEEK 4-8 Do Testing on Levitation and Propulsion WEEK 8-10 Design Controller and Implement WEEK General Troubleshooting WEEK Prepare for Presentation and Final report The partners will be working on almost all aspects of this project together since no systems are independent enough to work on alone. All systems scheduled earlier have to be completed before work on the next system can begin. Bibliography: Electromagnetic analysis of inductrack magnetic levitation Murai, Toshiaki; Hasegawa, Hitoshi Source: Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi), v 142, n 1, Jan 15, 2003, p6774 MAGLEV projects technology aspects and choices Cassat, A. (Swiss Federal Institute of Technol., Laboratory of Electromechanics); Jufer, M. Source: IEEE Transactions on Applied Superconductivity, v 12, n 1, March, 2002, p Design and analysis framework for linear permanent-magnet machines Trumper, David L. (Massachusetts Inst of Technology); Kim, Won-jong; Williams, Mark E. Source: IEEE Transactions on Industry Applications, v 32, n 2, Mar-Apr, 1996, p