Magnetic Levitation

Optimizing the Controller Design to Guide the Motion of a Maglev Train

The challenge: To design a robust feedback controller and optimize the control parameters to guide the motion of a Maglev train along the guideway

© Maplesoft, a division of Waterloo Maple Inc., 2008

Introduction Problem Definition 1. Model Development

1.1 Linear Model of the Magnet 1.2 Model for the Linearized Magnet Force 1.3 Model of Magnet Dynamics

2. Control System Design

2.1 PI Controller 2.2 Control Specifications and Measurements 2.3 Control System Transfer Function 2.4 Controller Gains & Closed Loop System 2.5 The Final Design

3. Vehicle Model

3.1 Equations of Motion 3.2 Response Plots

Results

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Introduction

Magnetically Levitated (Maglev) trains differ from conventional trains in that they are levitated, guided and propelled along a guideway by a changing magnetic field rather than by steam, diesel or electric engine. The absence of direct contact between the train and the rail allows the Maglev to reach record ground transportation speeds, which are on par to that of commercial airplanes.

Figure 1: (A) Cross sectional view of cabin & (B) Expanded view of magnet support structure

An Electromagnetic Suspension (EMS) Maglev train uses the attractive forces of magnets (& electro-magnets), positioned below a guideway, to levitate a train and guide it along the guideway (fig 1). Three phase AC propulsion coils mounted along the steel rails of the guideway provide a moving magnetic field that interacts with the periodic magnetic field created by the lifting magnets to propel the train forward. There are 24 lifting magnet pairs (48 magnets all together) mounted along the length of the train. The lifting magnets, which are canted at an 37° angle towards the steel rails, consists of high temperature superconducting (HTS) magnets and conventional (non-superconducting) coils (fig 2). A periodic magnetic field is generate by...