Design and Control of Levitation and Guidance Systems for a Semi-High-Speed Maglev Train Maglev;Levitation;Guidance;Semi-high-speed train; Research on Maglev (Magnetic Levitation) train is currently being conducted in Korea, concerning Urban Transit (110 km/h of maximum speed), semi-high-speed (200 km/h of maximum speed), and high-speed (550 km/h of maximum speed) trains. This paper presents a research study on the levitation and guidance systems for the Korean semi-high-speed maglev train. A levitation electromagnet was designed, and the need for a separate guidance system was analyzed. A guidance electromagnet to control the lateral displacement of the train and ensure its stable operation was then also designed, and its characteristics were analyzed. The dynamic performance of the designed levitation and guidance electromagnets was modeled and analyzed, using a linearized modeling of the system equations of motion. Lastly, a test setup was prepared, including manufactured prototypes of the designed system, and the validity of the design was verified and examined with performance evaluation tests.

A semi-high-speed magnetic levitation (maglev) train with a maximum speed of 200 km/h is being developed in Korea. It utilizes linear induction motors for propulsion and adopts electromagnetic suspension for levitation. For high-speed operation, guidance systems should be adopted to stabilize the train especially on curved tracks. For compatibility of the rail with previously developed urban maglev trains, the installation of the guidance electromagnet has to be restricted to be placed near the levitation electromagnet. Owing to the spatial closeness, mutual magnetic flux by the levitation and guidance electromagnets is produced at an overlapping portion of the rail. For stable control of the two systems, the coupling effects must be analyzed, because the levitation and guidance electromagnets are not operated independently. This paper aims to analyze the coupling effects by considering the magnetic field and a magnetic equivalent circuit. This paper suggests levitation and guidance systems for the semi-high-speed maglev train by considering each electromagnetic characteristic depending on the current direction.

This paper presents the analysis and experimental evaluation of the effective normal force and power consumption in maglev vehicle. Maglev vehicle employs the electromagnets as a suspension and linear motors for propulsion. These components give the higher ride comfort but suffered from energy efficiency. Therefore, vector control based algorithm and various air gap are employed to increase the propulsion efficiency and lower the system energy consumption. The effective levitation load according to levitation gap and normal force of a linear induction motor (LIM) is calculated by power consumption in levitation system and compared with finite element analysis results. The experiment is carried out with the full scaled train in test line and the efficiency of propulsion system is also presented.

Motor design can be said as multi-modal optimization problem, as many performances should be considered. In addition, a time-consuming finite element method (FEM) is required for accurate analysis of the motor, and such computational burden becomes worse when the FEM is applied to multi-modal optimization problem. In this paper, adaptive-sampling kriging algorithm (ASKA) is proposed to relieve the computation cost of multi-modal optimization problem. The ASKA utilizes kriging interpolation model with generated samples by Compact Search Sampling (CSS) and Exclusive Space-filling Method (ESM). The CSS improves the accuracy of the solutions by generating samples near the expected solutions, and the ESM guarantees the diversity of solutions by generating samples far from existing samples, avoiding solution-near area. Using CSS and ESM, the ASKA adjusts the number of samples effectively and reduces function call considerably. The superior performance of the ASKA was verified by mathematical test functions with complex objective function regions. To validate the feasibility of actual electric machines, the ASKA was applied to optimal design of permanent magnet assisted synchronous reluctance motors for electric vehicles and optimum design with diminished torque ripple is derived.

This paper describes the levitation and guidance characteristics of a semi-high-speed magnetic levitation (MAGLEV) vehicle. For a MAGLEV, which operates at 200 km/h, the guidance magnet is essential for high-speed operation at curves and against a side wind. The levitation and guidance magnets are electromagnetically and dynamically coupled, because both are used in a single rail. Because of the interactions between the levitation and guidance systems, clear establishment of their correlation is required for robust and stable control. We identify the electromagnetic/dynamic correlation of the levitation and guidance systems of the MAGLEV using a magnetic equivalent circuit and motion equations. A controller is developed to realize stable control by considering the system correlation. The control properties are obtained through simulation to achieve stable levitation and guidance.

This paper presents the analyses and experimental results of a single-sided linear induction motor (SLIM) thrust and normal force for the propulsion of semi-high-speed magnetic levitation (maglev) trains. These trains are composed of a levitation system that uses electromagnetic suspension and a propulsion system that uses SLIMs. The propulsion system of maglev trains using SLIMs has better low noise and dynamic characteristics compared with those using rotators. However, it has nonlinear characteristics due to the effect of slip that occur in the secondary eddy-current induction process; the normal force generated by the SLIM can negatively affect the levitation control. Therefore, a new slip-control algorithm is proposed for the safe operation of maglev trains, reflecting the normal force of the motor in propulsion control. First, the SLIM thrust and normal force are analyzed through the finite-element method (FEM) for a precise analysis of the slips. Furthermore, a slip range with a low normal force was derived based on the FEM analysis results, and these results are reflected in the propulsion control algorithm. Finally, the new algorithm was validated by an application to a full-sized testing apparatus.