• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.733-734
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• 2006

In this parer, characteristics of the flexible rail in levitation control system are analysed. The magnetic levitation system is an electromagnet type and is full-scaled vehicles. The system consists of electromagnet, chopper, flexible rail, secondary suspension system and levitation controller. The mathematical modelling for the whole system is carried out. Especially, the flexible rail is modelled using second-order mass-spring-damper system. Using the derived model, the dynamic characteristics for the system are presented with different vehicle speed.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.2
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• pp.129-135
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• 2014

In the paper, we propose a design method for the logistics transportation system using magnetic levitation that has a good characteristics without mechanical friction, noise and dust. The proposed transportation system consists of a levitation control system and a propulsion control system. Magnetic levitation system is an electromagnetic suspension system in which electromagnet generates magnetic attractive force and the attractive force pulls the rail. We design a PID controller for the current control of electromagnets. We use linear induction motors for propulsion of the proposed logistics transportation system and adapt the space vector PWM method for the propulsion control system. The proposed transportation system using magnetic levitation is verified performances through levitation and propulsion experiments.

• Journal of Power System Engineering
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• v.14 no.1
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• pp.65-70
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• 2010

Magnetic levitation system is nonlinear and inherently unstable, so it is difficult to control. Analog control circuit was widly used as the controller of magnetic levitation system, but digital controller is now substituted for analog controller according to development of digital electronics. In this study, Atmel AVR series, ATmega 128 which is a kind of $\mu$-processor for digital controller is used because the chip is cheap and popular. We designed and made ATmega 128 one-board controller and aimed to verify validity through the experiance of levitation response.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.175-181
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• 1996

The magnetic levitation system is utilized in the magnetic bearing of high-speed rotor because of little friction, no lubrication, no noise and so on. The magnetic levitation system need the feedback controller for the stabilization of system, and gap sensors are usually used to measure the gap. The use of sensor is troublesome such as sensor trouble, discord between the measurement point and the control point etc. This paper presents the design of robust stabilizing controller by H$_{\infty}$ control theory using the sensorless method proposed already by authors in the magnetic levitation system. And we investigated both the validity of the designed controller and the usefulness of the sensorless method proposed by authors of magnetic levitation system through results of actual experiment..

• Journal of Power System Engineering
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• v.1 no.1
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• pp.144-153
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• 1997

The magnetic levitation system is utilized in the magnetic bearing of high-speed rotor because of little friction, no lubrication, no noise and so on. The magnetic levitation system need the feedback controller for the stabilization of system, and gap sensors are generally used to measure the gap. The use of gap sensors brings out the increase of the number of troublesome, and the decrease of the control performance because of the dislocation between the measurement point and the control point. This paper presents the design of the gap estimation circuit for the sensorless method proposed by authors in the magnetic levitation system. We made the gap estimation circuit which was composed of both the superposition circuit and the measuring circuit. And we investigated the validity of the usefulness of the proposed sensorless method in the magnetic levitation system through results of actual experiment.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.316-320
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• 1993

Electromagnetic suspension (E.M.S) type levitation system is studied in the control system design viewpoint. Dynamic characteristics in theoretical analysis as well as hardware implementation is considered. Open loop unstable, non-linear and timevarying characteristics are reviewed in the theoretcal section, while levitation control system for multi-vehicle train as well as magnet drive system is reviewed in the practical section. This paper suggests not only some well-known problem appearing in levitation control system design but also a subtle problem and solution candidates. But there exist many unmentioned problems wating for a smart problem solver.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.647-648
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• 2006

In this paper, magnetic levitation characteristics of hybrid magnets are experimentally shown under the newly proposed airgap condition. The digital PID controller is utilized to control the airgap of the magnetic levitation system.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.117-125
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• 2017

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.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.7
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• pp.875-880
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• 2016

A new hybrid permanent magnet biased magnetic levitation actuator (maglev) is developed. This new maglev actuator is composed of two C-core electromagnetic cores separated with two permanent magnets. Compared to the conventional hybrid maglev actuators, the new actuator has unique flux paths such that bias flux paths are separated with control flux paths. The control flux paths have minimum reluctances only developed by air gaps, so the currents to produce control fluxes can be minimized. The gravity load can be compensated with the permanent magnet bias fluxes developed at off-centered air gap positions while external disturbances are controlled with control fluxes by currents. The consumed power to operate this levitation system can be minimized. 1-D magnetic circuit model is developed for this model such that the flux densities and magnetic forces are extensively analyzed. 3-D finite element model is also developed to analyze the performances of the maglev actuator.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.4
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• pp.715-721
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• 2010

This paper deals with the design and characteristic analysis of electro-magnet/permanent-magnet (EM-PM) hybrid levitation and propulsion device for high-speed magnetically levitated (maglev) vehicle. The machine requires PMs with high coercive force in order to levitate the vehicle by only PMs, and propulsion force is supplied by long-stator linear synchronous motor (LSM). The advantages of this configuration are an increasing levitation airgap length and decreasing total weight of the vehicle, because of the zero-power levitation control. Several design considerations such as machine structure, manufacturing, and control strategy are described. Moreover, the levitation and propulsion device for high-speed maglev vehicle has been designed and analyzed usign the electromagnetic circuit and FE analysis. In order to verify the design scheme and feasibility of maglev application, 3-DOF static force test set is implemented and tested. The obtained experimental data using the static tester shows the validity of the design and analysis approaches.