The Experts below are selected from a list of 52191 Experts worldwide ranked by ideXlab platform

Chang-hyun Kim - One of the best experts on this subject based on the ideXlab platform.

  • Experimental development of Levitation control for a high-accuracy magnetic Levitation transport system
    ISA transactions, 2020
    Co-Authors: Jaeyoung Kim, Galen B. King, Chang-hyun Kim
    Abstract:

    Abstract In this paper, we present the experimental Levitation control development in a high-accuracy magnetic Levitation transport system. With this Levitation control implementation, the input and output of sub-systems can be verified through a real-time system. The Levitation control loop has a fast response, and the control algorithms are easily implemented. In addition, a notch filter and a low-pass filter are designed to minimize mechanical resonance and sensor noise, respectively. Moreover, a section control algorithm is developed to reduce sudden changes in the Levitation forces. From the results, the total current required to levitate the carrier is approximately 3.1 A, and it is decreased to approximately 2.45 A at the desired airgap. The maximum peak-to-peak variation of the airgap measurement at a standstill is approximately 50 μ m , and at low and high movement speeds, it is approximately 300 μ m and 700 μ m , respectively. Moreover, the good Levitation control performance in the deadzone, where one pair of the Levitation electromagnets is disabled, is also verified.

  • Analysis of the Levitation control system of the super-speed magnetic Levitation train
    2015
    Co-Authors: Ju-byeong Chae, Chang-hyun Kim, Jaewon Lim, Seok-jo Yang, Hyung-suk Han
    Abstract:

    One of the core technology of the super-speed magnetic Levitation train is a Levitation control technology to maintain a constant Levitation gap between the rail and bogie. For the precise Levitation control, Levitation controller should be verified with the strict Levitation system modeling. In this paper, the Levitation system is modeled based on currently developing super-speed magnetic Levitation train, the Levitation control simulator is developed. The characteristic analysis of the Levitation controller is carried out by utilizing this simulator. Finally, the utility of the designed Levitation controller is verified applying the proposed Levitation controller in actual vehicle.

  • ISR - Levitation and guidance control of passive magnetic Levitation tray system
    IEEE ISR 2013, 2013
    Co-Authors: Chang-hyun Kim, Changsun Ahn, Jin-woo Park, Doh-young Park
    Abstract:

    This paper describes the Levitation and guidance control of a passive magnetic Levitation tray system. In this system, a moving tray is completely contactless and has no electric equipments. Lifting, guiding and propelling forces are generated by external electromagnets. Especially, we focused on the Levitation and guidance control in this paper. We designed the controllers and evaluated their performances through experiments.

  • Equivalent Magnetic Circuit Based Levitation Force Computation of Controlled Permanent Magnet Levitation System
    IEEE Transactions on Magnetics, 2012
    Co-Authors: Han-wook Cho, Chang-hyun Kim, Seok-myeong Jang, Jong-min Lee, Hyung-suk Han
    Abstract:

    This paper proposes an analytical Levitation force computation method using the equivalent magnetic circuit (EMC) of a controlled-permanent magnet (CPM) Levitation system that has potential applications in a magnetically levitated vehicles. The airgap field and Levitation force characteristics of the CPM are investigated using the EMC, considering airgap fringing and leakage flux path for longitudinal and lateral direction surfaces. The computation results are validated using finite-element analysis and experimental results. The Levitation performance was tested using a dynamic force test facility, which confirms the validity of the EMC computation scheme for the description of a CPM Levitation system.

Xiaoli Wang - One of the best experts on this subject based on the ideXlab platform.

  • independent control of average torque and radial force in bearingless switched reluctance motors with hybrid excitations
    IEEE Transactions on Power Electronics, 2009
    Co-Authors: Xi Cao, Zhiqua Deng, Gang Yang, Xiaoli Wang
    Abstract:

    Radial force and torque are the control objectives that determine the machine performance of Levitation and rotation in a bearingless switched reluctance motor (BSRM). This paper proposes a control scheme for rotating and levitating a 12/8 BSRM. The motor average torque and radial force are independently controlled with hybrid excitations in main windings and Levitation windings. First, the mathematical relationship between radial force and currents, which is utilized in this paper, is derived by using the Maxwell stress tensor method. Then, the proposed control scheme is analyzed. The average torque of each phase generated in the Levitation region equals zero for its symmetry of the aligned position. Accordingly, the current calculating algorithm is deduced to minimize the magnitude of instantaneous torque in the Levitation region. The principle and realization of the proposed scheme are demonstrated with finite-element (FE) analysis. Experimental results show that the proposed scheme is effective for a stable Levitation.

Zhiquan Deng - One of the best experts on this subject based on the ideXlab platform.

  • compensation strategy of Levitation forces for single winding bearingless switched reluctance motor with one winding total short circuited
    IEEE Transactions on Industrial Electronics, 2016
    Co-Authors: Xin Cao, Han Yang, Lei Zhang, Zhiquan Deng
    Abstract:

    In order to take advantage of conventional switched reluctance motors (SRMs), the SRM is integrated with the bearingless motor technology and then a reluctance type of bearingless motor is created, named as bearingless SRM (BSRMs). Not only electromagnetic torque but also the Levitation forces should be controlled in BSRMs, which is different from SRMs. The Levitation forces should always exist even when winding fault occurs. Therefore, the absent Levitation forces that ought to be produced by the fault winding should then be compensated by other winding. This paper proposes the compensation strategy of Levitation forces for BSRMs when one stator winding is short circuited. The short-circuit fault is investigated and the short-circuit current is expressed for the derivation of radial forces. Then, the winding compensation rule and the mathematical model of Levitation forces are developed to facilitate the compensation control for the motor Levitation. After that, the proposed compensation strategy is verified by simulation results in MATLAB/Simulink. Experimental results are also presented to demonstrate the performance.

Jangyoung Choi - One of the best experts on this subject based on the ideXlab platform.

  • analysis and control of electromagnetic coupling effect of Levitation and guidance systems for semi high speed maglev train considering current direction
    IEEE Transactions on Magnetics, 2017
    Co-Authors: Jaehoon Jeong, Jaewon Lim, Jangyoung Choi
    Abstract:

    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.

  • analysis and control of the electromagnetic coupling effect of the Levitation and guidance systems for a semi high speed maglev using a magnetic equivalent circuit
    IEEE Transactions on Magnetics, 2016
    Co-Authors: Jaehoon Jeong, Changwan Ha, Jangyoung Choi
    Abstract:

    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.

Jiasu Wang - One of the best experts on this subject based on the ideXlab platform.

  • Influence of YBCO Bulk’s Movement Speed and Operation Time on Levitation Force at Different Temperatures
    Journal of Superconductivity and Novel Magnetism, 2012
    Co-Authors: Hua Jing, Suyu Wang, Ming Jiang, Jiasu Wang
    Abstract:

    In order to enhance Levitation performance of the high temperature superconducting (HTS) magnetic Levitation (Maglev) vehicle and have more stable and safer operation, Levitation forces of YBCO bulk with different movement speeds and operation time at different temperatures are studied. The Levitation force is measured using a cryogenic measurement system which has advanced instrumentation. Experimental results show that the Levitation force is not only dependent on the temperature but also on the YBCO bulk’s movement speed and operation time. It is found that the effect of YBCO bulk’s movement speed and operation time on the Levitation force is larger at higher temperatures, while such effect is smaller at lower temperatures.

  • Flux Concentrator Optimization of PMG for High-Temperature Superconducting Maglev Vehicle System
    Journal of Low Temperature Physics, 2009
    Co-Authors: Lu Liu, Suyu Wang, Jiasu Wang, Lulin Wang
    Abstract:

    The permanent magnetic guideway (PMG) composed of permanent magnet (PM) and steel is developed under flux concentration principle, which is the crucial component of high-temperature superconducting (HTS) maglev vehicle system. Optimum PMG design is an effective way to increase Levitation force and associated stiffness for improving the load capability of HTS maglev vehicle. In order to realize higher vertical field component B z in upper surface, three PMG demonstrators with three different forms of flux concentrator are fabricated with same volume of magnet. The Levitation performances of onboard HTS bulks array over them are studied. The experimental results indicate that the PMG with a permanent magnet as the flux concentrator would produce biggest Levitation force, Levitation stiffness and trapped flux when interacting with HTS superconductor.

  • Levitation force of a ybacuo bulk high temperature superconductor over a ndfeb guideway
    IEEE Transactions on Applied Superconductivity, 2001
    Co-Authors: Jiasu Wang, Suyu Wang, Zhongyou Ren, He Jiang, Min Zhu, Q X Tang
    Abstract:

    One of the prospective applications of YBaCuO bulk high temperature superconductors (HTS) is for superconducting magnetic Levitation (Maglev) vehicles. The Levitation force of a single permanent magnet over a single superconducting YBaCuO bulk has been researched, but this is not enough for practical Maglev vehicles. In this paper, properties of the Levitation force of a YBaCuO bulk HTS over a NdFeB guideway are investigated. The magnetic field at the guideway surface is up to 1.2 T. During the experiment, bulk YBaCuO is placed in a columnar liquid nitrogen vessel, whose bottom thickness is only 3.5 mm, and it is over the guideway. The YBaCuO is cooled in a zero magnetic field with liquid nitrogen and can move up and down at different velocities. The measurement process is fully controlled by a computer. In this case, there is a 103.4 N Levitation force at a 5 mm gap between the YBaCuO (diameter=30 mm, thickness=14 mm) sample and the NdFeB guideway. In addition, the authors compare the Levitation force over the NdFeB guideway with that over a single cylindrical NdFeB permanent magnet.