Levitation-guidance stabilization of superconducting maglev through LSM currents
This paper presents a modeling and simulation of a superconducting maglev vehicle with a levitation and guidance assist method we have proposed. The assist system stabilizes and assists the vehicle operation so that the vehicle does not need to depend on the mechanical wheels as much as possible at low speeds. By controlling the LSM armature currents, the auxiliary levitation and guidance forces are provided. The results show that the assist system produces appropriate levitation and guidance forces, establishing the reference levitation height and a sufficient guidance at low speeds even against the disturbance force of lateral wind.
Levitation force assist through LSM armature currents in superconducting maglev vehicle
In a superconducting maglev vehicle, levitation forces produced by the interaction between the ground levitation coils and the onboard SCMs become insufficient when the running speed is low. This paper presents a levitation force assist method through the control of LSM armature currents, which usually function to generate propulsion forces. The levitation assist system is constructed in terms of d‐axis armature currents, leading to the definition of the vertical force coefficient of propulsion system. The calculated results show the feasibility of the system, which produces damping forces as well as levitation assist forces. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(4): 45–52, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20260
Linear synchronous motor feedback controls
This paper is concerned with the theoretical behaviour of the linear synchronous motor as a propulsion means for a high speed vehicle. The performance during acceleration and steady state operation is obtained from a set of state variable equations which are solved using a digital computer. The inherent performance is oscillatory with little damping. A general feedback control scheme is presented which provides damping and control of the force angle (the angle between the vehicle field and track field). Velocity and force angle errors control voltage magnitude and frequency of the power conditioner (cycloconverter). The effectiveness of the control scheme is measured in terms of its ability to have the vehicle follow a velocity profile, to maintain a constant force angle and to eliminate fast changes in the cycloconverter output voltage. The study shows that effective damping and control of the force angle can be obtained when the cycloconverter voltage and frequency are simultaneously controlled by velocity and force angle feedback signals.