Affiliations: [a] Department of Environmental and Energy Sciences Field,
University of Toyama Gofuku, Toyama, Japan
Correspondence:
[*]
Corresponding author: Takahisa Ohji, Department of Environmental
and Energy Sciences Field, University of Toyama 3190 Gofuku, 930-8555, Toyama,
Japan. Tel./Fax: +81 76 445 6983; E-mail: ohji@eng.u-toyama.ac.jp
Abstract: This paper describes the operating state improved by using
phase-advanced capacitors for the ac induction type magnetic levitation
(maglev) system. In case many coils are set up in yoke such as this type of
maglev, the impedance of electric circuit of the stator has strong inductivity;
therefore, a phase-advanced capacitor should be inserted to achieve
power-saving operation for the inductive circuit. However, the ferroresonance
state occurs as the power-factor of the circuit approaches 1, and then the
current steeply increases even if the voltage increases slowly. Thereby, a
non-magnetic plate greatly oscillates when it starts to levitate. To improve
the starting oscillation, we adopted the method of switching two different
capacitors. As a result, both smooth starting of levitation and minimum input
power operation functioned successfully.
Keywords: Ac induction type maglev, phase-advanced capacitor, power-factor correction, ferroresonance
