JPH0217806A - Vibration damping of magnetic levitation vehicle - Google Patents

Abstract

PURPOSE:To effectively damp vibrations in all directions by adding a short- circuiting coil having a small time constant for periodic damping to a levitation coil disposed on the side face of a track. CONSTITUTION:Superconducting coils 1 are disposed on the side faces of a truck 2. Levitation coils 3 in which upper and lower stages of coils are connected reversely are disposed on the side faces of a rail. Further, short-circuiting coils 4 in which upper and lower stages of coils are connected reversely are disposed to be superposed on the coils 3. Here, the resistance R and the inductance L of the coil 3 are set to omegaL/R>>1 (omega is the angular velocity of a current flowing when a train travels at a highest speed). The resistance R1 and the inductance L1 of the coil 4 are set to omegaL1/R1<1 and R1>omegaL. Thus, vibrations not only in upward and downward directions but in all directions can be effectively damped.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling train vibrations caused by track irregularities and other disturbances in an induced repulsion magnetic levitation train.

[Conventional technology and its! Problem 1] It is known that negative damping acts between the superconducting coil of induced repulsion magnetic levitation and the levitation ground coil. In other words, when vibration occurs in a system in which only superconducting coils and levitation ground coils are arranged, the vibration gradually increases, which is unfavorable in terms of riding comfort.For this reason, conventional methods of passive damping or active damping have been used. Proposed. Passive damping is a method in which a conductive plate is placed between the superconducting coil and the levitation ground coil, and vibration energy is absorbed by the eddy current flowing through the conductive plate as the bogie vibrates.

Although this method has a simple structure, it is difficult to obtain sufficient force. In addition, active damping involves installing a control coil on the bogie opposite the levitation ground coil, mounting a control device on the vehicle, and applying a current proportional to the speed of vertical vibration to the control coil to apply damping force. It's something you get. In order to obtain sufficient effect, this method requires a thick control device and requires the installation of a control coil.
The problem was that the weight increased.

[Means for Solving the Problems] The present invention aims to solve the above-mentioned problems, namely, without installing a special device on the vehicle, a first levitation coil placed on the side of the track is provided. The present invention provides a method for obtaining sufficient vehicle control effects by adding a second short-circuited coil with a small time constant for vibration damping.

The first levitation coil has a large time constant, and with respect to the angular frequency ω (1/rad) of the current flowing when the train is at maximum speed, the resistance R (Ω) 5 inductance H) is ωL/R
)1, and in the train speed range, the running resistance (magnetic effect) accompanying magnetic levitation is extremely small, and as the speed decreases, the magnetic effect increases. However, it is known that this levitation coil has a negative vibration damping coefficient and the vibrations tend to diverge.

On the other hand, the second short-circuit coil has a small time constant, that is, the resistance R1 (Ω) and the inductance L, (H) are ωL + /
It is set to R+ < 1 and R, > ωL.

In the range where this inequality holds, the vibration damping coefficient becomes positive, so the negative damping coefficient generated from the first floating coil can be canceled out, and a positive damping coefficient can be obtained by summing the vibration damping coefficient. In addition, the magnetic efficacy of this second short-circuit coil increases with the speed of the train, but the first levitation coil and the second short-circuit coil are arranged in two stages, upper and lower, and the upper and lower coils are connected in opposite directions. , the magnitude of the magnetic effect can be kept small. Furthermore, since the first levitation coil and the second short-circuit coil can be made one on top of the other during manufacture, it is possible to save time and effort for attachment.

[Examples] Examples of the present invention will be described below with reference to the drawings. 1st
The figure shows an example of the coil arrangement of the magnetic levitation vehicle of the present invention, in which a second short-circuit coil 4 is attached to the surface of the first levitation coil 3. Figure 2 shows the first levitation coil 3.
This shows the method of connecting the second short circuit coil 4.

The vertical center of the superconducting magnet l of the vehicle is located at the first point on the track side.
The levitation blade is located at a position ΔZ slightly below the vertically symmetrical center position of the levitation coil 3, and when the vehicle travels, a levitation blade is generated to balance the weight of the vehicle.

If the magnetic flux linkage to the first levitation coil 3 by the train's superconducting magnet is φ, it is known that in the $■ region where the train speed is high, the magnitude of the current in the levitation coil 3 is approximately i = φ/L. It is being

On the other hand, the magnitude of the current in the second shorted coil is approximately i
l=φ/ωφR3. By the way, the resistance R of the second short circuit coil is R,>
Since ωL is selected, it can be seen that i, < 1 By keeping all small, the running resistance generated in the second short-circuited coil can be reduced. FIG. 3 shows the tendency of the magnetic effect generated in the coil.

When the superconducting magnet of the train vibrates in the vertical direction, the vibration damping coefficient is CCX:N-(ωL+ /R,)"l/R(1+ (
ωL, /R,)t l! In order to improve the performance for levitation, ωL/
It is necessary to increase R, so that the vibration damping coefficient C becomes negative.

Since the second short-circuit coil does not need to generate floating blades, ωL, /R, can be made small and C can be made positive. FIG. 4 shows trends in the attenuation coefficients of the first levitation coil and the second short circuit coil.

It is possible to obtain damping coefficients of vibrations generated by each of the first levitation coil and the second short circuit coil.

Furthermore, with this second short-circuit coil, it is possible to obtain a vibration damping effect not only for vertical vibrations but also for horizontal and angular displacement vibrations.

FIG. 5 shows an example of a coil side cross section of a structure in which the first levitation coil and the second short-circuiting coil 4 are stacked.

In this example, a second short-circuiting coil is attached thinly to the surface of the levitation coil 3, so that it can be constructed as an integral unit.

〔Effect of the invention〕

According to the vibration damping method for a magnetically levitated vehicle of the present invention, it has a function of effectively damping vibrations not only in the vertical direction but in all directions, so it is useful for improving the riding comfort of the magnetically levitated vehicle. Furthermore, since the installation method on the track can be carried out integrally with the levitation coil, the installation work is also easy.

[Brief explanation of the drawing]

FIG. 1 shows the coil arrangement in a cross section of an induction repulsion type magnetic levitation railway, and FIG. 2 shows the connection between the first levitation coil and the second short-circuit coil. FIG. 3 shows the characteristics of running resistance generated in the first levitation coil and the second short circuit coil. FIG. 4 shows the characteristics of the attenuation coefficient generated in the first levitation coil and the short-circuit coil, and FIG. 5 shows a coil side cross section when the first levitation coil and the second short-circuit coil are integrated. 1... superconducting coil, 2... trolley, 3...
First levitation coil, 4...Second shorting coil, 1
1... Curve showing running resistance due to the first levitation coil, 12... Curve showing running resistance due to the second short circuit coil, 13... Curve showing the damping coefficient of the first levitation coil Curve 14...Curve showing the damping coefficient of the second short circuit coil. 21... Winding of the first levitation coil 922... Winding of the second short-circuiting coil, 23...°-Sheath for hardening the coil, 24... Winding of the first levitation coil Layer insulating between the wire and the second short-circuit coil, 25... Molded coil side f, Ii Applicant Foundation Railway Technology Research Institute Speed (tk) shiσ 31st

Claims (1)

[Claims] (1) In an inductive repulsion magnetic levitation railway, a superconducting coil is arranged vertically on the side of the bogie, and the first levitation coil is installed in two stages, upper and lower, on the side wall of the track, facing the superconducting coil. The upper and lower coils are connected in opposite directions to create a closed circuit, and the second levitation coil is stacked on top of the first levitation coil.
short-circuiting coils are installed in two stages, upper and lower, and the coils in the upper and lower stages are connected in opposite directions to create a closed circuit. When the angular frequency of the current flowing when the train runs at maximum speed is ω, the ratio of the resistance R and inductance L of the first levitation coil is ωL/R)1, and the second short-circuit The ratio of the resistance R_1 and inductance L_1 of the coil is ωL_1/R_1<1, and R_1 to the inductance L of the first levitation coil.
A vibration damping method for a magnetically levitated vehicle characterized by obtaining a vibration damping force so that 1>ωL.