JPS5852401B2 - magnetic levitation vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improving the levitation characteristics of a magnetic levitation vehicle, which is one of the low-pollution, high-speed, large-capacity transportation systems.

FIG. 1 is a sectional view showing the configuration of a conventional magnetic levitation vehicle.

In the figure, 1 is an on-board coil for propulsion and guidance mounted on the car, and 2
3 is a propulsion/guidance track coil installed on the track opposite the propulsion/guidance onboard coil 1, and 4 is a levitation onboard coil 2 mounted on a bundle. levitation track coils installed on the tracks facing each other, 5 a propulsion power source connected to the propulsion/guidance track coil 3, 6 mounted on the propulsion/guidance onboard coil 1 and levitation onboard coil 2. car body,
7 is a propulsion/guidance orbit coil 3 and a levitation orbit coil 4
This is the orbit where the

here. The on-board coil is a superconducting coil wound with superconducting wire, and the orbital coil is a normal-conducting short-circuit coil wound with copper or aluminum wire.

Note that the same reference numerals indicate corresponding parts throughout the drawings.

FIG. 2 is a perspective view showing only the on-board coils 1 and 2 and the track coils 3 and 4 in one row of the cross-sectional view of the magnetically levitated vehicle shown in FIG.

FIG. 3 is a perspective view showing a method of connecting the left and right opposing coils of the propulsion/guidance orbital coil 3.

FIG. 3a shows a wiring method when the polarities of the on-vehicle propulsion/guidance coils 1 facing each other are opposite to each other.

FIG. 3 shows a wiring method when the left and right propulsion/guidance on-board coils 1 have the same polarity on the left and right sides.

In an actual track, a large number of propulsion/guidance track coils 3 connected on the left and right sides are connected in series to a propulsion power source 5 as shown in FIG.

The operating principle of the magnetically levitated vehicle will be explained using FIGS. 1 to 3.

First, I will explain about promotion. The on-vehicle propulsion/guidance coil 1 and the propulsion/guidance track coil 3 form a linear synchronous motor.

That is, the on-vehicle propulsion/guidance coil 1 is a magnetic field, and is excited with alternating polarities in the direction of travel of the vehicle.

The direction of the current is the direction of the arrow drawn on the on-vehicle propulsion/guidance coil 1 in FIG.

The propulsion/guidance track coil 3 is an armature, and for example, if the propulsion power source 5 is a three-phase power source and the propulsion/guidance track coil 3 is set as a three-phase power source as shown in FIG. ,
When excited in the manner of ■ phase, W phase, U phase, etc., the propulsion/guidance orbital coil 3 creates a moving magnetic field.

The vehicle is propelled at a speed synchronized with this moving magnetic field.

Next, levitation will be explained.

The levitation on-vehicle coil 2 is excited with alternating polarities in the vehicle traveling direction.

That is, current flows in the direction of the arrow shown on the on-vehicle levitation coil 2 in FIG.

Since the vehicle is propelled by the aforementioned linear synchronous motor, the levitation track coil 4 experiences alternating magnetic flux.

Therefore, a current is induced in the levitation orbital coil 4, which is a short-circuited coil.

The vehicle is supported by the electromagnetic repulsive force between this induced current and the current of the on-vehicle coil 2 for levitation.

Finally, I will explain the guidance.

As shown in FIG. 3, the propulsion/guidance orbital coils 3 are wired so that left and right opposing coils form a pair.

For this, if the vehicle is traveling without side-to-side displacement.

Propulsion/guidance linked to the paired propulsion/guidance orbital coils 3
The magnetic flux from the guide coil 1 always cancels out each other on the left and right sides and becomes zero.

Therefore, in this case, no current is induced in the propulsion/guidance track coil 3, and no electromagnetic force in the lateral direction acts on the vehicle.

However, when the vehicle moves left and right and runs, the magnetic flux from the on-vehicle propulsion/guidance coil 1 interlinking with the pair of propulsion/guidance track coils 3 cannot be canceled out on the left and right sides, and the propulsion/guidance track A current is induced in the coil 3.

The electromagnetic force acting between this induced current and the current flowing through the on-vehicle propulsion/guidance coil 1 becomes a restoring force, and the vehicle is always guided so as to eliminate left and right deviations.

The magnetically levitated vehicle is thus supported, guided and propelled without contact.

The levitation of such a magnetically levitated vehicle will now be explained in more detail.

When a magnetically levitated vehicle is traveling in levitation, the electromagnetic repulsion force between the current induced in the levitation track coil 4 and the current flowing in the levitation on-vehicle coil 2 causes magnetic levitation equal to the vehicle's own weight. It is floating at a constant levitation height due to the blade.

Here, if the levitation height increases due to disturbances such as track irregularities and gusts of wind, the electromagnetic repulsion between the induced current in the levitation track coil 4 and the current in the levitation on-board coil 2 decreases, causing the levitation height to increase. Since the force becomes smaller than the weight, the flying height tends to decrease.

Also, contrary to the above, if the levitation height decreases, the electromagnetic repulsion between the induced current in the levitation track coil 4 and the current in the levitation on-board coil 2 increases, resulting in a force greater than the vehicle weight. To achieve this, the flying height tends to increase.

As described above, if the flying height changes due to some kind of disturbance, the vehicle will vibrate up and down around the equilibrium flying height.

That is, the magnetically levitated vehicle travels while vibrating in the vertical direction.

This condition is undesirable because it makes the ride uncomfortable.

What functions to damp such vehicle vibrations is eddy current loss generated in the conductor plate attached to the on-vehicle levitation coil 2.

What is the conductor plate attached to the on-vehicle levitation coil 2?

Specifically, it is a metal low-temperature container that houses a levitation on-vehicle coil 2, which is a superconducting coil.3 Note that a special conductor plate may be additionally attached to dampen vehicle vibration.

When the vehicle vibrates up and down, an eddy current flows through the conductor plate due to the induced current in the levitation track coil 4 under the vehicle.

The eddy current loss in the conductor plate due to this eddy current consumes the vibration energy of the vehicle, and serves to damp the vertical vibration of the vehicle.

Therefore, it can be said that the greater the eddy current loss, the greater the moderation effect on vehicle vibration.

After excitation, the on-board coils 1 and 2, which are superconducting coils, are short-circuited by special switches called persistent current switches, and are operated in a state where they are disconnected from the excitation power source.

This switch has zero resistance in the closed state.

Since the superconducting coil and persistent current switch have zero resistance, the coil current can continue to flow without attenuation.

This kind of current is called persistent current.

Furthermore, since the short-circuited coil has zero resistance, the magnetic flux linkage of the on-board coil is constant.

(Conditions for Persistent Current) Now, suppose that a magnetically levitated vehicle causes vertical vibration due to some disturbance while it is traveling in levitation.

At this time, since a current is induced in the levitation track coil 4 at the bottom of the vehicle, this current causes the conductor plate attached to the levitation on-board coil to generate an alternating magnetic field corresponding to vehicle vibration. I will do it.

On the other hand, looking at the on-board coil, the levitation orbital coil 4
The magnetic flux linkage of the on-vehicle levitation coil 2 also changes in response to vehicle vibration.

However, since the on-board coil is operated by persistent current,
The current in the on-board coil 2 changes so that the magnetic flux linkage does not change.

That is, this change in current Δi is approximately expressed by the following equation.

△i=-△φ/L However, △φ=change in interlinkage magnetic flux of levitation on-board coil 2 s''L=self-inductance of levitation on-board coil 2 Current of this levitation on-board coil 2 The variation Δi acts to weaken the magnetic field from the levitation orbital coil.

Therefore, the alternating magnetic field experienced by the conductor plate attached to the levitation on-board coil 2 is weaker due to the fluctuating current △i of the levitation on-board coil 2 compared to when the current in the levitation on-board coil does not change. It will be done.

This will reduce the eddy currents generated in the conductor plate.

That is, the eddy current loss is reduced, the damping effect of vehicle vibration is poor, and the ride comfort is worsened.

As described above, conventional magnetically levitated vehicles have a drawback in that the braking effect on vertical vehicle vibrations is small, and as a result, vertical vibrations of the vehicle are not damped very much, resulting in poor ride comfort.

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and by connecting the windings of the on-board propulsion/guidance coil 1 and the on-board levitation coil 2 in series, it is possible to move the top and bottom of the vehicle. It is an object of the present invention to provide a magnetically levitated vehicle that eliminates the conventional drawbacks and has good ride comfort by increasing the damping effect against vibrations and promptly damping vertical vibrations of the vehicle.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 shows on-board coils 1 and 2 and track coils 3 and 4 in one row of a magnetic levitation vehicle according to an embodiment of the present invention.
FIG.

The windings of the on-board propulsion/guidance coil 1 and the on-board levitation coil 2 are connected in series.

FIG. 5 shows this as an equivalent circuit.

Here, 8 is a persistent current switch.

In the conventional system, the propulsion/guidance on-board coil and the levitation on-board coil were each short-circuited by the persistent current switch 8.

In a magnetically levitated vehicle configured in this manner, when a vertical disturbance is applied to the vehicle while it is traveling in levitation.

The vehicle vibrates vertically.

At this time, the current in the levitation on-vehicle coil 2 fluctuates so that the interlinkage magnetic flux does not change, as described above.

However, in the case of the present invention, the on-vehicle coil 2 for levitation and the propulsion
Since the windings of the guide coil 1 are connected in series, the change in current △i is approximately △i−−△φ/(LL+LG
) is given by.

Here, I, o = self-inductance of the propulsion/guidance on-board coil 1 Generally, "G" usually has a value several times as large as LL, so the change in current △i in this case is very small. Become.

Therefore, the effect of weakening the alternating magnetic field experienced by the conductor plate attached to the on-vehicle coil for levitation is significantly reduced.

Therefore, the eddy current in the conductor plate becomes large, and the eddy current loss also becomes large.

Namely. The damping effect on vehicle vibrations is strong, and vehicle vibrations are quickly attenuated to provide a good ride.

As described above, according to the present invention, the windings of the on-board coil for propulsion/guidance and the on-board coil for levitation are connected in series, so the braking force against vehicle vibration becomes a dog, and a magnetically levitated vehicle with good riding comfort is achieved. can get.

Another advantage is that the number of persistent current switches can be reduced to half of the conventional one.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the configuration of a conventional magnetic levitation vehicle;
The figure is a perspective view showing the arrangement of coils in one row of a conventional magnetic levitation vehicle, FIG. 3 is a perspective view showing how to connect the propulsion/guidance track coil, and FIG. FIG. 5 is a perspective view showing the arrangement of coils in one row of the levitation vehicle, and is a wiring diagram of the on-vehicle propulsion/guidance coil 1 and the on-vehicle levitation coil 2. In addition, in the figure, the Fi- symbol indicates the same or Osho part. In the figure, 1 is a propulsion/guidance on-board coil, 2 is a levitation on-board coil, 3 is a propulsion/guidance track coil, 4 is a levitation track coil, 5 is a propulsion power source, 6 is a vehicle body, 7 is a track, 8 is a persistent current switch.

Claims (1)

[Claims] 1. A propulsion/guidance track coil and a levitation track coil provided on the track, and an onboard propulsion/guidance coil and a levitation track coil mounted on the vehicle at predetermined mutual positions with the respective track coils. In a magnetic levitation vehicle equipped with a conductor plate and an on-vehicle levitation coil provided opposite to each other, a change in current in the on-board levitation coil is reduced to prevent weakening of the magnetic field from the levitation track coil. In order to
A magnetic levitation vehicle characterized in that the windings of the on-board coil for guidance and the on-board coil for levitation are connected in series.