DE9406330U1 - Brake device for a magnetic levitation vehicle - Google Patents

Description

83&Pgr; 5

Description

Braking device for a magnetic levitation vehicle

The invention relates to a braking device for a magnetic levitation vehicle according to the preamble of claim 1.

No buffers can be provided at the end of the track of a magnetic levitation system, as the magnetic levitation vehicles cannot be equipped with buffers for aerodynamic and mechanical reasons. Eddy current brakes are therefore used as braking devices at the Transrapid Emsland test facility (TVE), whereby the magnetic levitation vehicle is placed on friction skids after reaching a lower limit speed and braked to a standstill.

With the known braking system, the operational control system only allows the terminal stations to be approached at very low speeds or with very low decelerations, since the eddy current brake is less effective at lower speeds and the process of setting the brake down on the friction skids and the associated safe drive shutdown takes a lot of time. Due to the long braking processes, the total travel time is significantly extended.

The object of the present invention is to provide a braking device for a magnetic levitation vehicle which enables a significantly shorter braking process.

0 The object is achieved according to the invention by the features in the characterizing part of claim 1. Advantageous embodiments of the invention are described in claims 2 to 7.

5 In the braking device according to the invention, at least a part of the long stator is in a predeterminable range in short

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switched to a short circuit or can be switched to a short circuit. If the stopping point is located at the end of a track, then the predeterminable area, which consists of at least one stator section, is permanently switched to a short circuit, whereas the predeterminable area at a stopping point provided on the route can be switched to a short circuit if necessary.

When the magnetic levitation vehicle enters the predeterminable, short-circuited area of the long stator, the magnetic levitation vehicle induces voltage in the short-circuited area, which increases the longer the vehicle is in the short-circuited area. Along with the induced voltage, the portion of the short-circuit current that brakes the magnetic levitation vehicle also increases. The magnetic levitation vehicle is therefore braked more strongly as the effective length of the vehicle increases.

The predeterminable area in which at least part of the long stator can be switched to short-circuit can advantageously be adapted in its extent to the respective individual case. For example, the predeterminable area can end before the intended stopping point (claim 2) or it can include the intended stopping point (claim 3).

If the predeterminable area comprises several stator sections connected in series, the stator sections can be adapted in a particularly advantageous manner in terms of their length to the decreasing speed of the magnetic levitation vehicle (claim 5), which results in a particularly short braking time in view of the required energy expenditure.

Further advantages and details of the invention emerge from the following description of an embodiment based on the drawing and in conjunction with claims 2 to 7. They show:

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FIG 1 shows a long stator with the braking device according to the invention,

FIG 2 in a Cartesian coordinate system the qualitative relationship between speed, induced voltage and effective vehicle length in the predeterminable, short-circuited area of the long stator,

FIG 3 shows in a Cartesian coordinate system the qualitative relationship between induced voltage, short-circuit current and impedance in the given, short-circuited area of the long stator.

In FIG 1, 1 designates a stator section of a three-phase long stator 2. The phases R, S and T of the stator section 1 can be switched in a short circuit via a switching device 3, 4 and 5 respectively. The switching devices 3 to 5 are arranged for this purpose in the lines leading to a short circuit point 6. Between the short circuit point 6 and the switching devices 3 to 5, a resistor 7, 8 and 9 respectively is connected in each phase R, S and T. The pole pitch of the long stator is designated with ρ.

In the embodiment shown in FIG 1, the stator section 1 can be switched to short circuit if necessary - i.e. only if the magnetic levitation vehicle is to be stopped at this point. At a final stop (track end) the stator section 1 is always switched to short circuit, so that the switching devices 3 to 5 are omitted.

, or must always be closed. The arrangement of the resistors 7 to 9 is not limited to the embodiment shown in FIG 1. For example, it is sufficient if only two resistors are arranged on both sides of the short-circuit point 6.

From the qualitative curves shown in FIGS. 2 and 3, the expert recognizes that when the magnetic levitation

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vehicle into the predeterminable, short-circuited area of the long stator, more and more voltage is induced in the short-circuited area by the magnetic levitation vehicle, whereby the induced voltage Uj_ _nc j becomes greater the more the vehicle length 1 is in the short-circuited area. Together with the induced voltage Ui _nc j, the portion of the short-circuit current I^ that brakes the magnetic levitation vehicle also increases. The magnetic levitation vehicle is therefore braked more strongly as the effective vehicle length 1 increases.
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Claims (7)

&dgr; 3 I t 8 Protection claims 1. Braking device for a magnetic levitation vehicle, by means of which the vehicle can be braked to a standstill, characterized in that at least a part of the long stator (2) is short-circuited or can be short-circuited in a predeterminable area (1). 2. Braking device according to claim 1, characterized in that the predeterminable area (1) ends before a predeterminable stop. 3. Braking device according to claim 1, characterized in that the predeterminable area (1) begins before a predeterminable stop and includes it. 0 4. Braking device according to claim 1, characterized in that the predeterminable region comprises several consecutive stator sections (1). 5 5. Braking device according to claim 4, characterized in that the stator sections (1) are adapted in their length to the decreasing speed (vp) of the magnetic levitation vehicle are.
30 6. Braking device according to claim 1, characterized in that the predeterminable area (1) is controlled via switching devices (3 to 5) can be switched to short circuit.
35 03 M6 7. Braking device according to claim 1,
characterized in that a resistor (7 to 9) is connected in each case in at least two phases (R,S,T) leading to the short-circuit point (6).