Title of Invention	RAIL VEHICLE WITH A WAGON BODY AND METHOD FOR PROTECTIVELY GROUNDING SUCH A WAGON BODY
Abstract	The invention relates inter alia, to a rail vehicle (10) with a wagon body (60) and with contact means (20,30,40,50) which are connected to the wagon body and which remain in contact with at least one rail (15) on the track side during operation of the rail vehicle, wherein the wagon body and at least one of the contact means are connected to each other through an electrical resistance device (70). According to the invention, the resistance device (70) has a greater electric resistance (R1) in a voltage region (dU) with low voltage than in a voltage region (dU2) with comparatively higher voltage.

Title of Invention

RAIL VEHICLE WITH A WAGON BODY AND METHOD FOR PROTECTIVELY GROUNDING SUCH A WAGON BODY

Abstract

The invention relates inter alia, to a rail vehicle (10) with a wagon body (60) and with contact means (20,30,40,50) which are connected to the wagon body and which remain in contact with at least one rail (15) on the track side during operation of the rail vehicle, wherein the wagon body and at least one of the contact means are connected to each other through an electrical resistance device (70). According to the invention, the resistance device (70) has a greater electric resistance (R1) in a voltage region (dU) with low voltage than in a voltage region (dU2) with comparatively higher voltage.

Full Text	Description Rail vehicle with a wagon body and method for protectively- grounding such a wagon body The invention relates to a rail vehicle with a wagon body and with contact means, for example wheels or wheel sets, which are connected to the wagon body and which are in contact with at least one rail on the track side during operation of the rail vehicle, wherein the wagon body and at least one of the contact means are connected to one another by means of an electrical resistor device. Grounding concepts of contemporary electrical and diesel- electrical rail vehicles or railway vehicles must equally meet both the requirements which are made in terms of fault-free operational current feedback into the rail - that is to say the operational grounding - and the requirements made in terms of effective protection against electrical shocks, that is to say the protective grounding. The protection against electrical shocks requires all the metallic parts of the wagon body which could be connected to a voltage in the case of a fault to be connected with as low an impedance as possible to the railway ground, i.e. for example to the rails. Such a fault situation could take the form, for example, of a contact wire tearing off an overhead line of the route and entering into contact with the wagon body. In such a case, the wagon body would in fact be connected to a high voltage if no efficient protective grounding were provided. Protective grounding is implemented in previously known rail vehicles using, for example, ground cables which are connected to the wheel set contacts of the rail vehicle. The invention is based on the object of specifying a rail vehicle which has even better grounding behavior than previous rail vehicles. This object is achieved according to the invention by means of a rail vehicle having the features of claim 1. Advantageous refinements of the rail vehicle according to the invention are disclosed in the subclaims. According to the above, the invention provides that the resistor device has a larger electrical resistance in a voltage range with a low voltage than in a voltage range with a voltage which is higher in comparison. A significant advantage of the rail vehicle according to the invention is to be seen in the fact that the resistor device has two different ranges or operating modes, specifically an operating mode with a large electrical resistance and an operating mode with a resistance which is relatively low compared thereto. In the normal operating mode of the rail vehicle, that is to say when there is no high voltage applied to the wagon body, very low impedance protective grounding of the wagon body is not required and is in some cases disadvantageous for the operating behavior of the rail vehicle. If, in fact, the electrical resistance between the wagon body and the ground or the rails is too low, there may be penetration by electrical parallel currents from the track, for example by currents from other rail vehicles which are in the same track circuit. Such inputting of parallel currents will occur, in particular, if the electrical resistance of the rails on the track side is greater than the electrical resistance of the rail vehicle, or its wagon body, located thereon; this is because the electric current will be divided between the wagon body and rail in accordance with the component resistances. In order to prevent such penetration of undesired current into the wagon body, the grounding resistance for grounding the wagon body should be as large as possible, and at the same time the grounding resistance between the wagon body and the rails on the track side must, of course, not be too large, since otherwise there would be no efficient protective grounding in the case of a high voltage at the wagon body, since the voltage drop at a high impedance grounding resistance would be too large. This is where the invention comes in, in that the invention provides that a resistor device with a nonlinear behavior is to be connected between the wagon body and the rails on the track side, which resistor device has two different electrical resistances or resistance ranges, specifically a high impedance resistance for the normal operating mode of the rail vehicle and a low impedance resistance range for the case of a high voltage accident. In particular in the case of long rail vehicles, the described resistor device is advantageous because of the fact that the problem of the inputting of parallel currents into the wagon body occurs, or can occur, very frequently in such vehicles. "Long" rail vehicles are to be understood, for example, as being rail vehicles which have a length over 15 m, in particular over 20 m. Such rail vehicles may be formed, for example, by relatively long individual vehicles, by traction units or else by "normal" trains which have electrically through-connected wagons and therefore form a uniform rail vehicle, viewed in electrical terms. The contact means with which the rail vehicle forms electrical contact with the rails on the track side can be formed, for example, by means of wheels, wheel sets, under carriages or bogies of the rail vehicle. The resistor device is preferably dimensioned in such a way that an electrical resistance between 33 mO and 100 mO occurs at voltages below a predefined first limiting voltage, in particular below 100 volts apex value, and that in the case of voltages which correspond to the operating voltage of the rail vehicle a maximum electrical resistance of 10 mO occurs. The resistor device can be formed particularly easily and therefore advantageously by means of an ohmic resistance element and a nonlinear element which is connected electrically parallel thereto. Such a nonlinear element can be formed, for example, by means of a voltage arrestor, in particular a spark gap, which is activated or fired, when a predefined minimum voltage or firing voltage is applied. Alternatively or additionally, the resistor device can also comprise a varistor which has a lower electrical resistance at relatively high voltages than at low electrical voltages. It is also possible for the resistor device to have a semiconductor circuit which, when an electrical voltage is applied to external terminals of the semiconductor circuit turns on when the voltage exceeds a predefined turn-voltage, and in doing so reduces the resistance thereof between its external terminals. As already stated above, the large electrical resistance element serves to avoid parallel currents from being input in the case of low wagon body voltages or in the normal operating mode. For this reason, it is considered particularly advantageous if, at least in the central region of the rail vehicle, a corresponding nonlinear resistor device is connected to the wagon body; this is because the inputting of parallel currents is relevant in particular in the case of relatively long electrical lines in the wagon body unless such inputting is prevented by means of a correspondingly large ohmic resistance element between the wagon body and rails. All the contact means which produce electrical contact with the rails are particularly preferably connected to the wagon body by means of a corresponding resistor device with nonlinear behavior. The invention also relates to a method for protectively- grounding a wagon body of a rail vehicle, in which the wagon body is grounded via at least one electrical contact means with at least one rail on the track side. In order to ensure reliable protective grounding and at the same time prevent parallel currents being input from a rail on the track side into the wagon body, or at least kept small, the invention provides that at least one resistor device is used for protectively grounding, which resistor device is connected between the wagon body and the at least one contact means and has a larger electrical resistance in a voltage range with a low voltage than in a voltage range with a voltage which is higher in comparison. With respect to the advantages of the method according to the invention, reference is made to the above statements in conjunction with the rail vehicle according to the invention singe the advantages of the rail vehicle according to the invention correspond essentially to those of the method according to the invention. The invention will be explained in more detail below with reference to exemplary embodiments; in the drawings: figure 1 shows by way of example an exemplary embodiment of a rail vehicle according to the invention in longitudinal section on a rail on the track side, figure 2 shows by way of example the electrical behavior of a resistor device of the rail vehicle according to figure 1, figure 3 shows by way of example the rail vehicle according to figure 1 in cross section in a schematic illustration. For the sake of a clear overview, the same reference symbols are always used for identical or comparable components in figures 1 to 3. Figure 1 shows a rail vehicle 10 which is located on rails 15 of a track bed 18. The rail vehicle 10 has wheels 20, 30, 40 and 50 which produce electrical contact with the rails 15 of the track bed 18. In order to permit protective grounding of a wagon body 60 of the rail vehicle 10, individual wheels 20, 30, 40 and 50, or all thereof, are connected electrically to the wagon body 60. If an electrical current flows through the rails 15 of the track bed 18, as is indicated by the reference symbol Ig in figure 1, a part I1 of this current can be input into the wagon body 60 via the front wheels 20 and 30, and fed back into the track bed 18, again via the rear wheels 40 and 50. A proportion I1 of the total current Ig would therefore flow in the wagon body 60, specifically parallel to the component current I2 which flows in the rails 15 of the track bed 18. The following applies here: Ig = I1 + I2 The lower the electrical resistance of the wagon body 60 of the rail vehicle 10 compared to the electrical resistance of the rail 15, the larger the proportion I1 of current compared to the proportion I2 of current. In order to keep the proportion I1 of current in the wagon body 60 as low as possible, at least one of the wheels of the rail vehicle 10, particularly preferably each wheel, is respectively connected to the wagon body 60 via an electrical resistor device 70 which has a "nonlinear behavior" and a larger electrical resistance in a voltage range with a low voltage than in a voltage range with a voltage which is higher in comparison. The resistor device 70 ensures here that in the normal operating mode of the rail vehicle 10 a relatively large electrical resistance is brought about between the respectively- assigned wheel and the wagon body 60, with the result that the overall electrical resistance of the rail vehicle 10 becomes relatively large and the portion I1 of current remains relatively small compared to the portion I2 of current. Nevertheless, the resistor device 70 ensures efficient protective grounding of the wagon body 60 since, specifically in the case of a high voltage on a wagon body 60, said high voltage is passed on efficiently to the rails 15 and therefore into the track bed 18 via the resistor device 70. Such a high voltage could occur, for example, if a contact wire 80 (illustrated only schematically in figure 1) of an overhead line drops onto the rail vehicle 10 and therefore places the wagon body 60 at a high voltage. Figure 2 shows an exemplary embodiment of the electrical behavior of the resistor device 70 according to figure 1. The electrical profile of the electrical resistance R plotted against the voltage U dropping at the external terminals of the resistor device 70 is illustrated. It is apparent that in a lower voltage range dU1 below a voltage Us a relatively large electrical resistance R1 occurs, and in a relatively high voltage range dU2 above a threshold voltage Us the resistance drops to a value R2. Suitable value ranges for Us, Rl and R2 are, for example: dUl: 0 volt to 100 volts dU2: 100 volts to 100 kV R1: 33 mO to 100 mO R2: 0 O to 10 mO Us: between dU1 and dU2 Electrical behavior such as is illustrated in figure 2 can be brought about, for example, by means of an ohmic resistance R1 parallel to which a nonlinear element Rn1, such as for example an overvoltage arrestor or a spark gap, is connected (cf. figure 3). Alternatively, such a resistor device 70 can also comprise a varistor or a corresponding semiconductor circuit which brings about the correspondingly described electrical behavior. Figure 3 illustrates, by way of example, the rail vehicle 10 according to figure 1 in cross section. It is possible to see the contact wire 80 with which it is possible to make contact with one of the two pantographs 90 which permit the rail vehicle 10 to operate either in the alternating current selectively operating mode or in the direct current operating mode. An actuation circuit 100, which is accommodated in an electrically screened container 110, is connected to the two pantographs 90. The actuation circuit 100 comprises, for example, a four quadrant chopper 120, a drive control device 130 and a pulse-controlled inverter 140. As is apparent in figure 1, the container 110 is electrically connected to the wagon body 60 of the rail vehicle 10; only a base plate of the wagon body 60 is shown by way of example in figure 3. The connection between the wagon body 60 and the container 110 is made via a grounding line 150. The wagon body 60 is connected via a pivot spindle 160 to a bogie 170 in which a traction motor 180 is also accommodated. The housing of the traction motor 180 is connected to the bogie 170 via a grounding line 185. The bogie 170 is supported mechanically, but in an electrically isolated fashion, by two wheels 20 and 20' which are connected by an axle 190. The axle 190 is connected via a transmission 200 and a clutch 210 to the traction motor 180, wherein the housing of the traction motor 18 0 is isolated from the drive branch by- means of electrically isolated bearings 220. In figure 3, electrically isolated bearings are marked by a thicker line than electrically non-isolated bearings. Furthermore, conductive material is marked by hatching and nonconductive material 22 5 is marked in black. Furthermore, figure 3 shows a brake controller 230 which is connected to a rotational speed signal generator 24 0 which measures the rotational speed of the axle 190 and outputs corresponding signals. The brake controller 230 is electrically connected to the wagon body 60 via a grounding line 250. Figure 3 also shows an exemplary embodiment of the resistor device 70 according to figure 1. It is apparent that the resistor device 70 is electrically connected between the wagon body 60 and the axle 190 or the two wheels 20 and 20'. The resistor device 70 comprises an ohmic resistance element R1 and a nonlinear resistance element Rn1 which is connected parallel thereto and is formed, for example, by a spark gap. In the normal operating mode of the rail vehicle 10, the resistor device 70 has a relatively high electrical resistance Rl with the result that an undesired flow of current through the wheels 20 and 20' or the axle 190 and through the resistor device 7 0 into the wagon body 60 is avoided. In the case of a high voltage at the wagon body 60, such as could occur, for example, if the contact wire 80 drops to the wagon body 60 of the rail vehicle 10 or is placed in contact therewith, the high voltage is nevertheless efficiently diverted by the resistor device 70 because the latter assumes a low impedance specifically in the case of a spark flashover when there are high electrical voltages across the spark gap Rnl and diverts the high voltage via the wheels 20 and 20' or into the rails 50 of the track bed 18. WE CLAIM 1. A rail vehicle (10) with a wagon body (60) and with contact means (20, 30, 40, 50) which are connected to the wagon body and which are in contact with at least one rail (15) on the track side during operation of the rail vehicle, wherein the wagon body and at least one of the contact means are connected to one another by means of an electrical resistor device (70), characterized in that the resistor device (70) has a larger electrical resistance (R1) in a voltage range (dU1) with a low voltage than in a voltage range (dU2) with a voltage which is higher in comparison. 2. The rail vehicle as claimed in claim 1, characterized in that the at least one contact means is formed by a wheel, wheel set, undercarriage or bogie. 3. The rail vehicle as claimed in one of the preceding claims, characterized in that the resistor device is dimensioned in such a way that an electrical resistance of at least 33 mO occurs at voltages below 10 0 volts, and that in the case of voltages which correspond to the operating voltage of the rail vehicle a maximum electrical resistance of 10 mO occurs. 4. The rail vehicle as claimed in one of the preceding claims, characterized in that the resistor device comprises an ohmic resistance element (Rl) and an electrically nonlinear element (Rn1) which is connected parallel thereto. 5. The rail vehicle as claimed in claim 4, characterized in that the nonlinear element has an overvoltage arrestor, in particular a spark gap which is activated, in particular fired, when a predefined activation voltage is applied. 6. The rail vehicle as claimed in one of the preceding claims, characterized in that the resistor device comprises a varistor. 7. The rail vehicle as claimed in one of the preceding claims, characterized in that the resistor device has a semiconductor circuit which, when a voltage above a predefined turn-on voltage is applied to external terminals of the semiconductor circuit, turns on and reduces the resistance thereof between these external terminals. 8. The rail vehicle as claimed in one of the preceding claims, characterized in that at least one contact means which is in a central region of the rail vehicle is electrically connected to the wagon body by means of a resistor device. 9. The rail vehicle as claimed in claim 8, characterized in that the contact means located in the central region of the rail vehicle is a central wheel, wheel set, undercarriage or bogie. 10. The rail vehicle as claimed in claim 9, characterized in that all the wheels, wheel sets, undercarriages or bogies of the rail vehicle are electrically connected to the wagon body by means of one or more resistor devices. 11. A method for protectively grounding a wagon body (60) of a rail vehicle (10), in which the wagon body is grounded via at least one electrical contact means (20, 30, 40, 50) with at least one rail (15) on the track side, characterized in that at least one resistor device (70) is used for grounding, which resistor device (70) is connected between the wagon body (60) and the at least one contact means and which has a larger electrical resistance (R1) in a voltage range (dU1) with a low voltage than in a voltage range (dU2) with a voltage which is higher in comparison. 12. The method as claimed in claim 11, characterized in that at least one contact means, in particular a wheel, wheel set, undercarriage or bogie, which is located in a central region of the rail vehicle, is protectively grounded. 13. The method as claimed in claim 12, characterized in that all the wheels, wheel sets, undercarriages or bogies of the rail vehicle are protectively grounded by one or more resistor devices (70). The invention relates inter alia, to a rail vehicle (10) with a wagon body (60) and with contact means (20,30,40,50) which are connected to the wagon body and which remain in contact with at least one rail (15) on the track side during operation of the rail vehicle, wherein the wagon body and at least one of the contact means are connected to each other through an electrical resistance device (70). According to the invention, the resistance device (70) has a greater electric resistance (R1) in a voltage region (dU) with low voltage than in a voltage region (dU2) with comparatively higher voltage.

Full Text

Description
Rail vehicle with a wagon body and method for protectively-
grounding such a wagon body
The invention relates to a rail vehicle with a wagon body and
with contact means, for example wheels or wheel sets, which are
connected to the wagon body and which are in contact with at
least one rail on the track side during operation of the rail
vehicle, wherein the wagon body and at least one of the contact
means are connected to one another by means of an electrical
resistor device.
Grounding concepts of contemporary electrical and diesel-
electrical rail vehicles or railway vehicles must equally meet
both the requirements which are made in terms of fault-free
operational current feedback into the rail - that is to say the
operational grounding - and the requirements made in terms of
effective protection against electrical shocks, that is to say
the protective grounding.
The protection against electrical shocks requires all the
metallic parts of the wagon body which could be connected to a
voltage in the case of a fault to be connected with as low an
impedance as possible to the railway ground, i.e. for example
to the rails. Such a fault situation could take the form, for
example, of a contact wire tearing off an overhead line of the
route and entering into contact with the wagon body. In such a
case, the wagon body would in fact be connected to a high
voltage if no efficient protective grounding were provided.
Protective grounding is implemented in previously known rail
vehicles using, for example, ground cables which are connected
to the wheel set contacts of the rail vehicle.
The invention is based on the object of specifying a rail
vehicle which has even better grounding behavior than previous
rail vehicles.
This object is achieved according to the invention by means of
a rail vehicle having the features of claim 1. Advantageous
refinements of the rail vehicle according to the invention are
disclosed in the subclaims.
According to the above, the invention provides that the
resistor device has a larger electrical resistance in a voltage
range with a low voltage than in a voltage range with a voltage
which is higher in comparison.
A significant advantage of the rail vehicle according to the
invention is to be seen in the fact that the resistor device
has two different ranges or operating modes, specifically an
operating mode with a large electrical resistance and an
operating mode with a resistance which is relatively low
compared thereto. In the normal operating mode of the rail
vehicle, that is to say when there is no high voltage applied
to the wagon body, very low impedance protective grounding of
the wagon body is not required and is in some cases
disadvantageous for the operating behavior of the rail vehicle.
If, in fact, the electrical resistance between the wagon body
and the ground or the rails is too low, there may be
penetration by electrical parallel currents from the track, for
example by currents from other rail vehicles which are in the
same track circuit. Such inputting of parallel currents will
occur, in particular, if the electrical resistance of the rails
on the track side is greater than the electrical resistance of
the rail vehicle, or its wagon body, located thereon; this is
because the electric current will be divided between the wagon
body and rail in accordance with the component resistances. In
order to prevent such penetration of undesired current into the
wagon body, the grounding resistance for grounding the wagon
body should be as large as possible, and at the same time the
grounding resistance between the wagon body and the rails on
the track side must, of course, not be too large, since
otherwise there would be no efficient protective grounding in
the case of a high voltage at the wagon body,
since the voltage drop at a high impedance grounding resistance
would be too large.
This is where the invention comes in, in that the invention
provides that a resistor device with a nonlinear behavior is to
be connected between the wagon body and the rails on the track
side, which resistor device has two different electrical
resistances or resistance ranges, specifically a high impedance
resistance for the normal operating mode of the rail vehicle
and a low impedance resistance range for the case of a high
voltage accident.
In particular in the case of long rail vehicles, the described
resistor device is advantageous because of the fact that the
problem of the inputting of parallel currents into the wagon
body occurs, or can occur, very frequently in such vehicles.
"Long" rail vehicles are to be understood, for example, as
being rail vehicles which have a length over 15 m, in
particular over 20 m. Such rail vehicles may be formed, for
example, by relatively long individual vehicles, by traction
units or else by "normal" trains which have electrically
through-connected wagons and therefore form a uniform rail
vehicle, viewed in electrical terms.
The contact means with which the rail vehicle forms electrical
contact with the rails on the track side can be formed, for
example, by means of wheels, wheel sets, under carriages or
bogies of the rail vehicle.
The resistor device is preferably dimensioned in such a way
that an electrical resistance between 33 mO and 100 mO occurs
at voltages below a predefined first limiting voltage, in
particular below 100 volts apex value, and that in the case of
voltages which correspond to the operating voltage of the rail
vehicle a maximum electrical resistance of 10 mO occurs.
The resistor device can be formed particularly easily and
therefore advantageously by means of an ohmic resistance
element and a nonlinear element which is connected electrically
parallel thereto. Such a nonlinear element can be formed, for
example, by means of a voltage arrestor, in particular a spark
gap, which is activated or fired, when a predefined minimum
voltage or firing voltage is applied.
Alternatively or additionally, the resistor device can also
comprise a varistor which has a lower electrical resistance at
relatively high voltages than at low electrical voltages.
It is also possible for the resistor device to have a
semiconductor circuit which, when an electrical voltage is
applied to external terminals of the semiconductor circuit
turns on when the voltage exceeds a predefined turn-voltage,
and in doing so reduces the resistance thereof between its
external terminals.
As already stated above, the large electrical resistance
element serves to avoid parallel currents from being input in
the case of low wagon body voltages or in the normal operating
mode. For this reason, it is considered particularly
advantageous if, at least in the central region of the rail
vehicle, a corresponding nonlinear resistor device is connected
to the wagon body; this is because the inputting of parallel
currents is relevant in particular in the case of relatively
long electrical lines in the wagon body unless such inputting
is prevented by means of a correspondingly large ohmic
resistance element between the wagon body and rails.
All the contact means which produce electrical contact with the
rails are particularly preferably connected to the wagon body
by means of a corresponding resistor device with nonlinear
behavior.
The invention also relates to a method for protectively-
grounding a wagon body of a rail vehicle, in which the wagon
body is grounded via at least one electrical contact means with
at least one rail on the track side.
In order to ensure reliable protective grounding and at the
same time prevent parallel currents being input from a rail on
the track side into the wagon body, or at least kept small, the
invention provides that at least one resistor device is used
for protectively grounding, which resistor device is connected
between the wagon body and the at least one contact means and
has a larger electrical resistance in a voltage range with a
low voltage than in a voltage range with a voltage which is
higher in comparison.
With respect to the advantages of the method according to the
invention, reference is made to the above statements in
conjunction with the rail vehicle according to the invention
singe the advantages of the rail vehicle according to the
invention correspond essentially to those of the method
according to the invention.
The invention will be explained in more detail below with
reference to exemplary embodiments; in the drawings:
figure 1 shows by way of example an exemplary embodiment of a
rail vehicle according to the invention in
longitudinal section on a rail on the track side,
figure 2 shows by way of example the electrical behavior of a
resistor device of the rail vehicle according to
figure 1,
figure 3 shows by way of example the rail vehicle according to
figure 1 in cross section in a schematic
illustration.
For the sake of a clear overview, the same reference symbols
are always used for identical or comparable components in
figures 1 to 3.
Figure 1 shows a rail vehicle 10 which is located on rails 15
of a track bed 18. The rail vehicle 10 has wheels 20, 30, 40
and 50 which produce electrical contact with the rails 15 of
the track bed 18.
In order to permit protective grounding of a wagon body 60 of
the rail vehicle 10, individual wheels 20, 30, 40 and 50, or
all thereof, are connected electrically to the wagon body 60.
If an electrical current flows through the rails 15 of the
track bed 18, as is indicated by the reference symbol Ig in
figure 1, a part I1 of this current can be input into the wagon
body 60 via the front wheels 20 and 30, and fed back into the
track bed 18, again via the rear wheels 40 and 50. A proportion
I1 of the total current Ig would therefore flow in the wagon
body 60, specifically parallel to the component current I2
which flows in the rails 15 of the track bed 18. The following
applies here:
Ig = I1 + I2
The lower the electrical resistance of the wagon body 60 of the
rail vehicle 10 compared to the electrical resistance of the
rail 15, the larger the proportion I1 of current compared to
the proportion I2 of current.
In order to keep the proportion I1 of current in the wagon
body 60 as low as possible, at least one of the wheels of the
rail vehicle 10, particularly preferably each wheel, is
respectively connected to the wagon body 60 via an electrical
resistor device 70 which has a "nonlinear behavior" and a
larger electrical resistance in a voltage range with a low
voltage than in a voltage range with a voltage which is higher
in comparison.
The resistor device 70 ensures here that in the normal
operating mode of the rail vehicle 10 a relatively large
electrical resistance is brought about between the respectively-
assigned wheel and the wagon body 60, with the result that the
overall electrical resistance of the rail vehicle 10 becomes
relatively large and the portion I1 of current remains
relatively small compared to the portion I2 of current.
Nevertheless, the resistor device 70 ensures efficient
protective grounding of the wagon body 60 since, specifically
in the case of a high voltage on a wagon body 60, said high
voltage is passed on efficiently to the rails 15 and therefore
into the track bed 18 via the resistor device 70. Such a high
voltage could occur, for example, if a contact wire 80
(illustrated only schematically in figure 1) of an overhead
line drops onto the rail vehicle 10 and therefore places the
wagon body 60 at a high voltage.
Figure 2 shows an exemplary embodiment of the electrical
behavior of the resistor device 70 according to figure 1. The
electrical profile of the electrical resistance R plotted
against the voltage U dropping at the external terminals of the
resistor device 70 is illustrated. It is apparent that in a
lower voltage range dU1 below a voltage Us a relatively large
electrical resistance R1 occurs, and in a relatively high
voltage range dU2 above a threshold voltage Us the resistance
drops to a value R2.
Suitable value ranges for Us, Rl and R2 are, for example:
dUl: 0 volt to 100 volts
dU2: 100 volts to 100 kV
R1: 33 mO to 100 mO
R2: 0 O to 10 mO
Us: between dU1 and dU2
Electrical behavior such as is illustrated in figure 2 can be
brought about, for example, by means of an ohmic resistance R1
parallel to which a nonlinear element Rn1, such as for example
an overvoltage arrestor or a spark gap, is connected (cf.
figure 3). Alternatively, such a resistor device 70 can also
comprise a varistor or a corresponding semiconductor circuit
which brings about the correspondingly described electrical
behavior.
Figure 3 illustrates, by way of example, the rail vehicle 10
according to figure 1 in cross section. It is possible to see
the contact wire 80 with which it is possible to make contact
with one of the two pantographs 90 which permit the rail
vehicle 10 to operate either in the alternating current
selectively operating mode or in the direct current operating
mode.
An actuation circuit 100, which is accommodated in an
electrically screened container 110, is connected to the two
pantographs 90. The actuation circuit 100 comprises, for
example, a four quadrant chopper 120, a drive control
device 130 and a pulse-controlled inverter 140.
As is apparent in figure 1, the container 110 is electrically
connected to the wagon body 60 of the rail vehicle 10; only a
base plate of the wagon body 60 is shown by way of example in
figure 3. The connection between the wagon body 60 and the
container 110 is made via a grounding line 150.
The wagon body 60 is connected via a pivot spindle 160 to a
bogie 170 in which a traction motor 180 is also accommodated.
The housing of the traction motor 180 is connected to the
bogie 170 via a grounding line 185.
The bogie 170 is supported mechanically, but in an electrically
isolated fashion, by two wheels 20 and 20' which are connected
by an axle 190. The axle 190 is connected via a
transmission 200
and a clutch 210 to the traction motor 180, wherein the housing
of the traction motor 18 0 is isolated from the drive branch by-
means of electrically isolated bearings 220.
In figure 3, electrically isolated bearings are marked by a
thicker line than electrically non-isolated bearings.
Furthermore, conductive material is marked by hatching and
nonconductive material 22 5 is marked in black.
Furthermore, figure 3 shows a brake controller 230 which is
connected to a rotational speed signal generator 24 0 which
measures the rotational speed of the axle 190 and outputs
corresponding signals. The brake controller 230 is electrically
connected to the wagon body 60 via a grounding line 250.
Figure 3 also shows an exemplary embodiment of the resistor
device 70 according to figure 1. It is apparent that the
resistor device 70 is electrically connected between the wagon
body 60 and the axle 190 or the two wheels 20 and 20'. The
resistor device 70 comprises an ohmic resistance element R1 and
a nonlinear resistance element Rn1 which is connected parallel
thereto and is formed, for example, by a spark gap.
In the normal operating mode of the rail vehicle 10, the
resistor device 70 has a relatively high electrical resistance
Rl with the result that an undesired flow of current through
the wheels 20 and 20' or the axle 190 and through the resistor
device 7 0 into the wagon body 60 is avoided.
In the case of a high voltage at the wagon body 60, such as
could occur, for example, if the contact wire 80 drops to the
wagon body 60 of the rail vehicle 10 or is placed in contact
therewith, the high voltage is nevertheless efficiently
diverted by the resistor device 70 because the latter assumes a
low impedance specifically in the case of a spark flashover
when there are high electrical voltages across the spark gap
Rnl and diverts the high voltage via the wheels 20 and 20' or
into the rails 50 of the track bed 18.
WE CLAIM
1. A rail vehicle (10) with a wagon body (60) and with
contact means (20, 30, 40, 50) which are connected to the wagon
body and which are in contact with at least one rail (15) on
the track side during operation of the rail vehicle, wherein
the wagon body and at least one of the contact means are
connected to one another by means of an electrical resistor
device (70), characterized in that the resistor device (70) has
a larger electrical resistance (R1) in a voltage range (dU1)
with a low voltage than in a voltage range (dU2) with a voltage
which is higher in comparison.
2. The rail vehicle as claimed in claim 1, characterized in
that the at least one contact means is formed by a wheel, wheel
set, undercarriage or bogie.
3. The rail vehicle as claimed in one of the preceding
claims, characterized in that the resistor device is
dimensioned in such a way that an electrical resistance of at
least 33 mO occurs at voltages below 10 0 volts, and that in
the case of voltages which correspond to the operating voltage
of the rail vehicle a maximum electrical resistance of 10 mO
occurs.
4. The rail vehicle as claimed in one of the preceding
claims, characterized in that the resistor device comprises an
ohmic resistance element (Rl) and an electrically nonlinear
element (Rn1) which is connected parallel thereto.
5. The rail vehicle as claimed in claim 4, characterized in
that the nonlinear element has an overvoltage arrestor, in
particular a spark gap which is activated, in particular fired,
when a predefined activation voltage is applied.
6. The rail vehicle as claimed in one of the preceding
claims, characterized in that the resistor device comprises a
varistor.
7. The rail vehicle as claimed in one of the preceding
claims, characterized in that the resistor device has a
semiconductor circuit which, when a voltage above a predefined
turn-on voltage is applied to external terminals of the
semiconductor circuit, turns on and reduces the resistance
thereof between these external terminals.
8. The rail vehicle as claimed in one of the preceding
claims, characterized in that at least one contact means which
is in a central region of the rail vehicle is electrically
connected to the wagon body by means of a resistor device.
9. The rail vehicle as claimed in claim 8, characterized in
that the contact means located in the central region of the
rail vehicle is a central wheel, wheel set, undercarriage or
bogie.
10. The rail vehicle as claimed in claim 9, characterized in
that all the wheels, wheel sets, undercarriages or bogies of
the rail vehicle are electrically connected to the wagon body
by means of one or more resistor devices.
11. A method for protectively grounding a wagon body (60) of a
rail vehicle (10), in which the wagon body is grounded via at
least one electrical contact means (20, 30, 40, 50) with at
least one rail (15) on the track side, characterized in that at
least one resistor device (70) is used for grounding, which
resistor device (70) is connected between the wagon body (60)
and the at least one contact means and which has a larger
electrical resistance (R1) in a voltage range (dU1) with a low
voltage than in a voltage range (dU2) with a voltage which is
higher in comparison.
12. The method as claimed in claim 11, characterized in that
at least one contact means, in particular a wheel, wheel set,
undercarriage or bogie, which is located in a central region of
the rail vehicle, is protectively grounded.
13. The method as claimed in claim 12, characterized in that
all the wheels, wheel sets, undercarriages or bogies of the
rail vehicle are protectively grounded by one or more resistor
devices (70).

The invention relates inter alia, to a rail vehicle (10) with
a wagon body (60) and with contact means (20,30,40,50) which
are connected to the wagon body and which remain in contact with
at least one rail (15) on the track side during operation of the
rail vehicle, wherein the wagon body and at least one of the
contact means are connected to each other through an electrical
resistance device (70). According to the invention, the
resistance device (70) has a greater electric resistance (R1) in
a voltage region (dU) with low voltage than in a voltage region
(dU2) with comparatively higher voltage.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=R6CuEyu34ikcUaYd+PX0yg==&loc=wDBSZCsAt7zoiVrqcFJsRw==

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Patent Number

272880

Indian Patent Application Number

4458/KOLNP/2009

PG Journal Number

19/2016

Publication Date

06-May-2016

Grant Date

29-Apr-2016

Date of Filing

22-Dec-2009

Name of Patentee

SIEMENS AKTIENGESELLSCHAFT

Applicant Address

WITTELSBACHERPLATZ 2, 80333 MUNCHEN, GERMANY

Inventors:

#	Inventor's Name	Inventor's Address
1	ANDREAS KITZMÜLLER	HEINRICH-CASPER-G. 20 8010 GRAZ
2	MARKUS MATTHIAS GAUDENZ	AM KORNFELD 34 91056 ERLANGEN
3	RÜDIGER POLLEY	LEIPZIGER STRAβE 20A 91058 ERLANGEN
4	FRANZ-JOSEF	GLESINGERSTR. 62 8054 GRAZ
5	STEFAN ZEBUNKE	KELTENRING 11 96199 ZAPFENDORF

PCT International Classification Number

B60L9/00; B60L9/00

PCT International Application Number

PCT/EP2008/057959

PCT International Filing date

2008-06-23

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	102007029850.3	2007-06-28	Germany