Test device for a direct-current track system, direct-current track system having a test device, and method

Abstract

The invention relates to a test device (10) for a direct-current track system (1) for at least partially electrically driven rail-bound vehicles, to a direct-current track system (1) having at least one test device (10) according to the invention, and to a method for determining the total insulation resistance RisoG (6) in a rail network (3) of a direct-current track system (1) having at least one test device (10) according to the invention. The invention allows for easy detection of a general deterioration in the overall insulation or a decrease in the general insulation properties of the direct-current track system 1 over the entire extent of its routes.

Description

[0001] 202403968

[0002] 1

[0003] Description

[0004] Test device for DC railway system, DC railway system with test device and method

[0005] The power supply for DC railway systems uses the two-wire principle, in which the electric current flows from the corresponding power sources, such as substations, via forward conductors, such as overhead lines, or feeder lines, and return conductors back to the power sources. Return current that escapes from the return conductor(s), such as rails, and flows through the ground is called stray current and can cause significant corrosion damage to metallic structures buried in the ground. To prevent such harmful stray currents as much as possible, DC railway systems, especially the rails, are constructed with insulation from the ground. This is achieved using insulators made of insulating materials that do not provide infinite insulation and therefore exhibit an undesirable insulation resistance. This insulation resistance...The resistance of the insulating materials used in the insulators is measured during the commissioning of the relevant traffic control system. Over the system's service life, the overall insulation typically deteriorates, and individual, localized insulation components may fail. Such locally occurring insulation defects can be readily detected by a known stray current monitoring system.

[0006] In the aforementioned stray current monitoring system, the voltage between the return conductor and the structure's earth, the so-called rail potential cp, is measured during ongoing railway operations. These measurements are taken at several points along the track of the railway system. During railway operations, the rail potential changes over time at each point. <p in Abhängigkeit der fahrenden Züge. Dadurch ergibt sich aufgrund wiederholter Messungen eine Charakteristik des Potential- verlaufs, ein sogenannter „Fingerabdruck“, für jeden Ort der Fahrstrecke, an dem diese Messungen durchgeführt werden. Die jeweils aktuellen Messwerte der jeweiligen Messstelle werden bei der bzw. zur Auswertung mit den vorher aufgenommenen Referenzwerten dieses Ortes verglichen. Liegen die Messwerte außerhalb eines angegebenen Toleranzbereichs, wird eine entsprechende Meldung ausgegeben.This allows, as already mentioned, local, point-like insulation faults along the route to be reliably detected. 202403968.

[0007] 2

[0008] In contrast, a general deterioration of the overall insulation over the lifespan of the DC railway system, for example due to contamination, aging processes, etc., across the entire track or all track sections, is very difficult to detect using a stray current monitoring system. Therefore, corresponding insulation resistance measurements, as performed during the initial commissioning of the system, would need to be repeated at regular intervals throughout the years of operation. However, since precise specifications, particularly defined timeframes for repeat measurements, are lacking, and since such insulation resistance measurements, which are usually carried out outside of operating hours or when the track sections are in use, are very labor-intensive and require expert knowledge, such insulation resistance measurements are rarely performed on existing DC railway systems.

[0009] The invention is based on the objective of detecting a general deterioration of the overall insulation of a DC railway system in a simple way during its lifetime or operating period.

[0010] The problem is solved by the features of independent claim 1 and the dependent claims. Further developments and embodiments of the invention are found in the features of the dependent claims.

[0011] The test device according to the invention for a DC railway system for at least partially electrically powered rail vehicles, which is connected to the rail network of the DC railway system, comprises at least one switch and at least one test resistor R. test and at least one voltage source with a supply voltage Uo, wherein a total insulation resistance R is determined by means of the test device with the switch closed and the supply voltage Uo applied. iS0 G of the rail network of the DC railway system can be determined, wherein the total insulation resistance RjsoG can be determined at least by means of at least one insulation resistance, wherein the rail network of the DC railway system is insulated from the earth by means of the at least one insulation resistance.

[0012] The solution according to the invention has the advantage that by applying a fixed supply voltage Uo and closing the switch, the test resistor R tes The test device is firmly connected to the earth and forms a series circuit, thus a voltage divider, consisting of the test resistor R. test and the total insulation resistance RjsoG, arises. This allows the corresponding ratio of 202403968 to be calculated.

[0013] 3

[0014] Supply voltage Uo relative to the rail potential <p bei eingeschalteter Testvorrichtung, welches dem Verhältnis aus Summe des Testwiderstands R tes t and total insulation resistance RisoG To total insulation resistance Rj S0 G corresponds to an equation described in the following form:

[0015] Uo / | <p| — (Rtest "*■ Risoc) / RisoG, simply the total insulation resistance R iS0G of the relevant system can be calculated, since all other quantities are either known, such as the supply voltage Uo and the test resistance Rtest, or can be easily measured, such as the rail potential. <p. Da die Längsimpedanz über die Gleise bzw. Schienen vernachlässigbar klein ist, ca. 30 mOhm / km*Schiene, kann demzufolge ein im Wesentlichen konstantes Schienenpotential <p über die betrachtete Strecke des Gleichstrombahnsystems hinweg angenommen werden.

[0016] Measuring the rail potential <p des Schienennetzes kann dabei automatisiert durchgeführt werden. Üblicherweise sind entsprechende Messvorrichtungen in den betreffenden Anlagen vorhanden. Falls beispielsweise bereits ein Streustromüberwachungssys- tem in der betreffenden Anlage vorhanden bzw. eingebaut ist, kann eine bereits erfolgte Schienenpotentialmessung vorteilhafterweise ohne zusätzlichen Aufwand verwendet oder auch einfach wiederholt werden. Aufgrund des Aufbaus der Testvorrichtung können zur Überprüfung des Ergebnisses auch weitere Hilfsgrößen, wie beispielsweise der definiert fließende Strom l tes t and / or the voltage Utest across the test resistor R tes The decrease in t can also be measured very easily and used as needed. This allows for the detection of a general deterioration in the overall insulation of a DC railway system along its entire length.

[0017] Furthermore, the components required for constructing a test device according to the invention are very cost-effective. In addition, a test device according to the invention can be easily retrofitted into existing DC railway systems.

[0018] According to a further preferred embodiment of the invention, the voltage source of the test device is an alternating voltage source or a direct voltage source.

[0019] This allows for the use of virtually any existing local voltage source for the power supply, such as railway supply voltage, auxiliary voltages, power supplies, batteries, etc., depending on the requirements, provided a coordinated combination of voltage source, test resistor, and current carrying capacity is used. 202403968

[0020] 4

[0021] According to a further particularly preferred embodiment of the invention, when the supply voltage Uo > 50 volts AC or Uo > 120 volts DC is applied to the test device, at least one test resistor R tes t greater than the total insulation resistance Rj S0 G. In the presence of such high, potentially dangerous voltages, this ensures that the greatest voltage drop occurs across the test resistor R during the measurements. tes t and is not located between the rail network and the ground. This ensures that the potential of the rail is not affected. <p des Schienennetzes 3 keine Gefährdung ausgeht und keine weiteren Beeinträchtigungen hervorgerufen werden. Beim Vor- bzw. Anliegen einer Versorgungsspannung Uo <= 50 Volt Wechselspannung oder Uo <= 120 Volt Gleichspannung an der Testvorrichtung kann der Testwiderstand R tes t, on the other hand, is also smaller than the total insulation resistance Rj S0G should be chosen, since in these cases the adjacent rail potential <p ebenfalls keine Gefährdung ausgeht. So kann der Testwiderstand R tes In the case of using a voltage source with a very low supply voltage Uo, for example, when using a 24-volt battery as the voltage source, t becomes very small and, with a sufficiently low supply voltage Uo, can even drop to 0 ohms or be chosen to be 0 ohms in extreme cases. In this case, the total insulation resistance R can be mathematically determined using the following formula: iS0 Then the measurement of the rail potential. <p und des Stroms l tes t required or sufficient.

[0022] Another aspect of the present invention relates to a DC railway system for at least partially electrically powered rail vehicles, wherein the DC railway system includes at least one substation and a rail network with a rail potential. <p und wenigstens einem Isolationswiderstand aufweist, wobei das Schienennetz mittels dem wenigstens einen Isolationswiderstand gegenüber der Erde isoliert ist, mit wenigstens einer Testvorrichtung nach einem der Ansprüche 1 bis 3,

[0023] According to a further embodiment of the DC railway system according to the invention, at least one test device is permanently installed in the DC railway system.

[0024] It is particularly preferred that at least one test device be permanently installed in at least one substation of the DC railway system.

[0025] In this way, the test device is permanently available for measurement purposes at all times. During operation of the DC railway system, the test device's switch is open, thus disabling the test device. Due to the fixed and permanently installed test device, corresponding measurements can be taken. 202403968

[0026] 5

[0027] Insulation resistance measurements are always performed in the same way, virtually eliminating measurement errors caused by faulty setup or connections. No expert knowledge is required for the measurements themselves, meaning no experts are needed. Therefore, these measurements can be initiated by trained personnel and performed as often as required, for example, daily, weekly, monthly, etc. This allows for early intervention in case of a decline in overall insulation properties, thereby reducing costs and simultaneously increasing the safety of the entire system.

[0028] According to a further preferred embodiment of the DC railway system according to the invention, the DC railway system has at least one programmable unit, wherein the at least one programmable unit is configured such that the at least one programmable unit automatically regulates and / or controls the at least one test device.

[0029] In this way, the corresponding measurements can be triggered and carried out automatically, and the results of the measurement evaluation can be automatically transmitted and / or processed. Since no operation or traversal of the track should take place during the measurement(s) themselves, the measurements can therefore be carried out as a matter of course during nighttime hours without any additional personnel effort. "No operation" or "no traversal" refers exclusively to electric vehicles, i.e., vehicles powered by electricity from the designated supply system, such as overhead lines. Traversal by diesel-powered or battery-powered vehicles, for example, is also possible during the measurement.

[0030] Furthermore, the evaluation and its results can be used for other purposes, such as automated trend analyses. This further reduces the personnel effort and consequently the costs of such insulation resistance measurements.

[0031] Such a programmable unit can preferably be implemented as a suitably configured control and / or regulation device, etc., which automatically regulates or controls the test device or the sequence of the respective insulation resistance measurement procedure. Naturally, all other possible and appropriate programmable units are also included in the invention. 202403968

[0032] 6

[0033] Another aspect of the present invention relates to a method for determining the total insulation resistance Rj S0G of a rail network of a direct current railway system according to one of claims 4 to 7 comprising the following steps:

[0034] - Applying the supply voltage Uo to the test device;

[0035] Closing the switch of the DC railway system's test device; measuring the rail potential <p des Schienennetzes;

[0036] Determination of the total insulation resistance R iS0 G of the rail network of the DC railway system according to the following relationship: RisoG = (| <p|*Rtest) / (Uo — | <p|) ■

[0037] Uo and Rtest are already known, so by measuring the rail potential <p des Schienennetzes im entsprechenden Schritt des erfindungsgemäßen Verfahrens die mathematische Berechnung des Gesamtisolationswiderstands R iS0 G of the rail network of the DC railway system. The total insulation resistance R iS0G of the rail network of the DC railway system can be mathematically determined not only by the rail potential <p auch durch l tes Determine t or Utest, which can also be easily determined through further measurements. This applies when the rail potential has already been measured and is therefore known. <p sind die genannten, weiteren Messungen insbesondere von ltest oder Utest zur mathematischen Bestimmung des Gesamtisolationswiderstands RISOG des Schienennetzes nicht notwendig, da sie diesbezüglich an sich redundant sind. Jedoch können sie, falls gewünscht bzw. erforderlich, zusätzlich zur Verifizierung des bereits bestimmten Ergebnisses für den Gesamtisolationswiderstand Rj S0 G of the rail network, e.g. through the further relationship

[0038] Risk —| <p| / ltest entsprechend genutzt werden. Hier sind selbstverständlich auch alle weiteren und sinnvollen Berechnungsmöglichkeiten, beispielsweise durch Benutzung der gemessenen Spannung Utest etc., von der Erfindung mitumfasst.

[0039] According to a further particularly preferred embodiment of the method according to the invention, the method is carried out automatically by means of the at least one programmable unit of the DC railway system.

[0040] The previously described embodiments of the invention, and in particular its advantages, are transferable analogously to both the aforementioned DC railway system and the aforementioned method, and therefore apply accordingly to both, and vice versa. 202403968

[0041] 7

[0042] Preferred embodiments of the invention will now be explained in more detail with reference to the drawings. These show:

[0043] Fig. 1 A schematic representation of an embodiment of a test device according to the invention in a DC railway system with the switch open and

[0044] Fig. 2 shows a further schematic representation of the embodiment of a test device according to the invention in a DC railway system from Figure 1 with a closed switch.

[0045] In Figures 1 and 2, identical components are designated with the same reference numerals. The embodiments may differ. The term "rail potential" used in the following figure description refers to... <p bezieht sich dabei jeweils auf das in den Figuren 1 und 2 verwendete Symbol <j>.

[0046] Figure 1 shows a schematic representation of an embodiment of a test device 10 according to the invention in a DC railway system 1. The representation is limited to the essential components of the invention, in particular of the DC railway system 1, etc., and therefore does not show all components of the DC railway system 1 in its entirety. The DC railway system 1 is intended for operation with at least partially electrically powered, rail-bound vehicles, such as electric rail vehicles of all kinds, etc.

[0047] The DC railway system 1 shown in Figure 1 features a test device 10 permanently installed in a substation of the DC railway system 1, which is connected to the rail network 3 of the DC railway system 1 via connection 18. The substation itself is not shown for clarity. The test device 10 is thus permanently available for insulation resistance measurements at any time, allowing these measurements to be performed as often as desired, for example, daily, weekly, monthly, etc. Furthermore, the fixed and permanently installed test device 10 ensures that measurements can always be carried out in the same manner, thereby almost completely eliminating measurement errors caused by faulty setup or connections.

[0048] Rail network 3 with the rail potential <p ist mittels der hier beispielhaft dargestellten, vier voneinander beabstandeten Isolationswiderständen 5 gegenüber der Erde 7 202403968

[0049] 8 insulated. The insulation resistances 5 are not to be understood as individual, real electrical components, but rather, in the equivalent circuit diagrams according to Figures 1 and 2, they represent the corresponding property of the insulators used for insulating the rail network 3, which consist of insulating materials that do not insulate infinitely well and thus exhibit a corresponding, unwanted insulation resistance. The test device 10 has a voltage source 16, which can provide a supply voltage Uo, and a test resistor R. tes t 14 and a switch 12 are opened. The switch 12 is open, so the test device 12 is out of operation. This is the normal or usual case during the operation of the DC railway system 1. The voltage source 16 can be an AC voltage source or a DC voltage source, which means that, for the power supply, taking into account a coordinated combination of voltage source 16, test resistor Rtest 14 and current carrying capacity, advantageously almost all voltage sources already available on site, e.g. railway supply voltage, auxiliary voltages, power supplies, batteries, etc., can be used. The present DC railway system 1 is, for example, supplied by a railway supply voltage of 750 V, which is used as the supply voltage Uo of the voltage source 16 of the test device 10.

[0050] Figure 2 shows a further schematic representation of the embodiment of a test device 10 according to the invention in the DC railway system 1 from Figure 1 with the switch 12 closed during an insulation resistance measurement.

[0051] To perform an insulation resistance measurement, a supply voltage Uo is first applied using the voltage source 16, and the test device 10 of the DC railway system 1 is activated by closing the switch 12. This activates the test resistor R. tes t 14 of the test device 10 is firmly connected to earth 7, creating a series circuit and thus a voltage divider, consisting of the test resistor R tes t 14 and a total insulation resistance Rj S0 G 6, which, as can be seen from the equivalent circuit diagram in Figure 2, is composed of the individual insulation resistances 5. A current l then flows through the active circuit of the test device 10. tes t and across the test resistor R tes At t 14, the voltage Utest is applied. The rail potential then applied to the rail network 3 of the DC railway system 1 is... <p weicht in der Regel vom Schienenpotential <p vor der Aktivschaltung der Testvorrichtung 10 ab und hat demzufolge einen anderen Wert. Unabhängig davon ist in beiden Fällen die Längsimpedanz über die Gleise bzw. Schienen vernachlässigbar klein und liegt bei ca. 30 mOhm / km*Schiene, d.h., es kann demzufolge ein im Wesentlichen konstantes 202403968

[0052] 9

[0053] Rail potential <p über die betrachtete Strecke des Gleichstrombahnsystems hinweg angenommen werden.

[0054] Due to the creation or presence of the voltage divider through the active switching of the test device 10, the following formula applies: the ratio of supply voltage Uo to the magnitude of the rail potential <p bei eingeschalteter Testvorrichtung 10 dem Verhältnis aus der Summe des Testwiderstands R tes t 14 and the total insulation resistance RjsoG 6 to the total insulation resistance Rj S0 G 6 corresponds to:

[0055] (1) Uo / | <p| = (Rtest + Risoc) / RisoG-

[0056] By simple mathematical transformation(s) of equation (1), the total insulation resistance RISOG 6 is then obtained according to equation (2):

[0057] (2) RisoG = (| <p|*Rtest) / (Uo - |<p|)

[0058] From this, the total insulation resistance Rj can be easily calculated. S0 G 6 of the relevant Annex 1 can be determined or calculated, since all other quantities are either known, such as the supply voltage Uo of the voltage source 16, as well as the test resistor R. tes t 14, or can be easily measured, such as the rail potential <p. Die Messung des Schienenpotentials <p des Schienennetzes 3 kann dabei automatisiert durchgeführt werden. Üblicherweise sind entsprechende Messvorrichtungen in den betreffenden Anlagen vorhanden. Falls beispielsweise bereits ein Streustromüberwachungssystem in der Anlage 1 vorhanden bzw. eingebaut ist, kann eine bereits erfolgte Schienenpotentialmessung auch ohne weiteren, zusätzlichen Aufwand verwendet oder auch dementsprechend einfach wiederholt werden. Aufgrund des Aufbaus der Testvorrichtung 10 können zur Überprüfung des erhaltenen Ergebnisses für den Gesamtisolationswiderstand Rj S0 G 6 of the rail network 3 also includes other auxiliary quantities, such as the current flowing when the test device 10 is actively switched on. tes t and / or the voltage U tes t, which is above the test resistor R tes t 14 drops, is also very easy to measure and can be used as needed.

[0059] Since the present voltage source 16 of the test device 10 is used as the supply voltage Uo of the railway supply voltage of 750 V and thus represents a high, potentially dangerous DC voltage > 120 volts, the test resistor R tes t 14 is advantageously chosen to be larger than the total insulation resistance RISOG 6, so that the greatest voltage drop across the test resistor R tes t 14 and is not located between rail network 3 of the DC railway system 1 and Earth 7. Therefore, 202403968

[0060] 10 ensures that the adjacent rail potential <p des Schienennetzes 3 keine Gefährdung ausgeht und keine weiteren Beeinträchtigungen hervorgerufen werden.

[0061] In the present case, the DC railway system 1 also has a programmable unit, for example a correspondingly configured control and / or regulation device etc., which is not shown in the figures for the sake of clarity, and which automatically regulates or controls the test device 10 or the sequence of the procedure for the respective insulation resistance measurement described above.

[0062] This allows for automated triggering and execution of the corresponding measurements, as well as automated transmission and / or processing of the results. Since no operation or traversal of the track, particularly no rail traffic on rail network 3 of DC railway system 1, should take place during the measurement(s), the measurements can be carried out in this way without any additional personnel effort, typically during nighttime hours. "No operation" or "no traversal" refers exclusively to electric traversal, i.e., vehicles powered by electrical energy from DC railway system 1, for example, via an overhead line. Traversal of DC railway system 1 by, for example, diesel-powered or battery-powered vehicles is also possible during the measurement(s).

[0063] Furthermore, the evaluation and its results can be used for other purposes, such as automated trend analyses. Thus, a general deterioration of the overall insulation or a decline in the general insulation properties of the DC railway system 1 along its entire route can be easily detected, particularly at an early stage, using the invention, and countermeasures can be taken accordingly. This can reduce costs and simultaneously increase the safety of the entire system.

[0064] Furthermore, the invention is in no way limited to the embodiments described and shown in Figures 1 and 2. Rather, all possible further meaningful embodiments of the invention are also fully encompassed.< / j>

Claims

202403968 11 Patent claims 1. Test device (10) for a DC railway system (1) for at least partially electrically powered rail vehicles, wherein the DC railway system (1) has a rail network (3) with at least one insulation resistance (5) and wherein the rail network (3) is insulated from earth (7) by means of the at least one insulation resistance (5), wherein the test device (10) is connected to the rail network (3) of the DC railway system (1), characterized in that the test device (10) has at least one switch (12), at least one test resistor Rtest (14) and at least one voltage source (16) with a supply voltage Uo, wherein, with the switch (12) closed and the supply voltage Uo applied, a total insulation resistance Rj is measured by means of the test device (10). S0G (6) of the rail network (3) of the DC railway system (1) can be determined, wherein the total insulation resistance RISOG (6) can be determined at least by means of the at least one insulation resistance (5).

2. Test device (10) according to claim 1 , characterized in that the voltage source (16) of the test device (10) is an AC voltage source or a DC voltage source.

3. Test device (10) according to claim 1 or 2, characterized in that, when a supply voltage Uo > 50 volts AC or Uo > 120 volts DC is applied to the test device (10), the at least one test resistor (14) is greater than the total insulation resistance R iS0 G (6) is.

4. Direct current railway system (1) for at least partially electrically powered rail vehicles, wherein the direct current railway system (1) comprises at least one substation and a rail network (3) with a rail potential <p und wenigstens einem Isolationswiderstand (5) aufweist, wobei das Schienennetz (3) mittels dem wenigstens einen Isolationswiderstand (5) gegenüber der Erde (7) isoliert ist, mit wenigstens einer Testvorrichtung (10) nach einem der Ansprüche 1 bis 3, 202403968 12 5. DC railway system (1) according to claim 4, characterized in that the at least one test device (10) is permanently installed in the DC railway system (1).

6. DC railway system (1) according to claim 5, characterized in that the at least one test device (10) is permanently installed in the at least one substation of the DC railway system (1).

7. DC railway system (1) according to one of claims 4 to 6, characterized in that the DC railway system (1) has at least one programmable unit, wherein the at least one programmable unit is configured such that the at least one programmable unit automatically regulates and / or controls the at least one test device (10).

8. Method for determining the total insulation resistance Rj S0 G (6) of a rail network (3) of a direct current railway system (1) according to one of claims 4 to 7 comprising the following steps: - Applying the supply voltage Uo to the test device (10); Closing the switch (12) of the test device (10) of the DC railway system (1); Measurement of the rail potential <p des Schienennetzes (3); Determination of the total insulation resistance Rj S0 G (6) of the rail network (3) of the DC railway system (1) according to the following relationship: RisoG= (| <p|*Rtest) / (Uo — | <p|)9. Method according to claim 8, characterized in that the method is carried out automatically by means of the at least one programmable unit of the DC railway system (1).< / p|)

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