Method for locating an insulation fault in an on-board electrical system of a rail vehicle

Abstract

The invention relates to a method for locating an insulation fault in an on-board electrical system (BN) of a rail vehicle (TZ), wherein the rail vehicle (TZ) comprises a number of cars (EW1, MW1, MW2, EW2), wherein the on-board electrical system (BN) comprises at least one vehicle-wide bus bar (SS1, SS2) and load circuits (VSK connected to the bus bar (SS1, SS2), wherein the bus bar (SS1, SS2) and the load circuits (VSK) are designed to supply electrical energy to electrical loads (EV1, EV2) arranged in the number of cars (EW1, MW1, MW2, EW2), and wherein the on-board electrical system (BN) comprises controllable switching devices (ESS) arranged in the number of cars (EW1, MW1, MW2, EW2), which are designed to switch the load circuits (VSK), wherein the rail vehicle (TZ) comprises a central control device (SE) and a vehicle-wide communication network (KN), wherein the control device (SE) is connected by means of signals to the switching devices (ESS) via the communication network (KN), and wherein the control device (SE) is designed to control at least the switching devices (ESS), and wherein the rail vehicle (TZ) comprises a central insulation monitoring device (IUE), which is connected to the control device (SE) and the on-board electrical system (BN), and which is designed to determined the presence of at least one insulation fault in the on-board electrical system (BN). The switching devices (ESS) are controlled by the control device (SE) in such a way that, starting with a plurality of switched-off load circuits (VSK), the load circuits (VSK) are switched on individually, or that, starting with a plurality of switched-on load circuits (VSK), the load circuits (VSK) are switched off individually, the insulation monitoring device (IUE) determines the presence of an insulation fault as a result of the switching on of the load circuits (VSK) or determines the absence of an insulation fault as a result of the switching off of the load circuits (VSK), and, after determining the presence of an insulation fault in a switched-on load circuit (VSK) or the absence of a insulation fault in a switched-off load circuit (VSK) via the insulation monitoring device (IUE), the control device (SE) outputs at least one item of information relating to the determined load circuit (VSK), by means of which said load circuit (VSK) can be located in the on-board electrical system (BN).

Description

[0001] 202406858

[0002] 1

[0003] Description

[0004] Method for locating an insulation fault in the on-board electrical system of a railway vehicle

[0005] The invention relates to a method for locating an insulation fault in the on-board electrical system of a rail vehicle. The invention further relates to a rail vehicle with equipment for carrying out the method according to the invention.

[0006] Modern rail vehicles, especially multiple units with several passenger cars, incorporate a multitude of electrical consumers that serve both the function and control of the rail vehicle and the comfort of passengers. These consumers are typically supplied with electrical power via an on-board electrical system. Vehicle-wide busbars of the on-board electrical system are fed by at least one on-board power converter (BNU) or auxiliary power converter (HBU), with redundancy in the case of multiple converters. Each busbar can be divided into segments comprising one or more cars, which can be interconnected as needed, for example, via coupling contactors.The on-board power converters are, in turn, powered, for example, by a DC link of a traction converter or a special auxiliary winding of a traction transformer in the rail vehicle's traction system. The on-board power converters convert the input voltage, for example, into an output three-phase AC voltage of constant or variable frequency and / or into a DC voltage, and apply this to the connected busbar. A busbar for an example frequency-variable 480 V, 60 Hz three-phase AC voltage can, for instance, comprise three phase conductors to which auxiliary equipment such as coolers, fans, pumps, or compressors are connected.In contrast, a busbar for an exemplary constant 400 V, 50 Hz three-phase alternating voltage can include, in addition to three phase conductors, a neutral conductor, to which consumers requiring such a neutral conductor, such as the on-board kitchen, as well as consumers of lower power operated with only one phase, such as sockets with 230 V, 50 Hz alternating voltage and the interior lighting of the passenger compartments, are connected.

[0007] The various electrical consumers or their consumer circuits are connected either directly or indirectly via further converters or inverters, which convert the busbar voltage into an AC or DC voltage required for the consumer(s). 202406858

[0008] 2

[0009] DC voltage is converted and connected to the busbars. Alternatively or additionally, galvanic isolation between the busbar and a consumer circuit can be provided by means of a transformer. Due to the large number of consumers distributed throughout the rail vehicle, which in particular operate at different voltages, the on-board electrical system comprises a multitude of simple and, where applicable, branched consumer circuits to supply individual consumers or groups of consumers with the electrical energy required for their operation. These consumer circuits, or the consumers connected to them, are currently protected against overload currents and short circuits by miniature circuit breakers (MCBs). Additionally, contactors or relays are currently used to switch the consumer circuits or to connect them to the respective supplying busbar.A possible replacement of this previously common combination of circuit breakers and contactors by controllable electronic switching and protection devices, also known as Solid State Power Controllers (abbreviated SSPC), in the on-board network of a rail vehicle is described in the patent application DE 10 2016 226 148 A1.

[0010] In addition to protecting the onboard electrical system of a rail vehicle from overload currents, short circuits, or ground faults in the electrical lines of the consumer circuits and / or in the consumers themselves, which can be ensured by means of circuit breakers or electronic switching and protective devices, supplementary monitoring of the onboard electrical system and the consumer circuits for insulation faults is advisable to guarantee compliance with a specified permissible insulation level in the onboard electrical system. An insulation fault is defined as a high-resistance ground fault or a high-resistance electrical connection to the ground potential of the rail vehicle, which occurs, for example, due to defective insulation in an electrical line of a consumer circuit and leads to a reduction in the insulation resistance of this consumer circuit below the permissible insulation level.Due to the high-resistance electrical connection, an insulation fault typically results in a current flow of only a few microamperes to milliamperes, which may also occur only sporadically, for example, depending on humidity. Therefore, supplementary monitoring of the on-board electrical system for insulation faults is advisable or even necessary for the safe operation of the rail vehicle. 202406858.

[0011] 3

[0012] Such monitoring can be carried out, for example, by means of an actively measuring insulation monitoring device, which is connected to one or more busbars of the vehicle's electrical system and to the vehicle's ground potential during normal operation. An insulation monitoring device superimposes a measuring voltage onto the voltage applied to the busbar, resulting in a current flow proportional to the insulation resistance. This measuring current causes a voltage drop across a measuring resistor in the insulation monitoring device, which is then compared to a predefined threshold value.If the threshold is exceeded, a warning message is issued by the insulation monitoring device to a control unit of the rail vehicle connected to it via signaling technology, which, for example, causes an optical and / or acoustic warning message to be issued to a person driving or waiting on the rail vehicle.

[0013] In addition to the insulation monitoring device, which initially only detects the general presence of an insulation fault in the vehicle electrical system or busbar and the associated consumer circuits, insulation fault locating devices can be provided. These enable more precise localization of the detected insulation fault within the vehicle electrical system. For insulation fault locating, test current signals of a few milliamperes and a specific pulse duration are generated, for example, by the insulation monitoring device or a separate test current generator, and fed into the busbar of the vehicle electrical system during normal operation of the rail vehicle. The test current signals cause a current to flow through the conductors of the consumer circuits, the resistance of the insulation fault in the affected consumer circuit, and the ground conductor or chassis of the rail vehicle to the injection point.The insulation fault detection devices detect this current flow via current transformers installed in the consumer circuits. The current flow detected by each current transformer is evaluated in the insulation fault detection devices or in the insulation monitoring device connected to them to determine which consumer circuit of the on-board electrical system is affected by the insulation fault. Depending on the result of the evaluation, information about the consumer circuit identified by the detection can then be output visually and / or audibly to the person operating or maintaining the rail vehicle, originating from the insulation monitoring device. 202406858.

[0014] 4

[0015] Exemplary standards for the described equipment include, in particular, DIN EN 61557-8 "Electrical safety in low-voltage networks up to AC 1000 V and DC 1500 V - Equipment for testing, measuring or monitoring protective measures - Part 8: Insulation monitoring devices for IT systems" in the December 2015 version, and DIN EN 61557-9 "Electrical safety in low-voltage networks up to AC 1000 V and DC 1500 V - Equipment for testing, measuring or monitoring protective measures - Part 9: Insulation fault location devices for IT systems" in the October 2015 version. These standards are part of the IEC 61557 series of standards, which define requirements for insulation monitoring devices specifically for monitoring ungrounded AC and DC IT systems, and requirements for insulation fault location devices for locating network sections with insulation faults in such systems.The use of insulation monitoring devices and insulation fault detection devices in IT systems is also the subject of the standard DIN VDE 0100-410 “Erection of low-voltage installations - Part 4-41: Protection measures - Protection against electric shock” in the version of October 2018, which is based on the standard IEC 60364-4-41 of 2005 or 2017.

[0016] While, in principle, only one insulation monitoring device is required for insulation monitoring in the on-board network of a rail vehicle, an automated search for the consumer circuit in which an insulation fault has occurred requires a large number of insulation fault detection devices arranged in the consumer circuits, which result in both high costs and the provision of special installation spaces in the rail vehicle for their arrangement.

[0017] The object of the invention is therefore a technically simpler and thus more cost-effective automated localization of a high-resistance insulation fault in the on-board electrical system of a rail vehicle. This object is achieved by the respective features of the independent claims. Further developments are specified in the respective dependent claims.

[0018] The invention relates to a method for locating an insulation fault in the on-board electrical system of a rail vehicle, wherein the rail vehicle comprises a number of cars, wherein the on-board electrical system comprises at least one vehicle-wide busbar and consumer circuits connected to the busbar, wherein the busbar and the consumer circuits are configured, electrically arranged in the number of cars 202406858

[0019] 5

[0020] to supply consumers with electrical energy, and wherein the on-board electrical system comprises controllable switching devices arranged in the number of cars, which are configured to switch the consumer circuits, wherein the rail vehicle comprises a central control unit and a vehicle-wide communication network, wherein the control unit is connected to the switching devices via the communication network, and wherein the control unit is configured to control at least the switching devices, and wherein the rail vehicle comprises a central insulation monitoring device, which is connected to the control unit and the on-board electrical system, and which is configured to determine the presence of at least one insulation fault in the on-board electrical system. The switching devices are controlled by the control unit in such a way that, starting from a plurality of switched-off consumer circuits,The consumer circuits are individually switched on, or, starting from a plurality of switched-on consumer circuits, the consumer circuits are individually switched off; the insulation monitoring device determines the presence of an insulation fault as a result of the switching on of the consumer circuits, or the absence of an existing insulation fault as a result of the switching off of the consumer circuits; and after the insulation monitoring device has determined the presence of an insulation fault in a switched-on consumer circuit or the absence of an existing insulation fault in a switched-off consumer circuit, the control unit outputs at least one piece of information about the specific consumer circuit, by means of which this consumer circuit can be located in the vehicle electrical system.

[0021] The invention also relates to a rail vehicle comprising at least a number of carriages, wherein electrical consumers are arranged in each of the number of carriages, a vehicle-wide on-board network with at least one busbar and consumer circuits connected to the busbar, via which the consumers can be supplied with electrical energy, and with controllable switching devices via which the consumer circuits can be switched, a central control unit and a vehicle-wide communication network, wherein the control unit is connected to the switching devices via the communication network, and wherein at least the switching devices can be controlled by means of the control unit, and a central insulation monitoring device, which is connected to the central control unit and the on-board network, wherein the presence of at least one insulation fault in the on-board network can be determined by means of the insulation monitoring device.The control unit and 202406858.

[0022] 6 the insulation monitoring device is designed to carry out the method according to the invention.

[0023] The invention advantageously utilizes the fact that the individual consumer circuits can be individually connected to, or disconnected from, the busbar by means of switching devices, automatically controlled by the central control unit. This individual switching on and off allows the control unit, based on information from the connected central insulation monitoring device, to identify and thus locate the consumer circuit in which, after its connection, an insulation fault is detected, or, after its disconnection, an existing insulation fault is no longer detected by the insulation monitoring device. An arrangement of the insulation fault detection devices described in the introduction, or...Therefore, the use of measuring current transformers in the consumer circuits in addition to the central insulation monitoring device is no longer advantageously required.

[0024] As described in the introduction, the vehicle electrical system supplies power to a large number of electrical consumers located throughout the multiple cars of the rail vehicle. The rail vehicle may consist of a single car, but more commonly of several coupled cars, in which the consumers are distributed. The consumers are supplied, for example, via multiple vehicle-wide busbars, to which different voltages are applied, depending on the function of the connected consumers. For instance, the vehicle electrical system may include two busbars carrying different AC voltages and another busbar carrying a DC voltage. The two AC busbars can be connected to one or more other components.The AC busbar is preferably supplied redundantly by several on-board power converters, while the DC busbar is supplied by one or more on-board batteries or also by on-board power converters. Both the AC and DC busbars can be supplied by the same on-board power converters. The on-board power converters, in turn, are supplied, for example, from one or more DC intermediate circuits or from one or more auxiliary windings of one or more traction transformers of the rail vehicle's traction system. 202406858.

[0025] 7

[0026] The busbars encompass all the cars of the rail vehicle. Particularly with multiple cars, the busbars can preferably be divided into several segments, each corresponding to a number of cars. Each segment can contain several cars, or alternatively, several segments can be provided within a single car. The multiple busbar segments are connected to each other as needed, for example, by means of controllable coupling contactors. Preferably, the busbars of each segment are supplied by at least one on-board power converter assigned to that segment and, optionally, by an on-board power supply battery. In particular, if the on-board power converter of one of the segments fails, the affected segment can be connected to one or more, and especially all, segments to ensure a reliable power supply to the consumers connected to the affected segment despite the failure.Similarly, the busbar segments can be connected to each other using the coupling contactors to enable vehicle-wide determination and localization of an existing insulation fault in one of the consumer circuits by means of the central control unit and the central insulation monitoring unit.

[0027] The on-board electrical system, or the respective busbars including the electrical loads connected via consumer circuits, can be designed as either a grounded or an ungrounded system. In particular, an ungrounded IT system, as mentioned earlier, offers the advantage that a low-resistance or high-resistance first ground fault, for example, in a conductor of a consumer circuit with the earth potential of the rail vehicle, does not yet trigger a protective device. Instead, the system can continue to operate until a second ground fault, for example, due to an insulation fault, causes the protective device to trip. Therefore, even in such a system, it is necessary to identify and rectify any existing insulation fault in the on-board electrical system in order to prevent a subsequent failure due to another ground fault.In a rail vehicle, such a failure can have a detrimental effect, for example, making it impossible to maintain its operation or severely restricting it.

[0028] As described in the introduction, electrical loads can be connected to the busbars directly or indirectly. A direct connection is one in which the load is supplied with the voltage present at the busbar via the load's circuit. An indirect connection, on the other hand, can be in the load's circuit or this 202406858

[0029] 8. A converter or inverter may be provided upstream, which converts the voltage of the busbar into a voltage adapted to the load(s). Such a conversion may, in particular, include the conversion of an AC voltage from the busbar into a DC voltage, or the conversion of an AC voltage of a first voltage level into an AC voltage of a second, lower or higher, voltage level. Alternatively or additionally, galvanic isolation, for example by means of a transformer, may be provided, particularly as part of such a converter or inverter.

[0030] A consumer circuit connected to a busbar, which can be switched on or off by means of a switching device on the busbar, comprises a number of conductors depending on the supply voltage and the selected system. A consumer circuit can, for example, supply only a single consumer with electrical energy, or alternatively, several consumers, especially identical ones, can be connected to these conductors.

[0031] The controllable switching devices are electrically or electronically controlled by the control unit via the communication network. For example, the switching devices are designed as electronic switching devices, in particular as part of a previously described semiconductor protection switch or a solid-state power controller (SSPC), which, in addition to the controllable switching function, also performs a monitoring and protection function. The electronic switching devices or semiconductor protection switches can be designed for switching, or for switching and protecting, DC, AC, or both connections. They enable the opening and closing of electrical connections by means of controlled semiconductor switches, whereby the switching is controllable by the central control unit via a communication interface that can be connected to the rail vehicle's communication network.In addition to controlled switching, electronic switching and protective devices also serve to monitor and protect consumer circuits and the connected loads. For this purpose, the electronic switching and protective devices continuously measure, for example, the current flowing through the respective device and the voltage applied to it. From this, a microcontroller within the device, particularly by comparing the measured values ​​with a predefined tripping characteristic, can detect the presence of an overload or short circuit and disconnect the monitored connection by appropriately controlling the semiconductor switches. After such a shutdown occurs, 202406858.

[0032] Once the device has reached position 9, corresponding information can be transmitted to the central control unit via the communication interface of the device and the communication network. Thus, bidirectional communication links exist between the electronic switching and protective devices and the central control unit, allowing both the switching of the electronic switching and protective devices to be controlled and the respective status of these devices to be signaled to the central control unit.

[0033] The vehicle-wide communication network of the rail vehicle, which connects the central control unit to the switching devices via signaling, can, for example, be designed as a central bus system to which all sending and receiving devices are connected and communicate unidirectionally or bidirectionally according to one or more communication protocols. The communication network can be wired, in particular using electrical and optical lines, or wireless.

[0034] In addition to controlling the switching devices or electronic switching and protective devices relevant to the invention, as well as the insulation monitoring device, the central control unit can also control a multitude of other devices, particularly those required for the operation of the rail vehicle, including the electrical consumers. For this purpose, the central control unit has computing and storage means as well as communication means and communication interfaces, by means of which it can identify the consumer circuit affected by an insulation fault and locate it within the vehicle's electrical system or rail vehicle, based on the controlled switching of the consumer circuits and information received from the insulation monitoring device.The output of at least one piece of information about the identified consumer circuit is preferably via a suitable communication interface to an optical and / or acoustic display unit, so that this information is appropriately displayed optically and / or acoustically to a person operating the rail vehicle during normal ferry operations and / or to a person maintaining the rail vehicle during maintenance in a depot, and so that, if necessary, they can take appropriate measures based on this information to rectify the insulation fault or its temporary elimination, for example, by controlled shutdown of the consumer circuit. For example, the person can receive information concerning the carriage in which the identified consumer circuit is located, the routing of the consumer circuit's conductors in the carriage, and the affected consumer circuit 202406858.

[0035] The 10 connected consumers and their arrangement within the carriage are visually displayed in the form of unambiguous designations, descriptions, and graphic representations. Alternatively or additionally, the information can be transmitted via a radio interface to a trackside facility, which can then use it for planning future maintenance activities on the rail vehicle and for providing any necessary spare parts and repair tools, or from which a controlled shutdown of the affected consumer circuit can be initiated by the central control unit.

[0036] As described in the introduction, the insulation monitoring device can, for example, be designed as an actively measuring insulation monitoring device. This device is connected to at least one busbar of the vehicle's electrical system and to the ground potential of the rail vehicle. A measuring voltage superimposed on the voltage applied to the busbar results in a current flow proportional to the insulation resistance. This measuring current causes a voltage drop across a measuring resistor, which the insulation monitoring device compares to a predefined threshold value. If the threshold value is exceeded, the insulation monitoring device outputs a corresponding signal to the connected central control unit.

[0037] If the busbar monitored by the insulation monitoring device is divided into several segments and these are electrically isolated during normal operation of the rail vehicle, the central control unit first switches the coupling contactors to connect the respective segments in order to enable vehicle-wide detection of an insulation fault in the on-board electrical system by the insulation monitoring device. Alternatively, the segments can also be switched on successively, whereby the detection initially only includes the segment to which the insulation monitoring device is connected, and subsequently the other segments are switched on one after the other, so that the monitoring is extended to each newly added segment of the busbar.

[0038] According to a further development of the invention, the method is carried out automatically at predetermined time intervals and / or depending on manual initiation by a person operating and / or maintaining the rail vehicle and / or depending on the status of the on-board electrical system. 202406858

[0039] 11

[0040] According to a further development of the invention, the switching devices for locating the insulation fault are only controlled by the control unit after the insulation monitoring device has determined that an insulation fault is present in the vehicle electrical system.

[0041] Particularly when the vehicle electrical system is configured as an ungrounded IT system, the insulation monitoring device can first determine in general terms whether an insulation fault exists in the system. Only after such a fault has been determined, or the vehicle electrical system has been assigned the status of an existing insulation fault, can the central control unit, together with the insulation monitoring device, perform a localization of the insulation fault in the vehicle electrical system according to the invention. Such an initial general determination can be carried out regularly or based on a specific manual initiation by the central control unit and the insulation monitoring device.

[0042] According to a further development of the invention, if the rail vehicle comprises a plurality of cars, the switching devices are controlled by the control unit in such a way that, starting from the plurality of switched-off consumer circuits, a respective number or all consumer circuits of one of the cars are switched on, or that, starting from the plurality of switched-on consumer circuits, a respective number or all consumer circuits of one of the cars are switched off, the insulation monitoring device determines the presence of an insulation fault after switching on the number or all consumer circuits or the absence of the insulation fault after switching off the number or all consumer circuits, and the control unit determines, by means of the presence or absence of the insulation fault determined by the insulation monitoring device, the car in which the insulation fault is located.The insulation monitoring device determines the presence of an insulation fault after individually switching on the consumer circuits of the specified number or all consumer circuits of the particular car, or the absence of an insulation fault after individually switching off the consumer circuits of the specified number or all consumer circuits of the particular car; and the control unit, using the presence or absence of the insulation fault determined by the insulation monitoring device, determines the consumer circuit in which the insulation fault is present. 202406858

[0043] 12

[0044] Such iterative monitoring advantageously enables a faster determination of the consumer circuit affected by an insulation fault in the on-board network of the rail vehicle, whereby this is first determined at the level of the carriages and then individually, so that in the individual determination only the switching devices or electronic switching and protection devices of the consumer circuits in the previously determined carriage have to be individually controlled by the central control unit in order to determine the affected consumer circuit.The determination of the affected consumer circuit is carried out iteratively, for example, as follows: in a first iteration, the affected car (or multiple cars) of the rail vehicle is identified; in a subsequent second iteration, the affected group (or multiple groups) of consumer circuits within that specific car is identified; and in a final third iteration, the affected consumer circuit within that specific group is identified. Depending on the total number of consumer circuits in a car, the second iteration can be omitted, and after identifying the affected car, the third iteration, which involves individually switching on or off all consumer circuits in that car, can be performed immediately.

[0045] According to an alternative embodiment of the invention, if the rail vehicle comprises a plurality of cars, the switching devices are controlled by the control unit in such a way that, starting from the plurality of switched-off consumer circuits, a respective number of consumer circuits of all cars are switched on, or that, starting from the plurality of switched-on consumer circuits, a respective number of consumer circuits of all cars are switched off, the insulation monitoring device determines the presence of an insulation fault after switching on the number of consumer circuits or the absence of the insulation fault after switching off the number of consumer circuits, and the control unit determines, by means of the presence or absence of the insulation fault determined by the insulation monitoring device, the number of consumer circuits in which the insulation fault is present.The insulation monitoring device determines whether an insulation fault is present after individually switching on a specific number of consumer circuits, or whether an insulation fault is absent after individually switching off a specific number of consumer circuits. The control unit then uses this information, determined by the insulation monitoring device, to identify the consumer circuit in which the insulation fault is located. 202406858

[0046] 13

[0047] Such iterative monitoring is carried out at the vehicle level. For example, based on several groups of consumer circuits spanning multiple vehicles, the first iteration identifies the group affected by an insulation fault. In a subsequent second iteration, the affected subgroup is identified within that identified group, for example, on a vehicle-by-vehicle basis. Finally, in a third iteration, the affected consumer circuit within that subgroup is identified. Depending on the total number of consumer circuits in a given group, the second iteration can be omitted, and after identifying the affected group, the third iteration, involving the individual activation or deactivation of all consumer circuits within that group, can be performed immediately.

[0048] According to a further alternative embodiment of the invention, if the at least one vehicle-wide busbar comprises a plurality of segments, the switching devices are controlled by the control unit in such a way that, starting from the plurality of switched-off consumer circuits, a respective number or all consumer circuits of one of the segments are switched on, or that, starting from the plurality of switched-on consumer circuits, a respective number or all consumer circuits of one of the segments are switched off, the insulation monitoring device determines the presence of an insulation fault after switching on the number or all consumer circuits or the absence of the insulation fault after switching off the number or all consumer circuits.The control unit determines, by means of the presence or absence of an insulation fault as determined by the insulation monitoring device, the segment in which the insulation fault is present; the insulation monitoring device determines, by means of the presence of an insulation fault after individually switching on the consumer circuits of the number or all consumer circuits of the specified segment, or the absence of an insulation fault after individually switching off the consumer circuits of the number or all consumer circuits of the specified segment; and the control unit determines, by means of the presence or absence of an insulation fault as determined by the insulation monitoring device, the consumer circuit in which the insulation fault is present.

[0049] According to a further alternative embodiment of the invention, if the at least one vehicle-wide busbar comprises a plurality of segments, the switching devices are controlled by the control unit in such a way that, starting from the plurality of switched-off consumer circuits, a respective number of consumer circuits of all segments 202406858

[0050] 14 is switched on, or that, starting from the majority of switched-on consumer circuits, a respective number of consumer circuits of all segments is switched off, the insulation monitoring device determines the presence of an insulation fault after switching on the number of consumer circuits or the absence of the insulation fault after switching off the number of consumer circuits, the control device determines, by means of the presence or absence of the insulation fault determined by the insulation monitoring device, the number of consumer circuits in which the insulation fault is present, the insulation monitoring device determines the presence of an insulation fault after individually switching on the consumer circuits of the specified number of consumer circuits or the absence of the insulation fault after individually switching off the consumer circuits of the specified number of consumer circuits,and the control unit determines, by means of the presence or absence of the insulation fault as determined by the insulation monitoring device, the consumer circuit in which the insulation fault is present.

[0051] According to a further development of the invention, the method is terminated after the information about the specific consumer circuit has been output.

[0052] According to a further development of the invention, if the vehicle electrical system comprises several busbars with electrical consumers connected via consumer circuits, the method is carried out separately for each busbar of the vehicle electrical system and the consumer circuits connected to it.

[0053] The localization of the consumer circuit affected by an insulation fault is therefore carried out individually for each of several busbars in the vehicle electrical system, or for the consumers connected to that busbar. For this purpose, the insulation monitoring device can, for example, be connected exclusively to the busbar whose consumer circuits are to be checked for an insulation fault. The other busbars can continue to operate normally during the procedure for the busbar in question, so that the function of the consumers connected to them is not affected.

[0054] The rail vehicle according to the invention is designed, for example, as a multiple unit train, in particular as an electric multiple unit train for local, regional or long-distance transport. Such a rail vehicle, as a multiple unit train, typically comprises several cars, each with a passenger compartment in which passengers can sit, or as a railcar 202406858

[0055] 15 only one carriage. The passenger compartments can be accessed either via doors located in the side walls of the carriages or via gangways between adjacent carriages.

[0056] According to a further development of the invention, the at least one busbar and the consumers connected to it via consumer circuits are designed as a grounded or as an ungrounded system.

[0057] Particularly in the case of a vehicle electrical system with multiple busbars, different systems can be implemented and the procedure for locating an insulation fault can be adapted to the respective system, if necessary.

[0058] According to a further development of the invention, the at least one busbar and the consumer circuits are each designed as single- or multi-pole electrical connections.

[0059] Depending in particular on the chosen system and the electrical consumers being supplied, the consumer circuits can have a different number of poles.

[0060] After further training, at least one busbar is divided into a plurality of segments, with each segment comprising a number of cars.

[0061] According to a further development of the invention, the electrical consumers supplied via the consumer circuits are each designed as direct current or alternating current consumers.

[0062] According to a further development of the invention, the switching devices are designed as electrical or electronic switching devices, wherein the electronic switching devices in particular additionally comprise at least one protective device, and wherein the electronic switching and protective devices are in particular designed as a respective semiconductor protection switch.

[0063] The semiconductor protection switches can be designed, in particular, as solid-state power controllers as described in the introduction. 202406858

[0064] 16

[0065] The invention is explained below with reference to exemplary embodiments. These show:

[0066] FIG 1 shows a rail vehicle according to the invention with several carriages and an on-board network arranged therein, and

[0067] FIG 2 a flowchart of a method according to the invention

[0068] FIG 1 schematically shows a rail vehicle TZ designed as a multiple unit for the transport of passengers in a side view. The rail vehicle TZ comprises, by way of example, four coupled cars, with two cars being designed as end cars EW1 and EW2, and two further cars as intermediate cars MW1 and MW2. All cars EW1, MW1, MW2, and EW2 have a passenger compartment (not shown in detail), which is accessible to passengers both via doors in the side walls of the respective car and via a gangway between adjacent cars.The cars EW1, MW1, MW2, EW2 each support themselves via two bogies on rails (not shown) of a track of a route network, whereby the sides facing each other of the coupled end cars EW1, EW2 and the intermediate cars MW1, MW2 are supported on common bogies designed as running bogies LDB, while the sides facing away from each other of the end cars EW1, EW2 are supported on outer bogies designed as powered bogies TDG with drive motors of the drive or traction system arranged therein.

[0069] The rail vehicle TZ features, by way of example, two drive systems AS1 and AS2, the main components of which are located in the end cars EW1 and EW2. These components are preferably arranged in the roof and underfloor areas of the respective end cars EW1 and EW2 to provide a passenger compartment. The drive systems AS1 and AS2 are supplied with electrical energy by an overhead line (not shown) of a power supply network, to which a supply voltage, for example, a 25 kV, 50 Hz or 15 kV, 16.7 Hz single-phase AC voltage, or, for example, a 3 kV or 1.5 kV DC voltage, is applied. For an electrical connection of the drive systems AS1 and AS2 to the overhead line, the rail vehicle features, by way of example, two pantographs PAN1 and PAN2, each located in the roof area of ​​an end car EW1 or EW2.The pantographs PAN1, PAN2 can be electrically connected, for example via a vehicle-wide power line as shown in FIG. 1, so that the connection of only one of the pantographs PAN1, PAN2 to the overhead line is sufficient to supply both drive systems AS1, AS2. 202406858.

[0070] 17

[0071] Each of the two drive systems AS1, AS2 comprises, depending in particular on the supply voltage, for example a transformer which transforms the single-phase AC voltage on the primary side into a lower voltage on the secondary side, a drive converter connected to the secondary side of the transformer which converts the single-phase AC voltage into a DC voltage of a DC link by means of at least one rectifier, for example a four-quadrant converter, and this DC voltage is converted into a three-phase AC voltage of variable voltage level and frequency by means of at least one inverter, for example a pulse inverter, with which the drive motors in the traction bogies TDG are supplied.

[0072] In addition to the drive systems AS1 and AS2, the rail vehicle TZ has an on-board electrical network BN encompassing all cars EW1, MW1, MW2, and EW2. This network supplies electrical energy to numerous electrical consumers EV1 and EV2 distributed throughout the cars. These consumers, known as auxiliary systems, support, for example, the function of the various components of the drive systems AS1 and AS2, as well as the braking systems of the rail vehicle TZ. Other electrical consumers, EV1 and EV2, serve purposes such as passenger comfort, particularly air conditioning and lighting in the passenger compartments, or providing information to passengers.

[0073] According to the schematic representation in FIG. 1, the on-board electrical system BN of the rail vehicle TZ comprises two vehicle-wide busbars SS1, SS2. The two busbars SS1, SS2 are fed by two on-board power converters BNU1, BNU2 located in the end cars EW1, EW2, which in turn are each fed from a DC link of a drive system AS1, AS2. The supply to the busbars SS1, SS2 can, for example, be redundantly provided by both on-board power converters BNU1, BNU2. Alternatively, the busbars SS1, SS2 can also be divided into, for example, two segments each, with the first segment comprising the first end car EW1 and the first intermediate car MW1, and the second segment comprising the second end car EW2 and the second intermediate car MW2.A controlled splitting of the busbars SS1 and SS2 into their respective two segments can be achieved, for example, via coupling contactors located in the transition area between the two intermediate cars MW1 and MW2, which are not shown in detail. During such a splitting of the respective busbar SS1 and SS2 into two segments, the respective segments are powered by an on-board power converter BNU1 or BNU2 202406858.

[0074] 18. In the event of a failure of one of the two on-board power converters BNU1, BNU2, the respective segments can be reconnected to a continuous busbar SS1, SS2 by means of the coupling contactors, thereby ensuring the supply of power to the electrical consumers in all cars. A corresponding connection of the segments to continuous busbars SS1, SS2 and, if necessary, a disconnection also takes place during the localization of insulation faults according to the invention.

[0075] The consumers EV1 and EV2, arranged in the various cars EW1, MW1, MW2, and EW2 of the rail vehicle TZ (this arrangement is merely an example), are connected to the busbars SS1 and SS2 via consumer circuits VSK. The number of electrical lines or cables in the consumer circuits VSK depends primarily on the supply voltage and the selected system. The connection between the consumer circuits VSK and the busbars SS1 and SS2 is made via switching devices ESS. These switching devices ESS are each designed as electronic switching and protective devices, which, in addition to at least one switching device, also include at least one protective device, thus serving both the switching and protection of the respective consumer circuit VSK and of the one or more consumers EV1 and EV2 supplied by it.Such switching devices with supplementary protective devices are designed, for example, as controllable semiconductor circuit breakers or solid-state power controllers. In FIG. 1, for example, the first consumer circuits VSK each supply only one consumer EV1, and only the respective first consumer circuit VSK and the consumer EV1 supplied by it are connected to the first busbar SS1 via a switching device ESS.

[0076] In contrast, second consumer circuits VSK supply, for example, several consumers EV2 and are each connected to the second busbar SS2 via a switching device ESS. Additionally, converters (not shown) may be provided in or upstream of the consumer circuits VSK, which convert the voltage of the busbar SS1, SS2 into a voltage adapted to the consumer(s) EV1, EV2 and, if necessary, provide galvanic isolation between the busbar SS1, SS2 and the consumer circuit VSK.

[0077] The various electrical installations, in particular the drive systems AS1, AS2, the on-board power converters BNU1, BNU2, the coupling contactors between segments of the busbars SS1, SS2, the electrical loads EV1, EV2, and the switching devices ESS, are controlled by a central control unit SE, which is located, for example, in the first end car EW1. (202406858)

[0078] 19

[0079] The transmission of control signals from the control unit SE to the various devices for controlling the function or status of these devices is carried out via a communication network KN, which is schematically represented by dashed lines in FIG. 1. Such a communication network KN comprises, for example, a vehicle-wide central bus system with several communication nodes, in particular located in each of the cars EW1, MW1, MW2, EW2, from which signal lines extend to the various controlled devices in the respective car. Signal transmission can also take place from devices to the central control unit SE via the communication network, provided that these devices are designed for bidirectional communication.

[0080] A central insulation monitoring device (IUE), also located in the first end car EW1, is connected to the central control unit (SE) via signaling. The insulation monitoring device (IUE) is designed as an active measuring insulation monitoring device and is connected to the busbars SS1 and SS2 of the on-board electrical system (BN) and to the ground potential of the rail vehicle (TZ). To detect an insulation fault in the on-board electrical system (BN), the insulation monitoring device (IUE) applies a measuring voltage to one or both busbars SS1 and SS2. This voltage is superimposed on the voltage applied to the respective busbar SS1 and SS2 by the on-board electrical system converter(s) BNU1 and BNU2. The superimposed measuring voltage results in a current flow proportional to the insulation resistance between the electrical connection under consideration, in particular the entire on-board electrical system (BN), and the ground potential of the rail vehicle (TZ).This measuring current causes a voltage drop across a measuring resistor in the insulation monitoring device (IUE), which the IUE compares to a predefined threshold value. If this comparison shows that the predefined threshold value is exceeded, an insulation fault exists in the electrical connection under consideration. The IUE then signals this specific insulation fault to the central control unit (SE).

[0081] Together with the insulation monitoring device IUE, the central control unit SE is, according to the invention, able not only to determine an insulation fault in the entire on-board network BN of the rail vehicle TZ, but also, by appropriately switching consumer circuits VSK on or off, optionally following a prior suitable connection and disconnection of segments of the on-board network BN, to locate such an insulation fault at the level of the consumer circuits VSK. (According to 202406858)

[0082] 20

[0083] The central control unit SE can determine and locate the insulation fault by outputting information, for example via an optical display unit connected to the control unit SE, which is not specifically shown in FIG 1.

[0084] FIG 2 shows a flowchart of the inventive method for the automated localization of an insulation fault in the on-board network BN of the exemplary rail vehicle TZ of FIG 1. The flowchart is divided into four columns, wherein the information above relates to a first column a human-machine interface Ul, a second column the central control unit SE, a third column the central insulation monitoring unit IUE, and a fourth column the switching devices ESS or the consumer circuits VSK of the on-board network BN switched by them.

[0085] The procedure is initiated in a first step S1. This can be done by a person controlling or maintaining the rail vehicle TZ by entering a corresponding command via the human-machine interface Ul. Such an interface Ul can be designed, for example, as a touch-sensitive screen or as a mechanical actuating unit, in particular as a switch. The central control unit SE, which is connected to the interface Ul via signaling technology, receives the command and, in a second step S2, controls the central insulation monitoring unit IUE to perform insulation monitoring in the on-board network BN connected to it. The insulation monitoring unit IUE then starts this monitoring in a third step S3.

[0086] As an alternative to such manual input, the initiation of the automated localization of an insulation fault can also be carried out automatically by the central control unit SE, for example depending on a status of the on-board network BN, the presence of an insulation fault previously determined by the insulation monitoring device IUE in the on-board network BN, or the expiry of a predetermined time interval.

[0087] In a fourth step S4, the central control unit SE first controls all switching devices ESS in such a way that they each disconnect the connected consumer circuits VSK. Starting from this state of the vehicle electrical system BN, in which all consumer circuits VSK to be considered for insulation monitoring are initially disconnected from the busbar(s) SS1, SS2 by means of the switching devices ESS, the central control unit SE subsequently controls the switching devices ESS individually in the fourth step S4 in order to successively disconnect individual 202406858 in the fifth step S5.

[0088] 21

[0089] Consumer power circuits VSK are switched on again for a specific period of time and then switched off again.

[0090] In a sixth step, S6, the central insulation monitoring device (IUE) determines whether an insulation fault exists for each consumer circuit (VSK) that is switched on during the switching-on period. In a seventh step, S7, the central control unit (SE) checks whether the central insulation monitoring device (IUE) has determined an insulation fault for the currently switched consumer circuit (VSK). If no insulation fault is determined for the currently switched consumer circuit (VSK), the central control unit (SE) returns to the fourth step, S4, and activates another switching device (ESS) to switch on a different consumer circuit (VSK).However, if the central insulation monitoring device IUE detects an insulation fault for the currently connected consumer circuit VSK, the central control unit SE terminates the control of the switching devices ESS or the successive switching on and off of individual consumer circuits VSK in an eighth step S8 and controls the central insulation monitoring device IUE to terminate the insulation monitoring in a ninth step S9.

[0091] In addition, the central control unit SE, via a tenth step S10, transmits information about the consumer circuit VSK, for which an insulation fault has been determined, to the person initiating the procedure via the human-machine interface Ul. This information can include, for example, a specific identifier of the consumer circuit VSK, its specific arrangement or routing in the affected vehicle, and details about the consumer(s) EV1, EV2 supplied by the consumer circuit VSK.

[0092] In addition to the described individual switching on and off of consumer circuits (VSK), the central control unit (SE) can first switch on and off a group of several consumer circuits (VSK) using the switching devices (ESS) assigned to this group. This allows, after initiating the procedure, for the localization of an insulation fault to first take place at the level of the selected group and only then to perform the described localization at the level of the individual consumer circuits (VSK). Each group can be assigned, for example, to a car, a busbar, a segment of a busbar, and / or a consumer type. 202406858

[0093] 22

[0094] As an alternative to the aforementioned deactivation of all consumer circuits VSK, the central control unit SE can first control the switching devices ESS in such a way that, in the fourth step S4, they activate all consumer circuits VSK to be considered in the insulation monitoring. Based on this status of the vehicle electrical system BN, the central control unit SE then individually controls the switching devices ESS in order to successively deactivate and subsequently reactivate individual consumer circuits VSK for a specific period in the fifth step S5. During the deactivation period, the central insulation monitoring unit IUE determines the presence or absence of an insulation fault in the sixth step S6.In the seventh step, S7, the central control unit SE checks whether the central insulation monitoring unit IUE still detects an insulation fault for the currently deactivated consumer circuit VSK. If the fault persists despite the deactivated consumer circuit VSK, the central control unit SE returns to the fourth step, S4, and activates another switching device, ESS, to deactivate a different consumer circuit VSK. If, however, no insulation fault is detected for the currently deactivated consumer circuit VSK, or if no fault is detected, the central control unit SE terminates the control of the switching devices ESS (i.e., the successive deactivation and reactivation of individual consumer circuits VSK) in the eighth step, S8, and activates the central insulation monitoring unit IUE to deactivate insulation monitoring in a ninth step, S9.

Claims

202406858 23 Patent claims 1. Method for locating an insulation fault in an on-board network (BN) of a railway vehicle (TZ), wherein - the rail vehicle (TZ) comprises a number of wagons (EW1 , MW1, MW2, EW2), - the on-board electrical system (BN) comprises at least one vehicle-wide busbar (SS1, SS2) and consumer circuits (VSK) connected to the busbar (SS1, SS2), wherein the busbar (SS1, SS2) and the consumer circuits (VSK) are designed to supply electrical energy to electrical consumers (EV1, EV2) arranged in the number of cars (EW1, MW1, MW2, EW2), and wherein the on-board electrical system (BN) comprises controllable switching devices (ESS) arranged in the number of cars (EW1, MW1, MW2, EW2), which are designed to switch the consumer circuits (VSK), - the rail vehicle (TZ) comprises a central control unit (SE) and a vehicle-wide communication network (KN), wherein the control unit (SE) is connected to the switching devices (ESS) via the communication network (KN) using signaling technology, and wherein the control unit (SE) is designed to control at least the switching devices (ESS), and - the rail vehicle (TZ) includes a central insulation monitoring device (IUE) which is connected to the control device (SE) and the on-board network (BN) and which is designed to determine the presence of at least one insulation fault in the on-board network (BN), and wherein - the switching devices (ESS) are controlled by the control unit (SE) in such a way that, starting from a plurality of switched-off consumer circuits (VSK), the consumer circuits (VSK) are switched on individually, or that, starting from a plurality of switched-on consumer circuits (VSK), the consumer circuits (VSK) are switched off individually, - the presence of an insulation fault is determined by the insulation monitoring device (IUE) as a result of the switching on of the consumer circuits (VSK) or the absence of an existing insulation fault as a result of the switching off of the consumer circuits (VSK), and - from the control unit (SE), after the insulation monitoring device (IUE) has determined the presence of an insulation fault in a connected consumer circuit (VSK) or the absence of an insulation fault in a disconnected consumer circuit (VSK), at least one piece of information about the determined 202406858 24 Consumer current circuit (VSK) is output, by means of which this consumer current circuit (VSK) can be located in the vehicle network (BN).

2. Method according to claim 1, wherein the method is carried out automatically at predetermined time intervals and / or depending on a manual initiation by a person driving and / or maintaining the rail vehicle (TZ) and / or depending on a status of the on-board network (BN).

3. Method according to one of the preceding claims, wherein the switching devices (ESS) for localizing the insulation fault are controlled by the control device (SE) only after the insulation monitoring device (IUE) has determined that an insulation fault exists in the vehicle electrical system (BN).

4. Method according to any one of claims 1 to 3, wherein if the rail vehicle comprises a plurality of wagons (EW1, MW1 , MW2, EW2), - the switching devices (ESS) are controlled by the control unit (SE) in such a way that, starting from the majority of switched-off consumer circuits (VSK), a respective number or all consumer circuits (VSK) are switched on for one of the cars (EW1, MW1, MW2, EW2), or that, starting from the majority of switched-on consumer circuits (VSK), a respective number or all consumer circuits (VSK) are switched off for one of the cars (EW1, MW1, MW2, EW2), - the presence of an insulation fault is determined by the insulation monitoring device (IUE) after switching on the number or all consumer circuits (VSK) or the absence of an insulation fault after switching off the number or all consumer circuits (VSK), - is determined by the control unit (SE) by means of the presence or absence of the insulation fault of the carriages (EW1, MW1 , MW2, EW2) as determined by the insulation monitoring unit (IUE), in which the insulation fault is present, - the presence of an insulation fault is determined by the insulation monitoring device (IUE) after individually switching on the consumer circuits (VSK) of the number or all consumer circuits (VSK) of the specific car or the absence of an insulation fault after individually switching off the consumer circuits (VSK) of the number or all consumer circuits (VSK) of the specific car (EW1 , MW1 , MW2 , EW2 ), and 202406858 25 - the control unit (SE) determines, by means of the presence or absence of the insulation fault as determined by the insulation monitoring unit (IUE), the consumer circuit (VSK) in which the insulation fault is present.

5. Method according to any one of claims 1 to 3, wherein if the rail vehicle comprises a plurality of wagons (EW1, MW1 , MW2, EW2), - the switching devices (ESS) are controlled by the control unit (SE) in such a way that, starting from the majority of switched-off consumer circuits (VSK), a respective number of consumer circuits (VSK) of all cars (EW1 , MW1, MW2, EW2) are switched on, or that, starting from the majority of switched-on consumer circuits (VSK), a respective number of consumer circuits (VSK) of all cars (EW1 , MW1 , MW2, EW2) are switched off, - the presence of an insulation fault after switching on the number of consumer circuits (VSK) or the absence of an insulation fault after switching off the number of consumer circuits (VSK) is determined by the insulation monitoring device (IUE), - the number of consumer circuits (CFCs) in which the insulation fault is present is determined by the control unit (SE) by means of the presence or absence of the insulation fault as determined by the insulation monitoring unit (IUE), - the presence of an insulation fault is determined by the insulation monitoring device (IUE) after individually switching on the consumer circuits (VSK) of the specified number of consumer circuits (VSK) or the absence of an insulation fault after individually switching off the consumer circuits (VSK) of the specified number of consumer circuits (VSK), and - the control unit (SE) determines, by means of the presence or absence of the insulation fault as determined by the insulation monitoring unit (IUE), the consumer circuit (VSK) in which the insulation fault is present.

6. Method according to any one of claims 1 to 3, wherein if the at least one vehicle-wide busbar (SS1 , SS2) comprises a plurality of segments, - the switching devices (ESS) are controlled by the control unit (SE) in such a way that, starting from the majority of switched-off consumer circuits (VSK), a certain number or all consumer circuits (VSK) are each switched on to one of the segments, or that, starting from the majority of switched-on consumer circuits (VSK), a certain number or all consumer circuits (VSK) are each switched off to one of the segments, 202406858 26 - the presence of an insulation fault is determined by the insulation monitoring device (IUE) after switching on the number or all consumer circuits (VSK) or the absence of an insulation fault after switching off the number or all consumer circuits (VSK), - the segment in which the insulation fault is present is determined by the control unit (SE) by means of the presence or absence of the insulation fault as determined by the insulation monitoring unit (IUE), - the presence of an insulation fault is determined by the insulation monitoring device (IUE) after individually switching on the consumer circuits (VSK) of the number or all consumer circuits (VSK) of the specified segment, or the absence of an insulation fault after individually switching off the consumer circuits (VSK) of the number or all consumer circuits (VSK) of the specified segment, and - the control unit (SE) determines, by means of the presence or absence of the insulation fault as determined by the insulation monitoring unit (IUE), the consumer circuit (VSK) in which the insulation fault is present.

7. Method according to any one of claims 1 to 3, wherein if the at least one vehicle-wide busbar (SS1 , SS2) comprises a plurality of segments, - the switching devices (ESS) are controlled by the control unit (SE) in such a way that, starting from the majority of switched-off consumer circuits (VSK), a respective number of consumer circuits (VSK) of all segments are switched on, or that, starting from the majority of switched-on consumer circuits (VSK), a respective number of consumer circuits (VSK) of all segments are switched off, - the presence of an insulation fault after switching on the number of consumer circuits (VSK) or the absence of an insulation fault after switching off the number of consumer circuits (VSK) is determined by the insulation monitoring device (IUE), - the number of consumer circuits (CFCs) in which the insulation fault is present is determined by the control unit (SE) by means of the presence or absence of the insulation fault as determined by the insulation monitoring unit (IUE), - the presence of an insulation fault is determined by the insulation monitoring device (IUE) after individually switching on the consumer circuits (VSK) of the specified number of consumer circuits (VSK) or the absence of an insulation fault after individually switching off the consumer circuits (VSK) of the specified number of consumer circuits (VSK), and 202406858 27 - the control unit (SE) determines, by means of the presence or absence of the insulation fault as determined by the insulation monitoring unit (IUE), the consumer circuit (VSK) in which the insulation fault is present.

8. Method according to one of the preceding claims, wherein the method is terminated after the information about the specific consumer circuit (CSC) has been output.

9. Method according to one of the preceding claims, wherein if the vehicle electrical system (VES) comprises several busbars (SS1, SS2) with consumers (EV1, EV2) each connected via consumer circuits (VSK), the method is carried out separately for each busbar (SS1, SS2) of the vehicle electrical system (VES) and the consumer circuits (VSK) connected to it.

10. Rail vehicle (TZ), comprising at least - a number of cars (EW1, MW1, MW2, EW2), wherein electrical consumers (EV1, EV2) are arranged in each of the number of cars, - a vehicle-wide electrical system (BN) with at least one busbar (SS1, SS2) and consumer circuits (VSK) connected to the busbar (SS1, SS2) via which the consumers (EV1, EV2) can be supplied with electrical energy, and with controllable switching devices (ESS) via which the consumer circuits (VSK) can be switched, - a central control unit (SE) and a vehicle-wide communication network (KN), wherein the control unit (SE) is connected to the switching devices (ESS) via the communication network (KN) using signal technology, and wherein at least the switching devices (ESS) are controllable by means of the control unit (SE), and - a central insulation monitoring device (IUE) which is connected to the central control unit (SE) and the vehicle electrical system (BN), wherein the presence of at least one insulation fault in the vehicle electrical system (BN) can be determined by means of the insulation monitoring device (IUE), wherein the control unit (SE) and the insulation monitoring device (IUE) are configured to carry out the method according to one of claims 1 to 9.

11. Rail vehicle (TZ) according to claim 10, wherein the at least one busbar (SS1 , SS2) and the consumers (EV1, EV2) connected to it via consumer circuits (VSK) are designed as an earthed or as an unearthed system. 202406858 28 12. Rail vehicle (TZ) according to claim 10 or 11, wherein the at least one busbar (SS1 , SS2) and the consumer circuits (VSK) are each designed as single-pole or multi-pole electrical connections.

13. Rail vehicle (TZ) according to one of claims 10 to 12, wherein the at least one busbar (SS1 , SS2) is divided into a plurality of segments, each of which comprises a number of wagons (EW1 , MW1 , MW2, EW2).

14. Rail vehicle (TZ) according to one of claims 10 to 13, wherein the consumers (EV1, EV2) supplied via the consumer circuits (VSK) are designed as DC or AC consumers.

15. Rail vehicle (TZ) according to one of claims 10 to 14, wherein the switching devices (ESS) are designed as electrical or electronic switching devices, wherein the electronic switching devices in particular additionally each comprise at least one protective device, and wherein the electronic switching and protective devices in particular are designed as a respective semiconductor protection switch.

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