DC on-board electrical system of a rail vehicle

Abstract

The invention relates to an on-board electrical system of a rail vehicle, wherein the on-board electrical system comprises at least one vehicle-wide DC busbar, at least one on-board electrical system battery which is designed to supply the DC busbar, a plurality of distributed electrical loads, a plurality of load circuits which connect the loads to the DC busbar, and a plurality of controlled electronic switching and protection devices which are designed to switch and protect the load circuits, and wherein the on-board electrical system is characterised in that an adaptation device is arranged upstream and / or downstream of at least one of the electronic switching and protection devices, wherein the adaptation device comprises at least one passive electrical component which limits a rate of rise of current.

Description

[0001] 202417643

[0002] 1

[0003] Description

[0004] DC electrical system of a rail vehicle

[0005] The invention relates to a DC electrical system of a rail vehicle. Furthermore, the invention relates to a rail vehicle with at least one electrical system according to the invention.

[0006] Modern rail vehicles, especially multiple units with several passenger cars, incorporate a variety of electrical consumers that serve both the vehicle's operation and control, as well as passenger comfort. These consumers are typically supplied with electrical power via an onboard electrical system. Vehicle-wide busbars of the onboard electrical system are fed by at least one onboard power converter (BCU) or auxiliary power converter (APC), with multiple converters being redundant. The onboard power converters, in turn, are fed, for example, by a DC link of a traction converter or a dedicated auxiliary winding of a traction transformer within the rail vehicle's traction system.The onboard power converters transform the input DC or AC voltage into an output three-phase AC voltage of constant or variable frequency and apply it to the connected busbar. A busbar for a variable-frequency 480 V, 60 Hz three-phase AC voltage, for example, might have three phase conductors to which auxiliary equipment such as radiators, fans, pumps, or compressors are connected. In contrast, a busbar for a constant 400 V, 50 Hz three-phase AC voltage might have three phase conductors plus a neutral conductor. This neutral conductor connects loads requiring a neutral, such as the galley, as well as lower-power, single-phase loads, such as 230 V, 50 Hz AC sockets and the interior lighting of the passenger compartments.

[0007] In addition to one or more vehicle-wide AC busbars powered by on-board power converters, the electrical system of a rail vehicle typically includes a vehicle-wide DC busbar to which loads such as control units are connected. These loads must be reliably supplied with electrical energy even when the rail vehicle's external power supply is unavailable. Such a DC busbar is powered by one or more on-board batteries, each of which is charged by a battery charger (202417643).

[0008] 2. For example, they can be charged as part of an on-board power inverter. The DC voltage applied from the on-board batteries to the DC busbar is typically 110 V.

[0009] On-board batteries for rail vehicles have so far been based on lead-acid cells, which are advantageously robust and cost-effective, but their low energy density results in a heavy and bulky battery. Particularly due to these disadvantages of the known cells, lithium-ion-based battery cells are increasingly being used in on-board batteries. Since these cells have a significantly higher energy density, the on-board batteries can be made considerably lighter and more compact while maintaining the same performance and capacity.

[0010] The various busbars of the vehicle electrical system are connected to numerous simple and branched consumer circuits, which supply individual consumers or groups of consumers. These consumer circuits, and the consumers connected to them, are currently protected against overload currents and short circuits by circuit breakers. Short circuits can include, in particular, ground faults, conductor faults, and short circuits to exposed conductive parts. Contactors or relays are also used to switch the consumer circuits. The replacement of this combination of circuit breakers and contactors in each consumer circuit with controllable electronic switching and protection devices, also known as Solid State Power Controllers (SSPCs), in the electrical system of a rail vehicle is described in German patent application DE 102016226 148 A1.

[0011] In addition to the aforementioned higher energy density, lithium-ion-based cells, and on-board batteries based on them, possess the additional characteristic of rapid and high power output due to their low internal resistance. This leads to a very rapid increase in short-circuit current in the event of a short circuit in the vehicle's electrical system, particularly within a few microseconds. This current can be further amplified by capacitors in the consumer circuits, which, for example, serve to smooth current or compensate for voltage fluctuations, but also act as an additional energy source in the event of a short circuit.Such a short-circuit current with a high rate of current rise must be detected quickly enough by an electronic switching and protective device to switch the consumer circuit and thus protect its lines and connected consumers from the short-circuit current and possible damage or destruction 202417643.

[0012] 3. To be able to protect. In addition to the typical rated values ​​of the nominal voltage and nominal current, electronic switching and protective devices of the vehicle electrical system connected to the DC busbar must therefore have a sufficiently short tripping time.

[0013] The selection of a suitable and correctly dimensioned electronic switching and protection device is therefore highly dependent on the design of the rail vehicle's electrical system. This design includes, for example, the parameters of the at least one on-board battery, cable lengths and cross-sections, the number of poles in the cables, and the electrical and electronic components connected to the cables. A disadvantage of this is that for each rail vehicle and its electrical system, individual design values ​​must be defined that the electronic switching and protection devices must meet. This dimensioning process can be particularly complex when retrofitting or upgrading existing rail vehicles with on-board batteries based on lithium-ion cells and electronic switching and protection devices, as well as potentially other or additional electrical loads.Due to a lack of knowledge of the specific design of the vehicle electrical system, overly strict design values ​​may be set, which adversely leads to high costs for the electronic switching and protective devices.

[0014] The object of the invention is therefore to provide an on-board electrical system for a rail vehicle that enables the use of cost-effective and preferably standardized electronic switching and protection devices. This object is achieved by the respective features of the independent claims. Further developments are specified in the dependent claims.

[0015] The invention relates to an on-board electrical system of a rail vehicle, wherein the on-board electrical system comprises at least one vehicle-wide DC busbar, at least one on-board battery configured to supply the DC busbar, a plurality of distributed electrical loads, a plurality of load circuits connecting the loads to the DC busbar, and a plurality of controlled electronic switching and protection devices configured to switch and protect the load circuits, and wherein the on-board electrical system is characterized in that at least one of the electronic switching and protection devices has an adaptation device connected upstream and / or downstream, wherein the adaptation device comprises at least one passive electrical component that limits the rate of current rise. 202417643

[0016] 4

[0017] The adaptation device advantageously enables the cost-effective use of electronic switching and protection devices in a DC electrical system of a rail vehicle, by eliminating the need to adapt the electronic switching and protection devices to the specific conditions or characteristics of the electrical system. Instead, adaptation is achieved via cost-effective and easily customizable discrete components that are connected upstream and / or downstream of these devices.

[0018] After a first further development of the invention, at least one on-board power supply battery is designed with lithium-ion-based cells.

[0019] As described in the introduction, these on-board batteries have the advantage of a potentially lighter and more compact design compared to known conventional on-board batteries with lead-acid or nickel-cadmium based cells.

[0020] After further training, at least one adaptation device is designed as a coil.

[0021] A coil, as a passive component with inductance, is designed, for example, as at least one winding of a current conductor, particularly a copper conductor, whereby the winding can be wound, in particular, on a coil former with, for example, a core. The value of the coil's inductance can be individually determined by the arrangement and shape of the winding's turns, the diameter of the conductor, and the material of the former and the core. Alternatively, a coil can also be designed as at least one spiral conductor on a printed circuit board, in particular with a core enclosing the conductor.

[0022] A coil has the property of delaying a current flow because it generates an induced voltage which is proportional to the rate of increase of the current and counteracts the rapid increase of the current, thus limiting the current flow with a time delay.

[0023] The effect of inductance in a DC system occurs primarily during a switch-on process and during changes in current flow, such as those that occur during a short circuit. Inductance has no effect on the normal operation of the DC system with a substantially constant current flow. 202417643

[0024] As an alternative to a coil, other known passive components that also limit the rate of current rise, such as a resistor or a circuit of several resistors, especially in conjunction with a coil, can be used in the same way.

[0025] According to a further development of the invention, all electronic switching and protective devices connected to the DC busbar are designed identically.

[0026] Identical design means that the electronic switching and protective devices meet identical rated values, in particular with regard to a nominal voltage, a nominal current and a tripping time.

[0027] The electronic switching and protection devices are preferably designed as a respective semiconductor protection switch, in particular as a solid state power controller as described in the introduction.

[0028] According to a further development of the invention, all adaptation devices are designed identically or, with respect to a respective consumer circuit, effect at least an essentially identical limitation of the current rise rate.

[0029] The same effect can be achieved, for example, by means of one or more coils, which are arranged particularly before and after the electronic switching and protective device. Therefore, identical design of the adaptation devices is not absolutely necessary; rather, they can be individually adapted to the specific circumstances.

[0030] According to a further development of the invention, the at least one DC busbar and the consumer circuits are each designed as single- or multi-pole electrical connections.

[0031] The invention further relates to a rail vehicle comprising at least a number of carriages, wherein electrical consumers are arranged in each carriage, a vehicle-wide on-board network with at least one DC busbar and consumer circuits connected thereto, via which the consumers can be supplied with electrical energy, and with controllable electronic switching and protection devices, via which the 202417643

[0032] 6

[0033] Consumer circuits are switchable, wherein the rail vehicle is characterized by an on-board network designed according to the invention.

[0034] The rail vehicle 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 for passenger transport, or, as a railcar, just one car.

[0035] The invention is explained below using an exemplary embodiment. The figure shows a rail vehicle with several carriages and an on-board electrical system according to the invention arranged therein.

[0036] The figure schematically shows a rail vehicle TZ designed as a multiple unit for transporting 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 specifically shown), 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 rest on two bogies on rails (not shown) of a track of a route network, with the sides facing each other of the coupled end cars EW1, EW2 and the intermediate cars MW1, MW2 resting on common bogies designed as running bogies LDB, while the sides facing away from each other of the end cars EW1, EW2 resting on outer bogies designed as powered bogies TDG with drive motors of the drive or traction system arranged therein.

[0037] The rail vehicle TZ has, by way of example, two drive systems AS1, AS2, the respective main components of which are arranged in the end cars EW1, EW2, with these components preferably being located in the roof and underfloor areas of the respective end cars EW1, EW2. The drive systems AS1, AS2 are supplied with electrical energy by an overhead line (not shown) of a 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 a 3 kV or 1.5 kV DC voltage, is applied. For an electrical connection of the drive systems AS1, AS2 to the overhead line, the rail vehicle has, by way of example, two pantographs PAN1, PAN2, each located in the roof area of ​​a de 202417643

[0038] 7

[0039] The end cars EW1 and EW2 are arranged. The pantographs PAN1 and PAN2 can be electrically connected, for example via a vehicle-wide power line, meaning that the connection of only one of the pantographs PAN1 or PAN2 to the overhead line is sufficient to supply both drive systems AS1 and AS2.

[0040] 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.

[0041] In addition to the drive systems AS1 and AS2, the rail vehicle TZ has an on-board electrical system BN encompassing all cars EW1, MW1, MW2, and EW2, which supplies electrical energy to a large number of electrical consumers EV1 and EV2 distributed throughout the cars. The figure shows only one vehicle-wide DC busbar SS, encompassing all cars, while other AC busbars that are also present are not specifically shown. The DC busbar SS is powered by two on-board batteries BNB1 and BNB2.The power supply is redundant; alternatively, the DC busbar SS can also be divided into, for example, two segments, 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, and with the first segment being powered by the first on-board battery BNB1 and the second segment by the second on-board battery BNB2. The two segments of the DC busbar SS can be connected, for example, by means of coupling contactors.

[0042] The on-board batteries BNB1 and BNB2 are each charged by a battery charger, which is part of their respective on-board power inverters BNU1 and BNU2. The on-board batteries BNB1 and BNB2 are each based on lithium-ion cells. The on-board power inverters BNU1 and BNU2 are, in turn, powered, for example, by a DC link of the drive inverter or a special 202417643

[0043] 8

[0044] The auxiliary winding of the transformer is fed. The on-board power converters BNU1 and BNU2 convert the input voltage of the DC link or the transformer, for example, into a three-phase AC voltage of constant or variable frequency for supplying an AC busbar, which supplies auxiliary equipment such as coolers, fans, pumps, or compressors, and into a constant three-phase AC voltage for supplying another AC busbar, which supplies equipment such as a galley and single-phase, low-power consumers such as sockets.

[0045] 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 DC busbar SS via their respective consumer circuits VSK1 and VSK2. Each consumer circuit VSK1 and VSK2 has a number of electrical conductors corresponding to the number of conductors on the DC busbar SS. The connection between the consumer circuits VSK1 and VSK2 and the DC busbar SS is made via controllable electronic switching and protection devices (ESS). These devices include at least one switching device and at least one protective device, thus serving both to switch and protect the respective consumer circuit VSK1 and VSK2, as well as the one or more consumers EV1 and EV2 supplied by it. Such electronic switching devices with a supplementary protective device are, for example, controllable semiconductor circuit breakers or similar devices.The system is designed as a solid-state power controller. In the exemplary embodiment shown in the figure, first consumer circuits VSK1 each supply one consumer EV1, and only the respective first consumer circuit VSK1 and the consumer EV1 supplied by it are connected to the DC busbar SS via an electronic switching and protection device ESS. In contrast, second consumer circuits VSK2 each supply several consumers EV2 and are each connected to the DC busbar SS via an electronic switching and protection device ESS.

[0046] Starting from the DC busbar SS, each electronic switching and protection device ESS is preceded by an adaptation device AE. The adaptation devices AE are each designed as a coil, which is configured to limit the rate of current rise of an impulse current occurring during a short circuit in the vehicle electrical system to such an extent that the protective function of the electronic switching and protection device ESS can trigger and switch the consumer circuit VSK1, VSK2. This limitation of the rate of current rise prevents 202417643

[0047] 9. This includes the potential damage or destruction of the electronic switching and protective device ESS, the lines of the consumer circuit VSK1, VSK2, as well as the connected consumer(s) EV1, EV2 due to the current surge. In particular, the adaptation devices AE enable the use of electronic switching and protective devices ESS with a lower current-carrying capacity and / or a longer tripping time compared to a direct connection of the electronic switching and protective devices ESS to the DC busbar SS. The design of the adaptation devices AE also depends on the architecture of the on-board network BN and, in particular, on the characteristics of the on-board network batteries BNB1, BNB2, whereby, for example, an individual design is required for each rail vehicle TZ and its on-board network BN.The properties of the adaptation devices AE are adjusted, while the electronic switching and protection devices ESS used are uniformly or identically designed.

[0048] The various electrical systems, in particular the drive systems AS1 and AS2, the on-board power converters BNU1 and BNU2, the electrical loads EV1 and 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. Control signals are transmitted from the control unit SE to the various systems for controlling their function or status via a communication network KN, which is shown schematically in the figure by dashed lines. Such a communication network KN comprises, for example, a vehicle-wide central bus system with several communication nodes, located, in particular, in each of the cars EW1, MW1, MW2, and EW2, from which signal lines extend to the various controlled systems in the respective car.

Claims

202417643 10 Patent claims 1. On-board electrical system (ON) of a rail vehicle (DV), comprising: - at least one vehicle-wide DC busbar (SS), - at least one on-board battery (BNB1, BNB2) designed to supply the DC busbar (SS), - a plurality of distributed electrical consumers (EV1, EV2), - a plurality of consumer circuits (VSK1 , VSK2) which connect the consumers (EV1 , EV2) to the DC busbar (SS), and - a plurality of controlled electronic switching and protective devices (ESS) designed to switch and protect the consumer circuits (VSK1, VSK2), characterized in that - at least one of the electronic switching and protection devices (ESS) has an adaptation device (AE) upstream and / or downstream, wherein the adaptation device (AE) includes at least one passive electrical component which limits the rate of current rise.

2. On-board electrical system (BN) according to claim 1, characterized in that the at least one on-board electrical system battery (BNB1 , BNB2) is designed with lithium-ion-based cells.

3. On-board electrical system (ON) according to one of the preceding claims, characterized in that the at least one adaptation device (AD) is designed as a coil.

4. On-board power supply (BN) according to one of the preceding claims, characterized in that all electronic switching and protective devices (ESS) connected to the DC busbar (SS) are of the same design.

5. On-board network (BN) according to one of the preceding claims, characterized in that all adaptation devices (AE) are designed identically or, with respect to a respective consumer circuit (VSK1 , VSK2), effect at least an essentially identical limitation of the current rise rate.

6. On-board electrical system (BN) according to one of the preceding claims, characterized in that the at least one DC busbar (SS) and the consumer circuits (VSK1, VSK2) are each designed as single-pole or multi-pole electrical connections. 202417643 11 7. 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 on-board network (BN) with at least one DC busbar (SS) and consumer circuits (VSK1, VSK2) connected to it, via which the consumers (EV1, EV2) can be supplied with electrical energy, and with controllable electronic switching and protection devices (ESS), via which the consumer circuits (VSK1, VSK2) can be switched, characterized in that the on-board network (BN) is designed according to one of claims 1 to 6.

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