DC 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 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.

Description

[0001] 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.

[0002] 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 energy 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. The on-board 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.

[0003] 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. This busbar connects loads such as control units, which must be reliably supplied with electrical power 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, for example, as part of an on-board power converter. The DC voltage applied to the DC busbar by the on-board batteries is typically 110 V.

[0004] On-board batteries for rail vehicles have traditionally been based on lead-acid cells, which are advantageously robust and cost-effective, but their low energy density results in heavy and bulky batteries. It is primarily due to these drawbacks of conventional lead-acid cells that lithium-ion batteries are increasingly being used. Since these cells have a significantly higher energy density, on-board batteries can be made considerably lighter and more compact while maintaining the same power output and capacity.

[0005] 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. Additionally, contactors or relays are 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 vehicle electrical system of a rail vehicle is described in German patent application DE 10 2016 226 148 A1.

[0006] In addition to the aforementioned higher energy density, lithium-ion cells, and the on-board batteries based on them, also possess the characteristic of rapid and high power output. In the event of a short circuit in the vehicle's electrical system, this leads to a very rapid increase in short-circuit current, particularly within a few microseconds. This current may be further amplified by capacitors in the consumer circuits, which, for example, serve to smooth the current or compensate for voltage fluctuations. Such a short-circuit current with its rapid rise rate must be detected quickly enough by an electronic switching and protection device to switch the consumer circuit and thus protect its wiring and connected devices from the short-circuit current and potential damage or destruction.In addition to the typical rated values ​​of the nominal voltage and the 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.

[0007] 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 characteristics 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.

[0008] 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.

[0009] 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 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.

[0010] 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 not adapting the electronic switching and protection devices to the specific conditions or characteristics of the electrical system, but by using cost-effective and easily individually adaptable discrete components that are connected upstream and / or downstream of them.

[0011] Following an initial further development of the invention, at least one on-board power supply battery is designed based on lithium-ion cells.

[0012] As described in the introduction, these on-board batteries have the advantage of a potentially lighter and more compact design compared to known on-board batteries based on lead-acid cells.

[0013] After further training, at least one adaptation device is designed as a coil.

[0014] An inductor, as an inductive passive component, is designed, for example, as at least one winding of a conductor, particularly a copper conductor, whereby the winding can be wound, in particular, on a coil former with, for example, a core. The inductance of the coil can be individually determined by the arrangement and shape of the windings, the diameter of the conductor, and the material of the former and the core. Alternatively, an inductor can also be designed as at least one spiral conductor on a printed circuit board, in particular with a core enclosing the conductor.

[0015] 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, thereby limiting the current flow.

[0016] 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. In contrast, inductance has no effect on the normal operation of the DC system with a substantially constant current flow.

[0017] 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.

[0018] According to a further development of the invention, all electronic switching and protective devices connected to the DC busbar are designed identically.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] The invention further relates to a rail vehicle comprising at least a number of cars, wherein electrical consumers are arranged in each of the number of cars, a vehicle-wide on-board network with at least one DC busbar and consumer circuits connected to it, via which the consumers can be supplied with electrical energy, and with controllable electronic switching and protection devices, via which the consumer circuits can be switched, wherein the rail vehicle is characterized by an on-board network designed according to the invention.

[0025] 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.

[0026] 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.

[0027] 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 designated 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 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.

[0028] 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, preferably in the roof and underfloor areas of the respective end cars EW1 and EW2. The drive systems AS1 and 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 between the drive systems AS1 and AS2 and the overhead line, the rail vehicle features, by way of example, two pantographs PAN1 and PAN2, each located in the roof area of ​​one of the end cars EW1 and EW2.The pantographs PAN1, PAN2 can be electrically connected, for example via a vehicle-wide power line, whereby the connection of only one of the pantographs PAN1, PAN2 to the overhead line is sufficient to supply both drive systems AS1, AS2.

[0029] 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 amplitude 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.

[0030] 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.

[0031] 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 converter or a special auxiliary winding of the transformer. The on-board power inverters BNU1 and BNU2 convert the input voltage of the DC link or...The transformer, for example, can be used to convert a three-phase alternating voltage of constant or variable frequency for supplying an AC busbar, which supplies auxiliary equipment such as coolers, fans, pumps or compressors, and a constant three-phase alternating voltage for supplying another AC busbar, which supplies, for example, a galley and single-phase consumers of lower power, such as sockets.

[0032] The consumers EV1, EV2, distributed only as examples in the various cars EW1, MW1, MW2, EW2 of the rail vehicle TZ, are connected to the DC busbar SS via their respective consumer circuits VSK1, VSK2. The consumer circuits VSK1, VSK2 have a number of electrical conductors corresponding to the number of DC busbar SS. The connection of the consumer circuits VSK1, VSK2 to the DC busbar SS is made via controllable electronic switching and protection devices ESS, which, in addition to at least one switching device, also have at least one protective device and thus serve both to switch and protect the respective consumer circuit VSK1, VSK2, as well as the one or more consumers EV1, EV2 supplied by it. Such electronic switching devices with supplementary protective devices are, for example, controllable semiconductor circuit breakers or...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.

[0033] 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 configured to limit the rate of current rise of a surge current occurring during a short circuit in the vehicle electrical system. This limiting of the current rise rate prevents potential damage or destruction of the electronic switching and protection device (ESS), the conductors of the consumer circuits (VSK1, VSK2), and the connected loads (EV1, EV2) due to the current surge.In particular, the adaptation devices (AE) enable the use of electronic switching and protection devices (ESS) with a lower current-carrying capacity and / or a longer tripping time compared to a direct connection of the electronic switching and protection 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). For example, the properties of the adaptation devices (AE) are individually designed and adapted for each rail vehicle (TZ) and its on-board network (BN), while the electronic switching and protection devices (ESS) used are uniformly designed.

[0034] 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. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2016 226 148 A1

[0005]

Claims

[1] On-board electrical system (AN) of a rail vehicle (RT), 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 by , 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 (ONS) according to claim 1, characterized by that at least one on-board power supply battery (BNB1, BNB2) is based on lithium-ion cells. [3] On-board electrical system (ONS) according to one of the preceding claims, characterized by that at least one adaptation device (AD) is designed as a coil. [4] On-board electrical system (ONS) according to one of the preceding claims, characterized by that all electronic switching and protective devices (ESS) connected to the DC busbar (SS) are of the same design. [5] On-board electrical system (ONS) according to any of the preceding claims, characterized bythat all adaptation devices (ADs) are designed identically or, with regard to a respective consumer circuit (VSK1, VSK2), result in at least an essentially identical limitation of the current rise rate. [6] On-board electrical system (ONS) according to one of the preceding claims, characterized by , that at least one DC busbar (SS) and the consumer circuits (VSK1, VSK2) are each designed as single-pole or multi-pole electrical connections. [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 electrical system (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 by , that the on-board network (BN) is designed according to one of claims 1 to 6.

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