Drive system for a rail vehicle

Abstract

The invention relates to a drive system for a rail vehicle, wherein the drive system comprises an internal combustion engine, a generator which can be driven by the internal combustion engine and which is designed to generate a three-phase alternating voltage in generator mode, an uncontrolled first rectifier, a first connection which electrically connects the generator to the first rectifier, a first DC link, in which at least a first DC link capacitor is arranged, at least one controlled first inverter, at least one first drive motor which can be operated by way of an alternating voltage of the first inverter, a second connection which electrically connects the first inverter to the first drive motor, and a control device. The drive system is characterised in that the generator is designed to start the internal combustion engine in engine mode, in that the drive system comprises a third connection by way of which the generator can be electrically connected to the first inverter, and in that the control device is additionally designed to drive the first inverter in such a way that it provides an alternating voltage by way of which the generator can be operated in engine mode when the third connection is closed.

Description

[0001] Description

[0002] Drive system for a rail vehicle

[0003] The invention relates to a drive system for a rail vehicle, a corresponding rail vehicle, a use of the drive system and a method for operating such a drive system.

[0004] WO 2020 / 114659 A1 discloses an arrangement for driving a locomotive with different energy supply systems, wherein a main energy supply system is arranged in the locomotive as a main system and at least one further energy supply system is arranged as a secondary system in a carriage connected to the locomotive. Components that can be used by both the main system and the at least one secondary system are implemented only once, and components that can only be used by the at least one secondary system are arranged on the carriage.According to embodiments of the arrangement, for example, the main system is designed as a diesel drive and the secondary system as a direct current, alternating current and / or energy storage-based energy supply system, or the main system is designed as a direct current or alternating current-based energy supply system and the secondary system as a diesel-based energy supply system. The diesel drive as the main or secondary system comprises as components a diesel engine, a generator connected to the latter and a converter for adapting the power generated by the generator to a direct voltage of an intermediate circuit, which electrically connects the main and secondary systems.

[0005] In diesel-electric locomotive drives, an uncontrolled rectifier, particularly a diode rectifier, is typically used as the input-side rectifier. This converts a three-phase alternating voltage generated by a three-phase generator into a direct voltage from a DC link fed by the rectifier. Compared to a controlled rectifier, such as an active front-end (AFE) converter used for industrial drives operated on a mains supply, such an uncontrolled rectifier has the advantages of being more cost-effective to manufacture, requiring less space, and offering greater availability due to the elimination of the need for a control system.

[0006] From EP 1110799 A1, starting of the internal combustion engine, in particular a diesel engine, by means of an asynchronous machine is known, wherein an input-side controlled inverter is fed from a DC voltage intermediate circuit and controlled in such a way that the inverter generates a rotating field necessary for starting the asynchronous machine and the asynchronous machine starts the internal combustion engine in motor operation.

[0007] Starting the internal combustion engine using the generator is not possible when using an uncontrolled rectifier on the input side, as this cannot generate the rotating field necessary to start the generator. Therefore, the internal combustion engine has traditionally been started using a separate electric or pneumatic starter motor.

[0008] The object of the invention is therefore to provide a drive system with an uncontrolled rectifier on the input side, which enables starting of the internal combustion engine without a separate starter motor. This object is achieved by the drive system and the method with the respective features of the independent patent claims. Further developments are specified in the respective dependent patent claims. A drive system according to the invention for a rail vehicle comprises an internal combustion engine, a generator which can be driven by the internal combustion engine and which is designed to generate a three-phase alternating voltage in generator mode, an uncontrolled first rectifier which is designed to convert the three-phase alternating voltage generated by the generator and applied to the input-side terminals into a direct voltage and to provide this at the output-side terminals, a first connection,which electrically connects the terminals of the generator to the input-side terminals of the first rectifier, a first DC intermediate circuit which is connected to the output-side terminals of the first rectifier and in which at least one first intermediate circuit capacitor is arranged, at least one controlled first inverter, the first terminals of which are electrically connected to the first DC intermediate circuit and which is designed to convert the DC voltage of the first DC intermediate circuit into an AC voltage of variable magnitude and frequency and to provide it at second terminals, at least one first drive motor which is operable by means of the AC voltage of the first inverter, a second connection which electrically connects the second terminals of the first inverter to terminals of the first drive motor, and a control device which is designedto control at least the first inverter, and is characterized in that the generator is additionally designed to start the internal combustion engine in motor operation, that the drive system comprises a third connection by means of which the terminals of the generator can be electrically connected to the second terminals of the first inverter, and the control device is additionally designed to control the first inverter in such a way that it provides an alternating voltage at its second terminals, by means of which the generator can be operated in motor operation when the third connection is closed.

[0009] A rail vehicle according to the invention comprises at least one carriage and at least one drive system according to the invention. In particular, the rail vehicle can comprise at least two carriages, wherein a first carriage is designed as a locomotive and a second carriage is designed as a carriage for passenger transport and / or baggage transport.

[0010] A method according to the invention for starting an internal combustion engine of a drive system according to the invention of a rail vehicle comprises at least the steps of closing the third connection between the first inverter and the generator, providing an alternating voltage at the terminals of the generator by means of the first inverter, and starting the internal combustion engine in a motor mode of the generator.

[0011] The invention with a drive system comprising an uncontrolled first rectifier provides for starting the internal combustion engine by means of the controlled first inverter and the generator, so that a separate electric or pneumatic starter motor as described in the introduction can be dispensed with. In addition to the lower costs and smaller space requirements achievable by dispensing with a separate starter motor and any other devices required for operating the starter motor, the starting of the internal combustion engine according to the invention by means of the generator also advantageously has greater reliability. Compared to a drive system also described in the introduction with a controlled first rectifier, the invention has at least significantly lower costs.

[0012] The internal combustion engine of the drive system can be designed as a combustion engine powered by a fuel, in particular diesel, gasoline, or gas, and the generator driven by the internal combustion engine can be designed, in particular, as a three-phase asynchronous machine. The uncontrolled first rectifier is designed, in particular, as a diode rectifier, with passive diodes serving to rectify the three-phase alternating voltage applied on the input side.

[0013] The at least one first drive motor of the drive system can be designed as a three-phase asynchronous machine or synchronous machine, wherein, in particular depending on this design, the first inverter is connected to one or more first drive motors.

[0014] First, second and third connections each comprise a plurality of electrical lines, wherein for example one or more electrical lines are provided for each phase of the alternating voltage transmitted by means of the connections.

[0015] The control device of the drive system is particularly designed to control power semiconductor switches of the first inverter in order to convert the direct voltage of the first direct voltage intermediate circuit into a desired three-phase alternating voltage for the at least one first drive motor or the generator.

[0016] The internal combustion engine is started when the generator is in motor operation by exciting the windings of the generator stator, whereby its rotor is set in rotation. By mechanically coupling the rotor shaft to a crankshaft of the internal combustion engine, in particular via a mechanical clutch, the crankshaft is also set in rotation, which together with a supply of fuel and air and optionally ignition leads to the internal combustion engine being started. According to the invention, the electrical energy required to excite the stator windings of the generator is provided by the first inverter when the third connection is closed, the electrical energy converted by means of the first inverter being in turn provided by the first DC voltage intermediate circuit, in particular by the first intermediate circuit capacitor.After the internal combustion engine has been started and the third connection has been separated, the then driven generator can generate electrical energy for the uncontrolled first rectifier in generator mode.

[0017] According to a development of the invention, the drive system comprises at least one further first inverter and at least one further first drive motor, wherein a further second connection electrically connects second terminals of the further first inverter to terminals of the further first drive motor and wherein first terminals of the further first inverter are electrically connected to the first DC voltage intermediate circuit, the second terminals of the further first inverter can be electrically connected to the terminals of the generator by means of the third connection or a further third connection, and the control device is additionally designed to control the further first inverter in such a way that it provides an AC voltage at its second terminals, by means of which AC voltage the generator can be operated in motor mode when the third or further third connection is closed.

[0018] At least two first inverters of the drive system, each of which is connected to one or more first drive motors, enable redundancy for operating the generator in engine mode to start the internal combustion engine. This can advantageously ensure reliable starting of the internal combustion engine even if one of the first inverters fails. For this purpose, the additional first inverter is also electrically connected to the third connection or via a separate additional third connection to the generator, and the control device controls one or the other first inverter accordingly in order to provide the AC voltage for the generator.

[0019] If the drive system comprises more than two first inverters, for example four inverters each connected to a first drive motor, two of these first inverters and accordingly a third connection and, if necessary, a further third connection should suffice for the advantageous redundancy.

[0020] According to a further development of the invention, the drive system comprises at least one first switch, by means of which the third connection and / or the further third connection can be switched, and the control device is additionally designed to control the first switch in such a way that it switches the third connection and / or the further third connection.

[0021] By means of the first switch, the third connection can be opened and / or closed under the control of the control device, so that the first inverter is electrically disconnected from or connected to the generator. In the case of a third and a further third connection and / or a first inverter and a further first inverter, a first switch can be provided for each of the third connections or for each of the first inverters.

[0022] The first switch is designed, for example, as a contactor with a number of electrical contacts corresponding to the number of phases of the alternating voltage to be switched. Since a current can still flow via the third connection, in particular after the internal combustion engine has been started by means of the generator, the first switch or contactor preferably has an arc-extinguishing device in order to be able to switch it even with such a current flow or under load. An arc-extinguishing device can be dispensed with if the current flow can be prevented by suitable control of components of the drive system, so that the first switch can also be designed as a circuit breaker or isolator. This control can, for example, comprise briefly exciting the generator more than necessary after the internal combustion engine has been started.Alternatively, the control can cause an increase in the target speed of the internal combustion engine after its start-up. Furthermore, the control of the first inverter can be modified so that it operates like an active front-end converter mentioned above and specifically increases the voltage of the first DC link. Each of the aforementioned measures leads to an increase in the voltage of the DC link.

[0023] Preferably, the first switch is open in a rest position, so that the first inverter is electrically separated from the generator. To start the internal combustion engine or to operate the generator, the first switch is closed, controlled by the control device, whereby the first inverter is electrically connected to the generator via the third connection. After the internal combustion engine has been started by the generator, the first switch is opened again, again controlled by the control device.

[0024] According to a further development of the invention based on the above development, the drive system comprises at least one second switch, by means of which a respective second connection can be switched, and the control device is additionally designed to control the second switch in such a way that it switches the respective second connection. By means of the second switch, the second connection can be opened and / or closed in a controlled manner by the control device, so that the first inverter is electrically disconnected from or connected to the at least one first drive motor.

[0025] The second switch is designed, for example, as a circuit breaker or isolator with a number of electrical contacts corresponding to the number of phases of the alternating voltage to be switched. In particular, if the first drive motor or motors connected to the first inverter are designed as asynchronous machines or separately excited synchronous machines, load-free switching is possible even when the rotor of the first drive motor is rotating and there is therefore no need to provide an arc quenching device. If load-free switching is not possible, the second switch can also be designed as a contactor, in particular as a motor contactor with an arc quenching device.

[0026] Preferably, the second switch is closed in a rest position, so that the first inverter is electrically connected to the at least one first drive motor. In preparation for starting the internal combustion engine, the control device switches or opens the second switch so that the second connection between the second inverter and the at least one first drive motor is severed, and then switches or closes the first switch to connect the first inverter to the generator via the third connection.

[0027] According to a further development of the invention, the first connection between the terminals of the generator and the first terminals of the first rectifier is switch-free. A switch-free first connection means that the first connection to the first rectifier does not have to be severed when the internal combustion engine is started, but can remain intact. In particular, in the case of a three-phase first inverter with freewheeling diodes connected anti-parallel to the power semiconductor switches and when a similar diode type is used for the diodes of the first rectifier and the first inverter, the diodes of a respective phase are connected in parallel when the third connection exists. The current therefore commutates in the first inverter from the power semiconductor switch partly to both the diodes of the first inverter and the diodes of the first rectifier.

[0028] According to a further development of the invention, the drive system comprises a second DC voltage intermediate circuit in which at least one second intermediate circuit capacitance is arranged and which is separably electrically connected to the first DC voltage intermediate circuit.The drive system further comprises a first current collector, a mains transformer and at least one controlled second rectifier, wherein the mains transformer has at least one primary winding and at least one secondary winding, wherein the at least one primary winding can be connected to a track-side AC voltage supply network by means of the first current collector, and wherein first terminals of the second rectifier are electrically connected to terminals of a secondary winding of the mains transformer, the second rectifier is designed to convert a single-phase AC voltage provided by the secondary winding and applied to the first terminals into a DC voltage and to provide this at second terminals, and the second terminals are electrically connected to the second DC voltage intermediate circuit.Alternatively or additionally, the drive system further comprises a second current collector and in particular a first DC-DC converter, wherein the second current collector is connectable to a DC voltage supply network, and wherein first terminals of the first DC-DC converter are electrically connected to the current collector and second terminals of the DC-DC converter are electrically connected to the second DC voltage intermediate circuit.

[0029] In addition to an energy supply via a generator driven by an internal combustion engine, this further development enables the rail vehicle's drive system to be supplied by a trackside supply network, to which the drive system is electrically connected via one or more on-board pantographs. The trackside supply is typically provided by overhead lines or so-called third rails. A typical trackside supply network, particularly in Europe, carries a single-phase alternating voltage of 25 kV, 50 Hz, or 15 kV, 16.7 Hz, or a direct voltage of 750 V, 1.5 kV or 3 kV. In the United States in particular, however, a trackside supply network carries a single-phase alternating voltage of 25 kV, 60 Hz. The nominal alternating and direct voltages mentioned are specified in particular in Chapter 4 of the international standard IEC 60850 in the version from November 2011.Advantageously, the rail vehicle can be operated on such electrified track sections using electrical energy from the supply network, while on non-electrified track sections it is operated using electrical energy from the generator driven by the internal combustion engine. Particularly at a transition from an electrified track section to a non-electrified track section, the energy from the trackside supply network can also advantageously be used to start the internal combustion engine.

[0030] If the rail vehicle comprises a plurality of carriages, the additional components of the drive system according to this development can be arranged in a second carriage, while the other components of the drive system are arranged in a first carriage connected to the second carriage. This enables an existing rail vehicle, for example an internal combustion engine-powered locomotive, to be easily supplemented by an additional power supply, wherein essentially only a cross-car connection of the two DC voltage intermediate circuits and control lines is required. A separable connection of the two DC voltage intermediate circuits can be implemented, for example, by means of a third switch, in particular by means of a disconnector. The third switch can be arranged in the first carriage, the second carriage or in the region of the transition between the carriages.

[0031] According to a further development based on the above development, the drive system comprises at least one controlled second inverter and at least one second drive motor, wherein first terminals of the second inverter are electrically connected to the second DC voltage intermediate circuit, the second inverter is designed to convert the DC voltage of the second DC voltage intermediate circuit into an AC voltage of variable magnitude and frequency and to provide it at second terminals, and the second terminals of the second inverter are electrically connected to terminals of the at least one second drive motor, and wherein the at least one second drive motor can be operated by means of the AC voltage of the second inverter.

[0032] Supply via a track-side supply network enables the drive system to achieve a higher output than supply via a generator. Since, particularly in an existing rail vehicle, the output of the drive motors is matched to the supply via the generator, the drive power of the rail vehicle can advantageously be increased by means of the at least one second drive motor. If the rail vehicle has several cars, these additional components can in turn be arranged in the second car. The second inverter and the second drive motor can also be different from the first inverter or the first drive motor. For example, each second inverter can supply two second drive motors in parallel, whereas each first inverter only supplies one drive motor.In addition, the specific power of the second drive motor may be lower than that of the first drive motor.

[0033] According to a further development of the invention, the drive system comprises at least one electrical energy store and in particular a second DC-DC converter, wherein terminals of the energy store are electrically connected to first terminals of the second DC-DC converter and second terminals of the second DC-DC converter are electrically connected to the first or to the second DC-DC intermediate circuit, or the terminals of the energy store are electrically connected directly to the first or to the second DC-DC intermediate circuit.

[0034] Such an electrical energy storage device is designed, for example, as a traction battery with a plurality of electrochemical battery cells and / or supercapacitors connected according to the desired voltage and capacity. For charging of the energy storage device from the DC intermediate circuit and discharging into the DC intermediate circuit, in particular controlled by the control device, the energy storage device is preferably connected to the DC intermediate circuit via a bidirectional DC-DC converter. If the rail vehicle has several carriages, the energy storage device and, if applicable, the DC-DC converter can in turn be arranged in the second carriage and connected to the second DC intermediate circuit.

[0035] The invention is described below with reference to

[0036] Explained by examples. In the following: FIG 1 shows a rail vehicle, and

[0037] FIG 2 shows a drive system according to the invention.

[0038] For reasons of clarity, the same reference symbols are used for components that are identical or have the same or almost identical functions.

[0039] FIG 1 shows a schematic side view of a rail vehicle SF. The rail vehicle SF comprises, for example, a plurality of carriages, wherein a first carriage WG1 or end carriage of the rail vehicle SF has, in addition to a space for the person driving the vehicle RFF, a space RAS for the arrangement of components of the drive system and can in principle be designed like a locomotive. A second carriage WG2 coupled to the first carriage WG1, on the other hand, has a space RAS for the arrangement of components of the drive system and a passenger compartment RFG. The space RAS for the components of the drive system can comprise not only parts of the interior of the car body of the respective car WG1, WG2, but also the roof and / or underfloor area of ​​the car body. For example, all of the components of the drive system arranged in the second car WG2 can be arranged predominantly or exclusively in the roof and underfloor area.The passenger compartment RFG of the second car WG2 is preferably connected to a passenger compartment RFG of a third car WG3 of the rail vehicle coupled to the second car WG2 via a car gangway.

[0040] The car bodies of the first and second cars WG1, WG2 and other cars of the rail vehicle SF are each supported by two bogies on rails (not shown) of a track of a route network. The two bogies DG1, DG2 of the first car WG1 and the two bogies DG3, DG4 of the second car WG2 are each designed as TDG powered bogies with drive motors of the drive system arranged therein, so that the rail vehicle SF comprises at least eight driven wheel sets. Other cars of the rail vehicle, in particular cars designed exclusively for passenger transport, such as the third car WG3, can, in contrast, have exclusively non-powered trailer bogies.

[0041] FIG. 2 shows a schematic diagram of a drive system AS according to the invention with components distributed over the carriages WG1, WG2 of the rail vehicle SF in FIG. 1, which are schematically marked by dashed lines. For starting the internal combustion engine BKM according to the invention, the components arranged in the first carriage WG1, specifically the components BKM, GEN, GR1, ZK1, WRI, AMI arranged next to one another in the upper row and their electrical connections EVI, EV2, EV3, switches SI, S2 arranged therein, as well as the control device ST, are sufficient. Other auxiliary systems required for the operation of the rail vehicle SF and their supplies are not shown in FIG. 2.

[0042] The control device ST of the drive system AS, for example, a drive control unit, is arranged in the first carriage WG1 and is signal-connected to components of the drive system AS. This signal-connection is schematically indicated by a dashed line and a circle on both the control device ST and the components controlled by it.

[0043] The energy supply arranged in the first car WG1 is limited to an internal combustion engine BKM, for example a diesel engine, and a generator GEN, for example a three-phase asynchronous machine. The internal combustion engine BKM or its crankshaft is mechanically connected to the generator GEN or its rotor, for example via a separable clutch. When the internal combustion engine BKM is operating, the generator GEN generates a three-phase alternating voltage applied to its electrical connections due to the rotating rotor. The generator GEN is connected to an uncontrolled first rectifier GR1, for example a diode rectifier, via a first electrical connection EVI. For this purpose, the connections of the generator GEN are electrically connected to input-side connections of the first rectifier GR1, for example via three electrical lines.The first rectifier GR1 converts the three-phase alternating voltage applied to the input terminals into a direct voltage which is applied to its output electrical terminals.

[0044] The output-side terminals of the first rectifier GR1 are connected to a first DC link ZK1, in which a first DC link capacitor CZK1 is arranged as an electrical energy store. The specified first DC link capacitor CZK1 can be designed as a single capacitor or as several capacitors connected in parallel, which are, in particular, distributed and assigned to a respective first inverter WRI. Further components can be arranged in the first DC link ZK1 or connected to it, although these are not specifically shown.

[0045] A total of four controlled first inverters WRI, for example pulse-controlled inverters, are connected to the first DC voltage intermediate circuit ZK1. The first inverters WRI, each controlled by the control device ST, convert the DC voltage of the first DC voltage intermediate circuit ZK1 present at the first electrical connections into a three-phase AC voltage of variable magnitude and frequency, with which a respective first drive motor AMI, for example a three-phase asynchronous machine, is supplied. For this purpose, second electrical connections of the respective first inverter WRI are connected to electrical connections of the associated first drive motor AMI via a respective second electrical connection EV2, for example three electrical lines or motor cables.Each first drive motor AMI drives a wheelset of a bogie of the first car WG1, so that the two upper first drive motors AMI in the first car WG1 are arranged in the first bogie DG1 and the two lower first drive motors AMI are arranged in the second bogie DG2.

[0046] First and second connections EVI, EV2 are connected to one another via a third electrical connection EV3, for example three electrical lines. The third connection EV3 connects the second electrical connections of a first inverter WRI, in FIG 2 the uppermost of the four first inverters WRI, to the electrical connections of the generator GEN, so that when the third connection EV3 is closed, a three-phase alternating voltage generated by the first inverter WRI can be applied to the generator GEN in order to start the internal combustion engine BKM by means of the generator GEN. A first switch S1, for example a contactor, which can be switched under the control of the control device ST is arranged in the third connection EV3. Furthermore, a second switch S2, for example a circuit breaker or motor contactor, which can be switched under the control of the control device ST is arranged in the second connection EV2.The second switch S2 is arranged behind the first switch S1, viewed in the direction of current flow from the first inverter WRI to the first drive motor AMI.

[0047] During normal operation of the drive system AS, in particular when all of the first drive motors AMI for driving the rail vehicle SF are supplied by the respective first inverter WRI, the first switch S1 is open, so that the third connection EV3 is disconnected, and the second switch S2 is closed, so that the first drive motor AMI is connected to the first inverter WRI via the second connection EV2. To start the internal combustion engine BKM, first the second switch S2 is opened under the control of the control device ST, so that the second connection EV2 to the first drive motor AMI is disconnected, and then the first switch S1 is closed under the control of the control device ST, so that the first inverter WRI is connected to the generator GEN.The control device ST then controls the first inverter WRI in such a way that it generates a rotating field required to start the generator GEN, and the generator GEN starts the internal combustion engine BKM in motor mode. After the internal combustion engine BKM has been started, the first switch S1 is opened again under the control of the control device ST and then the second switch S2 is closed again, so that the first inverter WRI can then supply the first drive motor AMI again. The energy required to generate the rotating field is provided by the first DC intermediate circuit ZK1, in particular by the first intermediate circuit capacitor CZK1.

[0048] 2, the third connection EV3 is likewise connected to a further inverter, specifically the second-highest first inverter WRI, via a further first switch S1, and a second switch S2 is likewise arranged in the second connection EV2 between this first inverter WRI and the associated further first drive motor AMI. This means that the generator GEN can be supplied redundantly in a simple manner, so that, for example, if the top first inverter WRI fails, the second-highest further first inverter WRI can supply power. In the example in FIG. 2, the second connections EV2 are connected to a common third connection EV3 via a respective first switch S1. Alternatively, for example, two third connections EV3 can be provided, by means of which the respective first inverter WRI can be connected to the generator GEN.Likewise, the first two switches S 1 can be combined, for example, into a single switch, in particular in the form of a changeover switch.

[0049] Additional components of the AS drive system of the SF rail vehicle are located in the second car WG2. These enable an electrical connection of the AS drive system to a trackside supply network with a single-phase AC voltage of, for example, 25 kV, 50 Hz, or 15 kV, 16.7 Hz. Alternatively or additionally, components for an electrical connection to a supply network with a DC voltage of, for example, 750 V, 1.5 kV, or 3 kV can also be provided in the second car WG2.

[0050] The drive system AS is electrically connected to a trackside single-phase AC supply network by means of a first current collector PANI. This is connected to one or more primary windings of a mains transformer TF, which transforms the mains-side high voltage, for example 25 kV, 50 Hz or 15 kV, 16.7 Hz, into a lower voltage. Electrical connections of two secondary windings of the mains transformer TF are each connected to first electrical connections of a controlled second rectifier GR2, for example a four-quadrant rectifier. The second rectifiers GR2, controlled by the control device ST, each convert the single-phase AC voltage applied to the first connections into a DC voltage, which is applied to their respective second connections.

[0051] In contrast, an electrical connection of the drive system AS to a trackside DC voltage supply network is established by means of a second pantograph PAN2. This is connected to a first DC voltage converter GSW1 controlled by the control device ST, which converts the network-side DC voltage, for example 3 kV or 1.5 kV, into a desired lower voltage of the second DC voltage intermediate circuit ZK2. If the desired voltage of the second DC voltage intermediate circuit ZK2 corresponds to the voltage of the DC voltage supply network, a first DC voltage converter GSW1 can be dispensed with if necessary. If the rail vehicle SF is operated exclusively on lines of the rail network with a trackside single-phase AC voltage supply network and non-electrified line sections, a second pantograph PAN2 can be dispensed with accordingly.

[0052] The electrically parallel-connected output-side terminals of the second rectifier GR2 are connected to a second DC intermediate circuit ZK2, in which a second intermediate circuit capacitor CZK2 is arranged as an electrical energy store. The specified second intermediate circuit capacitor CZK2 can be designed as a single capacitor or as several capacitors connected in parallel, which are in particular distributed and assigned to a respective second inverter WR2. Arranged in the second DC intermediate circuit ZK2 or electrically connected to it is, for example, an energy store ES, for example a drive battery with a plurality of interconnected battery cells, and a controlled second DC-DC converter GSW2.The second DC-DC converter GSW2 controlled by the control device ST serves to adapt the voltage of the energy storage device ES to that of the second DC-DC intermediate circuit ZK2 in order to control charging and discharging of the energy storage device ES.

[0053] Two controlled second inverters WR2, for example pulse-controlled inverters, are connected to the second DC intermediate circuit ZK2. The second inverters WR2, each controlled by the control device ST, convert the DC voltage applied to the second DC intermediate circuit ZK2 into a three-phase AC voltage of variable magnitude and frequency, which is used to supply two second drive motors AM2, for example three-phase asynchronous machines. For this purpose, the second inverters WR2 are each connected to the assigned second drive motors AM2 via a respective electrical connection, for example three electrical lines or motor cables.Each second drive motor AM2 drives a wheel set of a bogie DG3, DG4 of the second car WG2, so that the two upper second drive motors AM2 in the second car WG2 are arranged in the third bogie DG3 and the two lower second drive motors AM2 are arranged in the fourth bogie DG4.

[0054] The first ZK1 and the second DC intermediate circuit ZK2 are connected via a third switch S3 which can be switched by the control device ST. The third switch S3 is arranged in the first car WG1, but can also be arranged in the same way in the second car WG2 or in the area of ​​the transition between the cars WG1, WG2. The third switch S3 and the electrical connection of the two DC intermediate circuits ZK1, Zk2 switched by it make it possible, for example, when the rail vehicle SF is operated in an electrified section of track in which the first PANI or the second pantograph PAN2 is connected to a trackside supply network and the third switch S3 is closed, both the second inverters WR2 in the second car WG2 and the first inverters WRI in the first car WG1 can be supplied.On the other hand, when the rail vehicle SF is operated in a non-electrified section of track with the third switch S3 open, the first inverters WRI can be supplied exclusively by means of the internal combustion engine BKM and the generator GEN, while the second inverters WR2 can, for example, be additionally supplied exclusively by means of the energy storage device ES or, if the drive system AS does not include an energy storage device ES, are not supplied at all.

Claims

Patent claims 1. Drive system (AS) for a rail vehicle (SF), wherein the drive system (AS) comprises: - an internal combustion engine (BKM), - a generator (GEN) driven by the internal combustion engine (BKM), which is designed to generate a three-phase alternating voltage in generator mode, - an uncontrolled first rectifier (GR1) which is designed to convert the three-phase alternating voltage generated by the generator (GEN) at the input terminals into a direct voltage and to provide this at the output terminals, - a first connection (EVI) which electrically connects terminals of the generator (GEN) to the input terminals of the first rectifier (GR1), - a first DC voltage intermediate circuit (ZK1) which is connected to the output-side terminals of the first rectifier (GR1) and in which at least one first intermediate circuit capacitor (CZK1) is arranged, - at least one controlled first inverter (WRI), the first terminals of which are electrically connected to the first DC intermediate circuit (ZK1) and which is designed to convert the DC voltage of the first DC intermediate circuit (ZK1) into an AC voltage of variable magnitude and frequency and to provide it at second terminals, - at least one first drive motor (AMI) which can be operated by means of the alternating voltage of the first inverter (WRI), - a second connection (EV2) which electrically connects the second terminals of the first inverter (WRI) to terminals of the first drive motor (AMI), and - a control device (ST) which is designed to control at least the first inverter (WRI), characterized in that - the generator (GEN) is additionally designed to start the internal combustion engine (BKM) in engine operation, - the drive system (AS) comprises a third connection (EV3) by means of which the terminals of the generator (GEN) can be electrically connected to the second terminals of the first inverter (WRI), and - the control device (ST) is additionally designed to control the first inverter (WRI) in such a way that it provides an alternating voltage at its second terminals, by means of which the generator (GEN) can be operated in motor mode when the third connection is closed.

2. Drive system (AS) according to claim 1, characterized in that - the drive system (AS) comprises at least one further first inverter (WRI) and at least one further first drive motor (AMI), wherein a further second connection (EV2) electrically connects second terminals of the further first inverter (WRI) to terminals of the further first drive motor (AMI) and wherein first terminals of the further first inverter (WRI) are electrically connected to the first DC voltage intermediate circuit (ZK1), - the second terminals of the further first inverter (WRI) are electrically connectable to the terminals of the generator (GEN) by means of the third connection (EV3) or a further third connection, and - the control device (ST) is additionally designed to control the further first inverter (WRI) in such a way that it provides an alternating voltage at its second terminals, by means of which the generator (GEN) can be operated in motor mode when the third or further third connection is closed.

3. Drive system (AS) according to claim 1 or 2, characterized in that - the drive system (AS) has at least one first switch (51), by means of which the third connection (EV3) and / or the further third connection can be switched, and - the control device (ST) is additionally designed to control the first switch (Sl) in such a way that it switches the third connection (EV3) and / or the further third connection.

4. Drive system (AS) according to one of the preceding claims, characterized in that - the drive system (AS) has at least one second switch (52), by means of which a respective second connection (EV2) is switchable, and - the control device (ST) is additionally designed to control the second switch (S2) in such a way that it switches the respective second connection (EV2).

5. Drive system (AS) according to one of the preceding claims, characterized in that the first connection (EVI) between the terminals of the generator (GEN) and the first terminals of the first rectifier (GR1) is switch-free.

6. Drive system (AS) according to one of the preceding claims, characterized in that the drive system (AS) comprises a second DC intermediate circuit (ZK2), in which at least one second intermediate circuit capacitor (CZK2) is arranged and which is separably electrically connected to the first DC intermediate circuit (ZK1), and the drive system (AS) comprises a first current collector (PANI), a mains transformer (TR) and at least one controlled second rectifier (GR2), wherein - the mains transformer (TF) has at least one primary winding and at least one secondary winding, wherein the at least one primary winding is connected by means of the first pantograph (PANI) is connectable to a trackside AC supply network, and - first terminals of the second rectifier (GR2) with terminals of a secondary winding of the mains transformer (TF) are electrically connected, the second rectifier (GR2) is designed to convert a single-phase alternating voltage provided by the secondary winding and applied to the first terminals into a direct voltage and to provide this at second terminals, and the second terminals are electrically connected to the second direct voltage intermediate circuit (ZK2), and / or the drive system (AS) comprises a second current collector (PAN2) and in particular a first direct voltage converter (GSW1), wherein - the second pantograph (PAN2) is connectable to a DC voltage supply network, and - first terminals of the first DC-DC converter (GSW1) are electrically connected to the second current collector (PAN2) and second terminals of the first DC-DC converter (GSW1) are electrically connected to the second DC-DC intermediate circuit (ZK2).

7. Drive system (AS) according to claim 6, characterized in that the drive system (AS) comprises at least one controlled second inverter (WR2) and at least one second drive motor (AM2), wherein - first terminals of the second inverter (WR2) are electrically connected to the second DC intermediate circuit (ZK2), the second inverter (WR2) is designed to convert the DC voltage of the second DC intermediate circuit (ZK2) into an AC voltage of variable magnitude and frequency and to provide it at second terminals, and the second terminals of the second inverter (WR2) are electrically connected to terminals of the at least one second drive motor (AM2), and - the at least one second drive motor (AM2) can be operated by means of the alternating voltage of the second inverter (WR2).

8. Drive system (AS) according to one of the preceding claims, characterized in that the drive system (AS) comprises at least one electrical energy storage device (ES) and in particular a second DC-DC converter (GSW2), wherein - connections of the energy storage device (ES) are electrically connected to first connections of the second DC-DC converter (GSW2) and second connections of the second DC-DC converter (GSW2) are electrically connected to the first (ZK1) or to the second DC-DC intermediate circuit (ZK2), or - the terminals of the energy storage device (ES) are electrically connected directly to the first (ZK1) or the second DC link (ZK2).

9. Rail vehicle (SF), characterized in that it comprises at least one carriage (WG1) and at least one drive system (AS) according to one of claims 1 to 8.

10. Rail vehicle (SF) according to claim 9, characterized in that in a first car (WG1) of the rail vehicle (SF) the internal combustion engine (BKM), the generator (GEN), the first rectifier (GR1), the first DC intermediate circuit (ZK1), the at least one first inverter (WRI), the at least one first drive motor (AMI) and the control device (ST) are arranged, and in a second car (WG2) of the rail vehicle (SF) the second DC intermediate circuit (ZK2) and - the first current collector (PANI), the mains transformer (TF) and the at least one second rectifier (GR2), and / or - the second current collector (PAN2) and in particular the first DC-DC converter (GSW1) are arranged.

11. Rail vehicle (SF) according to claim 10, characterized in that the at least one second inverter (WR2) and the at least one second drive motor (AM2) are arranged in the second car (WG2).

12. Rail vehicle (SF) according to claim 10 or 11, characterized in that the at least one electrical energy storage device (ES) and in particular the second DC-DC converter (GSW2) are arranged in the first car (WG1) or in the second car (WG2).

13. Rail vehicle (SF) according to one of claims 9 to 12, characterized in that the first car (WG1) is designed as a locomotive and the second car (WG2) is designed as a car for passenger transport and / or baggage transport.

14. Use of a drive system (AS) according to one of claims 1 to 8 in a rail vehicle (SF).

15. Method for starting an internal combustion engine (BKM) of a drive system (AS) of a rail vehicle (SF) according to one of claims 1 to 8, at least with the steps: - Closing the third connection (EV3) between the first inverter (WRI) and the generator (GEN), - Providing an alternating voltage at the terminals of the generator (GEN) by means of the first inverter (WRI), and - Starting the internal combustion engine (BKM) in a motor mode of the generator (GEN).

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