Supply of electric energy to electric traction motors and additional electric auxiliaries of a railway vehicle

Abstract

An arrangement for supplying electric energy to traction motors and auxiliaries of a railway vehicle includes, at least two internal-combustion engines, each in combination with an assigned electric machine. At least one internal-combustion engine/machine combination is operated, whereupon the electric machine generates alternating current during a generator mode of operation, which alternating current, in a first operating mode, is rectified by at least one generator rectifier and supplied to a direct-current link in the form of direct current. The direct-current link supplies electric energy to at least one traction motor of the railway vehicle. In the first operating mode, electric energy from the direct-current link is supplied to the auxiliaries via an auxiliaries inverter and via an auxiliaries connector. In a second operating mode the auxiliaries inverter is out of operation, and which is an emergency operation condition, electric energy is supplied to the auxiliaries by the electric machine of one of the internal-combustion engine/machine combination through an emergency operation electric line.

Claims

1. An arrangement for supplying electric energy to electric traction motors in a railway vehicle and for supplying electric energy to additional electric auxiliaries for operation of the railway vehicle, in which the arrangement comprises the following: at least two internal-combustion engines; for each of the at least two internal-combustion engines, an electric machine assigned to it for generating electric energy, with the electric machine being mechanically coupled to the internal-combustion engine, so that during generator mode of operation of the electric machine the electric machine is driven by the internal-combustion engine, so that at least a first and a second internal-combustion engine/machine combination are formed; at least one generator rectifier for rectifying alternating currents generated by the electric machines during generator mode of operation of the respective electric machine; a direct-current link which is electrically connected to the electric machines or some of the electric machines via the at least one generator rectifier, while the electric machine or the electric machines supplies or supply energy to the direct-current link, and which is electrically connected to at least one traction motor; an auxiliaries inverter with a direct-voltage connector and an alternating-voltage connector, the auxiliaries inverter being connected to the direct-current link via the direct-voltage connector and to an auxiliaries connector of the auxiliaries via the alternating-voltage connector to supply electric energy from the direct-current link to the auxiliaries; an emergency operation electric line by means of which the electric machine of the first internal-combustion engine/machine combination is connected to the auxiliaries during emergency operation, during which the auxiliaries inverter is out of operation, to supply energy to the auxiliaries during emergency operation, the electric machine of the first internal-combustion engine/machine combination being electrically connected to the direct-current link, via the generator rectifier or via one of the generator rectifiers, while the electric machine of the first internal-combustion engine/machine combination supplies energy to the direct-current link; and switches which, during emergency operation, disconnect the auxiliaries inverter from the auxiliaries connector and couple the electric machine of the first internal-combustion engine/machine combination to the auxiliaries via the emergency operation electrical line.

2. The arrangement according to claim 1, in which, during emergency operation, the electric machine of the second internal-combustion engine/machine combination is connected to the direct-current link, via the generator rectifier or via at least one of the generator rectifiers, to supply electric energy from the direct-current link to the at least one traction motor connected to the direct-current link.

3. The arrangement according to claim 1, wherein the switches include a first switch located between the alternating-voltage connector of the auxiliaries inverter and the auxiliaries connector, which, during emergency operation, disconnects the auxiliaries inverter from the auxiliaries connector.

4. The arrangement according to claim 1, wherein the switches include a second switch combined with the emergency operation electrical line, via which second switch the electrical connection between the emergency operation electrical line from the electric machine of the first internal-combustion engine/machine combination to the auxiliaries is established only during emergency operation.

5. The arrangement according to claim 1, in which one machine inverter is provided for each of the electric machines, with an alternating-voltage connector of the machine inverter being connected to the electric machine to operate the electric machine as a motor during a motor mode of operation of the electric machine, the arrangement having an electrical connector for connecting an energy storage, from which electric energy is capable of being drawn, and where the electrical connector is connected to at least one of the machine inverters to supply energy from the energy storage for the motor mode of operation of the electric machine.

6. The arrangement according to claim 1, in which a machine inverter is provided for each of the electric machines, with an alternating-voltage connector of the machine inverter being connected to the electric machine to operate the electric machine as a motor during a motor mode of operation of the electric machine, and with the direct-current link being connected to at least a part of the machine inverters to supply energy from the direct-current link to the respective electric machine during the motor mode of operation.

7. A railway vehicle, featuring an arrangement according to claim 1, with at least one traction motor of the railway vehicle being electrically connected to the direct-current link and additional electric auxiliaries of the railway vehicle being connected or connectable to the emergency operation electrical line of the arrangement.

8. A method for supplying electric energy to electric traction motors in a railway vehicle and for supplying electric energy to additional electric auxiliaries for operation of the railway vehicle, whereby: at least two internal-combustion engines, each in combination with an assigned electric machine, are operated in such a way that at least one first and one second internal-combustion engine/machine combination are operated; driven by the internal-combustion engine, the electric machines generate alternating current during a generator mode of operation of the respective electric machine, which alternating current, in a first operating mode, is rectified by at least one generator rectifier and supplied to a direct-current link in the form of direct current; the direct-current link supplies electric energy to at least one traction motor of the railway vehicle; in the first operating mode, electric energy is drawn from the direct-current link and supplied to the auxiliaries via an auxiliaries inverter and via an auxiliaries connector; and in a second operating mode, in which the auxiliaries inverter is out of operation, and which is an emergency operation condition, electric energy is supplied to the auxiliaries by the electric machine of the first internal-combustion engine/machine combination through an emergency operation electric line, wherein, during the emergency operation condition, switches disconnect the auxiliaries inverter from the auxiliaries connector and couple the electric machine of the first internal-combustion engine/machine combination to the auxiliaries via the emergency operation electrical line.

9. The method according to claim 8, whereby, during the emergency operation condition, the electric machine of the second internal-combustion engine/machine combination supplies electric energy to the direct-current link, via the generator rectifier or via at least one of the generator rectifiers, and electric energy from the direct-current link is supplied to the at least one traction motor.

10. The method according to claim 8, whereby, for changing from the first operating mode to the second operating mode, the switches include a first switch between an alternating-voltage connector of the auxiliaries inverter and an auxiliaries connector, wherein, during the emergency operation condition, the first switch is opened to electrically isolate the auxiliaries inverter from the auxiliaries connector.

11. A method for manufacturing an arrangement for supplying electric energy to electric traction motors in a railway vehicle and for supplying electric energy to additional electric auxiliaries for operation of the railway vehicle, whereby: at least two internal-combustion engines are provided; for each of the at least two internal-combustion engines, an assigned electric machine for generating electric energy is provided and mechanically coupled to the internal-combustion engine in such a way that, during generator mode of operation of the electric machine, the electric machine is driven by the internal-combustion engine, so that at least a first and a second internal-combustion engine/machine combination are formed; the electric machines are electrically connected to a direct-current link via at least one generator rectifier for rectifying direct currents; an electric traction connection is provided at the direct-current link for connecting at least one traction motor; an auxiliaries inverter is provided and a direct-voltage connector of the auxiliaries inverter is connected to the direct-current link and an alternating-voltage connector of the auxiliaries inverter is connected to an auxiliaries connector for connecting the auxiliaries; and the electric machine of the first internal-combustion engine/machine combination is electrically connected to an electrical line of the auxiliaries by means of an emergency operation electric line, wherein, during an emergency operation of the auxiliaries, a first switch disconnects the auxiliaries inverter from the auxiliaries connector and a second switch couples the electric machine of the first internal-combustion engine/machine combination to the auxiliaries via the emergency operation electrical line to enable the emergency operation of the auxiliaries without the auxiliaries inverter.

12. The method according to claim 11, in which the first switch is located between an alternating-voltage connector of the auxiliaries inverter and the auxiliaries connector, and the first switch is operative for isolating the auxiliaries inverter from the auxiliaries connector for the emergency operation of the auxiliaries.

13. The method according to claim 11, whereby one machine inverter is provided for each of the electric machines, with an alternating-voltage connector of the machine inverter being connected to the electric machine to operate the electric machine as a motor during a motor mode of operation of the electric machine, and with an electrical connector for connecting an energy storage, from which electric energy is capable of being drawn, being connected to at least one of the machine inverters to supply energy from the energy storage for the motor mode of operation of the electric machine.

14. The method according to claim 11, whereby the direct-current link is connected to at least one of the machine inverters to supply energy from the direct-current link to the respective electric machine during a motor mode of operation.

15. The method according to claim 9, whereby, for changing from the first operating mode to the second operating mode, a first switch between an alternating-voltage connector of the auxiliaries inverter and the auxiliaries connector is opened to electrically isolate the auxiliaries inverter from the auxiliaries connector.

16. The method according to claim 12, whereby one machine inverter is provided for each of the electric machines, with an alternating-voltage connector of the machine inverter being connected to the electric machine to operate the electric machine as a motor during a motor mode of operation of the electric machine, and with an electrical connector for connecting an energy storage, from which electric energy is capable of being drawn, being connected to at least one of the machine inverters to supply energy from the energy storage for the motor mode of operation of the electric machine.

17. The method according to claim 12, whereby the direct-current link is connected to at least one of the machine inverters to supply energy from the direct-current link to the respective electric machine during a motor mode of operation.

18. The method according to claim 13, whereby the direct-current link is connected to at least one of the machine inverters to supply energy from the direct-current link to the respective electric machine during a motor mode of operation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, embodiments of the invention are described making reference to the enclosed drawing. The individual figures of the drawing show the following:

(2) FIG. 1 A first embodiment of an arrangement for supplying electric energy to at least one traction motor and additional electric auxiliaries in a railway vehicle; and

(3) FIG. 2 a second embodiment of an arrangement for supplying electric energy to at least one traction motor and additional electric auxiliaries in a railway vehicle.

(4) The embodiment shown in FIG. 1 features four internal-combustion engine/machine combinations 1, 3, with the internal-combustion engines 1a, 1b, 1c, 1d preferably being diesel engines. The electric machines 3a, 3b, 3c, 3d are, for example, permanent magnet synchronous motors.

DETAILED DESCRIPTION OF THE INVENTION

(5) Each of the combinations 1, 3 is connected to a generator rectifier 5a, 5b, 5c, 5d assigned to the combination 1, 3, via a three-phase connector line 4a, 4b, 4c, 4d. The three-phase connector line 4 of each of the combinations is routed via a three-phase isolating switch 14a, 14b, 14c, 14d, so that the three-phase electrical connection between the electric machine 3 and the generator rectifier 5 can be interrupted, in particular when the electric machine 3 of the combination 1, 3 is operated as a motor. The rectifiers 5 are connected to the direct-current link with the lines 8, 10, via connecting lines 33, 34 designed as collecting lines for all rectifiers 5.

(6) With its two DC voltage side connector lines, an auxiliaries inverter 12 is connected to the lines 8, 10 of the direct-current link. With its three-phase AC voltage side, the auxiliaries inverter 12 is connected to an auxiliaries connector 11, via an isolating transformer 13 and a filter arrangement 15, which is e.g. designed as a sinusoidal filter, and via a switch 16. In FIG. 1, the electrical connections from the auxiliaries connector 11 to the auxiliaries not shown here are represented by three parallel arrows pointing upward.

(7) Furthermore, via another transformer 21, the auxiliaries connector 11 is connected to the AC voltage side of a rectifier 20 and to a three-phase emergency operation line 2 running to the three-phase connector line 4a of the first combination 1a, 3a via an isolating switch 18. At least one of the transformers 13, 21 can be omitted or replaced by an other voltage converter. The advantage of a transformer or voltage converter between the auxiliaries inverter 12 and the auxiliaries connector 11 is that, in addition to the auxiliaries inverter 12, the voltage can be adjusted to the voltage level required for the auxiliaries. In particular, a transformer 13, moreover, effects galvanic isolation. The additional transformer 21 likewise enables voltage adjustment, both in emergency operation and when energy is supplied to the electric machines 3 from the direct-current link for their motor mode of operation, which voltage adjustment, as already mentioned, can also be achieved by an other voltage converter. For the purpose of this energy supply from the direct-current link, the already mentioned rectifier 20 is connected to DC voltage connectors of the machine inverters 23a, 23b, 23c, 23d. The AC voltage sides of the machine inverters 23 are each connected to the three-phase connector line 4 of the combination by means of a switch 24a, 24b, 24c, 24d.

(8) The advantage of coupling the emergency operation line 2 via an additional transformer 21 or via a voltage converterthe AC voltage side of the rectifier 20 for supplying the machine inverters likewise being connected to the auxiliaries connector 11 via the voltage converteris that the voltage level can be adjusted by means of just one voltage converter and that the voltage at the auxiliaries connector 11 in particular may be lower than in the emergency operation line and for the supply of the machine inverters. Therefore, such a solution is generally preferred, irrespective of the embodiment shown in FIG. 1.

(9) Preferably, as shown in FIG. 1, the three-pole switch 16 between the AC voltage side of the auxiliaries inverter 12 and the auxiliaries connector 11, and the isolating switch 18 in the emergency operation line 2, are actuated by a common control unit 19. Upon transition from normal operation, in which electric energy is supplied to the auxiliaries from the direct-current link 8, 10 via the auxiliaries inverter 12, to emergency operation, in which the auxiliaries are supplied via the emergency operation line 2, the control unit 19 controls the switches 16, 18 in such a way that the switch 16 is opened and the isolating switch 18 is closed. Consequently, in normal operation, at least one of the combinations 1, 3 supplies electric energy generated by its electric machine 3 to the direct-current link 8, 10, via the three-phase connector line 4 and the generator rectifier 5, that energy being available to the auxiliaries via the auxiliaries inverter 12, and also to at least one traction motor of the railway vehicle, via at least one traction inverter not shown. By contrast, in the embodiment shown in FIG. 1, in emergency operation, the electric machine 3a of the first combination 1, 3 supplies electric energy generated by it into the respective connecting lines leading to the auxiliaries, via the emergency operation line 2 and the optionally provided voltage converter 21. At the same time, at least one additional combination 1b, 3b, 1c, 3c, 1d, 3d can generate electric energy with its electric machine 3 and supply that electric energy to the direct-current link 8, 10 via the three-phase connector line 4b, 4c, 4d and the generator rectifier 5b, 5c, 5d. That energy is then available to at least one traction motor, in a similar way as in normal operation. Optionally, energy can be drawn from the direct-current link 8, 10 for other applications, both in normal operation and in emergency operation, e.g. for electrical installations not absolutely necessary for driving operation which are e.g. connected via the train connector in the case of a train.

(10) In the usual fashion, a capacitor CD is installed between the lines 8, 10 of the direct-current link to equalize DC voltage fluctuation and/or to absorb energy.

(11) Moreover, another electric line 28 is connected to the DC voltage side of the rectifier 20 for supplying the machine inverters 23, which in particular has two poles and allows to draw energy from an electric energy storage (e.g. vehicle battery) via a switch 27 and a voltage converter 26, and via an optional protective switch 25. Accordingly, at least one of the machine inverters 23 can be operated with energy from the additional energy storage. In particular in emergency operation, when none of the internal-combustion engines 1 has yet started, energy is in this way drawn from the additional energy storage and used to start at least one combination 1, 3. For instance, the combination 1b, 3b is started first, then its electric machine 3b is operated as a generator, and the electric energy generated is supplied to the direct-current link 8, 10 via the generator rectifier 5b. That energy is thus available to operate at least one traction motor and, optionally, other consumers, using the direct-current link.

(12) Alternatively, the combination 1a, 3a may be started first by drawing energy from the additional energy storage and supplying it to its machine inverter 23 via the line 28. After starting, the electric machine 3a can be operated as a generator and supply its electric energy through the emergency operation line 2. That energy can then be used to start other combinations 1, 3 via the rectifier 20.

(13) In an embodiment which is an alternative to FIG. 1, the electric energy required for starting a combination can be supplied to the machine inverter of the combination directly from the direct-current link once one of the combinations has started which supplies energy to the direct-current link. This mode of operation is possible e.g. in the embodiment described in the following.

(14) Moreover, the voltage converter 26 is connected to the line 10 at the higher electric potential of the direct-current link, via a resistor 29 and a diode 30. The line 22 can be disconnected from the voltage converter 26 by means of the switch 27. The direct-current link can be pre-charged via the line 22, i.e. an electric potential can be generated between line 10 and line 8. By closing the switches 14, this prevents short-circuit currents when the generators 3 are connected.

(15) FIG. 2 shows an arrangement similar to that in FIG. 1. Details of individual components of the arrangement are shown. Identical reference signs, in particular identical numbers, refer to the same or corresponding components as in FIG. 1. In particular, additional characteristic features of the arrangement shown in FIG. 1, which are not shown in FIG. 2, may also exist in the arrangement, e.g. the isolating switch between the alternating-voltage connector of the auxiliaries inverter and the auxiliaries connector.

(16) The arrangement comprises n combinations, each with an internal-combustion engine 1a . . . 1n and a mechanically coupled generator 3a . . . 3n, where n is a positive integer. In practice, e.g. two or four such combinations occur in a locomotive or other railway vehicle.

(17) Each of the combinations 1, 3 is connected to a generator rectifier 5a . . . 5n, via a three-phase connector line 4a . . . 4n. In the embodiment, the rectifiers 5 are non-controlled three-phase bridge circuits. The different potentials at the DC voltage sides of the rectifiers 5 are termed U+ and U, respectively. The connections of the rectifiers 5 with the direct-current link, with the lines 8, 10, are established via connecting lines 33, 34 designed as collecting lines for all rectifiers 5.

(18) As an alternative, several direct-current links might be provided, each of which supplies electric energy to at least one traction motor. In that case, however, there is at least one direct-current link to which the auxiliaries inverter is connected.

(19) In the embodiment shown in FIG. 2, the one potential of the direct-current linkthe higher potential U+ (line 10)is electrically connected to a machine inverter 36a . . . 36n of the respective combination 1, 3, each via one additional connecting line 6a . . . 6n. The other potential of the direct-current linkthe lower potential U (line 8)is e.g. connected to vehicle ground. Furthermore, in the embodiment, a vehicle energy storage 38 (e.g. an electrochemical storage) for storing electric energy is connected to the line 10 of the direct-current link, e.g. via a DC/DC converter (not shown). By means of a connector 39, the energy storage 38 and/or the direct-current link can be charged additionally, e.g. via a so-called batter charger, which may also be the DC/DC converter.

(20) The machine inverters 36 are connected to the three-phase line 4a . . . 4n by means of a three-phase line and an isolating contactor 40a . . . 40n.

(21) In an alternative embodiment, a converter may be provided instead of the uncontrolled rectifier bridge and the generator-inverter, which converter can be operated both as a rectifier (during generator mode of operation of the electric machine 3) and as an inverter (during motor mode of operation of the electric machine 3). The advantage of the embodiment shown in FIG. 2, with separate rectifier bridge and generator-inverter, is that the machine inverter can be dimensioned for the transmission of lower electric voltages and powers than the rectifier bridge, because just low power is required in the motor mode of operation of the electric machine 3 to run the internal-combustion engine at no-load speed. By contrast, a controlled or regulated integrated converter for both rectification and power inversion would have to be dimensioned for high power during traction operation.

(22) At least one of the combinations, to with the combination 1a, 3a in the embodiment, can be disconnected from the direct-current link 8, 10 by means of a switch 17. In the embodiment shown in FIG. 2, the switch 17 is located between the DC voltage side of the rectifier 5a and the connecting lines 33, 34. The switch has two poles. Alternatively, the switch may be located in the three-phase connector line 4a, as shown in the example in FIG. 1, and hence have three poles. In either case, when the switch 17 is opened, the combination is disconnected from the direct-current link, and the combination 1a, 3a can supply electric energy to the auxiliaries 9 via the emergency operation line 2. In the example of FIG. 2, the emergency operation line 2 has three phases as well, as in FIG. 1, and is connected to the auxiliaries connector. Switches for interrupting the emergency operation line 2 or for disconnecting the emergency operation line 2 from the auxiliaries connector 11, and switches for disconnecting the auxiliaries inverter 12, which is connected to the direct-current link at its DC voltage side, are not shown in FIG. 2. They may be designed in particular as shown in FIG. 1. In FIG. 2, the auxiliaries inverter 12 is, at the DC voltage side, connected directly to the connecting line 34 at the higher potential and, with the other DC voltage side connector, connected to vehicle ground. Alternatively, the auxiliaries inverter 12 may be connected directly to a line of the direct-current link, e.g. line 8 or connecting line 33.