Electric vehicle, composition of several electric vehicles and method for operating an electric vehicle

Abstract

An electric vehicle, in particular a rail vehicle, with a current collection device (2). The current collection device has at least one contact device (2a, 2b). An electrically conductive contact, of the current collection device (2) to an external power supply (1), can be achieved by the contact device (2a, 2b). The vehicle comprises a DC link (11) and at least one electric traction motor (10). During normal driving operation, the current is conducted from the current collection device (2), via the DC link (11), into the one of the traction motors (10) and a current connection is formed between the contact device (2a, 2b) and the DC link (11). The current connection is at least partially bidirectional. A disconnecting device (5) is arranged between contact device (2a, 2b) and DC link (11). The disconnecting device (5) is designed to be interrupted unidirectionally.

Claims

1. An electric vehicle with a current collection device having at least one contact device, wherein by means of the at least one contact device an electrically conductive contact of the current collection device to an external power supply can be achieved, a DC link, at least one electric traction motor, the current from the current collection device can be conducted, via the DC link, into the at least one electric traction motor during a traction operation, and a current connection is provided between the at least one contact device and the DC link, and the current connection being at least partially bidirectional, and a disconnecting device is arranged between the at least one contact device and the DC link, and the disconnecting device is designed in such a way that the power supply can only be interrupted unidirectionally and wherein an energy storage device is provided and the energy storage device is arranged in electrical connection to the DC link.

2. The electric vehicle according to claim 1, wherein the disconnecting device is an electronic switch.

3. The electric vehicle according to claim 1, wherein a main switch is arranged between the at least one contact device and the DC link.

4. The electric vehicle according to claim 1, wherein the current collection device comprises a measuring device for current.

5. The electric vehicle according to claim 1, wherein a detection device is designed to detect power supply interruptions, it being possible to detect the presence of a power supply interruption directly by the detection device and/or to process position data of a power supply interruption in the detection device.

6. A composition of several electric vehicles wherein at least one electric vehicle is provided according to claim 1.

7. A method for operating an electric vehicle according to claim 1, wherein the electric vehicle comprises a DC link and a current collection device, comprising the following steps: detecting a power interruption with a detection device, interrupting the power supply in a direction of the external power supply by opening a disconnecting device, whereby a power supply from the external power supply to the DC link is still unidirectionally possible.

8. The method according to claim 7, wherein after detection of the current interruption, a voltage level of the DC link is raised to a voltage level equal to or higher than the voltage level of the external power supply up to a maximum permissible voltage of the external power supply.

9. The method according to claim 7, wherein a restart of the external power supply is detected by the detecting device and a voltage level in the DC link is reduced after detecting the restart of the external power supply, whereby the disconnecting device is closed again so that a bidirectional current flow is possible.

10. The method according to claim 7, wherein raising of the voltage level in the DC link takes place by feeding in braking energy from the at least one electric traction motor and/or by feeding in energy from an energy storage device.

11. The method according to claim 7, wherein, in the case of an electric vehicle with more than one current collection device, the detection of the current interruption takes place at the current collection device arranged at a front in a direction of travel.

12. The method according to claim 7, wherein a length of a section of the power interruption of the external power supply is determined.

13. The method according to claim 7, wherein a composite comprises at least two longitudinally spaced current collection devices and the interruption of the power supply only takes place if a length of a section of the external power supply without power supply is longer than a distance between the two current collection devices.

14. The method according to claim 7, wherein a length of a section of the power interruption of the external power supply is transmitted to another vehicle and/or stored.

15. An electric vehicle according to claim 1, wherein a current flow in a direction of the external power supply can be interrupted.

16. The electric vehicle according to claim 1, wherein the energy storage device is a battery, a capacitor or a supercapacitor.

17. The electric vehicle according to claim 1, wherein a current storage device is connected to the DC link via a step-up converter.

18. The electric vehicle according to claim 1, wherein the main switch is arranged between the current collection device and the disconnecting device.

19. The method according to claim 7, wherein the voltage level in the DC link is reduced, after detecting the restart of the external power supply, to a level below the voltage level of the external power supply.

Description

(1) The invention is explained using the following figures as examples. It shows

(2) FIG. 1: A plan of an electrical power supply of a vehicle in a first embodiment,

(3) FIG. 2: A plan of an electrical power supply of a vehicle in a second embodiment.

(4) FIG. 1 shows a plan of an electrical power supply of a vehicle in a first embodiment. It shows a current collection device 2 with two contact devices 2a, 2b, which bring the vehicle into electrically conductive contact with an external power supply 1.

(5) The contact devices 2a, 2b are each connected to a current transformer 13a, 13b for current measurement. In general, the connection is designed so that a current conducting line is arranged between the components.

(6) The two current transformers 13a, 13b are connected to a main switch 3. An additional voltage transformer 20 is arranged on the line from current transformer 13a to main switch 4.

(7) The main switch 3 is connected to an inductor 14, which in turn is connected to a line contactor 4 and a charging contactor 15 connected in parallel. The line contactor 4 and the charging contactor 15 are connected to the disconnecting device 5. The disconnecting device 5 in this version comprises two parallel connected freewheeling diodes 12.

(8) In an alternative design (not shown here) the two current transformers 13a, 13b can be connected directly or via a fuse to the inductor 14.

(9) The disconnecting device 5 is connected to the DC link 11. The DC link 11 includes a capacitor 16. An energy storage device, here capacitance 6, is connected in parallel with the DC link 11 and connected to it via a step-up converter 21. The capacitor 6 can take over the power supply of the DC link 11 or be charged via it.

(10) Also shown are two traction motors 10 and auxiliary devices 9. The traction motors 10 are connected to the DC link 11 via a motor converter 7. The auxiliary devices 9 are also connected to the DC-link 11 via auxiliary converters 8.

(11) During normal operation, current is supplied from the external power supply 1 via the current collection device 2 and the DC link 11 to the motors 10 and the auxiliary gears 9. In this case, the isolator 5 is closed, allowing current to be conducted from the current collection device 2 to the DC link 11 and vice versa. When the vehicle now enters a current-free section, the disconnecting device 5 is opened, which prevents current from the DC link 11 from flowing into the external power supply 1. However, it is still possible for current from the external power supply 1 to flow into the DC link 11. This means that the connection between the DC link 11 and the external power supply is unidirectionally interrupted. The motors 10 and the auxiliaries 9 are supplied with power by the capacitor 6 via the DC link 11.

(12) After passing through the current-free section, the disconnecting device 5 is closed again, and current can now flow bidirectionally again. Capacity 6 is recharged via the DC link.

(13) Furthermore, a ground brush 17 for the reverse current is shown.

(14) FIG. 2 shows a plan of an electrical power supply of a vehicle in a second version. Only the differences to the first version are explained here.

(15) The disconnecting device 5 in this version is located between the current transformers 13a, 13b and the main switch 3. The disconnecting device here comprises a freewheeling diode 18, which is connected in parallel with an IGBT switch.