Method for operating parallel auxiliary converters in a rail vehicle

• US 10,000,122 B2
• Filed: 03/23/2015
• Issued: 06/19/2018
• Est. Priority Date: 03/31/2014
• Status: Active Grant

• Current Assignee: Siemens Mobility GmbH (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Wu, Xiao Qiang, Echkilev, Nikolaj, Wellner, Andreas
• Primary Examiner(s): CAVALLARI-SEE, DANIEL
• Application Number:
  US15/300,594
• Publication Number:
  US 20170207717A1
• Time in Patent Office: 1,184 Days
• CPC Class Codes: B60L 1/00 Supplying electric power to auxiliary equipment of vehicles circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 3/003 relating to inverters
• CPC Class Codes: B60L 3/0069 relating to the isolation, e.g. ground fault or leak current
• CPC Class Codes: B60L 9/00 Electric propulsion with power supply external to the vehicle electric propulsion for monorail vehicles, suspension vehicles or rack railways B60L13/00; in combination with batteries or fuel cells within the vehicle B60L50/53
• CPC Class Codes: H02H 11/001 in case of incorrect or interrupted earth connection disconnection by breaking of earth connection H02H5/105
• CPC Class Codes: H02H 3/16 responsive to fault current to earth, frame or mass with balanced or differential arrangement H02H3/26 ; monitoring earth connection H02H5/105
• CPC Class Codes: H02H 5/10 responsive to mechanical injury, e.g. rupture of line, breakage of earth connection
• CPC Class Codes: H02J 1/06 Two-wire systems
• CPC Class Codes: H02J 1/082 Plural DC voltage, e.g. DC supply voltage with at least two different DC voltage levels
• CPC Class Codes: H02J 3/36 Arrangements for transfer of electric power between ac networks via a high-tension dc link
• CPC Class Codes: H02M 1/14 Arrangements for reducing ripples from dc input or output
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 7/493 the static converters being arranged for operation in parallel
• CPC Class Codes: H02M 7/53803 with automatic control of output voltage or current
• CPC Class Codes: H02M 7/53871 with automatic control of output voltage or current

Abstract

In a method for supplying an electrical load of a vehicle with electrical energy by auxiliary converters connected in parallel on the alternating-voltage side, a current flow between the auxiliary converters and a grounded N conductor of an energy supply network is interrupted in the presence a ground fault. The auxiliary converters connected in parallel on the alternating-voltage side are operated with fundamental-wave and pulse synchronicity. An energy supply system of a vehicle, in particular of a rail vehicle, performs this method, with the energy supply system including at least two auxiliary converters arranged in parallel, an energy supply network for supplying electrical loads, at least one switch for interrupting a current flow between the auxiliary converters and the energy supply network.

Claims

1. A method of supplying an electrical load in an on-board energy supply network of a vehicle with electrical energy, said energy supply network having at least two auxiliary converters, said auxiliary converters configured to be switched in parallel on an AC voltage side and to feed the energy supply network of the vehicle, comprising the steps of:

interrupting a connection between a grounded N conductor of the energy supply network and the auxiliary converters in the event of a short circuit to ground; and

operating the auxiliary converters with phase position and frequency synchronicity by switching the auxiliary converters in parallel.

2. The method of claim 1, wherein the short circuit to ground occurs in the energy supply network.

3. The method of claim 1, wherein the vehicle is a rail vehicle.

4. The method of claim 1, wherein the connection between a grounded N conductor of the energy supply network and respective auxiliary converters is interrupted by opening respective switches.

5. The method of claim 1, wherein the auxiliary converters are operated with phase position, frequency and voltage level synchronicity.

6. A method of supplying an electrical load in an on-board energy supply network of a rail vehicle With electrical energy, said energy supply network having a grounded N conductor and at least two auxiliary converters that are switched in parallel on an AC voltage side, comprising the steps of:

switching off the auxiliary converters in the event of a short circuit to ground;

interrupting a connection between the switched-off auxiliary converters and the energy supply network by opening at least one respective switch;

switching on one of the switched-off auxiliary converters;

synchronizing the phase position and frequency of the converter that is switched-on while switching on a further auxiliary converter that was switched off; and

closing the at least one switch that interrupted the connection between the auxiliary converters and the energy supply network, once absence of the short circuit to ground has been established, thereby operating the auxiliary converters with phase position and frequency synchronicity.

7. The method of claim 6, wherein the further auxiliary converter is synchronized with respect to phase position, frequency and voltage level.

8. An on-board energy supply system of a vehicle, comprising:

at least two auxiliary converters configured to be switched in parallel on an AC voltage side and to be synchronous in phase position and frequency;

an energy supply network configured to supply an electrical load with electrical energy and having a grounded N conductor that is connected to the converters; and

a switch configured to interrupt a connection between the grounded N conductor and the auxiliary converters of the energy supply network.

9. The energy supply system of claim 8, configured to supply energy in a rail vehicle.

10. The energy supply system of claim 8, further comprising at least one short circuit to ground monitoring facility.

11. The energy supply system of claim 8, wherein each auxiliary converter is connected in parallel with others and includes a switch configured to switch the auxiliary converter on an AC voltage side of the auxiliary converter.

12. The energy supply system of claim 8, wherein the energy supply system has a three-phase energy supply network and a single-phase energy supply network that are electrically connected to one another.

13. The energy supply system of claim 12, wherein the electrical connection between the three-phase energy supply network and the single-phase energy supply network is implemented by an auxiliary converter.

14. The energy supply system of claim 8, wherein the auxiliary converters are configured to be synchronous in phase position, frequency and voltage level.