Method for operating parallel auxiliary converters in a rail vehicle

{
  "publication_number": "US10000122B2",
  "country": "US",
  "kind": "B2",
  "title": "Method for operating parallel auxiliary converters in a rail vehicle",
  "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."
  ],
  "description_excerpt": "The invention relates to a method for supplying electrical loads of a vehicle with electrical energy. The invention further relates to an energy supply system of a vehicle, especially of a rail vehicle, for carrying out this method.\n\nAn auxiliary converter is used to supply electrical energy to an on-board network of a vehicle and to the loads connected to said network. Typical loads of a vehicle, especially of a rail vehicle, are on-board electronics for controlling/regulating the vehicle, compressors, air conditioning systems, lighting, electrical sockets etc. The loads are subdivided into a group of three-phase loads and a group of single-phase loads.\n\nThe three-phase loads are fed via a three-phase energy supply network, such as an alternating current network for example. This energy supply network comprises three phases, which are frequently referred to as L 1, L 2 and L 3. In most cases this three-phase network does not have a neutral conductor (N conductor). However applications are also known in which the three-phase energy supply network is embodied with an N conductor. The N conductor represents the system ground. In rail vehicles in particular the three-phase energy supply network is frequently embodied as a 3AC train power supply line.\n\nWith single-phase loads the behavior is different. These are supplied with energy via a phase and a neutral conductor. Thus the single-phase energy supply network does have an N conductor. For reasons of safety this is connected at low impedance to the ground potential.",
  "cpc": [
    "B60L 3/003",
    "B60L 1/00",
    "B60L 2200/26",
    "B60L 3/0069",
    "B60L 9/00",
    "H02H 11/001",
    "H02H 3/16",
    "H02H 5/10",
    "H02J 1/06",
    "H02J 1/082",
    "H02J 3/36",
    "H02J 3/46",
    "H02M 1/14",
    "H02M 1/32",
    "H02M 7/06",
    "H02M 7/493",
    "H02M 7/53803",
    "H02M 7/53871"
  ],
  "ipc": [
    "H02M 7/06",
    "B60L 3/00",
    "H02H 5/10",
    "H02J 3/36",
    "H02M 7/493",
    "B60L 1/00"
  ],
  "assignees": [
    "Siemens AG"
  ],
  "inventors": [
    "Xiao Qiang Wu",
    "Nikolaj Echkilev",
    "Andreas Wellner"
  ],
  "filing_date": "2015-03-23",
  "publication_date": "2018-06-19",
  "grant_date": "2018-06-19",
  "priority_date": "2014-03-31",
  "application_number": "US-201515300594-A",
  "family_id": "50391076",
  "cited_by_count": 41,
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  ]
}