Method, device and system for determining the fault location of a fault on a line of an electrical energy supply network

Patent metadata

Field	Value
Publication number	US-10228408-B2
Application number	US-201715465802-A
Country	US
Kind code	B2
Filing date	Mar 22, 2017
Priority date	Mar 22, 2016
Publication date	Mar 12, 2019
Grant date	Mar 12, 2019

Abstract

The fault location of a fault on a line of an electrical energy supply network is determined. First and second current and/or voltage values are measured and provided with a timestamp at the line ends of the line. Following the occurrence of a fault, the timestamped first and second values are used to determine the fault location. Profiles of travelling waves propagating along the line towards the line ends when the fault occurs are determined from the timestamped first and second values at both line ends. The fault location is defined from the profiles of the travelling waves from a time difference with which the travelling waves arrive at the two line ends. The time difference is derived from a pattern comparison of the profiles of the travelling waves determined for the line ends.

First claim

The invention claimed is:

1. A method for determining a fault location of a fault on a line of an electrical energy supply network, the method comprising:
measuring first values selected from a group consisting of current values and voltage values at a first line end of the line and providing the first values with a timestamp;
measuring second values selected from the group consisting of current values and voltage values at a second line end of the line and providing the second values with a timestamp; and
following an occurrence of a fault on the line, determining profiles of travelling waves propagating along the line in a direction of the line ends using the timestamped first and second values at both line ends; and
determining the fault location from the profiles of the travelling waves determined for both line ends by defining a time difference with which the travelling waves arrive at the first and second line ends, respectively, the time difference being defined from a pattern comparison of the profiles of the travelling waves determined for the line ends.

2. The method according to claim 1 , which comprises carrying out a cross-correlation of the profiles for the pattern comparison of the profiles of the travelling waves.

3. The method according to claim 1 , which comprises using an angle of the cross-power spectrum of the profiles of the travelling waves for the pattern comparison.

4. The method according to claim 1 , which comprises carrying out a minimization of a target function formed from a difference of the profiles of the travelling waves for the pattern comparison.

5. The method according to claim 1 , which comprises, before the pattern comparison, correcting a profile of the travelling wave of at least one line end and thereby taking into account an attenuation of the line.

6. The method according to claim 1 , which comprises defining the fault location exclusively using current and voltage values which have been measured at the first and second line ends during an occurrence of a first wave pulse of the travelling wave.

7. The method according to claim 1 , which comprises defining the fault location exclusively using either the current values or the voltage values which have been measured at the first and second line ends during an occurrence of a first wave pulse of the travelling wave.

8. The method according to claim 1 , which comprises:
filtering the current values and voltage values measured at the line ends, to form first and second filtered current and voltage values which indicate a selected frequency range of the measured current and voltage values; and
defining the profiles of the travelling waves using the first and second filtered current and voltage values.

9. The method according to claim 8 , wherein the selected frequency range comprises high-frequency transient components or band-limited transient components of the measured current and voltage values.

10. The method according to claim 8 , wherein a filter characteristic of the filter used to filter the current and voltage measured values dampens the frequency ranges in which current and voltage transformers used to measure the current and voltage measured values have measurement errors.

11. The method according to claim 8 , which comprises:
where the electrical energy supply network is a multiphase electrical energy supply network, performing a mathematical transformation in respect of the first and second filtered current and voltage values, to decouple individual phase components, to form first and second transformed current and voltage values; and
defining the profiles of the travelling waves using the first and second transformed current and voltage values.

12. The method according to claim 1 , which comprises determining the fault location upon identifying a jump that exceeds a predefined threshold in a characteristic of a value selected from the group consisting of the first current and voltage values, values derived therefrom, the second current and voltage values, and values derived therefrom.

13. The method according to claim 1 , which comprises:
determining the fault location in each case by way of a device at each of the first and second line ends; and
outputting the fault locations thus determined with the devices by the devices.

14. The method according to claim 1 , which comprises:
determining the fault location with a device configured for the purpose; and
outputting the determined fault location by the device.

15. A device for determining a fault location of a fault on a line of an electrical energy supply network, the device comprising:
a processor configured to determine the fault location of the fault using first values selected from a group consisting of current values and voltage values measured and timestamped at a first line end of the line and second values selected from current values and voltage values measured and timestamped at a second line end of the line following an occurrence of a fault on the line;
said processor being configured to determine profiles of travelling waves propagating along the line in a direction of the line ends when the fault occurs using the timestamped first and second current and/or voltage values at the first and second line ends; and
said processor being configured to define the fault location from the profiles of the travelling waves determined for the first and second line ends by defining a time difference with which the travelling waves arrive at the first and second line ends, respectively, wherein the time difference is defined from a pattern comparison of the profiles of the travelling waves determined for the line ends.

16. A system for determining a fault location of a fault on a line of an electrical energy supply network, the system comprising:
two devices each being a device according to claim 15 ;
a communication connection interconnecting said two devices to one another for data exchange therebetween;
said devices being configured for determining the fault location by carrying out the following process steps:
measuring first values selected from the group consisting of current values and voltage values at a first line end of the line and providing the first values with a timestamp;
measuring second values selected from the group consisting of current values and voltage values at a second line end of the line and providing the second values with a timestamp;
following an occurrence of a fault on the line, determining profiles of travelling waves propagating along the line in a direction of the line ends using the timestamped first and second values at both line ends; and
determining the fault location from the profiles of the travelling waves determined for both line ends by defining a time difference with which the travelling waves arrive at the first and second line ends, respectively, the time difference being defined from a pattern comparison of the profiles of the travelling waves determined for the line ends.

Assignees

• Siemens Ag

Inventors

• Dzienis Cezary
• Jurisch Andreas

Classifications

• H03H7/0138

  Electrical filters or coupling circuits · CPC title

• G01R31/086 Primary

  in power transmission or distribution networks, i.e. with interconnected conductors · CPC title

• G01R31/088

  Aspects of digital computing · CPC title

• G01R31/085 Primary

  in power transmission or distribution lines, e.g. overhead · CPC title

• G01R31/11

  using pulse reflection methods · CPC title