Method and device for identifying the location of a fault in an electrical power distribution network

Patent metadata

Field	Value
Publication number	US-11467200-B2
Application number	US-202117471432-A
Country	US
Kind code	B2
Filing date	Sep 10, 2021
Priority date	Sep 10, 2020
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

Method and device for determining a fault location in an electric power distribution network with an infeed and lines in the form of a main strand and a multiplicity of branches of the main strand. First and second measured values are acquired at a first and second measurement point of the power distribution network, and a fault location is determined based on the first and the second measured values. Arrival of respective traveling waves are identified based on the first and the second measured values, and the times of the respective arrival of the traveling wave are stored. A first fault location value is generated using the respective times of both measurement points and a second fault location value is generated using the times of only the first measurement point. The fault location is determined based on the first fault location value and the second fault location value.

First claim

The invention claimed is:

1. A method for determining a fault location in an electric power distribution network, wherein the power distribution network has at least one infeed and lines forming a main strand and a plurality of branches branching off from the main strand, the method comprising:
acquiring first measured values at a first measurement point of the power distribution network;
acquiring second measured values at a second measurement point of the power distribution network;
determining the fault location of the fault that has occurred in the power distribution network based on the first and the second measured values;
identifying an arrival of respective traveling waves based on the first and the second measured values, the traveling waves indicating a fault that has occurred in the power distribution network, and storing the times of the respective arrival of the traveling waves;
performing a first fault-locating process using the respective times of the first and second measurement points for generating a first fault location value;
performing a second fault-locating process using the times of only the first measurement point for generating a second fault location value; and
determining the fault location based on the first fault location value and the second fault location value.

2. The method according to claim 1 , further comprising:
breaking down the acquired measured values into modal components, wherein at least two of the modal components have different propagation speeds along the lines of the power distribution network; and
applying at least partially different modal components for the first and second fault-locating processes.

3. The method according to claim 2 , further comprising using the respective times at which a first wave edge of a modal zero component of the traveling wave arrived at the first and second measurement point for the first fault-locating process for forming the first fault location value.

4. The method according to claim 2 , further comprising using the respective times at which a first wave edge of a modal zero component and of a modal α or β component of the traveling wave arrived at the first measurement point for the second fault-locating process for forming the second fault location value.

5. The method according to claim 1 , further comprising ascertaining a corresponding location on the main strand as the fault location if the first fault location value and the second fault location value match.

6. The method according to claim 1 , further comprising Identifying the fault location as being located on one of the branches if the first fault location value differs from the second fault location value.

7. The method according to claim 6 , further comprising indicating a faulty branch on which the fault location is located by the first fault location value.

8. The method according to claim 7 , further comprising ascertaining the specific fault location on the faulty branch as the difference between the second fault location value and the first fault location value.

9. The method according to claim 1 , further comprising measuring high-frequency current and/or voltage values at the respective measurement point and using the high-frequency current and/or voltage values as measured values.

10. The method according to claim 1 , further comprising storing the measured values in a ring buffer, the content of which is frozen as soon as a traveling wave has been identified in the course of acquiring at least one of the measured values.

11. A device for determining a fault location in an electric power distribution network, wherein the power distribution network has at least one infeed and lines forming a main strand and a plurality of branches branching off from the main strand, the device comprising:
an evaluation device configured to determine the fault location of a fault that has occurred in the power distribution network based on times at which respective traveling waves arrive at a first measurement point and a second measurement point of the power distribution network;
said evaluation device being configured to perform a first fault-locating process using the respective times of the first and second measurement points and generating a first fault location value;
said evaluation device being configured to perform a second fault-locating process using the times of only the first measurement point and generating a second fault location value; and
the evaluation device is designed to determine the fault location based on the first fault location value and the second fault location value.

12. The device according to claim 11 , wherein the device is a central data processing device that has a communication unit configured to receive information that indicates the times of arrival of said traveling waves at said first and said second measurement point.

13. The device according to claim 12 , wherein said device is a cloud data processing device.

14. The device according to claim 11 , further comprising:
an internal measuring device configured to acquire first measured values at said first measurement point of the power distribution network and to ascertain a respective time of arrival of a traveling wave; and
a communication module configured to receive information about a respective time of arrival of a traveling wave at said second measurement point from a remotely arranged measuring device.

Assignees

• Siemens Ag

Inventors

• Dzienis Cezary
• Jurisch Andreas

Classifications

• G01R31/085 Primary

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

• G01R19/2506

  Arrangements for conditioning or analysing measured signals, e.g. for indicating peak values (G01R19/003 takes precedence); Details concerning sampling, digitizing or waveform capturing (displaying waveforms G01R13/00; analog sampling G01R19/0053) · CPC title

• G01R31/086 Primary

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

• Y04S10/52

  Outage or fault management, e.g. fault detection or location · CPC title

• G01R19/28

  adapted for measuring in circuits having distributed constants · CPC title