Method for automatically coordinating protection settings in an electric power distribution network

Patent metadata

Field	Value
Publication number	US-10581235-B2
Application number	US-201815902344-A
Country	US
Kind code	B2
Filing date	Feb 22, 2018
Priority date	Feb 22, 2018
Publication date	Mar 3, 2020
Grant date	Mar 3, 2020

Abstract

Methods and systems are provided for automatically coordinating protection settings for relays within an electrical power distribution network. A method includes using a graph traversal mechanism to analyze geographical-based equipment data that contains information about overcurrent relays within the electrical power distribution network. A customizable rule base is applied to protection guidelines. Protection settings are determined based upon the applied customizable rule base and the direction of fault current flow from each source. The determined protection settings are used for the overcurrent relays to control switches in the electrical power distribution network in response to a detected fault.

First claim

The invention claimed is:

1. A method for automatically coordinating protection settings for relays within an electrical power distribution network, comprising:
using a graph traversal mechanism to analyze geographical-based equipment data that contains information about overcurrent relays within the electrical power distribution network;
applying a customizable rule base to protection guidelines;
determining protection settings based upon the applied customizable rule base and a direction of fault current flow from each source; and
using the determined protection settings for the overcurrent relays to control switches in the electrical power distribution network in response to a detected fault.

2. The method of claim 1 , wherein a plurality of the switches is downstream of multiple different interconnected sources, including distributed generation.

3. The method of claim 1 , wherein the determined protection settings facilitate coordinating protection settings for the overcurrent relays that are geographically dispersed in the electrical power distribution system;
wherein optimization is performed using valid protection settings based on a user-defined preference.

4. The method of claim 1 , wherein the graph traversal mechanism identifies a network hierarchy of electrical equipment located within the geographically-dispersed distribution network and collects data to determine a response of equipment to fault current; and
utilizing the collected network data to determine fault current availability at each device based on equivalent impedance calculations and fault characteristics for use in a relay coordination process.

5. The method of claim 4 , wherein the geographical-based equipment data contains properties of equipment in the electrical power distribution network including fuses, reclosers, voltage regulators, capacitors, distribution transformers, and conductors, wherein these properties at least include location, ampacity, rating, impedance, tap position, existing time-current curves, and pertinent control parameters.

6. The method of claim 1 , wherein the analyzed geographical-based equipment data is stored in data arrays that are structured to contain directed equipment connectivity data, sequence of network equipment data, and data related to nodes of equipment closest to a source as related to each of a plurality of interconnected sources in a network.

7. The method of claim 1 , wherein the customizable rule base includes rules that allow for the relays to not be coordinated at user-defined conditions;
wherein at least one of the rules specifies that ground curves operate faster than downstream fuses up to a multiple of a fuse minimum melt current.

8. The method of claim 1 , wherein an upstream network traversal mechanism provides for minimization of overcurrent relay operation time;
wherein a downstream network traversal mechanism provides for maximization of overcurrent relay operation time.

9. The method of claim 1 , wherein an advanced protection method is used in the event of a miscoordination;
wherein the advanced protection method includes a pulse-finding method or a communication enhanced coordination method.

10. The method of claim 1 , wherein an upstream network traversal mechanism provides for minimization of overcurrent relay operation time by using a traversal to set the overcurrent relay minimum pick-up above the downstream protection pick-ups and a multiple of downstream load.

11. The method of claim 10 , wherein the minimization of the overcurrent relay operation time is performed by setting a time dial during operation of the upstream network traversal mechanism.

12. The method of claim 1 , wherein fuse size and speed is selected based on user-defined preferences.

13. The method of claim 1 , wherein the customizable rules base includes rules to use different protection elements;
wherein the rules include coordinating ground protection elements up to a maximum single-phase-to-ground current.

14. The method of claim 13 , wherein the rules include considering fuse pre-loading and effect of multiple reclosing attempts.

15. The method of claim 1 , wherein relays are set to save downstream fuses in a coordinated manner based on the customizable rules base.

16. The method of claim 1 , wherein the customizable rule base is customized so that different rules are applied to different reclosing shot attempts.

17. A system for automatically coordinating protection settings for relays within an electrical power distribution network, comprising one or more data processors to:
use a graph traversal mechanism to analyze geographical-based equipment data that contains information about overcurrent relays within the electrical power distribution network;
apply a customizable rule base to protection guidelines;
determine protection settings based upon the applied customizable rule base and a direction of fault current flow from each source; and
use the determined protection settings for the overcurrent relays to control switches in the electrical power distribution network in response to a detected fault.

18. The system of claim 17 , wherein a plurality of the switches is downstream of multiple different interconnected sources, including distributed generation.

19. The system of claim 17 , wherein the determined protection settings facilitate coordinating protection settings for the overcurrent relays that are geographically dispersed in the electrical power distribution system;
wherein optimization is performed using valid protection settings based on a user-defined preference.

20. The system of claim 17 , wherein the graph traversal mechanism identifies the network hierarchy of electrical equipment located within the geographically-dispersed distribution network and collects data to determine the response of equipment to fault current; and
utilizing the collected network data to determine fault current availability at each device based on equivalent impedance calculations and fault characteristics for use in the relay coordination process.

Assignees

• S & C Electric Co

Inventors

• Seuss John
• Sharon Yoav

Classifications

• H02H3/006

  Calibration or setting of parameters · CPC title

• G05B2219/2639

  Energy management, use maximum of cheap power, keep peak load low · CPC title

• H02H3/08 Primary

  responsive to excess current (responsive to abnormal temperature caused by excess current H02H5/04) · CPC title

• H02H1/0092

  concerning the data processing means, e.g. expert systems, neural networks · CPC title

• H02H7/26

  Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured (locating faults in cables G01R31/08) · CPC title