Systems and methods for protection of components in electrical power delivery systems

• US 8,792,217 B2
• Filed: 09/15/2010
• Issued: 07/29/2014
• Est. Priority Date: 09/15/2010
• Status: Active Grant

• Current Assignee: Schweitzer Engineering Laboratories, Incorporated
• Original Assignee: Schweitzer Engineering Laboratories, Incorporated
• Inventors: Shah, Saurabh B., Garg, Kamal, Manson, Scott M.
• Primary Examiner(s): Gami, Tejal
• Application Number:
  US12/882,521
• Publication Number:
  US 20120063039A1
• Time in Patent Office: 1,413 Days
• Field of Search: 700/292, 700/295, 700/286, 361/20, 361/64, 702/60
• US Class Current: 361/20
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24
• CPC Class Codes: G06F 11/0793 Remedial or corrective actions recovery from an exception in an instruction pipeline G06F9/3861; by retry G06F11/1402; for recovering from a failure of a protocol instance or entity H04L69/40
• CPC Class Codes: H02H 7/00 Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
• CPC Class Codes: H02H 7/062 for parallel connected generators
• CPC Class Codes: H02H 7/261 involving signal transmission between at least two stations transmission of signals in general H02H1/0061

Abstract

Various embodiments disclosed herein provide protection to monitored equipment at both a local level and a system level, in order to offer more comprehensive protection. In one particular embodiment, the protected equipment may include one or more generators. The protection system may utilize time-synchronized data in order to analyze data provided by systems having disparate sampling rates, that are monitored by different equipment, and/or equipment that is geographically separated. Various embodiments may be configured to utilize a variety of sampling rates.

Claims

1. A system to monitor and control a plurality of pieces of monitored equipment in an electric power delivery system, the system comprising:

a data network;

a first local protection IED and a second local protection IED, each of the first and second IEDs comprising;

a local protection IED network interface in communication with the data network;

a monitored equipment interface to receive monitored equipment data including a plurality of measurements indicating electrical conditions associated with monitored equipment, wherein the monitored equipment comprise electrical generators;

a local protection IED processor; and

a local protection IED computer-readable storage medium, comprising;

software instructions executable on the local protection IED processor that enable the local protection IED to;

record the plurality of measurements indicating electrical conditions associated with monitored equipment received via the monitored equipment interface;

associate a plurality of measurements with a time stamp indicating the time at which each of the plurality of measurements is made to generate a plurality of time-synchronized measurements;

analyze the plurality of time-synchronized measurements;

determine a local-level protection action based upon the analysis of the plurality of time-synchronized measurements;

transmit the plurality of time-synchronized measurements via the data network;

a system protection IED configured to operate at a supervisory level with respect to the first local protection IED and the second local protection IED, the system protection IED, comprising;

a system protection IED network interface in communication with the data network;

a system protection IED processor;

a system protection IED computer-readable storage medium, comprising;

software instructions executable on the system protection IED processor that enable the system protection IED to;

receive the plurality of time-synchronized measurements transmitted by each of the first and the second local protection IEDs;

analyze the plurality of time-synchronized measurements received from each of the first and the second local protection IEDs;

determine a system-level protection action based upon the analysis of the plurality of time-synchronized measurements by;

detecting a common-mode fault, where the common-mode fault is a fault on a generator;

determine operating conditions of the electric power delivery system based on the plurality of time-synchronized measurements; and

;

comparing the operating conditions with predetermined acceptable operating conditions of the electric power delivery system; and

,

performing the system-level protection action by disconnecting the generator with the fault.

2. The system of claim 1, wherein the system-level protection action comprises one of:

load-dependent start or stop, generator running order selection, load shedding, heavy-consumer start block, blackout start and recovery, generator control, and manual override.

3. The system of claim 1, wherein the local-level protection action comprises one of:

excess or reverse power protection, reactive power protection, differential power protection, loss of excitation protection, out of step protection, resistance temperature detector protection, trip-coil monitoring, current/voltage unbalance protection, phase reversal protection, negative sequence protection, under-voltage and over-voltage protection, under-frequency and over-frequency protection.

4. The system of claim 1, wherein the first local protection IED implements a low impedance protection scheme.

5. The system of claim 1, wherein the first local protection IED further comprises a time input configured to receive a time signal, and wherein the software instructions executable on the first local protection IED enable the first local protection IED to associate a plurality timestamps based on the received signal.

6. The system of claim 1, wherein the first local protection IED further comprises a sensor component, and wherein at least one of the plurality of measurements indicating electrical conditions associated with monitored equipment is measured using a sensor component.

7. The system of claim 1, wherein the system protection IED comprises:

an access controller; and

a vector processor;

wherein each of the access controller and vector processor are in communication with the data network.

19. The system of claim 1, wherein the system-level protection action comprises response to the common-mode fault.

20. The system of claim 1, wherein a configuration of the first local protection IED and the second local protection IED prevents the first local protection IED and the second local protection IED from detecting an external fault.

21. The system of claim 1, wherein the first local protection IED and the second local protection IED are configured to provide protection to a first piece of monitored equipment and a second piece of monitored equipment, respectively, following a loss of communication with the system protection IED.

22. The system of claim 1, wherein the electric power delivery system comprises a micro-grid.

23. The system of claim 1, wherein the first location protection IED and the second location protection IED operate in a redundant configuration.

24. The system of claim 1, wherein the operating conditions comprise frequency and percent of maximum load.

25. The system of claim 24, wherein the software instructions further enable the system protection IED to perform the system-level protection action when the operating conditions fall outside of the predetermined acceptable operating conditions of the electric power delivery system.

8. A method for managing an electric power transmission and distribution system, comprising:

providing a plurality of local protection blocks;

each of the local protection blocks recording a plurality of time-synchronized measurements indicating an electrical condition in each local protection block;

each of the local protection blocks analyzing the plurality of time-synchronized measurements;

each of the local protection blocks determining a local-level protection action based upon the analysis of the plurality of time-synchronized measurements;

providing a system protection block configured to operate at a supervisory level with respect to the plurality of local protection blocks;

the system protection block receiving the plurality of time-synchronized measurements from the plurality of local protection blocks;

the system protection block analyzing the plurality of time-synchronized measurements from the plurality of local protection blocks;

the system protection block detecting a common-mode fault based on the time-synchronized measurements from the plurality of local protection blocks;

the system protection block determining operating conditions of the electric power delivery system;

the system protection block comparing the operating conditions with predetermined acceptable operating conditions of the electric power delivery system; and

when the common-mode fault comprises a fault on a generator and when the operating conditions fall outside of the predetermined acceptable operating conditions, the system protection block performing a system-level protection action of disconnecting the generator with the fault.

9. The method of claim 8, wherein the plurality of time-synchronized measurements from at least one of the plurality of local protection block this indicates the status of an electrical generator.

10. The method of claim 8, wherein the system-level protection action further comprises one of:

load-dependent start or stop, generator running order selection, load shedding, heavy-consumer start block, blackout start and recovery, generator control, and manual override.

11. The method of claim 8, further comprising performing a local-level protection action.

12. The method of claim 11, wherein performing the local-level protection action occurs without user intervention.

13. The method of claim 11, wherein the local-level protection action comprises one of:

excess or reverse power protection, reactive power protection, differential power protection, loss of excitation protection, out of step protection, resistance temperature detector protection, trip-coil monitoring, current/voltage unbalance protection, phase reversal protection, negative sequence protection, under-voltage and over-voltage protection, under-frequency and over-frequency protection.

14. The method of claim 8, wherein the recording of the plurality of time-synchronized measurements is performed at a first sampling rate by at least one of the plurality of local protection blocks, and wherein the recording of the plurality of time-synchronized measurements is performed at a second sampling rate by at least one of the plurality of local protection blocks.

15. The method of claim 8, wherein analyzing the plurality of time-synchronized measurements from the plurality of local protection blocks comprises a modal analysis.

16. The method of claim 8, wherein the plurality of time-synchronized measurements from at least one local protection block comprises an indication of an arc-flash.

17. The method of claim 8, the plurality of time-synchronized measurements indicate the status of an electrical generator.

18. The method of claim 8, further comprising:

at least one of the plurality of local protection blocks receiving a time signal; and

wherein recording a plurality of time-synchronized measurements by the at least one of a local protection blocks comprises associating a plurality of time stamps based on the received time signal with a plurality of measurements indicating an electrical condition in at least one of the plurality of local protection blocks.