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

• US 9,898,062 B2
• Filed: 07/28/2014
• Issued: 02/20/2018
• 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): Pan, Yuhui R
• Application Number:
  US14/444,295
• Publication Number:
  US 20140359351A1
• Time in Patent Office: 1,303 Days
• Field of Search: 714 14
• 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 electric power generators in an electric power delivery system, the system comprising:

a system protection Intelligent Electronic Device (“

IED”

) processor;

a system protection IED computer-readable storage medium, comprising instructions executable on the system protection IED processor that enable the system protection IED to;

analyze a plurality of time-synchronized measurements indicating conditions associated with the plurality of generators, wherein the plurality of time-synchronized measurements are generated based on a common time reference;

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

detecting a common-mode fault condition as a condition of one generator of the plurality of generators that affects operating conditions of another generator of the plurality of generators;

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

detecting the generator associated with the detected common-mode fault condition;

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

when a common-mode fault is detected and when the operating conditions are outside of the predetermined acceptable operating conditions, determining the system-level protection action to be disconnection of the generator associated with the detected common-mode fault; and

,

when a common-mode fault is detected and when the operating conditions are within the predetermined acceptable operating conditions, determining that the system-level protection action on the generator associated with the detected common-mode fault is not required;

based on the comparison of the operating conditions with the predetermined acceptable operating conditions, perform the system-level protection action by disconnecting the electrical generator associated with the common-mode fault; and

evaluate response time of controls of the generator associated with the detected common-mode fault before disconnecting the generator associated with the detected common-mode fault.

2. The system of claim 1, wherein the plurality of time-synchronized measurements indicate status of the electrical generator.

3. The system of claim 1, wherein the conditions comprise deviation from a droop curve.

4. The system of claim 1, further comprising a plurality of local protection IEDs in communication with the system protection IED, and each including:

a local protection IED processor;

a local protection IED computer-readable storage medium, comprising instructions executable on the local protection IED processor that enable the local protection IED to;

record a plurality of measurements indicating conditions associated with the plurality of generators;

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

analyze the plurality of time-synchronized measurements;

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

transmit the plurality of time-synchronized measurements to the system protection IED.

5. The system of claim 4 wherein the local-level protection action comprises one of:

excess power protection;

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 protection;

over-voltage protection;

under-frequency protection; and

, over-frequency protection.

6. A method for managing a plurality of electric power generators in an electric power delivery system, comprising:

operating a system protection block at a supervisory level, the system protection block configured to manage the plurality of electric power generators;

the system protection block receiving a plurality of time-synchronized measurements associated with the plurality of electric power generators, wherein the plurality of time-synchronized measurements are generated based on a common time reference;

the system protection block analyzing the plurality of time-synchronized measurements indicating conditions associated with the plurality of electric power generators;

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

detecting a common-mode fault condition as a condition of one generator of the plurality of generators that affects operating conditions of another generator of the plurality of generators;

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

detecting the generator associated with the common-mode fault condition;

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

when a common-mode fault is detected and when the operating conditions are outside of the predetermined acceptable operating conditions, determining the system-level protection action to be disconnection of the generator associated with the detected common-mode fault; and

,

when a common-mode fault is detected and when the operating conditions are within the predetermined acceptable operating conditions, determining that the system-level protection action on the generator associated with the detected common-mode fault is not required;

based on the comparison of the operating conditions with the predetermined acceptable operating conditions, the system protection block performing the system level protection action by disconnecting the electrical generator associated with the common-mode fault, and

the system protection block evaluating response time of controls of the generator associated with the detected common-mode fault before disconnecting the generator associated with the detected common-mode fault.

7. The method of claim 6, wherein the plurality of time-synchronized measurements indicate status of the electrical generator.

8. The method of claim 6, wherein the conditions comprise deviation from a droop curve.

9. The method of claim 6, further comprising:

recording the plurality of time-synchronized measurements by a plurality of local protection blocks associated with the plurality of electrical power generators;

the local protection blocks associating the plurality of measurements with time stamps indicating the times at which each of the measurements is made to generate the plurality of time-synchronized measurements;

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

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

the local protection blocks transmitting the plurality of time-synchronized measurements to the system protection block.

10. The method of claim 9, wherein the local-level protection action comprises one of:

excess power protection;

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 protection;

over-voltage protection;

under-frequency protection; and

, over-frequency protection.

11. An intelligent electronic device (IED) for monitoring and control of a plurality of electric power generators in an electric power delivery system, the IED comprising:

a system protection IED processor;

a system protection IED computer-readable storage medium, comprising instructions executable on the system protection IED processor that enable the system protection IED to;

analyze a plurality of time-synchronized measurements indicating conditions associated with the plurality of generators, wherein the plurality of time-synchronized measurements are generated based on a common time reference;

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

detecting a common-mode fault condition as a condition of one generator of the plurality of generators that affects operation conditions of another generator of the plurality of generators;

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

detecting the generator associated with the detected common-mode fault condition;

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

when a common-mode fault is detected and when the operating conditions are outside of the predetermined acceptable operating conditions, determining the system-level protection action to be disconnection of the generator associated with the detected common-mode fault; and

,

when a common-mode fault is detected and when the operating conditions are within the predetermined acceptable operating conditions, determining that the system-level protection action on the generator associated with the detected common-mode fault is not required;

based on the comparison of the operating conditions with the predetermined acceptable operating conditions, perform the system-level protection action by disconnecting the electrical generator associated with the common-mode fault; and

evaluate response time of controls of the generator associated with the detected common-mode fault before disconnecting the generator associated with the detected common-mode fault.

12. The IED of claim 11, wherein the plurality of time-synchronized measurements indicate status of the electrical generator.

13. The IED of claim 11, wherein the IED comprises:

an access controller; and

a vector processor.