Location determination of power system disturbances based on frequency responses of the system

Abstract

A system for detecting and locating a disturbance event within a power grid includes a series of frequency disturbance recorders (FDRs) taking measurements in the power grid at dispersed points of the power grid, an information management system, configured to receive data from the series of FDRs and analyze the received data and a communications network interconnecting the series of FDRs and the information management system. The information management system is configured to examine orders and patterns of receipt of frequency changes at the FDRs in the data caused by the disturbance event and to triangulate a location of the disturbance event based on the orders and patterns of receipt of the frequency changes. Example methods of detection and location of disturbance events are also described.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aims, objectives, aspects, features and advantages of the invention will be better understood from a consideration of the following detailed description of the best mode contemplated for practicing the invention, taken with reference to certain preferred embodiments and methods, and the accompanying drawings in which:

FIG. 1 is a schematic illustrating components in a frequency monitoring network system architecture, according to one embodiment of the present application;

FIG. 2 illustrates a Frequency Disturbance Recorder (FDR), with FIG. 2(a) illustrating a schematic of the recorder and FIG. 2(b) illustrating a photo of an FDR, according to one embodiment of the present application;

FIG. 3 is a map illustrating current FDR locations in the United States, according to one embodiment of the present application;

FIG. 4 is a map illustrating generator trip locations used to study power grid, according to one embodiment of the present application;

FIG. 5 is a schematic illustrating a multi-tier information management system structure, according to at least one embodiment of the present application;

FIG. 6 is a map providing visualization of frequency dynamic data, according to embodiments of the present application;

FIG. 7 is a graph illustrating a typical frequency signature of a generator trip, according to one embodiment of the present application;

FIG. 8 is a map providing an LS event location estimate for one case, according to one embodiment of the present application;

FIG. 9 is a map providing an LS event location estimate for another case, according to one embodiment of the present application;

FIG. 10 is a map providing an LS event location estimate for another case, according to one embodiment of the present application;

FIG. 11 is a map providing a Newtonian event location estimate for one case, according to one embodiment of the present application;

FIG. 12 is a map providing a Newtonian event location estimate for another case, according to one embodiment of the present application;

FIG. 13 is a map providing a Newtonian event location estimate for another case, according to one embodiment of the present application;

FIG. 14 is a flowchart illustrating a method of gradient search event location, according to one embodiment of the present application;

FIG. 15 is a map providing a Newtonian event location estimate for another case, according to one embodiment of the present application;

FIG. 16 is a map providing a Newtonian event location estimate for another case, according to one embodiment of the present application;

FIG. 17 is a map providing a Newtonian event location estimate for another case, according to one embodiment of the present application;

FIG. 18 is a graph illustrating a response to a generation drop in a radial distribution network, according to one embodiment of the present application;

FIG. 19 is a graph illustrating a response to a generation drop in a mesh distribution network, according to one embodiment of the present application;

FIG. 20 is a more detailed view of a graph illustrating a response to a generation drop in a radial distribution network, according to one embodiment of the present application;

FIG. 21 is a more detailed view of a graph illustrating a response to a generation drop in a mesh distribution network, according to one embodiment of the present application;

FIG. 22 is a graph illustrating a response to a load rejection in a radial distribution network, according to one embodiment of the present application;

FIG. 23 is a graph illustrating a response to a load rejection in a mesh distribution network, according to one embodiment of the present application;

FIG. 24 is a graph illustrating an example of a standard generator trip frequency signature, according to one embodiment of the present application;

FIG. 25 is an illustration of how frequency perturbations might travel through a power grid, according to at least one embodiment of the present application;

FIG. 26 is an illustration of how frequency perturbations might travel throughout the power grid, according to one embodiment of the present application;

FIG. 27 is a figure of a plane containing two points, according to one embodiment of the present application;

FIG. 28 is a figure of a plane containing four points, according to one embodiment of the present application;

FIG. 29 is a figure of a plane containing four points, according to one embodiment of the present application;

FIG. 30 is map showing lines representing half-planes in the eastern United States, according to one embodiment of the present application;

FIG. 31 is a figure showing shaded regions of probability, according to one embodiment of the present application;

FIG. 32 is a figure showing vector relationships governing the half-plane method, according to one embodiment of the present application;

FIG. 33 is a set of graphs illustrating windowing functions for a Parzen window approach method, according to one embodiment of the present application;

FIG. 34 is drawing showing the probability density estimate for the Parzen window approach method, according to one embodiment of the present application;

FIG. 35 is a drawing showing a probability density estimate for a particular generator trip using a first windowing method, according to one embodiment of the present application;

FIG. 36 is a drawing showing a probability density estimate for a particular generator trip using a second windowing method, according to one embodiment of the present application;

FIG. 37 provides a comparison of windowing functions, with FIG. 37(a) illustrating a side view and FIG. 37(b) illustrating a top view, according to one embodiment of the present application;

FIG. 38 is a drawing showing a probability density estimate for a particular generator trip using a first windowing method, according to one embodiment of the present application; and

FIG. 39 is a drawing showing a probability density estimate for a particular generator trip using a second windowing method, according to one embodiment of the present application.

Claims

1. A system for detecting and locating a disturbance event within a power grid, said system comprising: a series of frequency disturbance recorders (FDRs) taking measurements in the power grid at dispersed points of the power grid;an information management system, configured to receive data from the series of FDRs and analyze the received data; anda communications network interconnecting the series of FDRs and the information management system;wherein information management system is configured to examine orders and patterns of receipt of frequency changes at the FDRs in the data caused by the disturbance event and to triangulate a location of the disturbance event based on the orders and patterns of receipt of the frequency changes.

2. The system of claim 1, wherein the information management system is configured to detect disturbance events comprising transmission line trips, generator trips and load rejections.

3. The system of claim 1, wherein the series of FDRs comprises at least three FDRs.

4. The system of claim 1, wherein the information management system is configured to apply a least squares analysis to the data of the orders and patterns of receipt of frequency changes at the FDRs to determine the location of the disturbance event.

5. The system of claim 1, wherein the information management system is configured to apply Newton's method for solving non-linear equations to the data of the orders and patterns of receipt of frequency changes at the FDRs to determine the location of the disturbance event.

6. The system of claim 1, wherein the information management system is configured to apply a gradient search to the data of the orders and patterns of receipt of frequency changes at the FDRs to minimize distances between a probable event location and the series of FDRs to determine the location of the disturbance event.

7. The system of claim 1, wherein the information management system is configured to compare the data of the orders and patterns of receipt of frequency changes at the FDRs with other data received from past events to determine the location of the disturbance event.

8. The system of claim 1, wherein the information management system is configured to compute propagation delays from a possible event to the series of FDRs and compare the data of the orders and patterns of receipt of frequency changes at the FDRs with the computed propagation delays to determine the location of the disturbance event.

9. The system of claim 1, wherein the information management system is configured to apply a Parzen window approach to the orders and patterns of receipt of frequency changes at the FDRs to determine the location of the disturbance event.

10. The system of claim 1, wherein each FDR of the series of FDRs is synched to remaining FDRs through communication with Global Positioning System satellites.

11. The system of claim 1, wherein each FDR of the series of FDRs is configured to send data packets to the information management system through the communications network which are network time-stamped.

12. A method for detecting and locating a disturbance event within a power grid, said method comprising the steps of: receiving frequency changes, caused by the disturbance event, at a series of frequency disturbance recorders (FDRs) taking measurements in the power grid at dispersed points of the power grid;transferring data based on the frequency changes to an information management system from the series of FDRs through a communications network interconnecting the series of FDRs and the information management system;analyzing the received data by the information management system by examining orders and patterns of receipt of the frequency changes at the FDRs; andtriangulating a location of the disturbance event based on the orders and patterns of receipt of the frequency changes.

13. The method of claim 12, wherein the step of triangulating the locations comprises triangulating locations of disturbance events comprising transmission line trips, generator trips and load rejections.

14. The method of claim 12, wherein the step of transferring data comprises transferring data from at least three FDRs.

15. The method of claim 12, wherein the analyzing step comprises applying a least squares analysis to the data of the orders and patterns of receipt of frequency changes at the FDRs to determine the location of the disturbance event.

16. The method of claim 12, wherein the analyzing step comprises applying Newton's method for solving non-linear equations to the data of the orders and patterns of receipt of frequency changes at the FDRs to determine the location of the disturbance event.

17. The method of claim 12, wherein the analyzing step comprises applying a gradient search to the data of the orders and patterns of receipt of frequency changes at the FDRs to minimize distances between a probable event location and the series of FDRs to determine the location of the disturbance event.

18. The method of claim 12, wherein the analyzing step comprises comparing the data of the orders and patterns of receipt of frequency changes at the FDRs with other data received from past events to determine the location of the disturbance event.

19. The method of claim 12, wherein the analyzing step comprises computing propagation delays from a possible event to the series of FDRs and comparing the data of the orders and patterns of receipt of frequency changes at the FDRs with the computed propagation delays to determine the location of the disturbance event.

20. The method of claim 12, wherein the analyzing step comprises applying a Parzen window approach to the orders and patterns of receipt of frequency changes at the FDRs to determine the location of the disturbance event.

21. The method of claim 12, further comprising synching each FDR of the series of FDRs to remaining FDRs through communication with Global Positioning System satellites.

22. The method of claim 12, wherein the step of transferring data comprises sending data packets to the information management system through the communications network which are network time-stamped.

23. A method of detecting and locating events in a collective, the method comprising the steps of: receiving changes, caused by the event, at a series of recorders taking measurements in the collective at dispersed points of the collective;transferring data based on the changes to an information management system from the series of recorders through a communications network interconnecting the series of recorders and the information management system;analyzing the received data by the information management system by examining orders and patterns of receipt of the changes at the recorders; andtriangulating a location of the event based on the orders and patterns of receipt of the changes by the recorders.

24. The method of claim 23, wherein the step of triangulating the locations comprises triangulating locations of disturbance events in a power grid comprising transmission line trips, generator trips and load rejections.

25. The method of claim 23, wherein the step of transferring data comprises transferring data from at least three recorders.

26. The method of claim 23, wherein the step of receiving changes comprises receiving changes in systems monitoring at least one of weather, lightening strikes, voting and traffic.

27. The method of claim 23, further comprising synching each recorder of the series of recorders to remaining recorders through communication with Global Positioning System satellites.

28. The method of claim 23, wherein the step of transferring data comprises sending data packets to the information management system through the communications network which are network time-stamped.