Performance analysis of power grid monitors

Patent metadata

Field	Value
Publication number	US-2016252562-A1
Application number	US-201415030573-A
Country	US
Kind code	A1
Filing date	Oct 20, 2014
Priority date	Oct 21, 2013
Publication date	Sep 1, 2016
Grant date	—

Abstract

Systems and methods for analyzing performance of a power grid monitor are disclosed herein. In one embodiment, a method includes receiving test data from a test power grid monitor coupled to a power grid signal source and receiving reference data from a reference power grid monitor coupled to the same power grid signal source. The method also includes identifying a power grid condition based on the received test data and/or reference data, extracting a subset of the test data and a subset of the reference data corresponding to the identified power grid condition, and comparing the subset of the test data to the subset of the reference data to determine a measurement accuracy of the test power grid monitor.

First claim

I/We claim:

1 . A method performed by a computing system having a processor, the method comprising:
with the processor,
receiving test data from a test power grid monitor coupled to a power grid signal source;
receiving reference data from a reference power grid monitor coupled to the same power grid signal source;
identifying a power grid condition based on the received test data and/or reference data;
extracting a subset of the test data and a subset of the reference data corresponding to the identified power grid condition; and
comparing the subset of the test data to the subset of the reference data to determine a measurement accuracy of the test power grid monitor.

2 . The method of claim 1 wherein the test data or the reference data includes one or more of a time stamp, a voltage magnitude, a voltage angle, a current magnitude, a current angle, a frequency, or a rate of change of frequency.

3 . The method of claim 1 wherein:
the test data and the reference data individually include a plurality of data points with an associated time stamp; and
the method further includes aligning the data points of the test data and the reference data based on the associated time stamps.

4 . The method of claim 1 wherein identifying the power grid condition includes identifying a steady state condition or a dynamic condition.

5 . The method of claim 1 wherein identifying the power grid condition includes identifying one of (1) a power system is balanced, (2) the power system is at off-nominal frequency, (3) the power system has harmonics, or (4) the power system is at off-nominal frequency and has harmonics.

6 . The method of claim 1 wherein:
identifying the power grid condition includes identifying one of (1) a power system is balanced, (2) the power system is at off-nominal frequency, (3) the power system has harmonics, or (4) the power system is at off-nominal frequency and has harmonics; and
comparing the subset of the test data to the subset of the reference data includes calculating at least one of a total vector error, a frequency error, or a change error based on the subset of test data and the subset of reference data.

7 . The method of claim 1 wherein:
identifying the power grid condition includes identifying a steady state condition having (1) a voltage or current magnitude change, (2) a voltage or current angle change, or (3) a frequency change; and
comparing the subset of the test data to the subset of the reference data includes calculating at least one of a total vector error, a frequency error, or a change error based on the subset of test data and the subset of reference data.

8 . The method of claim 1 wherein:
identifying the power grid condition includes identifying a dynamic condition having (1) a voltage or current magnitude step change, (2) a voltage or current angle step change, (3) a frequency step change, (4) a frequency ramp, or (5) an amplitude, phase or frequency modulation; and
comparing the subset of the test data to the subset of the reference data includes calculating at least one of a total vector error, a frequency error, a change error, a response time, a delay time, a percent peak overshoot, or a rate of change of frequency based on the subset of test data and the subset of reference data.

9 . The method of claim 1 , further comprising generating the power grid signal via at least one of measuring current power grid parameters with the test power grid monitor and the reference power grid monitor, simulating a power grid using a power grid simulator, or retrieving historical power grid parameters.

10 . A computing system, comprising:
a processor and a memory operative coupled to the processor, the memory containing instructions that when executed by the processor, cause the processor to perform a process include:
receiving test data from a test power grid monitor and reference data from a reference power grid monitor both coupled to a power grid signal source, the test data and the reference data individually including a plurality of data points with associated time stamps;
aligning the test data with the reference data based on the time stamps;
extracting a subset of the test data and a subset of the reference data corresponding to a power grid condition; and
determining an error of the subset of the test data in comparison to the subset of the reference data.

11 . The computing system of claim 10 wherein determining the error includes determining a total vector error, a frequency error, or a change error based on the subset of test data and the subset of reference data.

12 . The computing system of claim 10 wherein the power grid condition includes a steady state condition having (1) a voltage or current magnitude change, (2) a voltage or current angle change, or (3) a frequency change.

13 . The computing system of claim 10 wherein the power grid condition includes a steady state condition having (1) a voltage or current magnitude change, (2) a voltage or current angle change, or (3) a frequency change, and wherein determining the error includes determining a total vector error, a frequency error, or a change error based on the subset of test data and the subset of reference data.

14 . The computing system of claim 10 wherein the power grid condition includes a dynamic condition having (1) a voltage or current magnitude step change, (2) a voltage or current angle step change, (3) a frequency step change, (4) a frequency ramp, or (5) an amplitude, phase or frequency modulation.

15 . The computing system of claim 10 wherein the power grid condition includes a dynamic condition having (1) a voltage or current magnitude step change, (2) a voltage or current angle step change, (3) a frequency step change, (4) a frequency ramp, or (5) an amplitude, phase or frequency modulation, and wherein determining the error includes calculating at least one of a total vector error, a frequency error, a change error, a response time, a delay time, a percent peak overshoot, or a rate of change of frequency based on the subset of test data and the subset of reference data.

16 . The computing system of claim 10 wherein the process performed by the processor further includes determining a measurement accuracy of the test power grid monitor based on the determined error of the subset of the test data in comparison to the subset of the reference data.

17 . A method performed by a computing system having a processor, the method comprising:
with the processor,
receiving test data from a test phasor measurement unit receiving input from a power grid signal source and reference data from a reference phasor measurement unit receiving input from the same power grid signal source;
monitoring a power grid condition based on the received test data and/or reference data, the power grid condition including at least one of a steady state condition or a dynamic condition and corresponding to a subset of the test data and the reference data;
determining a deviation between the subset of test data and reference data;
comparing the determined deviation to a threshold; and
in response to the determined deviation being less than the threshold, indicating the test phasor measurement unit as accurate.

18 . The method of claim 17 wherein determining the deviation includes determining a total vector error, a frequency error, or a change error based on the subset of test data and the subset of reference data.

19 . The method of claim 17 wherein the power grid condition includes

Assignees

• Univ Washington State

Inventors

• Biswas Saugata Swapan
• Srivastava Anurag

Classifications

• G01R31/088 Primary

  Aspects of digital computing · CPC title

• G01R19/2513 Primary

  Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging · CPC title

• Y02E40/70

  Smart grids as climate change mitigation technology in the energy generation sector · CPC title

• Y04S10/22

  Flexible AC transmission systems [FACTS] or power factor or reactive power compensating or correcting units · CPC title

• G01R31/086

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