Compendium ofTexas Synchrophasor Network Reports
for2011 and 2012
Prof. Mack Grady Department of Electrical & Computer Engineering
Baylor UniversityWaco, Texas
September 20, 2013
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Texas Synchrophasor Network, WECC Event, Jan. 19, 2011
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Texas Synchrophasor Network, WECC Event, Jan. 19, 2011
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Texas Synchrophasor Network, WECC Event, Jan. 19, 2011
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Texas Synchrophasor Network, WECC Event, Jan. 19, 2011
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Texas Synchrophasor Network, WECC Event, Jan. 19, 2011
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Texas Synchrophasor Network, WECC Event, Jan. 19, 2011
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Texas Synchrophasor Network, WECC Event, Jan. 19, 2011
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Texas Synchrophasor Network, WECC Event, Jan. 19, 2011
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Texas Synchrophasor Network, WECC Event, Jan. 19, 2011
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Texas Synchrophasor Network Special Report, Prof. Mack Grady, U.T. Austin, Feb. 9, 2011 Page 1 of 9
The ERCOT Rolling Blackout
Wednesday, Feb. 2, 2011
• This new winter peak of 53334 MW was only 500 MW greater than the 2010 winter peak
• BUT, 5000 MW of generation was out of service due to the effect of extreme cold
Page 11 of 38
Texas Synchrophasor Network Special Report, Prof. Mack Grady, U.T. Austin, Feb. 9, 2011 Page 2 of 9
`` ERCOT Min and Max Frequency for Each Minute, Feb. 2, 2011
59.5
59.6
59.7
59.8
59.9
60.0
60.1
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17Hour of Feb. 2, 2011
Freq Max
Min
West Texas Voltage Phase Angle wrt Central ERCOT for Each Minute, Feb. 2, 2011
-15
-10
-5
0
5
10
15
20
25
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17Hour of Feb. 2, 2011
Volta
ge A
ngle
Wind generation increasing
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Texas Synchrophasor Network Special Report, Prof. Mack Grady, U.T. Austin, Feb. 9, 2011 Page 3 of 9
ERCOT Min and Max Frequency for Each Minute, Feb. 2, 2011
59.5
59.6
59.7
59.8
59.9
60.0
60.1
4 5 6 7 8 9Hour of Feb. 2, 2011
Freq Max
Min
West Texas Voltage Phase Angle wrt Central ERCOT for Each Minute, Feb. 2, 2011
-15
-10
-5
0
5
10
15
20
25
4 5 6 7 8 9Hour of Feb. 2, 2011
Volta
ge A
ngle
Wind MW generation is not presently available on ERCOT’s public web site. However, by observing the voltage phase angle of West Texas with respect to U.T. Austin (i.e., central ERCOT), we believe that wind MW generation was low but on the rise at 5am when grid problems began, and that wind MW generation rose to moderate levels (approx. 10% of total generation) through the troubled 5am – 10am generation shortage period.
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Texas Synchrophasor Network Special Report, Prof. Mack Grady, U.T. Austin, Feb. 9, 2011 Page 4 of 9
2-minute wide frequency window at the lowest point
Corresponding West Texas phase angle with respect to central ERCOT
West Texas Phase Angle Increases with Wind Generation to Help Arrest the Freq Drop
Page 14 of 38
Texas Synchrophasor Network Special Report, Prof. Mack Grady, U.T. Austin, Feb. 9, 2011 Page 5 of 9
Frequency (Hz) of Main Oscillation Mode
0.70
0.75
0.80
0.85
3.5 4.5 5.5 6.5 7.5 8.5 9.5
One Hour Window Average, Centered on the Half-Hour
McDPanAm
Normalized Damping Ratio of Main Oscillation Mode
0.00
0.05
0.10
0.15
0.20
0.25
0.30
3.5 4.5 5.5 6.5 7.5 8.5 9.5
One Hour Window Average, Centered on the Half-Hour
McDPanAm
Magnitude (Degrees) of Main Oscillation Mode (Top 1/4 Points Are Above This Value)
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
3.5 4.5 5.5 6.5 7.5 8.5 9.5
One Hour Window Average, Centered on the Half-Hour
McDPanAm
Decreasing Inertia
Increasing Inertia
More Damping
Less Damping
More Damping
Stronger Oscillation
Unusually low damping in Rio Grande Valley
Page 15 of 38
Texas Synchrophasor Network Special Report, Prof. Mack Grady, U.T. Austin, Feb. 9, 2011 Page 6 of 9
5:14 am
5:39 am
5:46 am
5:50 am
5:56 am
6:04 am
5:14 am
5:39 am
5:46 am
5:50 am
5:56 am
6:04 am
Progression of Ringdowns, 5 am to 6 amWest Texas Voltage Phase Angle with respect to Central Texas
Page 16 of 38
Texas Synchrophasor Network Special Report, Prof. Mack Grady, U.T. Austin, Feb. 9, 2011 Page 7 of 9
Average Hourly Price for Generation in ERCOT, $ / MWh, Feb. 1, 2, 3, 2011
0
200
400
600
800
1000
1200
Feb. 1 Feb. 2 (Rolling Blackout) Feb. 3
Dr. Mack Grady, U.T. Austin
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Texas Synchrophasor Network Special Report, Prof. Mack Grady, U.T. Austin, Feb. 9, 2011 Page 8 of 9
Average Hourly Load in ERCOT, GW, Feb. 1, 2, 3, 2011
0
10
20
30
40
50
60
70
80
Feb. 1 Feb. 2 (Rolling Blackout) Feb. 3
Dr. Mack Grady, U.T. Austin
Page 18 of 38
Texas Synchrophasor Network Special Report, Prof. Mack Grady, U.T. Austin, Feb. 9, 2011 Page 9 of 9
Hourly Price Multiplied by Load, $Millions / Day, Feb. 1, 2, 3, 2011(Is this what we were expecting from the Texas Nodal Market during an emergency?)
0
100
200
300
400
500
600
700
800
Feb. 1 Feb. 2 (Rolling Blackout) Feb. 3
Dr. Mack Grady, U.T. Austin
Page 19 of 38
Voltage Phase Angles Relative to Central ERCOT, 1-Minute Averages
-10
0
10
20
30
Five Hours Beginning 00:00 CDT, Sunday, April 17, 2011
McDUTPA
One Example, Sunday Morning, April 17, 2011
Texas Nodal Market Creates a New West Texas Oscillation Mode with Time Period ≈ 30 minutes
Prof. Mack Grady, U.T. Austin
Page 20 of 38
Voltage Phase Angles Relative to U.T. Austin (One-Minute Averages, 1800 Readings in Each Minute)
-60
-40
-20
0
20
40
60
0 24 48 72 96 120 144 168 192 216 240 264 288 312 336 360 384 408
Hour Beginning 00:00 CST, Sunday, March 27, 2011
McDUTPA
Voltage Phase Angles, 1-Minute Averages
-20
-10
0
10
20
30
40
50
24 Hours Beginning 18:00 CST, Saturday, April 2, 2011
McDUTPA
Zoom-In, 24 hours wide
1
1 1
1. Unusual large, slow angle rings I had not noticed before. Period ≈ 30 mins, 10º to 15º peak-to-peak.
Texas Synchrophasor Network News, April 18, 2011. Page 1 of 5.
Texas Nodal Market Has Created a New West Texas Oscillation Mode with Time Period ≈ 30 minutes
Prof. Mack Grady, U.T. Austin
Page 21 of 38
Voltage Phase Angles, 1-Minute Averages
-20
-10
0
10
20
30
40
50
24 Hours Beginning 18:00 CST, Saturday, April 2, 2011
McDUTPA
1
1 1
Voltage Phase Angles, 1-Minute Averages
-20
-10
0
10
20
30
40
50
8 Hours Beginning 10:00 CST, Sunday, April 3, 2011
McDUTPA
Zoom-In, 8 Hours Wide
Texas Synchrophasor Network News, April 18, 2011. Page 2 of 5.
Texas Nodal Market Has Created a New West Texas OscillationMode with Time Period ≈ 30 minutes
Prof. Mack Grady, U.T. Austin
Page 22 of 38
Voltage Phase Angles Relative to Central ERCOT, 1-Minute Averages
-10
0
10
20
30
Five Hours Beginning 00:00 CDT, Sunday, April 17, 2011
McDUTPA
Sunday Morning, April 17, 2011
Texas Synchrophasor Network News, April 18, 2011. Page 3 of 5.
Texas Nodal Market Has Created a New West Texas Oscillation Mode with Time Period ≈ 30 minutes
Prof. Mack Grady, U.T. Austin
Page 23 of 38
McDonald Observatory Voltage Phase Angle Relative to Central ERCOT
-20
-10
0
10
20
30
40
0 1 2 3 4 5 6 7 8 9 10 11 12
Hour of March 11, 2011
Deg
rees
ERCOT’s graph of West-to-North P flow
Texas SynchrophasorNetwork’s graph of West-to-Central ERCOT Voltage Angle
Page 4 of 5
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UT Pan Am Voltage Phase Angle Relative to Central ERCOT
-20
-10
0
10
20
30
40
0 1 2 3 4 5 6 7 8 9 10 11 12
Hour of March 11, 2011
Deg
rees
McDonald Observatory Voltage Phase Angle Relative to Central ERCOT
-20
-10
0
10
20
30
40
0 1 2 3 4 5 6 7 8 9 10 11 12
Hour of March 11, 2011
Deg
rees
Page 5 of 5
Texas SynchrophasorNetwork’s graph of West-to-Central ERCOT Voltage Angle
Texas SynchrophasorNetwork’s graph of South-to-Central ERCOT Voltage Angle
Page 25 of 38
West Texas Voltage Phase Angle Advances 80+ Degrees in 6 Hours
Voltage Phase Angle Relative to UT Austin1-Minute Averages, Tuesday, April 26, 2011, Beginning 09:00 CDT
-50-40-30-20-10
01020304050
57 58 59 60 61 62 63 64 65 66 67
Hour of the Week, CDT
Deg
rees McD
PanAm
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Texas_Synchrophasor_Network_Observations_110505.doc
Page 1 of 1
Strong 30-Minute Oscillations Caused by Texas Nodal Market Price Fluctuations Continue to Break Out in West Texas Phase Angle
http://users.ece.utexas.edu/~grady/Texas_Synchrophasor_Network.html Texas Synchrophasor Network. Funding provided by EPRI, equipment provided by Schweitzer Engineering Labs, Utility members are Austin Energy and (new) Brazos Electric Cooperative, Waco.
Voltage Phase Angle Relative to UT Austin1-Minute Averages, Wednesday, May 4, 2011, Beginning 00:00 CDT
-20
-10
0
10
20
30
40
50
72 73 74 75 76 77 78 79 80 81 82 83 84
Hour of the Week, CDT
Deg
rees McD
PanAm
Voltage Phase Angle Relative to UT Austin1-Minute Averages, Sunday, May 1, 2011, Beginning 00:00 CDT
-20
-10
0
10
20
30
40
50
0 1 2 3 4 5 6 7 8 9 10 11 12
Hour of the Week, CDT
Deg
rees McD
PanAm
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Texas_Synchrophasor_Network_Observations_110510.doc
Page 1 of 1
Strong 30-Minute Oscillations Due to Texas Nodal Market Price Fluctuations Are Now Observed in South Texas Voltage Phase Angle
http://users.ece.utexas.edu/~grady/Texas_Synchrophasor_Network.html Texas Synchrophasor Network. Funding provided by EPRI, equipment provided by Schweitzer Engineering Labs, Utility members are Austin Energy and (new) Brazos Electric Cooperative, Waco.
Voltage Phase Angle Relative to UT Austin1-Minute Averages, Sunday, May 8, 2011, Beginning 00:00 CDT
-20
-10
0
10
20
30
40
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Hour of the Week, CDT
Deg
rees McD
PanAm
West Texas
South Texas
Page 28 of 38
Texas_Synchrophasor_Averages_Week_of_Jan_01_2012.doc users.ece.utexas.edu/~grady/Texas_Synchrophasor_Network.html
Page 1 of 2
McDonald Observatory Average Voltage Phase Angle1-Minute Intervals, Beginning Sunday, January 1, 2012
-60-50-40-30-20-1000102030405060
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Deg
rees
wrt
UT
Aus
tin
Waco Average Voltage Phase Angle1-Minute Intervals, Beginning Sunday, January 1, 2012
-20
-10
00
10
20
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Deg
rees
wrt
UT
Aus
tin
UT Pan Am Average Voltage Phase Angle1-Minute Intervals, Beginning Sunday, January 1, 2012
-20
-10
00
10
20
30
40
50
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Deg
rees
wrt
UT
Aus
tin
ERCOT Power Flow North to South
ERCOT Power Flow South to North
South Texas Exports
South Texas Imports
West Texas Exports
West Texas Imports
370 miles
280 miles
100 miles
Straight-Line Miles
Page 29 of 38
Texas_Synchrophasor_Averages_Week_of_Jan_01_2012.doc users.ece.utexas.edu/~grady/Texas_Synchrophasor_Network.html
Page 2 of 2
Harris 69kV Substation Minimum Frequency
1-Minute Intervals, Beginning Sunday, January 1, 2012
59.7
59.8
59.9
60.0
60.1
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Hz
Harris 69kV Substation Maximum Frequency1-Minute Intervals, Beginning Sunday, January 1, 2012
59.9
60.0
60.1
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Hz
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Texas_Synchrophasor_Averages_Week_of_Jan_08_2012.doc users.ece.utexas.edu/~grady/Texas_Synchrophasor_Network.html
Page 1 of 2
McDonald Observatory Average Voltage Phase Angle1-Minute Intervals, Beginning Sunday, January 8, 2012
-50-40-30-20-10001020304050
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Deg
rees
wrt
UT
Aus
tin
Waco Average Voltage Phase Angle1-Minute Intervals, Beginning Sunday, January 8, 2012
-20
-10
00
10
20
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Deg
rees
wrt
UT
Aus
tin
UT Pan Am Average Voltage Phase Angle1-Minute Intervals, Beginning Sunday, January 8, 2012
-10
00
10
20
30
40
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Deg
rees
wrt
UT
Aus
tin
ERCOT Power Flow North to South
ERCOT Power Flow South to North
South Texas Exports
South Texas Imports
West Texas Exports
West Texas Imports
370 miles
280 miles
100 miles
Straight-Line Miles
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Texas_Synchrophasor_Averages_Week_of_Jan_08_2012.doc users.ece.utexas.edu/~grady/Texas_Synchrophasor_Network.html
Page 2 of 2
Harris Minimum Frequency1-Minute Intervals, Beginning Sunday, January 8, 2012
59.7
59.8
59.9
60.0
60.1
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Hz
Harris Maximum Frequency1-Minute Intervals, Beginning Sunday, January 8, 2012
59.9
60.0
60.1
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Hz
Page 32 of 38
Texas_Synchrophasor_Averages_Week_of_Jan_15_2012.doc users.ece.utexas.edu/~grady/Texas_Synchrophasor_Network.html
Page 1 of 2
McDonald Observatory Average Voltage Phase Angle1-Minute Intervals, Beginning Sunday, January 15, 2012
-40-30-20-100010203040506070
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Deg
rees
wrt
UT
Aus
tin
Waco Average Voltage Phase Angle1-Minute Intervals, Beginning Sunday, January 15, 2012
-20
-10
00
10
20
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Deg
rees
wrt
UT
Aus
tin
UT Pan Am Average Voltage Phase Angle1-Minute Intervals, Beginning Sunday, January 15, 2012
-20
-10
00
10
20
30
40
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Deg
rees
wrt
UT
Aus
tin
ERCOT Power Flow North to South
ERCOT Power Flow South to North
South Texas Exports
South Texas Imports
West Texas Exports
West Texas Imports
370 miles
280 miles
100 miles
Straight-Line Miles
Page 33 of 38
Texas_Synchrophasor_Averages_Week_of_Jan_15_2012.doc users.ece.utexas.edu/~grady/Texas_Synchrophasor_Network.html
Page 2 of 2
Harris Minimum Frequency1-Minute Intervals, Beginning Sunday, January 15, 2012
59.7
59.8
59.9
60.0
60.1
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Hz
Harris Maximum Frequency1-Minute Intervals, Beginning Sunday, January 15, 2012
59.9
60.0
60.1
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Hz
Page 34 of 38
Texas_Synchrophasor_Averages_Week_of_Jan_22_2012.doc users.ece.utexas.edu/~grady/Texas_Synchrophasor_Network.html
Page 1 of 2
McDonald Observatory Average Voltage Phase Angle1-Minute Intervals, Beginning Sunday, January 22, 2012
-60-50-40-30-20-1000102030405060
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Deg
rees
wrt
UT
Aus
tin
Waco Average Voltage Phase Angle1-Minute Intervals, Beginning Sunday, January 22, 2012
-20
-10
00
10
20
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Deg
rees
wrt
UT
Aus
tin
UT Pan Am Average Voltage Phase Angle1-Minute Intervals, Beginning Sunday, January 22, 2012
-20
-10
00
10
20
30
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Deg
rees
wrt
UT
Aus
tin
ERCOT Power Flow North to South
ERCOT Power Flow South to North
South Texas Exports
South Texas Imports
West Texas Exports
West Texas Imports
370 miles
280 miles
100 miles
Straight-Line Miles
Profs: Mack Grady and Surya Santoso at U.T. Austin, Jaime Ramos at U.T. Pan American
Equipment and Engineering Support: Donated by Schweitzer Engineering Labs.
Utility Partners: Austin Energy, Brazos Electric Power Coop Friends: Thanks to Schweitzer, we are rich in equipment. However, to be honest, we are out of cash. There is no better way to support a future power engineer than through this project. You can do that by sending a check to any one of us, made out to our respective university. Make sure the phrase “to support Prof XXX’s synchrophasor research” is somewhere on the check. Thank you.
Page 35 of 38
Texas_Synchrophasor_Averages_Week_of_Jan_22_2012.doc users.ece.utexas.edu/~grady/Texas_Synchrophasor_Network.html
Page 2 of 2
Harris Minimum Frequency1-Minute Intervals, Beginning Sunday, January 22, 2012
59.7
59.8
59.9
60.0
60.1
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Hz
Harris Maximum Frequency1-Minute Intervals, Beginning Sunday, January 22, 2012
59.9
60.0
60.1
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Hz
Page 36 of 38
Texas_Synchrophasor_Network_Jan_29_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer.
Page 1 of 1
Comments – Synchronized rms voltage measurements are also useful. The top graph shows consecutive deep rms voltage sags at UT Pan Am (red). The lower graph shows a zoom-in of the Harris 69 substation (adjacent to UT Austin campus), and Waco. We used the Harris substation voltage instead of UT Austin because it was less choppy. McDonald voltage showed no response. Point spacing is 30 points per second. Though low in magnitude, the voltage sags are clearly visible at Austin and Waco. Synchronization confirms the timing of the sag points.
Voltage Sag, 1/29/2012, 19:43:00 GMT
0.75
0.80
0.85
0.90
0.95
1.00
1.05
2.5 3.0 3.5 4.0 4.5
Seconds
Vrm
s, p
er u
nit
Harris 69
UT Pan Am
Waco
Zoom-In of Voltage Sag, 1/29/2012, 19:43:00 GMT
0.997
0.998
0.999
1.000
1.001
2.5 3.0 3.5 4.0 4.5
Seconds
Vrm
s, p
er u
nit
Harris 69
Waco
370 miles
280 miles
100 miles
Straight-Line Miles
Page 37 of 38
Texas Synchrophasor Network, Sunday, Feb. 19, 2012, 03:17 GMT740 MW Trip Causes ERCOT Frequency to Drop to 59.73 Hz
ERCOT Load = 33301 MW
Two minute window
Page 38 of 38