loss of 1,365 mw followed by 59.7 hz load...
TRANSCRIPT
Loss of 1,365 MW Followed by 59.7 Hz Load Shedding
On 11/29/11, a sudden loss of generation occurred at 03:29 totaling 1,365 MW. Frequency declined to 59.694 HZ, ERCOT load was 30,071 MW.
59.6
59.7
59.8
59.9
60.0
60.1
1 2 3 4 5 6 7 8 9 10
Minutes
On 11/29/11, a sudden loss of generation occurred at 03:29 totaling 1,365 MW. Frequency declined to 59.694 HZ, ERCOT load was 30,071 MW.
59.6
59.7
59.8
59.9
60.0
60.1
2 2.1 2.2 2.3
Minutes
Zoom
Texas_Synchrophasor_Network_Events_Jan_1_thru_15_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 1 of 11
West Texas Voltage Phase Angle wrt UT Austin
-36
-35
-34
0 10 20 30 40 50 60
South Texas Voltage Phase Angle wrt UT Austin
20
21
22
0 10 20 30 40 50 60
Waco Voltage Phase Angle wrt UT Austin
01
02
03
0 10 20 30 40 50 60
West Texas, South Texas, Waco Frequency
59.90
59.95
60.00
0 10 20 30 40 50 60
Seconds
Event 1. Jan. 03, 2012. 01:44 GMT
370 miles
280 miles
100 miles
Straight-Line Miles
No unit tripped.
Steady-state angle rises.
No wind generation. West Texas is importing power.
Conclusion – line trip or opening of series caps to South Texas. Easily visible throughout ERCOT.
Texas_Synchrophasor_Network_Events_Jan_1_thru_15_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 2 of 11
West Texas Voltage Phase Angle wrt UT Austin
28
29
30
31
32
0 10 20 30 40 50 60
South Texas Voltage Phase Angle wrt UT Austin
17
18
19
20
21
0 10 20 30 40 50 60
Waco Voltage Phase Angle wrt UT Austin
06
07
08
09
10
0 10 20 30 40 50 60
West Texas, South Texas, Waco Frequency
59.95
60.00
60.05
0 10 20 30 40 50 60
Seconds
Event 2. Jan. 03, 2012. 13:14 GMT
No unit tripped.
Good wind.
Strong ringdown, but steady-state angle does not change.
Conclusion – South Texas event, cause unknown.
Texas_Synchrophasor_Network_Events_Jan_1_thru_15_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 3 of 11
West Texas Voltage Phase Angle wrt UT Austin
20.5
21.5
22.5
23.5
24.5
0 10 20 30 40 50 60
South Texas Voltage Phase Angle wrt UT Austin
23
24
25
26
27
0 10 20 30 40 50 60
Waco Voltage Phase Angle wrt UT Austin
08
09
10
11
12
0 10 20 30 40 50 60
West Texas, South Texas, Waco Frequency
60.00
60.05
60.10
0 10 20 30 40 50 60
Seconds
Event 3. Jan. 03, 2012. 18:06 GMT
Moderate wind. Steady-state angle rises.
Frequency a bit high, but no unit trip.
Small drop in steady-state angle. Less power flowing from south to central.
Small steady-state angle rise in the short distance between Waco and Austin. More power flowing from north to central.
Conclusion – possible line trip to West Texas.
Texas_Synchrophasor_Network_Events_Jan_1_thru_15_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 4 of 11
West Texas Voltage Phase Angle wrt UT Austin
27
28
29
30
31
0 10 20 30 40 50 60
South Texas Voltage Phase Angle wrt UT Austin
-01
00
01
02
03
0 10 20 30 40 50 60
Waco Voltage Phase Angle wrt UT Austin
06
07
08
09
10
0 10 20 30 40 50 60
West Texas, South Texas, Waco Frequency
59.90
59.95
60.00
60.05
0 10 20 30 40 50 60
Seconds
Event 4. Jan. 07, 2012. 08:55 GMT
Unit trip. Poor frequency recovery.
Conclusion – unit trip in West Texas.
Good wind. Sudden drop in steady-state angle.
Texas_Synchrophasor_Network_Events_Jan_1_thru_15_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 5 of 11
West Texas Voltage Phase Angle wrt UT Austin
34
35
36
37
38
0 10 20 30 40 50 60
South Texas Voltage Phase Angle wrt UT Austin
01
02
03
04
05
0 10 20 30 40 50 60
Waco Voltage Phase Angle wrt UT Austin
05
06
07
08
09
0 10 20 30 40 50 60
West Texas, South Texas, Waco Frequency
59.95
60.00
60.05
0 10 20 30 40 50 60
Seconds
Event 5. Jan. 09, 2012. 09:25 GMT
Unit trip. Poor frequency recovery.
Conclusion – unit trip in South Texas.
Strong wind. Small steady-state angle drops.
Steady state angle drops.
Texas_Synchrophasor_Network_Events_Jan_1_thru_15_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 6 of 11
West Texas Voltage Phase Angle wrt UT Austin
35.5
36.5
37.5
38.5
39.5
30 40 50 60 70 80 90
South Texas Voltage Phase Angle wrt UT Austin
00
01
02
03
04
30 40 50 60 70 80 90
Waco Voltage Phase Angle wrt UT Austin
05
06
07
08
09
30 40 50 60 70 80 90
West Texas, South Texas, Waco Frequency
59.95
60.00
60.05
30 40 50 60 70 80 90
Seconds
Event 6. Jan. 09, 2012. 09:31-32 GMT
Abrupt load shedding?
Conclusion – load shedding. Shedding was not in South Texas, and was not in West Texas.
Strong wind. West Texas steady-state angle drops slightly.
Slight angle drop in South Texas.
Slight drop in steady-state angle, and power flowing south.
Texas_Synchrophasor_Network_Events_Jan_1_thru_15_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 7 of 11
West Texas Voltage Phase Angle wrt UT Austin
35.5
36.5
37.5
30 50 70 90 110
South Texas Voltage Phase Angle wrt UT Austin
21
22
23
30 50 70 90 110
Waco Voltage Phase Angle wrt UT Austin
09
10
11
30 50 70 90 110
West Texas, South Texas, Waco Frequency
59.95
60.00
60.05
30 50 70 90 110
Seconds
Event 7. Jan. 10, 2012. 13:42 GMT
South Texas Voltage Phase Angle wrt UT Austin
21
22
45 46 47 48 49 50
Zoom-In Shows ≈ 0.6 Hz Oscillation
Initially not a frequency event. Undamped oscillation clearly visible in frequency as well as angle.
Strong wind. West Texas sees a bump, followed by a 10-15 sec. of undamped oscillation.
Conclusion – Strong ERCOT-wide undamped oscillation, freq ≈ 0.6 Hz, lasting 20 seconds, then restarting after a pause. Most significant in South Texas, but visible everywhere. Cause unknown.
Zoom
Small unit trip?
Texas_Synchrophasor_Network_Events_Jan_1_thru_15_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 8 of 11
West Texas Voltage Phase Angle wrt UT Austin
24.5
25.5
26.5
0 10 20 30 40 50 60
South Texas Voltage Phase Angle wrt UT Austin
12
13
14
0 10 20 30 40 50 60
Waco Voltage Phase Angle wrt UT Austin
06
07
08
0 10 20 30 40 50 60
West Texas, South Texas, Waco Frequency
59.90
59.95
60.00
0 10 20 30 40 50 60
Seconds
Event 8. Jan. 11, 2012. 00:59 GMT
No unit tripped.
No significant steady-state angle change.
Good wind. Steady-state angle rises.
Conclusion – line trip to West Texas
Slight steady-state angle rise.
Texas_Synchrophasor_Network_Events_Jan_1_thru_15_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 9 of 11
West Texas Voltage Phase Angle wrt UT Austin
26
27
28
0 10 20 30 40 50 60
South Texas Voltage Phase Angle wrt UT Austin
12
13
14
0 10 20 30 40 50 60
Waco Voltage Phase Angle wrt UT Austin
02
03
04
0 10 20 30 40 50 60
West Texas, South Texas, Waco Frequency
59.95
60.00
60.05
0 10 20 30 40 50 60
Seconds
Event 9. Jan. 12, 2012. 03:49 GMT
Load shed?
No significant change in steady-state angle.
Good wind. Steady-state angle drops slightly.
Conclusion – possible load shedding
Slight steady-state angle drop.
Texas_Synchrophasor_Network_Events_Jan_1_thru_15_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 10 of 11
West Texas Voltage Phase Angle wrt UT Austin
-19.5
-18.5
-17.5
0 10 20 30 40 50 60
South Texas Voltage Phase Angle wrt UT Austin
24
25
26
0 10 20 30 40 50 60
Waco Voltage Phase Angle wrt UT Austin
-01
00
01
0 10 20 30 40 50 60
West Texas, South Texas, Waco Frequency
59.95
60.00
60.05
0 10 20 30 40 50 60
Seconds
Event 10. Jan. 12, 2012. 22:24 GMT
Unit trip.
Steady-state angle rises slightly.
Poor wind. Steady-state angle drops slightly.
Conclusion – Unit trip in North or West Texas
Steady-state angle drops slightly.
Texas_Synchrophasor_Network_Events_Jan_1_thru_15_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 11 of 11
To run the program, unzip and place the hourly files and program in one folder. When you execute the program,
• Pick your hour • Pick your minute (default is one minute, but you can also display two or more
consecutive minutes • Include the PMUs – in these graphs we show McDonald, UT Pan Am, and Waco. • Note the line below the graph “Above graph saved as XXX.” That file has the
points, suitable for plotting in Excel. • Top right buttons do auto screen. Presently, the program takes about 30 minutes
to screen one day, flagging the events of interest in an output text file. Re-run the program (no auto-screen) to view those events and create the saved text files.
• Have fun.
PMU Waveform Analyzer Display for Event 7
Texas_Synchrophasor_Network_Events_Jan_15_thru_21_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 1 of 5
West Texas Voltage Phase Angle wrt UT Austin
43.5
44.5
45.5
46.5
40 50 60 70 80 90 100
South Texas Voltage Phase Angle wrt UT Austin
02
03
04
05
40 50 60 70 80 90 100
Waco Voltage Phase Angle wrt UT Austin
08
09
10
11
40 50 60 70 80 90 100
West Texas, South Texas, Waco Frequency
59.85
59.90
59.95
60.00
40 50 60 70 80 90 100
Seconds
370 miles
280 miles
100 miles
Straight-Line Miles
Event 1. Jan. 15, 2012. 20:04 GMT
Conclusion –
Texas_Synchrophasor_Network_Events_Jan_15_thru_21_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 2 of 5
West Texas Voltage Phase Angle wrt UT Austin
33
34
35
0 10 20 30 40 50 60
South Texas Voltage Phase Angle wrt UT Austin
17
18
19
0 10 20 30 40 50 60
Waco Voltage Phase Angle wrt UT Austin
06
07
08
0 10 20 30 40 50 60
West Texas, South Texas, Waco Frequency
59.85
59.90
59.95
60.00
0 10 20 30 40 50 60
Seconds
Event 2. Jan. 16, 2012. 16:48 GMT
Conclusion –
Texas_Synchrophasor_Network_Events_Jan_15_thru_21_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 3 of 5
West Texas Voltage Phase Angle wrt UT Austin
-24.5
-23.5
-22.5
40 50 60 70 80 90 100
South Texas Voltage Phase Angle wrt UT Austin
35
36
37
40 50 60 70 80 90 100
Waco Voltage Phase Angle wrt UT Austin
-05
-04
-03
40 50 60 70 80 90 100
West Texas, South Texas, Waco Frequency
59.95
60.00
60.05
40 50 60 70 80 90 100
Seconds
Event 3. Jan. 18, 2012. 09:50 GMT
Conclusion –
Texas_Synchrophasor_Network_Events_Jan_15_thru_21_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 4 of 5
West Texas Voltage Phase Angle wrt UT Austin
6.5
7.5
8.5
9.5
10.5
0 10 20 30 40 50 60
South Texas Voltage Phase Angle wrt UT Austin
09
10
11
12
13
0 10 20 30 40 50 60
Waco Voltage Phase Angle wrt UT Austin
06
07
08
09
10
0 10 20 30 40 50 60
West Texas, South Texas, Waco Frequency
60.00
60.05
0 10 20 30 40 50 60
Seconds
Event 4. Jan. 18, 2012. 19:15 GMT
Conclusion –
Texas_Synchrophasor_Network_Events_Jan_15_thru_21_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer
Page 5 of 5
West Texas Voltage Phase Angle wrt UT Austin
-30
-29
-28
-27
0 10 20 30 40 50 60
South Texas Voltage Phase Angle wrt UT Austin
-12
-11
-10
-09
-08
0 10 20 30 40 50 60
Waco Voltage Phase Angle wrt UT Austin
02
03
04
05
06
0 10 20 30 40 50 60
West Texas, South Texas, Waco Frequency
59.75
59.80
59.85
59.90
59.95
60.00
0 10 20 30 40 50 60
Seconds
Event 5. Jan. 21, 2012. 19:34 GMT
Conclusion –
On 01/21/12, a sudden loss of generation occurred at 13:34 totaling 584 MW. Frequency declined to 59.752 HZ, ERCOT load was 31,275 MW.
59.7
59.8
59.9
60.0
60.1
0 1 2 3 4 5 6 7 8 9 10
Minutes
It is amazing what 584 MW can do when there is little reserve.More fallout from the Texas Nodal Market?
Texas_Synchrophasor_Network_Jan_25_2012.doc
Page 1 of 1
West Texas Voltage Angle Oscillation, Beginning Jan. 25, 2012, 07:35 GMTOscillation Continued for About 20 Minutes
26.5
27.5
28.5
300 310 320 330 340 350 360
Seconds
Undamped Oscillation, Approx. 1.8 Hz
South Texas Voltage Angle Oscillation, Beginning Jan. 25, 2012, 07:35 GMT
13.5
14.5
15.5
300 310 320 330 340 350 360
Seconds
Control action
Texas_Synchrophasor_Network_Events_Jan_25.doc. Events automatically detected by our PMU_Waveform_Analyzer. Data from 120V Wall Outlets.
Page 1 of 2
370 miles
280 miles
100 miles
Straight-Line Miles
Event 1. Jan. 15, 2012. 20:04 GMT
West Texas Voltage Phase Angle wrt UT Austin
18
19
20
21
22
50 60 70 80 90 100 110
South Texas Voltage Phase Angle wrt UT Austin
04
05
06
07
08
50 60 70 80 90 100 110
Waco Voltage Phase Angle wrt UT Austin
-01
00
01
02
03
50 60 70 80 90 100 110
West Texas, South Texas, Waco Frequency
59.80
59.85
59.90
59.95
60.00
60.05
50 60 70 80 90 100 110
Seconds
West Texas Voltage Phase Angle wrt UT Austin
18
19
20
21
22
55 56 57 58 59 60 61 62 63 64 65
West Texas, South Texas, Waco Frequency
59.80
59.85
59.90
59.95
60.00
60.05
55 56 57 58 59 60 61 62 63 64 65
Seconds
Zoom
Zoom
Comments – We believe there are two, possibly three events here. The first is a unit trip, where the frequency drop begins. The second is at the frequency minimum, where frequency immediately ramps up at the same rate it ramped down. Now, see the Waco and South Texas phase angle curves (these are with respect to U.T. Austin). The first angle ringdown starts at the unit trip, but is then interrupted at the frequency minimum, where a second angle ringdown begins. West Texas phase angle does not show much. However, the undamped West Texas 1.8 Hz oscillation pointed out on an earlier Jan. 25 event is visible in both phase angle and frequency.
Jan. 25, 2012. 18:22 GMT
Texas_Synchrophasor_Network_Events_Jan_25.doc. Events automatically detected by our PMU_Waveform_Analyzer. Data from 120V Wall Outlets.
Page 2 of 2
West Texas Voltage Phase Angle wrt UT Austin
00
01
02
03
04
0 10 20 30 40 50 60
South Texas Voltage Phase Angle wrt UT Austin
04
05
06
07
08
0 10 20 30 40 50 60
Waco Voltage Phase Angle wrt UT Austin
-02
-01
00
01
02
0 10 20 30 40 50 60
West Texas, South Texas, Waco Frequency
59.85
59.90
59.95
60.00
60.05
60.10
0 10 20 30 40 50 60
Seconds
West Texas, South Texas, Waco Frequency
59.80
59.85
59.90
59.95
60.00
60.05
5 6 7 8 9 10 11 12 13 14 15
Seconds
Comments – About the same situation as 18:22 GMT. There appear to be two events. Rate of frequency drop is less. Less 1.8 Hz visible in West Texas.
Zoom
Jan. 25, 2012. 20:29 GMT
370 miles
280 miles
100 miles
Straight-Line Miles
Texas_Synchrophasor_Network_Jan_26_2012.doc. Events automatically detected by our PMU_Waveform_Analyzer. Data from 120V Wall Outlets.
Page 1 of 1
West Texas Voltage Phase Angle wrt UT Austin
-53-52-51-50-49-48-47-46-45
0 60 120 180 240 300 360 420 480 540 600
South Texas Voltage Phase Angle wrt UT Austin
101112131415161718
0 60 120 180 240 300 360 420 480 540 600
Waco Voltage Phase Angle wrt UT Austin
-09-08-07-06-05-04-03-02-01
0 60 120 180 240 300 360 420 480 540 600
West Texas, South Texas, Waco Frequency
59.85
59.90
59.95
60.00
60.05
60.10
60.15
0 60 120 180 240 300 360 420 480 540 600
Seconds
370 miles
280 miles
100 miles
Straight-Line Miles
Jan. 26, 2012. 04:04 GMT
Comments – Zero wind, West Texas angle less than −50º. Unit trip, likely in Central Texas, drops frequency to 59.87 Hz. After a rocky start, frequency climbs past 60.10 Hz in eight minutes. Wind, or other West Texas generation, ramps up then levels out.