These are about 1pu
Why are Synchrophasors Important?
Here’s All You Need to Remember
Average Power Flow P Through a Mostly Inductive Transmission Line (138kV and above)
)sin( 2121 X
VVP
11 V 22 V
jX
+
─
+
─ground
For small x, sin(x) = x
Charles Steinmetz, developed phasor theory to analyze
AC circuits
Stability limit is when the angle difference reaches 90 degrees
410 miles
460 miles
370 miles
McDONALD OBSERVATORY
UT PAN AM
BAYLOR
• Idaho National Lab• Colorado Springs• Los Alamos Nat. Lab• Cloudcroft, NM (near White
Sands Nat’l Monument)
• Western and Eastern Nebraska• Two in Kansas City area• Little Rock• N.E. Texas (Eastern Grid)• Washington D.C. area• Texas Panhandle (Eastern Grid)
• Austin – 3M• DFW area• Houston
Waco Brazos Electric Coop
Three 50 ft. (or two 75 ft.) pieces of RG-6 coax with TNC male connectors. A mail-to-mail TNC-TNC adapter is on one end of two of the cables.
15 ft. RG-6. One end connects to GPS antenna, the other end to a lightning arrestor. Ground the arrestor.
GPS antenna screws onto ¾” threaded male-to-1” smooth PVC adapter, which in turn slides into a 1” coupling. A 1” PVC pipe slides into the other end of the coupling. You may want to use a longer pipe to get a good sky view.
Power supply for satellite clock.
SEL2401 satellite clock receives RG-6 from GPS antenna, and connects to SEL421 through a small coax.
Terminated T-BNC fits on left BNC jack
120V hot and neutral are jumpered over to phase A inputs.
SEL2890 Internet transceiver screwed to Port 3
PMU Station Equipment
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
De
gre
es
ERCOT’s graph of West-to-North P flow
Texas Synchrophasor Network’s graph of West-to-Central ERCOT Voltage Angle
This is probably the world’s first electricity market-induced grid oscillation!
Price went down, then wind gens responded, then price went up, then wind gens responded, • • •
12-hour window
12 hour window
Candidate for Ripley’s Believe It or Not?
ERCOT Load, Wind Gen, Conventional GenWeek Starting 00.00 GMT, Sunday, Dec. 29, 2013
0
10000
20000
30000
40000
50000
0 1 2 3 4 5 6 7Day of Week
MW
Load
Wind
Conv.
ERCOT Wind Gen (Percent of Load)Week Starting 00.00 GMT, Sunday, Dec. 29, 2013
0
5
10
15
20
25
30
0 1 2 3 4 5 6 7
Day of Week
Hours of wind curtailment
Weekly Report for Last Week
Sweetwater Wind SpeedWeek Beginning Sunday, Dec. 29, 2013, 00:00 GMT
0
5
10
15
20
25
30
0 1 2 3 4 5 6 7
Day of Week
MP
H
ERCOT Wind Gen MWWeek Starting 00.00 GMT, Sunday, Dec. 29, 2013
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
0 1 2 3 4 5 6 7
Day of Week
Hours of wind curtailment
Average Voltage Phase Angle at McDonald Observatory and U.T. Pan Am1-Minute Intervals, Beginning Sunday, Dec. 29, 2013, 00:00 GMT
-50
-40
-30
-20
-10
00
10
20
30
40
50
0 24 48 72 96 120 144 168
Hour of the Week, GMT
Deg
rees w
rt B
aylo
r
Avg. SumStart Sec Stop Sec A B T1 Tau1 C T2 Tau2 Tdamp Fdamp Zeta Squared Error
17.5 22 21.81 20.40 18.04 0.31 -1.72 18.38 1.42 1.47 0.683 0.162 0.0044Alpha0.704
F00.692
Exponential Steady State Transition Curve Damped Sinusoidal Term
U.T. Pan Am Voltage Phase Angle wrt Baylor, December 30, 2013, 15:44 GMT
19
20
21
22
17 18 19 20 21 22 23 24 25
Second
Deg
rees
59.8
59.9
60.0
60.1
5 6 7 8 9 10
Hz
Hour of the Day, CST
Baylor Max/Min Frequency for Each MinuteMonday, Jan. 6, 2014, CST
This Week Has Been Rough
ERCOT Load and Wind MWWeek Starting 00.00 CST, Sunday, Jan. 05, 2014
0
10000
20000
30000
40000
50000
60000
0 0.5 1 1.5 2 2.5 3
Day of Week
Load
Wind
ERCOT Wind Gen (Percent of Load)Week Starting 00.00 CST, Sunday, Jan. 05, 2014
0
5
10
15
20
25
30
35
0 0.5 1 1.5 2 2.5 3
Day of Week
ERCOT Capacity-to-Load RatioWeek Starting 00.00 CST, Sunday, Jan. 05, 2014
1.0
1.1
1.2
1.3
1.4
1.5
0 0.5 1 1.5 2 2.5 3
Day of Week
ERCOT DC Export MWWeek Starting 00.00 CST, Sunday, Jan. 05, 2014
-1000
-500
0
500
1000
0 0.5 1 1.5 2 2.5 3
Day of Week
Baylor Minimum Frequency1-Minute Intervals, Beginning Sunday, Jan. 05, 2013, 00:00 CST
59.8
59.9
60.0
60.1
0 24 48 72
Hour of the Week, CST
Hz
Omaha, Nebraska Area, Eastern Grid, Minimum Frequency1-Minute Intervals, Beginning Sunday, Jan. 05, 2013, 00:00 CST
59.8
59.9
60.0
60.1
0 24 48 72
Hour of the Week, GMT
Hz
59.8
59.9
60.0
60.1
0 24 48 72
Hour of the Week, GMT
Hz
Internet dropouts at the Cloudcroft, NM, mountain cabin cause the sparse appearance of this graph
Omaha, NE, area. Lost signal on Wednesday
ERCOT
SPP
WECC
All Three Grids Had Problems
This Week
FrequencyJan. 06, 2014, 00:30 CST Event
59.85
59.90
59.95
60.00
60.05
0 10 20 30 40 50 60Seconds
Hz
Baylor
McD
PanAm
FrequencyJan. 06, 2014, 06:29 CST Event
59.85
59.90
59.95
60.00
60.05
0 10 20 30 40 50 60Seconds
Hz
Baylor
McD
PanAm
FrequencyJan. 06, 2014, 08:10 CST Event
59.85
59.90
59.95
60.00
60.05
30 40 50 60 70 80 90Seconds
Hz
Baylor
McD
PanAm
Voltage Phase AngleJan. 06, 2014, 00:30 CST Event
10
20
30
40
50
0 10 20 30 40 50 60Seconds
De
gre
es
Re
lati
ve
to
Ba
ylo
r
McD
PanAm
Voltage Phase AngleJan. 06, 2014, 06:29 CST Event
10
20
30
40
50
0 10 20 30 40 50 60Seconds
De
gre
es
Re
lati
ve
to
Ba
ylo
r
McD
PanAm
Voltage Phase AngleJan. 06, 2014, 08:10 CST Event
10
20
30
40
50
30 40 50 60 70 80 90Seconds
Deg
rees
Rel
ativ
e to
Bay
lor
McD
PanAm
Voltage MagnitudeJan. 06, 2014, 00:30 CST Event
0.99
1.00
1.01
0 10 20 30 40 50 60Seconds
PU
Baylor
McD
PanAm
Voltage MagnitudeJan. 06, 2014, 06:29 CST Event
0.99
1.00
1.01
0 10 20 30 40 50 60
PU
Baylor
McD
PanAm
Voltage MagnitudeJan. 06, 2014, 08:10 CST Event
0.99
1.00
1.01
30 40 50 60 70 80 90Seconds
PU
Baylor
McD
PanAm
