Transcript PDCWG Report to ROS January 13, 2011 Sydney Niemeyer 1:2:3:4:5:6:7:8:9:10 5 :1 11 5 :1 12 5 :1 13 5 :1 14 5 :1 15 5 :1 16 5 :1 17 5 :1 18 5 :1 19 5 :1 20 5 :1 21 5 :1 22

PDCWG Report to ROS
January 13, 2011
Sydney Niemeyer
15
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5
0:
ERCOT CPS1 15 Minute Average - Monthly Score
180
December-2010
Interval Ending
CPS1 = 141.7
160
140
120
100
80
60
40
20
0
-20
141.70
Monthly CPS1 for ERCOT
200
70000
190
66500
180
63000
170
59500
160
56000
150
52500
140
49000
130
45500
120
42000
110
38500
100
35000
90
31500
80
28000
70
24500
60
21000
50
17500
40
14000
30
10500
20
7000
10
3500
0
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 25 26 27 28 29 30 31
Day
CPS1
Avg CPS1
ERCOT Pk Energy
ERCOT Peak Energy
NERC CPS1
ERCOT CPS1 By Day - December 2010
92.91 Monthly CPS2 for ERCOT
100
100
98
98
96
96
94
94
92
92
90
90
88
88
86
86
84
84
82
82
80
80
78
78
76
76
74
74
72
72
70
70
68
68
66
66
64
64
62
62
60
60
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Day
CPS2
Avg CPS2
Cumulative NERC CPS2
NERC CPS2 - ERCOT has waiver
ERCOT CPS2 - December 2010
1/
1/
2
7/ 00
1/ 0
2
1/ 00
1/ 0
2
7/ 00
1/ 1
2
1/ 00
1/ 1
7/ 200
1/ 2
2
1/ 00
1/ 2
7/ 200
1/ 3
2
1/ 00
1/ 3
2
7/ 00
1/ 4
2
1/ 00
1/ 4
2
7/ 00
1/ 5
2
1/ 00
1/ 5
2
7/ 00
1/ 6
2
1/ 00
1/ 6
7/ 200
1/ 7
2
1/ 00
1/ 7
7/ 200
1/ 8
2
1/ 00
1/ 8
7/ 200
1/ 9
2
1/ 00
1/ 9
2
7/ 01
1/ 0
20
10
Daily RMS1 of ERCOT Frequency
0.0400
0.0350
0.0300
0.0250
0.0200
0.0150
0.0100
1/
1
4 / /2 0
1/ 04
7/ 20
10 1/2 04
/1 00
4
1/ /200
1
4 / /2 0 4
1 0
7 / /2 0 5
10 1/2 05
/1 00
5
1/ /200
1
4 / /2 0 5
1 0
7 / /2 0 6
10 1/2 06
/1 00
1/ /20 6
1/ 06
4/ 20
1 0
7 / /2 0 7
10 1/2 07
/1 00
7
1/ /200
1
4 / /2 0 7
1/ 08
7/ 20
10 1/2 08
/1 00
8
1/ /200
1
4 / /2 0 8
1/ 09
7/ 20
10 1/2 09
/1 00
9
1/ /200
1
4 / /2 0 9
1 1
7 / /2 0 0
10 1/2 10
/1 01
/2 0
01
0
Daily RMS1 of ERCOT Frequency
0.0400
0.0350
0.0300
0.0250
0.0200
0.0150
0.0100
1/
2
1/
2
1/
2
00
7
00
7
10 007
/1
/2
00
7
1/
1/
20
4/ 08
1/
20
08
7/
1/
20
0
10
/1 8
/2
00
8
1/
1/
20
4/ 09
1/
20
7/ 09
1/
20
09
10
/1
/2
00
9
1/
1/
20
4/ 10
1/
20
10
7/
1/
20
10
10
/1
/2
01
0
7/
4/
1/
Daily RMS1 of ERCOT Frequency
0.0400
0.0350
0.0300
0.0250
0.0200
0.0150
0.0100
0
v- 1
Nop- 10
Se 0
l-1
Ju -10
y
Mar- 10
Ma 0
n-1
Ja - 09
v
N o - 09
p
S e 09
lJu y-09
Mar- 09
Ma -09
n
Ja - 08
v
Nop- 08
S e 08
lJu y-08
Mar- 08
Ma 8
n-0
Ja - 07
v
N o - 07
p
Se 7
l-0
Ju -07
y
Mar- 07
Ma 7
n-0
Ja - 06
v
Nop- 06
S e 06
lJu y-06
Mar- 06
Ma -06
n
Ja - 05
v
Nop- 05
S e 05
lJu -05
y
Mar- 05
Ma -05
n
Ja - 04
v
N o - 04
p
S e 04
lJu -04
y
Mar- 04
Ma -04
n
Ja - 03
v
Nop- 03
S e 03
lJu y-03
Ma
Monthly Average
Trend
12 Month Rolling Average
150
150
140
140
130
130
120
120
110
110
100
100
CPS1 Average
160
CPS1 12 Month Rolling
Average = 150.83
160
170
ERCOT CPS1 Score
170
ERCOT CPS2 Score*
*ERCOT as a single control
area is exempt from CPS2.
These scores are For
Information Only
100
95
CPS2
90
85
80
75
70
6
0
t-1
Oc
0
l -1
Ju
0
r-1
Ap
0
n-1
Ja
9
t-0
Oc
9
l -0
Ju
9
r-0
Ap
9
n-0
Ja
8
t-0
Oc
8
l -0
Ju
8
r-0
Ap
8
n-0
Ja
7
t-0
Oc
7
l -0
Ju
7
r-0
Ap
7
n-0
Ja
6
t-0
Oc
6
l -0
Ju
06
rAp
n-0
Ja
5
5
t-0
Oc
l -0
Ju
Month
Series1
Trend (Monthly CPS2 Score)
59
.90
0
59
.91
0
59
.92
0
59
.93
0
59
.94
0
59
.95
0
59
.96
0
59
.97
0
59
.98
0
59
.99
0
60
.00
0
60
.01
0
60
.02
0
60
.03
0
60
.04
0
60
.05
0
60
.06
0
60
.07
0
60
.08
0
60
.09
0
60
.10
0
Comparing December 2008 vs December 2010
profile of frequency in 5 mHz bins
0.09
0.08
0.07
0.06
0.05
0.04
0.03
0.02
0.01
0
Dec-10
Dec-08
ERCOT Frequency Profile Comparison
January through December of each Year
50000
45000
35000
30000
25000
20000
15000
10000
5000
60
60
.0
1
60
.0
2
60
.0
3
60
.0
4
60
.0
5
60
.0
6
60
.0
7
60
.0
8
60
.0
9
60
.1
0
59
.9
59
.9
1
59
.9
2
59
.9
3
59
.9
4
59
.9
5
59
.9
6
59
.9
7
59
.9
8
59
.9
9
One Minute Occurances
40000
2010
2008
January thru December 2008 0.036 db vs. 2010 0.016 db
MW Minute Movement of a 600 MW Unit @ 5% Droop
160000
550038.4
2010 MW Response of 0.0166 db
662574.0
2008 MW Response of 0.036 db
140000
16.98% Decrease in MW
movement with
lower deadband.
120000
MW
100000
80000
60000
40000
20000
6
60 0
.0
1
60
.0
60 2
.0
3
60
.0
60 4
.0
5
60
.0
60 6
.0
7
60
.0
8
60
.0
9
60
.1
59
.
59 9
.9
1
59
.9
2
59
.9
59 3
.9
4
59
.9
59 5
.9
6
59
.9
59 7
.9
8
59
.9
9
0
2008 MW Response of 0.036 db
2010 MW Response of 0.0166 db
Same 600 MW unit with MW movement due to all frequency change each year.
ERCOT Total Load and Wind
Generation
• Data source not EPS quality.
• Confidence in data is good with some
telemetry errors scrubbed.
• Next three slides for reference only.
ERCOT Total Energy
40,000,000
35,000,000
30,000,000
20,000,000
15,000,000
10,000,000
5,000,000
2008
Au
gu
st
Se
pt
em
be
r
O
ct
ob
er
N
ov
em
be
D
r
ec
em
be
r
Ju
ly
Ju
ne
ay
M
ril
Ap
h
ar
c
M
ar
y
br
u
Fe
ar
y
0
Ja
nu
MWH
25,000,000
2009
2010
ERCOT Total Energy from Wind Generation
ERCOT Discontinued
ICCP data of Total
Wind Generation so no
data is available to
report. This report will
be discontinued.
3,000,000
2,500,000
1,500,000
1,000,000
500,000
2010
r
N
ov
em
be
D
r
ec
em
be
r
ob
e
O
ct
m
be
pt
e
Se
Au
r
t
2009
gu
s
Ju
ly
ay
M
ril
Ap
Ju
ne
M
ar
c
h
y
ar
br
u
2008
Fe
ar
y
0
Ja
nu
MWH
2,000,000
ERCOT % Energy from Wind Generation
14.00%
ERCOT Discontinued
ICCP data of Total
Wind Generation so no
data is available to
report. This report will
be discontinued.
12.00%
10.00%
8.00%
6.00%
4.00%
2.00%
2010
O
ct
ob
e
r
N
ov
em
be
r
D
ec
em
be
r
Se
pt
e
m
be
r
t
gu
s
2009
Au
Ju
ly
ay
M
ril
Ap
Ju
ne
M
ar
c
h
y
ar
br
u
2008
Fe
Ja
nu
ar
y
0.00%
Frequency Event Evaluations
• ERCOT has developed a new Excel Spreadsheet to
evaluate each generator’s performance during events.
• This is the first month that the PDCWG has used the
spreadsheet to review an actual event while on Nodal
dispatch.
– We are slow at learning to navigate and still discovering what
information would help speed the analysis.
– The tool includes a graph of each generator’s actual generation,
updated Base Point, frequency and Generator Expected
Generation. The Expected Generation includes any Regulation
Deployed and expected frequency response.
– The graphs are clear and it is easy to determine if the generator
delivered regulation, provided frequency response and followed
their base points.
– It contains all generators in ERCOT and it is difficult to determine
which generators to look at. We will determine a method of
identifying key players in each event. (similar to the summing of
generator’s change in base points that I did for the 12-21-2010
low frequency event). This evaluates SCED’s performance as
well. Reference slide 19 in this report.
Dec 21, 2010 22:06
Low Frequency Review
• Differences between Nodal and Zonal
– In zonal, Responsive Reserve would have
automatically deployed at 21:59 when frequency
reached 59.910 Hz.
• Resources would have responded quickly to the schedule
change in the SCE equation to deliver the RRS.
• Nodal only moved Resources based on LMP without the
knowledge of the amount of MW Resources were ramping off
line.
• Zonal SCPS 1 & 2 measured QSE performance while
ramping generation on and off line while schedules and
balancing deployments accounted for generation ramping off
line.
• Regulation is deployed based on the frequency deviation.
When SCED runs, it will adjust the Base Points to recover
the deployed Regulation and accounts for forecasted load
change.
12/21/2010
Load and Generation
60.10
60.08
Generators with increasing Base Points
had a total MW change in BP of 1403
MW beginning 21:59 on 25 different
generators. Wind 65 MW and hydro
generators about 175 MW BP change is
included in total BP change.
1403
60.06
60.04
32600.
32520.
32440.
32360.
1312
60.02
32280.
1080
60.00
32200.
59.98
32120.
59.96
32040.
872
59.94
59.92
59.90
31960.
During the same time
period load decreased
about 550 MW. (21:59
to 22:08)
691
31880.
31800.
59.88
31720.
59.86
31640.
59.84
31560.
59.82
322
59.80
59.78
198
59.76
59.74
91
59.72
59.70
21:56:00
21:58:00
22:00:00
Hz
31480.
Except for 22:02,
SCED ran every
minute between
21:59 and 22:08.
(9 runs in 10
minutes).
22:02:00
22:04:00
Gen
22:06:00
Load
22:08:00
22:10:00
22:12:00
22:14:00
31400.
31320.
31240.
31160.
31080.
31000.
22:16:00
22:18:00
Load @ 60.000 Hz (Load Dampening Added to Actual Load)
22:20:00
12/21/2010
Total Wind Generation
60.10
1460.
60.08
1452.
60.06
1444.
60.04
1436.
60.02
1428.
60.00
1420.
59.98
1412.
59.96
1404.
59.94
1396.
59.92
1388.
59.90
1380.
59.88
1372.
59.86
1364.
59.84
1356.
59.82
1348.
Wind generation to
the rescue. Output
increased 64 MW
during the severe low
frequency period.
59.80
59.78
59.76
59.74
59.72
1340.
1332.
1324.
1316.
1308.
59.70
21:56:00
1300.
21:58:00
22:00:00
22:02:00
22:04:00
22:06:00
Hz
22:08:00
22:10:00
22:12:00
Wind Generation
22:14:00
22:16:00
22:18:00
22:20:00
Ideas to Consider
• Generators ramping off line could set HSL equal to their
normal LSL when beginning to ramp down. Or lower
their HSL in stages down to LSL.
• When operating below normal LSL during the shutdown
process the LSL and HSL could be set to zero.
– This would give SCED the information earlier to adjust other
generator’s BP. Ramp rate differences could still be an issue
(SCED Updated Base Point vs. actual unit shutdown ramp rate).
• SCED could include an adjustment for Load Dampening
that would move Base Points faster to account for Load
that has decreased due to low frequency or load that has
increased due to high frequency. This value would ramp
to zero as frequency returned to 60 Hz. The PDCWG
has a formula to calculate this value in real time.
Reference the 60 Hz load trend on the previous Load
Dec 22, 2010 High Frequency
Event
• Out of Down Regulation.
• Off Line generation ramping to LSL similar to
previous day’s low frequency event only
opposite direction.
• SCED without ability to ramp the Units based on
ramp rate due to ONTEST status of generators
in start-up target MW. Please refer ERCOT
Market Notice to mitigate this issue.
• Detailed analysis of each generator and SCED
Base Point changes has not been completed at
this time.
12/22/2010
Load and Generation
60.20
25615.
60.18
25554.
60.16
25493.
60.14
25432.
60.12
25371.
60.10
25310.
60.08
25249.
60.06
25188.
60.04
25127.
60.02
25066.
60.00
25005.
59.98
24944.
59.96
24883.
Sudden load drop at 04:47 was caused by nonconforming load change. Not a contributing
cause but it did delay the recovery.
59.94
59.92
59.90
4:35:00
24822.
24761.
24700.
4:37:05
4:39:10
4:41:15
4:43:20
4:45:25
Hz
4:47:30
4:49:35
Gen
Load
4:51:40
4:53:45
4:55:50
4:57:55
5:00:00
12/22/2010
Total Wind Generation
60.20
3355.
60.18
3342.
60.16
3329.
60.14
3316.
60.12
3303.
60.10
3290.
60.08
3277.
60.06
3264.
60.04
3251.
60.02
3238.
60.00
3225.
Wind generation increased about
150 MW during the high
frequency period. This is not a
major contributing cause but it
did delay recovery.
59.98
59.96
59.94
59.92
59.90
4:35:00
3212.
3199.
3186.
3173.
3160.
4:37:05
4:39:10
4:41:15
4:43:20
4:45:25
Hz
4:47:30
4:49:35
Wind Generation
4:51:40
4:53:45
4:55:50
4:57:55
5:00:00
PDCWG Meeting Jan 4, 2011
•
Frequency Event review
– The PDCWG would like a SME from ERCOT to attend the next meeting so
members can learn about the details of SCED’s operation and LFC.
•
•
•
•
•
•
Request approval of the new PDCWG Scope.
The PDCWG would like to review GREDP scores each month of all
generators to evaluate the effectiveness of the metric.
The PDCWG would like to work with ERCOT on LFC Regulation
deployment tuning as several members believe Regulation is overcontrolling generation. A sample graph of over deployment is included.
The PDCWG is concerned that the Base Point Deviation charges do not
account for the delivery of frequency response. Some fifteen minute
periods have frequency deviations greater than +/- 0.05 Hz one direction but
average frequency is the opposite direction for the fifteen minute period.
This could penalize generators that provide a vital reliability service.
Three Frequency Events in December had multiple sympathetic unit trips.
Proper implementation of frequency response and generator control tuning
is a concern. Further analysis of these events is needed.
PDCWG will meet again February 2, 2011.
12/11/2010
Regulation And Reserve
60.10
415.
60.08
384.
60.06
353.
60.04
322.
60.02
291.
60.00
260.
59.98
229.
59.96
198.
59.94
167.
The PDCWG believes that
too much Regulation was
deployed for each of these
frequency oscillations.
59.92
59.90
59.88
59.86
136.
105.
74.
43.
59.84
12.
59.82
-19.
59.80
-50.
23:33:00
23:35:05
23:37:10
23:39:15
23:41:20
Hz
23:43:25
23:45:30
23:47:35
Total Regulation Deployed
23:49:40
23:51:45
RRS Deployed
23:53:50
23:55:55