Transcript Power System Dynamics Analysis

Power System Dynamics Analysis
Complexity in the WSCC
August 10, 1996 System Disturbance
David P. Chassin, October 16, 2002
Contact: [email protected]
6Nov98
August 1996 West Coast Blackout
Summary of Events
WSCC 8-10-96 15:48 PAST major disturbance


4 islands, 7.5M customers out up to 9 hours
Initiating event: 500 kV Keeler-Allston flashover to trees


Trip cause: poor right-of-way maintenance
Numerous supporting events
Follow-up events

COI limit lowered to 3200 MW (Aug 11)
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
Account for limits at McNary (exciter) and The Dalles (fish)
Raised Aug 12-14 to 3600 MW to avoid blackouts in CA
2
PNNL and Power Systems
DOE Transmission Reliability Program
Real-Time Grid Reliability Management
 Reliability and Markets, Load as a Resource
 Distributed Energy Resources Integration

Infrastructure Assurance Outreach Program
Utility vulnerability assessments
 Interaction with NERC, others on security topics
 Interest in SCADA security

Energy System Transformation Initiative
Integrated econophysics modeling and simulation
 Next generation power technology development

3
Wide-Area Measurement System
Dynamic monitor network supports advanced
analysis
“Better information supports
better - and faster - decisions.”
Disturbances
Unobserved
response
System planning
Power
System operation
Automatic control
System
Observed
response
Decision
Processes
Measurement
Information
Based
Information
System
4
Real-Time System Data
Collected from various monitors throughout the grid
Bonneville Power Administration Phasor Data Concentrator
5
Power System Measurement Tools
Tools for managing data & signal analysis
6
“Ringdown” Analysis Tool
Advanced dynamic analysis
Extracting a linear model
from measured data
Malin MW
Brake insertio n #2, 09/04/97
(Alb erta stron gly co nn ected )
Un filtered sign als
1200
PACI Mode : 0 .294 Hz @ 5.3 % damping
Albe rta
: 0.418 Hz @ 5.1% damping
1100
1000
model fitting window
900
Dat a collected on D it tmer PPSM
sample rate = 60/second
Ref erence time 09-04-97 23H42m35s
165
170
175
180
Time in Secon ds
•Dynamic analysis
•Model validation
•Control design
7
Advanced Dynamic System
Analysis and Model Validation
August 10, 1996 post-disturbance analysis
Determine if model
calibration is needed.
4600
Observed COI Power (Dittmer Control Center)
4400
4200
4000
Simulated COI Power (initial WSCC base case)
4600
4400
4200
4000
0
10
20
30
40
50
60
70
80
90
Time in Seconds
Currently working with western utilities to improve power grid models
8
Power System Econophysics
3
2
PJM 1999 Load/Price Probability Distributions
100%
Q = Qmax (11/P2)4.54
 1.6  2 1.6Q 2
PQ   4π
 Qe
2
π

0
.
85


20.85
80%
Probability
$1,000
Price ($/MWh)
$750
$500
60%
40%
20%
0%
20000
$250
25000
30000
35000
40000
45000
Quantity (MWh/h)
$0
20000
100%
30000
40000
50000
Quantity (MWh/h)
Cout
Abstract
Transactive
Machine
Cprofit
Qin
Control
process
control
Thermodynamic
process
State m
data
State x
Cin
Probability
80%
Qout
Qwaste
60%
40%
20%
0%
$10
$100
$1,000
Price ($/MWh)
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Grid Friendly™ Appliances
60.020
59.940
59.920
…rapid, automatic response to grid crises
…platform for active communication &
control
…pre-heat/pre-cool to coast through peaks
…utilize & value thermal storage
…increase reliability & security
…unnoticeable by consumer
…mass customization/marketing
Frequency (Hz)
59.980
59.960
Grid-friendly appliances…
Four Corners Unit 5 Tripped with 710 MW on May 8, 2002 At 13:38
PDT
With GFA: Frequency Excursion Arrests at 59.950 Hz within 0.7
sec.
60.000
59.900
Without GFA: Frequency Drops to 59.886 Hz within 5.8
sec.
59.880
59.860
0.0
10.0
20.0
30.0
40.0
50.0
Seconds (from 13:38:20 PDT)
Grid-Friendly Appliance Controller
106
Loads and Reserves on a
Typical U.S. Peak Day
=100
Residential
(non-GFA)
10%
Industrial
28%
Commercial
29%
Residential
(GFA) 20%
Operating
reserves
13%
GFA potential
exceeds US
operating reserve
requirements!
“…given enough ants, you can move a mountain!...”
impromptu reaction from a utility power engineer
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Overview of WSCC August 10, 1996
15:48 PAST Disturbance
Based on WSCC Disturbance Report
Approved by WSCC Operations
Committee on October 18, 1996
High northwest transmission loading
High imports to CA

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Heavy imports from Canada
and Idaho
COI at 4750 MW
Similar to conditions prior to
7/2/96 disturbance

Warning signs visible
Previous high-load issues
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
Small power/large voltage
swings
Suggested voltage support
problems in NW
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Equipment out of service
Lines

x x
x
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500 kV: Big Eddy-Ostrander,
John Day-Marion, and MarionLane (reactive support around
Portland) flashover to trees
115 kV: Allston-Rainer degraded
hdwr, Longview-Lexington cable
installation.
Breakers

500 kV: Marion, Keeler
(modifications)
Transformers

500/230 kV: Keeler (modification)
Static VAR Comp (SVC)

Keeler reduced support to
500 kV (tied to 230 kV side)
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Triggering Events
15:42:37 Keller-Allston
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Sags into trees, flashes, trips
Overload par-lines hold 5 min
McNary react-power at max
15:47:29 St. Johns-Merwin
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! ! !
!
Lines trip on relay malfunc.
KA par-line loads increase
15:47:36 Ross-Lexington
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!
Tree flashover and trip
207 MW from Swift lost
System voltage sags
15:47:36 McNary
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Units trip, exciter problem
System power/voltage osc. begins
ID-UT-CO-AZ-NM-NV Surge
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COI power flows down east side
Out-of-step trips
CA-AZ remain tied together
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Final Result
28,000 MW of under-frequency load shedding
20,000 MW of undesired generation loss
Four major islands

Northern California (North of LA to Oregon border)
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Southern California (SoCal, NV, AZ, NM, El Paso, Baja)
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Losses: 15 820 MW load; 13,500 MW generation
Frequency excursions: 61.3 – 58.5, restored in 70 min.
Northern (BC, OR, WA, MT, WY, ID)
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Losses: 11,600 MW load; 7,900 MW generation
Frequency excursions: 58.54 – 60.7 – 58.3, restored in 2.5 hrs.
Losses: 2,100 MW load; 5,700 MW generation
Frequency excursions: 60.4, restored in 7 minutes
Alberta
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Losses: 970 MW load; 146 MW generation
Frequency excursions: 60.4 – 59.0, restored in 6 minutes
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Open Questions re. Complexity
Report only identifies the incontrovertible points
and fails to address more controversial questions:
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Why was line maintenance inadequate?
Why was system operated in single-contingency mode?
Why did AZ-CA separation scheme fail to operate?
Why did models fail to predict oscillations?
Why did system damping fail?
Lesson for us:

Don’t go just by the official reports. Much more is not
reported or discussed because of sensitivities. The
social dynamics of a tightly knit community factors into
what is knowable. We have to look deeper.
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Problems Persist
WECC Oct 8 2002 15:31 PDT
60.050
480 MW generation dropped
60.000
2900 MW generation tripped
1400 MW Chief Joe brake inserted
59.950
59.900
59.800
59.750
59.700
~350 MW load loss
59.650
~86 MW UFLS
59.600
22:32:09.60 GMT
22:32:00.96 GMT
22:31:52.32 GMT
22:31:43.68 GMT
22:31:35.04 GMT
22:31:26.40 GMT
22:31:17.76 GMT
22:31:09.12 GMT
22:31:00.48 GMT
22:30:51.84 GMT
59.550
22:30:43.20 GMT
Freq
59.850
Time
17
Questions and Comments