SuperVARTM
July 25, 2006
Edison Shrugged
Things alter for the worse spontaneously, if they be not altered for the better designedly.
DOE HTS Program Success:
Enabling Commercial Rotating Machinery
• AMSC builds on technology
from DOE SPI program
• 2005 – AMSC and TVA
successfully demonstrate
HTS synchronous
condenser prototype
• 2006 – AMSC expects to
ship first commercial HTS
synchronous condenser
• 2003: AMSC delivers
5 MW HTS ship propulsion
motor to U.S. Navy
• First 1600 hp HTS industrial
motor (1996-2000, DOE SPI –
Rockwell, AMSC)
• 2006: AMSC expects to
deliver 36.5 MW ship
propulsion motor to U.S. Navy
in September 2006
• Candidate propulsion motor
for DDX-class destroyers in
2010 and beyond
“If I have seen a little further, it is by standing on the shoulders of Giants.” — Newton
SuperVAR born with the question “What if ?”
In 2001, American Superconductor management
pitched their HTS product-line to TVA — including
motors. TVA management asked AMSC what if a
synchronous condenser was built using HTS
technology?
And so, the SuperVAR concept was born.
“He that will not apply new remedies must expect new evils; for time is the greatest innovator.” — Bacon
Steady State Benefits of HTS Rotating Machines
Conventional Machine Limit,
Overexcited Field Coil Heating
(required field current is very high)
Conventional Machine Limit,
Underexcited Instability
(field current goes to zero)
Reactive
Power
Capability Curve,
HTS, Low Synchronous
Reactance Machine
Synchronous Condensers
Operate on This Axis
Real
Power
SuperVAR
VARS ( Per Unit)
Additional VAR Capability of
SuperVAR Device
Absorbing
VARS
TM
Generating
VARS
1
Conventional
Machine
1
Additional VAR Capability of
SuperVAR Device
2
3
Field Current (Per Unit)
• Low synchronous reactance design removes under-excited stability limit of conventional
machines
• Field current is well above zero at full rating under-excited
• HTS field coils remove coil heating limit of conventional machines,
• Full rating over-excited is possible
• No thermal cycling of rotor coils yields improved machine life, no rotor rewinds projected
Low synchronous reactance, HTS machines are capable of more reactive output than a
conventional device for a given rating machine
What Is A SuperVAR System?
• A Synchronous Rotating Machine
• Just like a large synchronous motor or generator
• Armature and Support Equipment Conventional
• Makes extensive use of off-the-shelf components and technologies
• Rotating Field Winding Is Superconducting
•
•
•
•
Field windings cooled to very low temperatures in a rotating Thermos bottle
No thermal expansion/contraction degradation mechanisms
No chemical degradation mechanisms (kept in a vacuum)
Windings carry electricity without resistance
• Controlled and Transient VAR/MW Provided to System
•
•
•
•
Reactive power continuously adjustable (+/-12MVAR)
2X overload available for up to one minute
Voltage regulation or reactive power compensation possible
Transient MW/MVAR available (flicker, motor starting, other transients)
Major SuperVAR Condenser Systems
Refrigeration
Systems
Auxiliary
Drive Motor
480V Service
Exciter
Stator and HTS Rotor
25 feet
SuperVAR Condenser Technology Base
•
Leverages COTS (commercial off-theshelf) components
•
Stator – standard, air-cooled, iron core
stator
• 100 year old technology
•
•
•
•
•
Exciter
Cooling components
Ferro fluidic seal
Conventional journal bearings
Take advantage of technology base
developed
•
•
•
AMSC 5000HP motor project
5MW Navy program
PES, DVAR/DSMES
SuperVAR condenser leverages conventional technology, demonstrated HTS machine
features and other AMSC reactive power compensation products
SuperVAR Condenser Prototype Specifications
Rating
8 MVAR
Voltage
13.8 kV line to line
Ambient Temp
-30o to +40oC
Losses
1.7% rating at 8MVA
Including 50kW 480V
auxiliary power
The SuperVAR condenser prototype has industrial class specifications
Losses and Efficiency
• Auxiliary loads measured
• Losses at no load measured
• 54.52 kW measured in factory
test
• Contract specification: 136kW
110
100
90
Efficiency( %)
• System on-line, pony motor
coasting, all other systems
operating
• 480V measured with true RMS
clamp-on probe at site: 49kW
• 480V measured in factory test
with power analyzer: 46kW
• Contract specification: 50kW
80
70
60
50
0
0.2
0.4
0.6
0.8
1
Output (p.u.)
SuperVAR system auxiliary loads and losses meet contract specifications
1.2
1.4
SuperVAR Prototype Installation at
Hoeganaes Corporation
• Steel Mill
• 45MVA arc furnace, 13.8kV load
• Nearly continuous operation
• Multiple large voltage transients per
melt cycle
• Many melt cycles per day
• Gallatin Fossil Plant
About 5 miles
•
•
•
•
Four coal-fired generating units
Construction was completed in 1959
Peak capacity is 988 MW
Consumes about 7,400 tons of coal a
day
• About 5 miles from Hoeganaes
• Machine Installed at Hoeganaes
• Machine operating in conjunction with
arc furnace
SuperVAR prototype was operated in a demanding industrial application
Prototype SuperVAR System Operation
• Operation during over 2000
arc furnace melt cycles
• Over 260 million pounds of
steel melted
• Equivalent to melting 90,000
Porsche Boxsters
• Over 5 million load transients
• 40 Porsche Boxters
simultaneously accelerating
from 0 to full power, 5 million
times
SuperVAR prototype was operated in a very challenging environment
On-line Results
500
• Adjusted field current for overexcited and under-excited operation
140
300
120
250
100
200
80
150
60
100
40
50
20
0
0
200
400
600
800
1000
1200
1400
1600
0
1800
Time (secs)
• +/- 8MVAR was demonstrated
20000
• Line voltages were slightly elevated
200
Vab
Vbc
ROTOR I(A)
18000
Voltage l-l (Vrms)
and depressed as expected
160
350
180
16000
160
14000
140
12000
120
10000
100
8000
80
6000
60
4000
40
2000
20
0
0
200
400
600
800
1000
Time (secs)
System was operated on-line to verify full +/- 8MVAR operation
1200
1400
1600
0
1800
Field Current (A)
on-line
Stator Currents (Arms)
• Synchronized system and placed
400
180
Field Current (A)
• Without arc furnace in operation
200
Ia
Ib
Ic
ROTOR I(A)
450
On-line Transient Results
• Machine successfully operated
through extreme transients to
support voltage
500
Ia
400
Ic
• Reacts on the sub-cycle
• Transient output observed in
excess of machine rating
• Significant real and reactive
transient output observed
• 10^6 to 10^7 major transients
300
200
Stator Currents (A)
timescale
Ib
100
0
-100
-200
-300
-400
-500
10.25
10.27
10.29
10.31
10.33
10.35
10.37
10.39
10.41
Time (secs)
Results show dramatic, transient behavior providing support to furnace
10.43
10.45
On-line Results
Total Measurement Period
Voltage
(03-21/22–2005)
Hour 1
9pm – 3am
Hour 2
Hour 3
ARC Furnace & Svar
Current
Svar Current
SuperVar Online
Voltage
Hour 4
SuperVar Offline
Hour 5
ARC Furnace & Svar
Current
Svar Current
SuperVar Offline & Gallatin Bus-Tie Open
Graph based on electrical data collected by TVA and EPRI Solutions during 03/21 and 03/22 Gallatin Test
Hour 6
Cycle by Cycle Response of SuperVAR
SuperVAR Terminal Voltage & Reactive Power
16
Supervar Produces more MVAR
14
15.5
13
MVAR
12
15
11
14.5
10
9
14
8
7
13.5
As Terminal Voltage Decreases
6
5
177.8
177.9
178
178.1
178.2
178.3
178.4
178.5
13
178.6
Time (Seconds)
This characteristic of SuperVAR is beneficial in minimizing
voltage fluctuation due to rapidly fluctuating loads such as arc furnaces
Graph based on electrical data collected by TVA and EPRI Solutions during 03/21 and 03/22 Gallatin Test
Terminal Voltage (kV)
15
What does it all mean?
• Using appropriate statistical parameters,
SuperVAR impact can be measured even though
the condenser size is much smaller than the arc
furnace and the Gallatin generators.
• Reducing voltage/MVAR fluctuation at Hoeganaes
results in a more stable arc and increases the
operational efficiency of the arc furnace.
• Reducing the voltage/MVAR fluctuation at Gallatin
Steam Plant results in a more efficient operation of
the generators.
In theory there is no difference between theory and practice. In practice there is. — Dr. Y. Berra
489 Relay Event Log Data
Data
Peak 489 Data
Logged to Date
Note:
Negative
sequence current
70%
Response to AF
operation
MVAR supplied
13 MVAR
Response to AF
operation
MW supplied
11.7 MW
Response to AF
operation
MVAR consumed
33.5 MVAR
Response to cap
bank switching
Phase current
988 A RMS
Response to cap
bank switching
Phase voltage
19,879 V RMS
Response to cap
bank switching
• 489 Event Log captures
alarm and trip
parameters
• Alarm events used to
obtain a summary of
machine response
• Peak values measured
are shown to the right
SuperVAR system response of real AND reactive power noted of about 12 MVAR
or 1.5 PU to arc furnace transients
Flicker analysis by site recordings
Independent analysis by EDF
Waveform recorded during the tests
“arc furnace + SuperVAR
compensator”
-Extract of line voltage waveform from
raw binary file.
- Sampling frequency: 6.4kHz
With SuperVAR
Pst = 8 to 9
- Flicker calculation by Flickermeter
software: Pst during 10 min
Conclusion:
Flicker reduction is significant by using
SuperVAR.
Without
SuperVAR
Pst = 18 to 25
I compensator
Flicker is the amplitude modulation of the fundamental frequency voltage by one or more frequencies.
At some magnitudes, this modulation causes a visible brightening and dimming of lights connected to the modulated
voltage, hence the term flicker.
Summary Specifications of Production Units Incorporating
Prototype Lessons Learned
Specification Prototype Production Unit Notes
Rating
8MVAR
12MVAR
Rating achievable without major
rotor design changes
Transient
8PU
4PU
Limit fault torques to those proven
in prototype
Excitation
Speed
60
seconds
1 second
0 to full rating output for voltage
collapse applications
Mounting
Trailer
2 Skids
More secure mounting to withstand
vibration, separate auxiliaries
Cooling
Neon
Helium
Simplify operations
Controls
Custom
DVAR Derivative
Simplify operations and
maintenance
Compressor
Water
cooled
Air cooled
Eliminate chiller to simplify
operations
Machine Type and Specifications
Specifications
• Synchronous Condenser
• Superconducting field
windings
• Conventional armature
• Exciter based on
conventional components
Specification
Value
Continuous Rating
12MVAR leading or lagging
Overload Rating
(≥1 minute)
24MVAR leading or lagging
Transient Rating
12MVAR/MW to 50% sag
Voltage
13.8kV
Commanded
Response Time
≤1 second (0 to rated MVA
output)
Physical Attributes
Attributes
Characteristic
Synchronous
Condenser
Auxiliary
Equipment Skid
Length
20 feet
10 feet
Width
8 feet
8 feet
Height
8 feet
8 feet
Weight
90,000 pounds
10,000 pounds
SuperVAR Assemblies Will Be Delivered With Minimal Site Work Required
Next stop: Russellville, Kentucky
Logan Aluminum
premier manufacturing
facility with modern
high-speed equipment,
operational areas
include ingot casting,
hot rolling, cold rolling
and finishing.
Anything that won't sell, I don't want to invent. Its sale is proof of utility, and utility is success. — Edison
T3 Contributes Significantly to Var Injection
(Low Loading Condition)
T1 Bank Var Usage
14,000
12,000
10,000
8,000
kVAR
KVAR Lag
KVAR Lead
6,000
4,000
T2 KVAR
16,000
2,000
14,000
78
155 232 309 386 463 540 617 694 771 848 925 1002 1079 1156 1233 1310 1387 1464
12,000
1/2 hour intervals in August
10,000
KVAR
1
KVAR Lag
8,000
KVAR Lead
6,000
4,000
2,000
1
80
159 238 317 396 475 554 633 712 791 870 949 1028 1107 1186 1265 1344 1423
1/2 Hour Intervals in August 2005
Sir Francis Drake, 1577
Disturb us, Lord, when
We are too well pleased with ourselves,
When our dreams have come true
Because we dreamed too little,
When we arrived safely
Because we sailed too close to the shore.
This R&D engineer’s prayer …
naval pioneer and civil engineer, first captain to circumnavigate the Earth (1577-1580)