1. Agenda D-VAR DVC (Dynamic VAR Compensator)
SuperVAR (Synchronous Condenser)

2. D-VAR What are D-VAR Devices?
Dynamic VARs… Fully integrated modular STATCOM with proprietary 3X overload
Instantaneously injects precise amounts of reactive power into a network
Can be seamlessly integrated with static shunt devices as part of a larger solution
D-VAR mitigates wide variety of voltage and power quality related transmission problems

3. Application of D-VAR Transmission Problems That D-VAR Can Solve:
Voltage Stability / Voltage Collapse - Uncontrolled rapid decline
in system voltage
Steady State Voltage Regulation - Wind farms, radial lines, etc...
Import/ Transfer Capability Restrictions - Limited ability to
reliably import, export, or transfer power
Mitigate voltage flicker/ power quality - Wind farms, industrial
facilities
The first three issues are potentially related:
One of the potential answers for improving Transfer Restrictions is to add static capacitance to the system thus allowing the transfer of power to increase closer to the thermal limits of the system
When static capacitance is added in large chunks, it potentially will move a customer further to the right on the nose curve, thus bringing them potentially closer to a collapse situation if a contingency event were to occur. This is due to the fact that if the voltage were to begin to decline, the static VAR support would decline also at a rate that is the square of the voltage, thus causing transfer to be effected and creating a very quick cascading collapse
Steady State Low System Voltage enhances a collapse situation as you are not only further out on the nose curve, but you also limiting the effects of your static VARs as again, their effectiveness is a function of the square of the voltage
GE / AMSC performs full system analysis jointly with the customer to determine the least cost, best available solution

4. Just the FACTS… DVAR § High power, air cooled, inverters (STATCOM) §
No environmental permits required
Lowest cost
Quickest installation
Easily located in
distribution substations
No need for operator
control
24 X 7 remote
monitoring by AMSC

5. DVAR Basics….
Each D-VAR system has continuous reactive power… with temporary overload capability up to 3 times its continuous rating. Each phase is individually controlled.
Proprietary Power Electronics Technology

6. Typical Inverter Module

7. Stacked Inverter Array
Proprietary fault-tolerant array design provides additional reliability

8. D-VAR Injection Capability
Reactive Power
3.0 p.u.
1.0 p.u.
Rated MVA Current
Overload reactive current
Continuous reactive current
1.0
2.0 8
Proprietary technology provides combination of continuous
dynamic VARs with additional overload boost

9. American Superconductor field experience: 34 Statcoms leads the industry.

10. Field Operating Experience Summary
Key Facts:
Over 530,000 Operating Hours ~ > 60 years
Over 6200 stability/voltage sag responses recorded
Number of inverters modules in the field: 840 as of 1 Feb ‘05
Six dedicated voltage regulating D-VARs averaging 249 active regulating hours per month
Proven high availability
Last 36 months entire fleet: 99.4%
Last 12 months entire fleet: 99.7%
American Superconductor D-VAR Systems have unmatched experience and field performance

11. D-VAR Annual Preventive Maintenance
Output Breaker Cabinet: Annual connections check/torque
Overall General Condition Check: Annual - Lights, exterior condition, air intake & exhaust passages, exhaust fans, fire extinguishers
MIU: Annual General condition check, UPS Battery check/test/replace,
Inverters: Seasonal filter clean/replace, general condition check, Winterize louvers, fans, check heater operations.
Easy to maintain… 24 X 7 performance monitoring by AMSC

12. DVAR Application Examples
Keyspan/LIPA: Avoiding Voltage Collapse
NE Utilities: Increased Transfer Capability
Caprock wind: Wind Farm LVRT & Regulation

13. East End of Long Island Areas of Voltage Collapse Concerns
Southold
Orient Point
Generating
Peconic
Areas of Voltage Collapse Concerns
Mattituck
Tuthill
Riverhead
Bridgehampton
Amagansett
Hero
East Hampton
Southampton
Buell
Tiana
Double Circuit 69kV fault
Installation Site

14. Example of Study Area Voltage Collapse
Buell 69kV Bus Voltage
Bridgehampton 69kV Bus Voltage
Hero 23kV Bus Voltage
Reclosing Attempt
“East of Southamption” Fault and Clearing Event with Reclosing Attempt
1.00 p.u.
0.90 p.u.
0.80 p.u.
0.70 p.u.
0.60 p.u.
Example of Study Area Voltage Collapse
CASE DISCRIPTION
Load = LI(2500MW) – EE(133MW) – SF(92MW)
No East End Generation

15. To East Hampton Diesels
Proposed Solution for the East End Voltage Issues 8 MVA D-VAR Installed at Bridgehampton
Easthampton
69 kV
To Bridgehampton
To Buell
13.8 kV
Load
Load
To East Hampton Diesels
13.8 kV VT
8 MVA
D-VAR
Inputs to DVAR
for Voltage Control V
Padmount
Transformers VT

16. Voltage Response with D-VAR Installed
Bus Voltages:
Bridgehampton
Buell
Hero
0.90 p.u. Voltage
2.0 Seconds After Fault.
Voltage Response Meets Recovery Criteria.
D-VAR Output
“East of Southamption” Fault and
Clearing Event with Reclosing Attempt
CASE DISCRIPTION
Load = LI(2500MW) – EE(133MW) – SF(92MW)
No East End Generation
1.00 p.u.
0.90 p.u.
0.80 p.u.
0.70 p.u.
0.60 p.u.
23.4 MVAR

17. Northeast Utilities D-VAR Based Transmission Solution for Transfer Capability Improvement

18. Southwest Connecticut
Northeast Utilities – Power Transfer Increase
Southwest Connecticut's Danbury Area
Southwest Connecticut
345 kV and 115 kV transmission system
13.8 kV distribution system
Highly compensated with capacitors
235 MW Danbury Area
3600 MW SW Connecticut
Critical
Outage

19. Northeast Utilities Danbury Area
Loadflow Problem Results
Danbury Area 115 kV Substation Voltages
For outage of the Long Mountain-Plumtree 345 kV line, imports into the area are almost 2,300 MW before area voltages collapse.
Transfers into the area are curtailed when predicted contingency transmission voltages fall below 95%.
Per Unit Voltages
SW Connecticut Imports

20. Northeast Utilities Danbury Area
D-VAR Systems Solution
Install three D-VAR systems (rated at 8 MVAR each) at two existing distribution substations and D-VAR system controlled capacitor banks
one 8 MVAR distribution
two 37.8 MVAR transmission banks
Reasons for purchase:
low profile, no substation site expansion was necessary
low cost
flexibility / relocatable
installation time (<6 months)
summer ‘03 payback due to increased import capability
DVAR Dynamic Range = -55 to +130 MVAR

21. SW Connecticut Imports
Northeast Utilities Danbury Area
Comparison of Loadflow Results
Solution
Per Unit Voltages
Problem
SW Connecticut Imports

22. Caprock Wind Farm D-VAR Based Transmission Solution for steady-state voltage regulation and transient voltage support

23. Area One-Line Diagram Utility Substations Transmission Lines Utility
Wind
Farm
Site
Utility Substations
Transmission Lines
Utility
Interconnection
Point
60 Miles
Xcel Transmission
New Mexico

24. Dynamic Capacitor Banks
D-VAR™ Solution’s Dynamic Voltage Support Provides a total of -48 MVAR/+84 MVAR T1
60/90 MVA
with LTC
34.5 kV
115 kV
Utility
Interconnection
Point
600V
26 MW
9 X 3.6 MVAR
VTs
97%
Lagging PF
26 units
The dynamic MVARs are sized to prevent the wind farm from tripping off-line for the faults that the utility specified.
34.5 kV UDG
collector
system
600V
28 MW
Joslyn
VBM
Switch
97%
Lagging PF
8/24 MVAR
D-VAR
28 units
4x2500 KVA V
padmount
transformers
D-VARs
Dynamic 2 x 8 x 3 = 48 MVAR
8/24 MVAR
D-VAR
600V
1200 Amp
Breaker
26 MW
Joslyn
VBU
Switch
Dynamic Capacitor Banks
2 x 18 MVAR = 36 MVAR
97%
Lagging PF
26 units

25. Summary of large DVAR Applications
DVAR system output range
Rayburn Coop -36 to +86 MVAR
NE Utilities to +130 MVAR
Caprock wind farm -48 to +84 MVAR
NW Semiconductor -168 to +168 MVAR

26. American Superconductor Dynamic Var Compensator DVCTM
AMSC’s large single site solution is called a Dynamic VAR Compensator
or DVCTM.

27. DVCTM Solution Advantages
Hybrid Statcom / SVC
Exceeds performance of conventional SVC technology
Builds off of widely successful D-VARTM statcom platform and proven compenents
Modular components - easily expandable
% less cost than equivalent SVC solutions

28. SVC basic building blocks
TCR
Harmonic Filter Caps
5th & 7th harmonics
Always “on”
10-30 MVAR each
TSC
SVC Transformer
Sized for max VAR output
Can have overload rating as well
Specialty unit due to high V secondary HV
MV (12-20 kV)
Optional MSCs
TCR - Thyristor Controlled Reactor
Provides infinite control of reactor VARs from 0-100%
“On” all the time but VAR output changing per system needs
Sized to provide max lagging VARs (Reactor-filter caps = max)
TSC - Thyristor Switched Capacitors
“On“ only as needed to provide leading VARs
Fast switching in 1-2 cycles with Thyristor switch
MVAR -same or different sizes to allow smaller VAR steps

29. Example DVC Solution
Full interrupting capacity breaker
Joslyn VBU switch (1.5-2 cycle T&C)
Shunt reactor
20 MVAR
D-VAR
8MVA
34.5 kV
4x2000
KVA
1200 A
breaker
25 MVAR
2000 A
Inrush
Suppression
Reactors
67.5/112.5 MVA
HV-34.5 kV
Transformer
High Voltage
55 MVAR
Each
Statcom D-VAR modules with 3X overload rating
-35 to +210 MVAR of dynamic reactive compensation!

30. DVC Operation
1) STATCOM responds to any voltage deviation outside preset levels (use overload ratings as needed)
2) Primary Capacitors quickly switch in response to large voltage deviations
3) Secondary Capacitors switch to bring STACOM output within continuous rated output (below overload levels) as needed.

31. Capacitor and reactor switching using Joslyn VBU modified to include AMSC control board
Close Timing
From solenoid energization to contact touch: ms max.
Trip Timing
From solenoid energization to contact part: 17 ms max.
From contact part to full open: 7 ms max.
Low Maintenance
10,000 operation between inspections
Proven Performance
Over 500 three phase units installed during past 40 years

32. SaskPower DVC solution provides steady-state voltage regulation and transient voltage stability support

33. Saskatchewan Power’s Rush Lake Wind Farm One-Line Diagram
Critical Outage
Critical Bus for Post Fault
Voltage Requirement
Point of
Common
Coupling
230 kV Transmission Bus
Substation Transformer
100 MVA Base, 10% Z
10% LTC
34.5kV Main Collection Bus
Rush Lake Solution Requirements:
Regulate voltage at 230 kV transmission bus PCC
Install sufficient reactive capability to meet 95% lagging to 90% leading PF at PCC
Prevent tripping of wind farm turbines for worst fault
Prevent 138 kV bus from dropping below 0.70 pu voltage for worst fault (MAPP Criteria)
Collection Feeders
To 150 MW of
Wind turbines

34. Saskatchewan Power’s Rush Lake Wind Farm
DVCTM Dynamic Reactive Compensation Solution
Critical Outage
Critical Bus for Post Fault
Voltage Requirement
Point of
Common
Coupling
230 kV Transmission Bus
Substation Transformer
100 MVA Base, 10% Z
10% LTC
34.5kV Main Collection Bus
D-VAR
Collection Feeders
To 150 MW of
Wind turbines
D-VAR
2X25 MVAR Cap Bank
(Transient Use Only)
8 X 13.2 MVAR Cap Banks
(Steady State Regulation)
16/48 MVAR
DVAR Statcom
DVC System Total Short-term Dynamic VAR Capability = -48 to +98 MVAR

35. Critical Transmission
Bus Voltage
With Solution
Cap #1 Out
Cap #2 Out
Cap #2 In
Cap #1 In
0.70 p.u. Minimum Voltage Target
Critical Transmission
Bus Voltage
Without Solution
With DVC solution, critical transmission voltage remains above target

36. DVC Solution Advantages
Hybrid STATCOM / SVC
Exceeds performance of conventional SVC technology
Builds off of widely successful D-VAR STATCOM platform
Modular components - easily expandable
% less cost than equivalent SVC solutions

37. STATCOM Vs SVC Performance At Reduced Voltages
STATCOM is a Current Controlling Device
Q = I*V
Reactive Power is linearly dependent on Voltage
SVC is a Impedance Controlling Device
Q = V2/X
Reactive Power is dependent on the square of the Voltage

38. 80/200 MVAR STATCOM Capacitive Output Vs
80/200 MVAR STATCOM Capacitive Output Vs. Bus Voltage As Compared to 200 MVAR SVC
p.u.
1.00 p.u.
D-VAR Peak Output
Capability
SVC Peak Output Capability
.80 p.u.
p.u.
p.u.
.60 p.u.
p.u.
p.u.
69kV Bus Voltage
.40 p.u.
p.u.
p.u.
.20 p.u.
p.u.
8 .20 p.u.
50 MVAR
100 MVAR
150 MVAR
200 MVAR
D-VAR Capacitive Output

39. Performance Comparison DVC vs. SVC
Alternate DVC
Solution
SVC Solution
DVC outperforms conventional SVC technology!!

40. SuperVARTM Dynamic Synchronous Condenser

41. SuperVarTM SuperVAR – rotating machines platform
World’s first commercial product based on HTS technology
TVA launch customer – ordered first five production units
Successfully tested on the Ohio power grid
Delivered advanced prototype to TVA in August 2004 for final grid testing
Supplements D-VAR Solutions
Cooler
module
Support structure
EM shield / Vacuum shell
Brushless exciter
Torque tube
Shaft
Compressors
Conduction
cooling tube
Field coils
Stator coils
Back iron
Vacuum chamber

42. 8 MVAR SuperVARTM Condenser Cut Away
Refrigeration
Systems
Auxiliary
Drive Motor
480V Service
Exciter
Stator and HTS Rotor
25 feet

43. SuperVARTM Condenser Performance Features
Fast reacting dynamic voltage and stability support (leading and lagging VARs) at a multiple of the machine rating
+/-12 MVAR Continuous
Up to 2x continuous rating for 2 minutes
Fast exciter
Increases local fault power by 80 MVA due to low sub-synchronous reactance
Very low maintenance and operating costs
Connects direct to MV bus at kV
Simplified installation using compact container

44. Existing Utility and Customer System
Power Quality Problems - Motor Starting
Existing Utility and Customer System
Customer
Substation kV
Substation
4160V
1200 HP
Dredge Motor
12.5 kV M
Vista
1000 HP
Booster #1 Motor
4.5 MVA
N.O. M
Other customer loads
Riley
600 HP
Backwash Motor
4160V M
12.5 kV
69 kV
1000 HP
Booster#2 Motor M

45. Voltage Sags on 12.47 kV Bus due to Motor Starting on Existing System
Dredge
Booster#1
Backwash
Booster#2
13%
Motor starting is causing very noticeable and objectionable voltage sags

46. Add SuperVARTM Solution
Power Quality Problems - Motor Starting
Add SuperVARTM Solution
Customer
Substation kV
Substation
4160V
1200 HP
Dredge Motor
12.5 kV M
Vista
1000 HP
Booster #1 Motor
4.5 MVA
N.O. M
Other customer loads
Riley
600 HP
Backwash Motor
4160V M
12.5 kV
69 kV S
1000 HP
Booster#2 Motor M
12 MVA SuperVAR
Device
SuperVARTM Condenser solution is even better without a kV transformer

47. SuperVARTM Condenser Applied to Motor Starting Problem
Bus Voltage in kV
Bus Voltage Without SuperVARTM Condenser
Time (Seconds)
Bus Voltage With SuperVARTM Condenser
Bus Voltage in kV
Time (Seconds)
SuperVARTM MVAR Output
Output in MVAR
Time (Seconds)

48. Summary of benefits of SuperVARTM Solutions
Eliminates voltage sags from large motor starting events
Increases local fault MVA and adds inertia to system
Mitigates transient voltage problems including voltage flicker
Solves steady state voltage regulation problems

49. Proper Load Modeling for Voltage Studies
Detailed Load Modeling
Proper Load Modeling for Voltage Studies 56

50. Typical Loadflow Base Case
Sub C
Sub B
Load represented on the transmission bus, typically as constant MVA.
138 kV
Sub A 22

51. Necessary Detail That Need to be Added to the Loadflow Base Case
Sub C
Detailed Loadflow
Sub B
Sub-Transmission
System
13 kV
Small and Large Motors
Discharge Lighting
XFMR Exciting I
Constant Power
Remaining
Sub 1
Distribution
Capacitor
Banks
138 kV
Sub B
Sub A
115 kV
46 kV
Sub 2
The transmission flows and voltages between the loadflows should not change.
Sub 3
Dist. Transformer
and Dist. Line Z 23

52. Why go through all of this work to model the load?
Detailed Load Modeling
Why go through all of this work to model the load? 56

53. You Can’t Determine Your Risk Without It!
These are voltage responses using ZIP load models, for 138 kV and 12 kV buses after a fault.
Voltage In Per Unit
Time In Seconds 57

54. Compare ZIP Models and Detailed Models!
Compare the results using detailed load models with those for ZIP loads models.
Comparison of ZIP loads
Voltage In Per Unit
Time In Seconds 58

55. Questions?