Agenda DVAR DVC Dynamic VAR Compensator Super VAR

Agenda • D-VAR • DVC (Dynamic VAR Compensator) • Super. VAR (Synchronous Condenser) Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

D-VAR What are D-VAR Devices? • Dynamic VARs… Fully integrated modular STATCOM with proprietary 3 X 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 Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

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 GE / AMSC performs full system analysis jointly with the customer to determine the least cost, best available solution Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

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 Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

DVAR Basics…. Proprietary Power Electronics Technology 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 & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Typical Inverter Module Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Stacked Inverter Array Proprietary fault-tolerant array design provides additional reliability Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

D-VAR Injection Capability Rated MVA Current 3. 0 p. u. Reactive Power Overload reactive current 1. 0 p. u. Continuous reactive current 0 1. 0 2. 0 8 0 Proprietary technology provides combination of continuous dynamic VARs with additional overload boost Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

American Superconductor field experience: 34 Statcoms leads the industry. Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

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 Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

D-VAR Annual Preventive Maintenance Overall General Condition Check: Annual - Lights, exterior condition, air intake & exhaust passages, exhaust fans, fire extinguishers Output Breaker Cabinet: Annual connections check/torque Inverters: Seasonal filter clean/replace, general condition check, Winterize louvers, fans, check heater operations. MIU: Annual General condition check, UPS Battery check/test/replace, Easy to maintain… 24 X 7 performance monitoring by AMSC Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

DVAR Application Examples • Keyspan/LIPA: Avoiding Voltage Collapse • NE Utilities: Increased Transfer Capability • Caprock wind: Wind Farm LVRT & Regulation Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

East End of Long Island Southold Orient Point Generating Peconic Areas of Voltage Collapse Concerns Mattituck Tuthill Riverhead Bridgehampton East Hampton Southampton Amagansett Buell Tiana Double Circuit 69 k. V fault Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor Installation Site Hero

Example of Study Area Voltage Collapse 1. 00 p. u. 0. 90 p. u. 0. 80 p. u. “East of Southamption” Fault and Clearing Event with Reclosing Attempt Buell 69 k. V Bus Voltage Bridgehampton 69 k. V Bus Voltage Hero 23 k. V Bus Voltage 0. 70 p. u. 0. 60 p. u. CASE DISCRIPTION Load = LI(2500 MW) – EE(133 MW) – SF(92 MW) No East End Generation Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Proposed Solution for the East End Voltage Issues 8 MVA D-VAR Installed at Bridgehampton Easthampton 69 k. V To Bridgehampton Load To Buell 13. 8 k. V Load To East Hampton Diesels 13. 8 k. V 8 MVA D-VAR VT 480 -13800 V Padmount Transformers VT Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor Inputs to DVAR for Voltage Control

Voltage Response with D-VAR Installed 1. 00 p. u. 0. 90 p. u. Bus Voltages: Bridgehampton Buell Hero 0. 80 p. u. 0. 70 p. u. 0. 60 p. u. 23. 4 MVAR D-VAR Output 0. 90 p. u. Voltage 2. 0 Seconds After Fault. Voltage Response Meets Recovery Criteria. CASE DISCRIPTION Load = LI(2500 MW) – EE(133 MW) – SF(92 MW) No East End Generation “East of Southamption” Fault and Clearing Event with Reclosing Attempt Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Northeast Utilities D-VAR Based Transmission Solution for Transfer Capability Improvement Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Northeast Utilities – Power Transfer Increase Southwest Connecticut's Danbury Area Southwest Connecticut Critical Outage • 345 k. V and 115 k. V transmission system • 13. 8 k. V distribution system • Highly compensated with capacitors • 235 MW Danbury Area • 3600 MW SW Connecticut Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Northeast Utilities Danbury Area Loadflow Problem Results Per Unit Voltages Danbury Area 115 k. V Substation Voltages SW Connecticut Imports Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor • For outage of the Long Mountain-Plumtree 345 k. V 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%.

Northeast Utilities Danbury Area D-VAR Systems Solution DVAR Dynamic Range = -55 to +130 MVAR • 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 Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Northeast Utilities Danbury Area Comparison of Loadflow Results Per Unit Voltages Solution Problem SW Connecticut Imports Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Caprock Wind Farm D-VAR Based Transmission Solution for steady-state voltage regulation and transient voltage support Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Area One-Line Diagram Wind Farm Site Utility Interconnection Point 60 Miles Xcel Transmission New Mexico Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor Utility Substations Transmission Lines

D-VAR™ Solution’s Dynamic Voltage Support Provides a total of -48 MVAR/+84 MVAR 600 V 26 MW 97% Lagging PF 34. 5 k. V T 1 60/90 MVA with LTC 9 X 3. 6 MVAR 26 units 115 k. V VTs Utility Interconnection Point The dynamic MVARs are sized to prevent the wind farm from tripping off-line for the faults that the utility specified. 34. 5 k. V UDG collector system 600 V Joslyn VBM Switch 28 MW 97% Lagging PF 28 units 4 x 2500 KVA 34500 -480 V padmount transformers 600 V 26 MW 97% Lagging PF 26 units 8/24 MVAR D-VARs. Dynamic 2 x 8 x 3 = 48 MVAR 8/24 MVAR D-VAR 1200 Amp Breaker Joslyn VBU Switch Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor Dynamic Capacitor Banks 2 x 18 MVAR = 36 MVAR

Summary of large DVAR Applications • • DVAR Application DVAR system output range Rayburn Coop NE Utilities Caprock wind farm NW Semiconductor -36 to +86 MVAR -55 to +130 MVAR -48 to +84 MVAR -168 to +168 MVAR Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

American Superconductor Dynamic Var Compensator DVCTM AMSC’s large single site solution is called a Dynamic VAR Compensator or DVCTM. Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

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 • 20 - 30% less cost than equivalent SVC solutions Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

SVC basic building blocks HV SVC Transformer • Sized for max VAR output • Can have overload rating as well • Specialty unit due to high V secondary Optional MSCs MV (12 -20 k. V) TCR TSC TSC Harmonic Filter Caps • 5 th & 7 th harmonics • Always “on” • 10 -30 MVAR each 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 • 25 -100 MVAR -same or different sizes to allow smaller VAR steps Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Example DVC Solution High Voltage 67. 5/112. 5 MVA HV-34. 5 k. V Transformer 55 MVAR Each -35 to +210 MVAR of dynamic reactive compensation! 2000 A breaker 34. 5 k. V 2000 A breaker 1200 A breaker 4 x 2000 KVA Inrush Suppression Reactors 25 MVAR 20 MVAR Shunt reactor 8 MVA D-VAR Statcom D-VAR modules with 3 X overload rating Full interrupting capacity breaker Joslyn VBU switch (1. 5 -2 cycle T&C) Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

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. Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Capacitor and reactor switching using Joslyn VBU modified to include AMSC control board Close Timing From solenoid energization to contact touch: 20 - 28 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 Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Sask. Power DVC solution provides steady-state voltage regulation and transient voltage stability support Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Saskatchewan Power’s Rush Lake Wind Farm One-Line Diagram Critical Bus for Post Fault Voltage Requirement Substation Transformer 100 MVA Base, 10% Z 10% LTC Point of Common Coupling Critical Outage 230 k. V Transmission Bus 34. 5 k. V Main Collection Bus Rush Lake Solution Requirements: Collection Feeders To 150 MW of Wind turbines • Regulate voltage at 230 k. V 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 k. V bus from dropping below 0. 70 pu voltage. Must fornot worst fault or (MAPP Criteria) Proprietary & Confidential Information. be duplicated distributed without prior express written permission by American Superconductor

Saskatchewan Power’s Rush Lake Wind Farm DVCTM Dynamic Reactive Compensation Solution Critical Bus for Post Fault Voltage Requirement Substation Transformer 100 MVA Base, 10% Z 10% LTC Point of Common Coupling Critical Outage 230 k. V Transmission Bus 34. 5 k. V Main Collection Bus D-VAR Collection Feeders To 150 MW of Wind turbines D-VAR 16/48 MVAR DVAR Statcom 2 X 25 MVAR Cap Bank 8 X 13. 2 MVAR Cap Banks (Transient Use Only) (Steady State Regulation) DVC System Total Short-term Capability Proprietary & Confidential Information. Must not Dynamic be duplicated VAR or distributed without prior express written permission by American Superconductor = -48 to +98 MVAR

Critical Transmission Bus Voltage With Solution Cap #1 Out Cap #2 In Cap #1 In 0. 70 p. u. Minimum Voltage Target Critical Transmission Bus Voltage Without Solution Proprietary & Confidential Information. Must nottransmission be duplicated or distributed With DVC solution, critical voltage without prior express written permission by American Superconductor remains above target

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 • 20 - 30% less cost than equivalent SVC solutions Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

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 = V 2/X Reactive Power is dependent on the square of the Voltage Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

80/200 MVAR STATCOM Capacitive Output Vs. Bus Voltage As Compared to 200 MVAR SVC 200 MVAR @ 1. 00 p. u. D-VAR Peak Output Capability. 80 p. u. SVC Peak Output Capability 69 k. V Bus Voltage 160 MVAR @. 80 p. u. 128 MVAR @. 80 p. u. . 60 p. u. 120 MVAR @. 60 p. u. 72 MVAR @. 60 p. u. . 40 p. u. 80 MVAR @. 40 p. u. 32 MVAR @. 40 p. u. . 20 p. u. 40 MVAR @. 20 p. u. 8 MVAR @. 20 p. u. 50 MVAR 100 MVAR 150 MVAR 200 MVAR D-VAR Capacitive Output Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Performance Comparison DVC vs. SVC Alternate DVC Solution SVC Solution DVC outperforms conventional SVC technology!! Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Super. VARTM Dynamic Synchronous Condenser Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

TM Super. Var Super. VAR – rotating machines platform – World’s first commercial product based on HTS technology – TVA launch customer – ordered first five production units Cooler module Back iron Stator coils EM shield / Vacuum shell Torque tube Shaft Compressors Brushless exciter Vacuum chamber Support structure Conduction cooling tube Field coils – Successfully tested on the Ohio power grid – Delivered advanced prototype to TVA in August 2004 for final grid testing – Supplements D-VAR Solutions Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

8 MVAR Super. VARTM Condenser Cut Away Refrigeration Systems Auxiliary Drive Motor 480 V Service Exciter Stator and HTS Rotor 25 feet Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Super. VARTM 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 2 x 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 1. 5 -13. 8 k. V • Simplified installation using compact container Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Power Quality Problems - Motor Starting Existing Utility and Customer System 4160 V 1200 HP Dredge Motor 1000 HP Booster #1 Motor Customer Substation 12. 5 k. V M M 600 HP Backwash Motor M 1000 HP Booster#2 Motor M 69 -12. 5 k. V Substation 4. 5 MVA Vista N. O. Other customer loads Riley 4160 V Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor 12. 5 k. V 69 k. V

Voltage Sags on 12. 47 k. V 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 Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Power Quality Problems - Motor Starting Add Super. VARTM Solution 4160 V 1200 HP Dredge Motor 1000 HP Booster #1 Motor Customer Substation 12. 5 k. V M M 600 HP Backwash Motor M 1000 HP Booster#2 Motor M 69 -12. 5 k. V Substation 4. 5 MVA Vista N. O. Other customer loads Riley 4160 V 12. 5 k. V 69 k. V S 12 MVA Super. VAR Device Super. VARTM Condenser solution is even better without a 13. 8 -12. 5 k. V transformer Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Output in MVAR Bus Voltage in k. V Super. VARTM Condenser Applied to Motor Starting Problem Motor #1 Motor #2 Motor #3 Motor #4 Bus Voltage Without Super. VARTM Condenser Time (Seconds) Bus Voltage With Super. VARTM Condenser Time (Seconds) Super. VARTM MVAR Output Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor Time (Seconds)

Summary of benefits of Super. VARTM 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 Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Detailed Load Modeling Proper Load Modeling for Voltage Studies 56 Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Typical Loadflow Base Case Sub C Sub B 138 k. V Load represented on the transmission bus, typically as constant MVA. Sub A 22 Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Necessary Detail That Need to be Added to the Loadflow Base Case Sub C Sub B Detailed Loadflow 138 k. V Sub A Sub-Transmission System Small and Large Motors Discharge Lighting XFMR Exciting I Constant Power Remaining Sub 1 Sub B 115 k. V 13 k. V 46 k. V Sub 2 13 k. V The transmission flows and voltages between the loadflows should not change. Dist. Transformer and Dist. Line Z Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor Sub 3 Distribution Capacitor Banks 23

Detailed Load Modeling Why go through all of this work to model the load? 56 Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

You Can’t Determine Your Risk Without It! Voltage In Per Unit These are voltage responses using ZIP load models, for 138 k. V and 12 k. V buses after a fault. Time In Seconds Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor 57

Voltage In Per Unit Compare ZIP Models and Detailed Models! Compare the results using Comparison detailed load of models with those ZIP loads for ZIP loads models. Time In Seconds 58 Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor

Questions? Proprietary & Confidential Information. Must not be duplicated or distributed without prior express written permission by American Superconductor