System Components. David Mahlmann Spring 2003

Transcription

1 System Components David Mahlmann Spring 2003

2 Here s the plan. To describe all of the parts of the system, summarize how they work and interact In the next section on Transmission System Operation we will address how they work together

3 Parts is Parts! Generation Transmission Load System Interactions

4 Generation Reference 2002 Load & Capacity Report

5 Generators provide only two quantities MW - Real Power MVAR Reactive Power Let s look at the the MW first.

6 Generator MW - who needs em? Loads - Energy (aka the money maker) System - Control power distribution on the system System - Provide reserve System - Balance load and losses requirement to control net-interchange We will talk about the system needs for MW, and how they are met as we proceed through this program. Without the system energy can t get to the load and everyone loses.

7 Generators - MW output Equipment Prime Movers Boilers, Gas turbines, Hydro turbines, internal combustion, wind turbines, fuel cells

8 Generators - MW output Equipment

9 Restrictions on MW production Response rate limits thermodynamics Equipment failures tubes, boiler feed pumps, fans, water chemistry control Environmental limits emissions gases, air and water temperature limits On a given day, the generator operator should have a good handle on the MW generation capability.

10 Generator MVAR - who needs em? Load Provide reactive power demands of the load Maintain voltage quality Minimize sub-transmission/distribution losses System - Power Transfer Maintain secure voltage profile on Bulk Power System (BPS) Minimizes transmission losses System - Contingency Response Sustain post-contingency voltages Damp out system voltage and power swings to maintain system stability and avoid voltage collapse

11 Generators - MVAR output Equipment Exciters Automatic Voltage Regulators Power System Stabilizers Limits to MVAR output Generator heating Generator cooling systems Auxiliary system voltage requirements

12 Generators - MVAR output Equipment Stator Windings Field Coils Field Forging Coil Slot

13 Restrictions on MVAR production Stator and rotor heating conditions D-Curve Equipment failures AVR out of service System constraints station service voltages, local system voltage constraints On a given day, the generator operator should have a good handle on the MVAR generation capability.

14 MVARS are controlled along with voltage by adjusting excitation current. Higher Field Current produces LAGGING power factor (Vars out of Generator) Lower Field Current produces LEADING power factor (Generator absorbs Vars) Generator must be operated within the limits of the D Curve

15 Lag Per Unit MVAR PSI 45 PSI 30 PSI Per Unit MW.7.70PF.80PF.90PF PF.98PF.98PF.95PF.90PF.7 Generator D Curve

16 How is generation distributed in New York? By fuel type By location

17 Generation Sources Other Combined Cycle Gas Turbine Steam Oil/Gas Source: 2002 Load & Capacity Data Hydro Steam Nuclear Steam Coal MW % Steam Oil & Gas % Steam Coal % Steam Nuclear % Hydro % Combined Cycle % Gas Turbine % Other 448 1% Total Capability 36342

18 Saunders Chateauguay New York State Transmission System Moses- St. Lawrence Dennison Colton Massena Willis Plattsburgh Sandbar Legend: 765 kv 500 kv 345 kv 230 kv 115 kv Beck Niagara Huntley Stolle Rd. Gardenville Dunkirk Somerset Sta.80 Robinson Rd. Homer City Pannell Meyer Andover Palmiter Watercure Hillside Oswego Complex Oakdale Adirondack Marcy Clay Edic Lafayette Richfield Springs Central - East Hoosick Porter Inghams Fraser Coopers Corners Rock Tavern Gilboa Roseton Rotterdam Buchanan Ramapo W49St/Rainey Whitehall Blissville New Scotland Total - East Farragut Goethals Alps Leeds Pleasant Valley Millwood Sprainbrook Dunwoodie Bennington Shore Rd. E.Garden City

19 Transmission Reference 2002 Load & Capacity Report

20 Transmission - The switchyard and beyond What do I need to know about transmission, and why? What happens to my MW & MVARS when they leave the plant?

21 Transmission NY State - Large sources of generation are located far from heaviest load Bulk Power Transmission System transports energy from source to sink 765, 345, & 230 KV lines make up the Bulk Power System

22 Miles of NY Transmission by KV Class Miles of NY Transmission by KV Class KV Class Miles / KV 500KV 345 KV 230 KV 115/138 KV

23 Saunders Chateauguay New York State Transmission System Moses- St. Lawrence Dennison Colton Massena Willis Plattsburgh Sandbar Legend: 765 kv 500 kv 345 kv 230 kv 115 kv Beck Niagara Huntley Stolle Rd. Gardenville Dunkirk Somerset Sta.80 Robinson Rd. Homer City Pannell Meyer Andover Palmiter Watercure Hillside Oswego Complex Oakdale Adirondack Marcy Clay Edic Lafayette Richfield Springs Porter Inghams Fraser Coopers Corners Rock Tavern Gilboa Roseton Rotterdam Buchanan Ramapo W49St/Rainey Whitehall Blissville Hoosick New Scotland Farragut Goethals Alps Leeds Pleasant Valley Millwood Sprainbrook Dunwoodie Bennington Shore Rd. E.Garden City

24 Transmission Components Conductors - overhead and underground Breakers, disconnects and substation equipment Transformers voltage control, power control Voltage control equip. - capacitors, reactors, SVC

25 Capacitors Circuit Breakers Reactors Transformers

26 Transmission System MW Controls Phase Angle Regulators Flexiable AC Transmission (FACTS) HVDC Transmission HVDC Lines Back to back terminals

27 Transmission System MVAR Controls Load Tap Changing Transformers (LTCs) Supervisory controlled LTCs allow system operators to change tap ratios. Shunt Capacitor and Reactors Unlike AVRs and SVCs, these device provide step changes in the VAR support. Static VAR Compensators (SVCs) Static Var Compensators(SVCs) and STATCOM devices perform a special function of high speed continuous voltage support.

28 Restrictions on Transmission Equipment Heating Overhead wire sag Underground cable heating Transformer overheating Arcing high voltage Insulation breakdown loose connections

29 Transmission Equipment Ratings Normal permissible continuous loading 24/7 Long Term Emergency (LTE) typically 4 hours Short Term Emergency (STE) typically 15 min On a given day, the system operator should have a good handle on the transmission equipment limitations.

30 Load Reference 2002 Load & Capacity Report

31 Load and Losses All end users of energy are load Residential Customers Industrial Customers Pumped Storage units Losses are MW that are used by the system Transformers, wire losses, etc. Average is about 3.5% of system load Takes 900 MW of generation to run the NY system. A recent peak was 30,311 MW. Losses at that time were 1030 MW

32 Load is Variable that must be served Daily Load shape Weekday Weekend/Holiday Summer Winter Today usually similar to yesterday, with variations Daily Load Variations Temperature/humidity Cloud Cover / Wind Speed Economic Conditions Street lighting load in the state MW

33 A Summer Peak Load Pattern 24 Hour Load Profile :00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00 10:00 11:00 12: :00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 0:00 Time Load (MW)

34 Load (MW) A Typical Fall Weekday 24 Hour Load Profile :00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00 10:00 11:00 12: :00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 0:00 Time

35 Load (MW) A few days before Christmas 24 Hour Load Profile :00 1:00 2:00 3:00 4:00 5:00 6:00 7:00 8:00 9:00 10:00 11:00 12: :00 14:00 15:00 16:00 17:00 18:00 19:00 20:00 21:00 22:00 23:00 0:00 Time

36 System Interactions Power System Physics 101 Reference 2002 Operating Study

37 Power System Physics ) Power, Losses and voltage level 2) Wires, ground and electric fields 3) Power Distribution 4) Generic Security Constrained Operation 5) Transmission Interfaces

38 1) Power, Losses, and Voltage Level Power is the product of the voltage and the current. The same power transfer occurs with a high voltage/low current as with corresponding low voltage high current. Energy losses to heat on a line increase with the square of the current. Energy is efficiently transferred at high voltage an relatively low current.

39 2) Wires, Ground, and Electric fields Transmission is weird fact of physics #1 Based on the operating voltage and distance between the conductor and ground, transmission lines act like capacitors, generating MVARs

40 2) Wires, Ground and Electric fields (cont.) Transmission is weird fact of physics #2 Based on the conductor size, shape, spacing and current (power) flow, transmission lines act like big inductors, absorbing MVARs

41 2) Wires, Ground and Electric fields (cont.) Combining weird physics facts 1 & 2 MVAR Loading - MW Surge Impedance loading for a 100 mile 230KV line Depending on loading, a transmission line may be generating or absorbing MVARs

42 3) Transmission Flow a) Power flow distribute according to composite network impedance 100 MW 50 MW 50 MW 80 MW 20 MW

43 3) Transmission Flow a) Power flow distribution can be controlled by dispatch A 33 MW B 100 MW 0 MW 67 MW 33 MW A system with six lines of equal length, identical construction 100 MW C Loading per line BC = 33/2 =16.5MW Loading per line AC = 67/2 =33.5MW

44 3) Transmission Flow b) Power flow distribution can be controlled by dispatch 90 MW A 30 MW 3 MW B 10 MW 60 MW 3 MW A system with six lines of equal length, identical construction 100 MW C 30 MW 7 MW Loading per line BC = 37/2 =18.5MW Loading per line AC = 63/2 =31.5MW

45 3) Transmission Flow c) The flow redistributions can be calculated for any transmission or generation outage A 45 MW 2.5 MW 90 MW 10 MW B 45 MW 2.5 MW A system with six lines of equal length, identical construction 100 MW C 45 MW 7.5 MW Loading per line BC = 52.5/2 =26.25MW Loading per line AC = 47.5/1 =47.5MW

46 4) Generic Security Constrained Operation System Monitoring Contingency evaluation Loss of any transmission element Loss of any generator Security Constrained Dispatch & Scheduling Dispatch the system to a level where any single contingency will not cause a system overload (emergency) anywhere in the system

47 LOAD FLOW MAP UPNY Beck Somerset Sta. Oswego Oswego Complex Fitzpatrick Massena vvv Moses Chateauguay Willis Plattsburgh vvv Niagara Somerset Switch yard Sta.80 Pannell Sithe 9mi2 9mi1 Scriba Marcy Volney vvv vvv vvv vvv Porter Adirondack Rotterdam vvv Elm St. Packard Robinson Rd. Stolle Rd. Elbridge Clay DeWitt Edic Gilboa 99 BUS New Scotland Leeds Alps Athens Huntley Gardenville Meyer Watercure Lafayette Fraser Hurley Pleasant Valley Long Mt. Dunkirk Hillside vvv vvv Oakdale Coopers Corners Roseton E. Fishkill Pleasantville Dunwoodie Wood St. Millwood So. Ripley Erie So. \PRESENTATIONS\LOADFLOW_BASE 12/11/00 CHJ Homer City Towanda Legend: 765 kv 500 kv 345 kv 230 kv Rock Tavern Ramapo vvv Shore Rd. Buchanan Rainey Sprainbrook E. 13th W. 49th E.Garden City Tremont Farragut

48 5) Transmission Interfaces The transmission system has characteristics that may limit the amount of energy transfer Thermal Capability - by equipment or interface Megawatt limits A interface may load in way that one element hits a limit before all the lines have reached their limits. Voltage Limits - by equipment Low & High to avoid voltage & equipment damage Stability/Voltage Collapse Limits by interface To keep the system together

49 5) Transmission Interfaces (cont.) Transmission Interfaces are lines or groups of lines that have identified flow characteristics and operating limits Thermal limits System Stability Voltage collapse

50 Transmission Constraints on Central East Winter Operating Study 2001 Thermal Limit MW Emergency Limit 3450 MW Post Contingency Voltage Transfer Limit Dynamic Based on: Loss of Phase II in New England New Scotland #99 Bus Fault Marcy South Tower Fault Stability Limit 3100 MW w/ 3 Oswegos, 6 Sithe, both SVC s 3050 MW w/ #32 Oakdale-Fraser O/S 2900 MW w/ #4 Lafayette-Oakdale O/S

51 PENALTIES ON CENTRAL-EAST Oswego Complex Penalty Min Sithe Units I/S Both I/S Leeds/Fraser SVCs One SVC I/S Both O/S 4 of 5 units I/S of 5 units I/S of 5 units I/S of 5 units I/S of 5 units I/S STABILITY LIMIT = ( )

52 Dysinger East NEW YORK INTERNAL INTERFACES West - Central Central - East NS1 & SR2 Stolle - Meyer 67 Andover - Palmiter 932 Lockport - Telegraph Rd N. Akron N. Akron Oakfield Sweden Sweden 113 Moses South Pannel - Clay 1 & 2 Stolle - Meyer 67 Mortimer - Elbridge 1 & 2 Quaker - Sleight Rd. 13 Pannel - Farmington So. Perry - RGE 906 Clyde - NYSEG Farmington - NMPC Quaker - Macedon 930 Andover - Palmiter 932 Total East Plattsburgh - Vermont PV20 Edic - New Scotland 14 Marcy - New Scottland 18 Porter - Rotterdam 30 & 31 Richfield Springs - Inghams 942 Inghams PAR Inghams R81 (OCB) UPNY - Con Ed Massena - Marcy MSU1 Dennison - Sand Stone 5 Dennison - Colton 4 Alcoa - Browning Moses - Adirondak 1 & 2 Sprain Brook - Dunwoodie South Dunwoodie - Rainy 71 & 72 Dunwoodie - Sherman Creek 31 Dunwoodie So. - E 179th St Sprian Brook - Tremont X28 Sprain Brook - W 49th M51 & M 52 Jamaica - Valley Stream 901 Jamaica - Lake Success 903 Plattsburgh - Vermont PV20 Edic - New Scottland 14 Marcy - New Scottland 18 Porter - Rotterdam 30 & 31 Richfield Springs - Inghams 942 Inghams PAR Inghams R81 (OCB) Fraser - Gilboa GF5-35 West Woodbourne (T1-52) Ramapo - So. Mahwah 69 & 70 Ramapo - Branchburg 5018 Coopers Corners - Rock Tavern 34 & 42 Linden - Gothals A 2253 Hudson - Farragut B 3402 & C 3403 Ramapo - Buchanan 94 Ladentown - Buchanan 88 Roseton - East Fishkill 305 Pleasant Valley - East Fishkill F36 & F37 Pleasant Valley - Wood St. F30 Pleasant Valley - Millwood F31 Fishkill - Sylvan Lake 990 East Fishkill Bank Con Ed LIPA SprianBrook - E. Garden City Y49 Dunwoodie - Shore Rd Y50 Jamaca - Lake Success 901 Jamaca - Valley Stream 903 Northport - Norwalk Harbor 1385

53 NYISO Transmission System Constraints New York State Transmission System 2,500 MW Moses- St. Lawrence Dennison Moses South Colton Saunders Massena Chateauguay Willis Plattsburgh Sandbar 4,400 MW Legend: 765 kv 500 kv 345 kv 230 kv 115 kv Dysinger East Oswego Complex Somerset West - Central Beck Niagara Sta.80 Pannell Homer City Adirondack Marcy Central - East Hoosick Coopers Corners Rock Tavern Roseton Rotterdam Buchanan Ramapo W49St/Rainey Whitehall Blissville New Scotland Farragut Goethals Pleasant Valley Millwood Sprain Brook - Dunwoodie Sprainbrook Dunwoodie Bennington Robinson Rd. Clay Edic Porter Huntley Lafayette Gilboa Alps Stolle Rd. Richfield Inghams Leeds Gardenville Meyer Springs Dunkirk Andover Palmiter 4,700 MW Total - East 5,500 MW Fraser Watercure Hillside Oakdale 8,000 MW Upny - Con Ed Shore Rd. E.Garden City 5,000MW Con Ed-LIPA

54 Unique Features Phase Shifters Gilboa Pumped Storage Gas Turbines Wheel Through Energy Circulation

55 We have looked at the big pieces. Generation Transmission Load System Interactions Next we will go ahead with how the pieces work together to keep the lights on