Transmission System Operations TO1. Interconnection Training Program PJM State & Member Training Dept.

Transcription

1 Disclaimer This training presentation is provided as a reference for preparing for the PJM Certification Exam. Note that the following information may not reflect current PJM rules and operating procedures. For current training material, please visit: PJM 2014

2 Transmission System Operations TO1 Interconnection Training Program PJM State & Member Training Dept. 1

3 Agenda 6 modules Basic Theory Reliability, Limits, Failures Contingency Analysis Out of Merit Dispatch Voltage and Voltage Adjustment Outage Scheduling 2

4 Agenda Methods of Instruction Presentation Class discussion Exercises Operator Training Simulator Demonstrations EPRI OTS PC Simulation PowerWorld Simulator Demonstrations Videos? Quizzes 3 quizzes 3

5 Agenda Purpose and Function of the Transmission System TO1-1 System Voltage and VAR Characteristics TO1-2 Distribution and Generation Shift Factors TO1-3 4

6 Module Objectives Review the purpose and function of the transmission system. Review basic system voltage and VAR characteristics Demonstrate basic distribution factor theory. Determine power flows utilizing system distribution factors and generation shift factors Introduce the concept of $/MW effect. 5

7 Transmission System Fundamentals TO1-1 6

8 Module Objectives List the purpose and functions of the transmission system. Distinguish between the transmission system, the sub-transmission system and the distribution system. Given a simple one-line diagram, identify the major features of the PJM transmission system including: Lines, buses, and generating stations 7

9 Purpose and Function of the Transmission System Coordinated Operation Single system Part of the Eastern Interconnection Reliability Economy No transmission = Distributed Generation $$$$ 8

10 to Kammer (AEP) to Mountianeer /500 kv /500 kv N S N S A B A B CON CON -TMI TMI C MVAR 165 MW KEY ALB MW N S 165 MW Fall 2001 Jan MW CT1 CT2 CT3 ST1 SUN N SUN S Spring 2002 Jan 2003 Jan B A 4B #1 bank 832/985 MVA 2 K L M 1 7AB 7BB 2 12B 12C H J 6AB 6BB 11A 11B 11C A C 6 5AB 5BB 10B 10C 3 N N BLACK RED S transfomer breaker S 4A 4B N SUN N SUN S S N 115 W 1 ELN generator capacitor H B SQ2 N SQ2 S WES W JUN ELS WES E B W KEY- ALB JUN- HOS ALS G A WES N 2 WES S B E HOS E 138kV 765 kv 500 kv 21 New Construction 138 kv 1 1TRHS Created in Visio. All revisions should be made in Visio then copied to PPT Visio : DOC# Power Point : DOC# T Cabot PJM West PJM Susquehanna Sunbury 5045 to Ramapo South Bend 14 2 Keystone 5004 Juniata 5044 Wescosville Alburtis Branchburg TMI Deans Yukon Wylie Ridge Steel City Hosensack Elroy Smithburg Pleasants Fort Martin Hatfield 516 Fayette Conemaugh Black Oak Bedington 5006 PJM West PJM Hunterstown Conastone 5011 Brighton 5012 Peach Bottom Limerick Keeney Whitpain Red Lion New Freedom 5024 Hope Creek 5037 East Windsor Salem Doubs Chalk Point Calvert Cliffs Waugh Chapel Belmont Harrison 526 Pruntytown 510 to Mt. Storm Meadow Brook to Mt. Storm to Morrisville to Mt. Storm to Loudoun Burches Hill to Possum Point PJM & PJM West 500 kv Breaker Diagram KEY Date 11/13/2002 Description Layout of APS system with PJM Layout E.D. Colodonato Checked 9

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14 Transmission Paths (Bulk Transmission) Purpose Transfer bulk power from a generation source to load centers reliably and economically Typical Path lengths Range from 1/2 mile to 180 miles in Eastern U.S. PJM longest Dumont-Marysville 765 kv (AEP) 180 miles PJM shortest 5037 Hope Creek - Salem Longer in Western U.S. <1 Mile For EHV, longer path lengths is more economical 13

15 Transmission Paths (Bulk Transmission) Typical voltage values Transmission is generally characterized by high voltage values 69 kv - lowest voltage considered transmission 765 kv - Highest voltage level used in U.S. Different definitions depending on company Above 230 Kv considered EHV 14

16 Bulk Electric System (BES) ReliabilityFirst Corporation (RFC) adopted the definition of Bulk Electric System (BES) to include facilities 100kV and above The new BES definition new includes facilities that used to be controlled by Member TOs All NERC and Regional standards will apply to all BES facilities 15

17 Bulk Electric System (BES) The Bulk Electric System (BES) within the ReliabilityFirst footprint is defined as all:* Individual generation resources larger than 20 MVA or a generation plan with aggregate capacity greater than 75 MVA that is connected via a step-up transformer(s) to facilities operated at voltages 100 kv or higher Lines operated at voltages 100 kv or higher Transformers (other than generator step-up) with both primary and secondary windings of 100 kv or higher Associated auxiliary and protection and control system equipment that could automatically trip a BES facility, independent of the protection and control equipment s voltage level 16

18 Transmission Paths (Bulk Transmission) Voltage Transmission Subtransmission 765 kv 500 kv 345 kv 230 kv 138 kv 115 kv 69 kv 34.5 kv 25 kv 14.4 kv 13.2 kv 12 kv 4 kv 480 V 120 V Distribution Primary Secondary Typical Voltage Values 17

19 Transmission Paths (Bulk Transmission) Applications Backbone of the system ties generation to load Used to connect companies Used to connect to outside pools Generally controlled by ISO (Independent System Operator) Let s look at common flows on the transmission system on the PC simulator! H:\CorporateServices\Training\Powerworldcases\ExampleCases\ECAR\98FFECAR.pwb 18

20 Transmission Paths (Sub-transmission) General definition Medium voltage power transmission path underlying the bulk transmission system Typical voltage values 34.5 kv to 138 kv Typical path lengths 0.1 to 40 miles 19

21 Transmission Paths (Sub-transmission) Application Intra-company power flow paths Move power from one area of a company to another Serve larger loads 20

22 Transmission Paths (Distribution System) General definition Those power lines which supply energy to residential and commercial customers and some of the smaller industrials Two Typical Voltage Ranges Primary Distribution 12 kv - 25 kv Secondary Distribution 120 V V 21

23 Transmission Paths (Distribution System) Two types of distribution systems Networks Normally densely populated areas Radial Normally in rural areas Typical path lengths Several pole spans to many miles Applications Supply of power to customers 22

24 Transmission Line Standards - Glossary ACSR aluminum conductor steel reinforced; Bare aluminum conductors stranded around an inner core of galvanized steel wire(s). Often used in overhead power distribution and transmission lines. Kcmil a measure of conductor area in thousands of circular mills; a circular mil (Cmil) is the area of a circle with a diameter of one-thousandth (0.001) of an inch. kv kilovolt (1,000 volts) M million $ MVA megavolt-ampere (1 million volt-amperes); a unit of apparent power in an alternating-current circuit. A volt-ampere (VA) is the product of voltage (volts) times current (amperes). A device rated at 10 amps and 120 V has a VA rating of 1200 or 1.2 kva or MVA. 23

25 Overhead Transmission Line Standards Overhead Lines Voltage Conductor Size (kcmil) Right of Way Width Range Typical Normal Rating (MVA) Order of Magnitude Installation Cost per Circuit Mile (Millions) 69 kv 556 ACSR ft. 85 $ / mile 115 kv 795 ACSR ft. 175 $ / mile 138 kv 1033 ACSR ft. 250 $ / mile 230 kv 1590 ACSR ft. 650 $ / mile 345 kv 2167 ACSR ft $ 1.5 / mile 500 kv 2493 ACSR ft $ 1.8 / mile 765 kv 1351 ACSR (4 conductor bundled) ft $ 2.5 / mile 24

26 69 kv Line Conductor Size 556 ACSR Right of Way ft. Normal MVA Rating 85 MVA Cost per Circuit Mile $ M / mile Structure Type Single Pole, Steel or Wood 25

27 Double Circuit 115 kv Lines Conductor Size 795 ACSR Right of Way ft. Normal MVA Rating 175 MVA Cost per Circuit Mile $ M / mile Structure Type Single Pole, Steel or Wood 26

28 Double Circuit 138 kv Lines Conductor Size 1033 ACSR Right of Way ft. Normal MVA Rating 250 MVA Cost per Circuit Mile $ M / mile Structure Type Single Pole, Steel 27

29 230 kv Line Conductor Size 1590 ACSR Right of Way ft. Normal MVA Rating 650 MVA Cost per Circuit Mile $ M / mile Structure Type Wood H-Frame, Steel 28

30 345 kv Line Conductor Size 2167 ACSR Right of Way ft. Normal MVA Rating 1650 MVA Cost per Circuit Mile $1.5 M / mile Structure Type Wood H-Frame, Steel 29

31 500 kv Line Conductor Size 2493 ACSR (bundled) Right of Way ft. Normal MVA Rating 2700 MVA Cost per Circuit Mile $ 1.8 M / mile Structure Type Lattice Tower, Steel 30

32 756 kv Line Conductor Size 1351 ACSR (4 conductor bundled) Right of Way ft. Normal MVA Rating 4000 MVA Cost per Circuit Mile $ 2.5 M / mile Structure Type Lattice Tower, Steel 31

33 Underground Cable Standards Underground Cables Voltage 69 kv 115 kv 138 kv 230 kv 345 kv Cable Size (kcmil) 1500 Copper High Pressure Oil Filled Pipe Type cable 1500 Copper High Pressure Oil Filled Pipe Type cable 1500 Copper High Pressure Oil Filled Pipe Type cable 2500 Copper High Pressure Oil Filled Pipe Type cable 2500 Copper High Pressure Oil Filled Pipe Type cable Right of Way Width Typical Normal Rating (MVA) Order of Magnitude Installation Cost per Circuit Mile (Millions) N/A* 119 $ 1.2 / mile N/A* 180 $ 1.5 / mile N/A* 200 $ 1.8 / mile N/A* 406 $ 4.0 / mile N/A* 627 $ 6.0 / mile *Assumed to be installed in existing roadway right-of-ways; minimum access requirements and respective clearances to adjacent underground utilities would apply 32

34 Underground Cable Standards Voltage PJM (Miles) PJM Mid- Atlantic (Miles) PJM WEST (Miles) PJM SOUTH (Miles) 69 kv 8,014 4,618 3, kv 4,485 2, , kv 16,310 1,744 14, kv 7,456 4, , kv 7, ,995 N/A 500 kv 4,919 2, , kv 2,110 N/A 2,110 N/A 33

35 Transmission Paths (Distribution System) Exercise TO

36 Features of the Transmission System Generating Stations Source of the power (Car out of driveway) Transmission Lines Path of power flow (Freeway) Naming Conventions vary by company Number, Terminals, Voltage Level 35

37 Features of the Transmission System Buses Points of connection (Cloverleaf) Many breaker configurations Straight Ring Breaker and a half Double bus/double breaker Buses 36

38 Features of the Transmission System Circuit Breakers Switch to interrupt the flow of current in a circuit (Car accident or police stop) Transformers Circuit Breaker Used to transform voltage from one level to another (onramp or off-ramp) 37

39 Features of the Transmission System Other Devices Phase angle regulators Disconnects Capacitors Reactors Exercise TO1-1.2 Use PJM 500 kv one-line on following slide.. 38

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41 Summary List the purpose and functions of the transmission system. Distinguish between the transmission system, the sub-transmission system and the distribution system. Given a simple one-line diagram, identify the major features of the PJM transmission system including: Lines, buses, and generating stations 40

42 System Voltage and VAR Characteristics TO1-2 41

43 Lesson Objectives Identify situations which may cause the system voltage to drop below accepted standards. Identify situations which may cause the system voltage to rise above accepted standards. List the MVAR sources and sinks on the power system. Explain how system capacitance supplies MVARS to the system. 42

44 Lesson Objectives Define Surge Impedance Loading and state its significance to system operation. 43

45 System Voltage Characteristics Relationship between reactive flow and voltage Voltage levels most affected by VAR generation/absorption Reactive (MVAR) flow distribution Large reactive flows cause large voltage drops Large voltage differences cause large reactive flows Reactive Power (MVAR) are required for Real Power (MW) to flow. 44

46 System Voltage Characteristics Voltage profile On most lines voltage decreases from sending to receiving end of transmission line. 45

47 System Voltage Characteristics a = angle of voltage b = angle of current P = real power = VIr = VI cos(a-b) Q = reactive power = VIx = VI sin(a-b) S = complex power = VI cos(a-b) +jvi sin(a-b) power factor = cos (a-b) Q=VIsin(a-b) Var (a-b) P=VIcos(a-b) W 46

48 System Voltage Characteristics Factors affecting voltage VAR supply Excess VARs on system, voltage will rise Shortage of VARs on system, voltage will decrease VAR Sources System capacitance Capacitor banks Generators (lagging) 47

49 System Voltage Characteristics Factors affecting voltage (continued) VAR loads Motors VAR losses Generators (leading) Reactors Transformers Power (MW) Flow Increasing load (MW) causes larger I 2 R loss and IR voltage drop 48

50 System Voltage Characteristics Factors affecting voltage (continued) Reactive (MVAR) Flow Increasing reactive (MVAR) flow causes larger I 2 X loss and IX voltage drop Voltage drop due to reactive flow is larger than for real power flow VARs don t travel well. Solar Magnetic Disturbance Can cause a large VAR requirement in transformers May cause tripping of capacitor banks MVAR Simulation on Powerworld H:\Corporate Services\Training\Powerworld Cases\Chapter 2\Problem 2_24.pwb 49

51 System Voltage Characteristics Results Result is constantly changing voltage profile 50

52 System Voltage Characteristics Results For light loads, voltage can rise due to low losses and line capacitance 51

53 System Voltage Characteristics Results Voltage Varies with VAR supply and consumption 52

54 VARs From Transmission Lines Line open at one end VAR flow back toward closed end 53

55 VARs From Transmission Lines Equation for Ferranti Effect 54

56 VARs From Transmission Lines VARs supplied by charging of line MVARs Supplied by Lines and Cables Voltage Transmission Line Transmission Cable 765 kv 4.6 MVAR/Mile 500 kv 1.7 MVAR/Mile 345 kv 0.8 MVAR/Mile MVAR/Mile 230 kv 0.3 MVAR/Mile 5-15 MVAR/Mile 115 kv 0.1 MVAR/Mile 2-7 MVAR/Mile 55

57 VARs From Transmission Lines Attachment B - Transmission Operation Manual 56

58 VARs From Transmission Lines Attachment B - Transmission Operation Manual 57

59 VARs From Transmission Lines Attachment B - Transmission Operation Manual 58

60 VARs From Transmission Lines 550 KEYSTONE-JUNIATA Keystone 5004 Line Juniata V2 = 525 kv 59

61 VARs From Transmission Lines 550 KEYSTONE-JUNIATA Keystone 5004 Line Juniata kv MVAR 0 MVAR V1 = kv 60

62 VARs From Transmission Lines Line connected to load Power (MW) losses increase with load Reactive (MVAR) losses increase with load MW Flow increases MVAR Flow increases Load Load increases 61

63 VARs From Transmission Lines Surge Impedance Loading Loading point where VAR losses on a line equal VARs generated by line 62

64 VARs From Transmission Lines Surge Impedance Loading 765 kv = 2100 MW 500 kv = 850 MW 345 kv = 400 MW 230 kv = 135 MW 63

65 VARs From Transmission Lines MVAR absorbed by Transmission Line MW Limited by charging MVAR MVAR supplied by Transmission Line Long 500 kv line Short 500 kv line Surge Impedance Loading Example 64

66 VARs from Transmission Lines 1.0 pu 1.0 pu Line loaded above SIL MVAR Required Voltage Profile MVAR Required As line loading increases: Reactive losses increase proportional to I 2 Reactive supply decreases proportional to V 2

67 VARs from Transmission Lines 1.0 pu 1.0 pu Voltage Profile MVAR Supplied Line loaded below SIL MVAR Supplied As line loading decreases: Reactive losses decrease proportional to I 2 Reactive supply increases proportional to V 2

68 VARs From Transmission Lines Switching Operations Open one end Provides VARs to closed end of line due to line capacitance MVAR Flow 67

69 VARs From Transmission Lines Switching Operations (continued) Open both ends Removes that line from service No longer supplies VARs (high voltage) or uses VARs (low voltage) Switching Over-voltages Very high voltages which occur for a short duration Can be handled in insulation design or use of surge suppression devices 68

70 VARs From Transmission Lines Lightning Over-voltages Much more severe than switching surges >1000 kv Can cause insulation failure or flashover Controlled by surge arrestors or lightning rods 69

71 Summary Identify situations which may cause the system voltage to drop below accepted standards. Identify situations which may cause the system voltage to rise above accepted standards. List the MVAR sources and sinks on the power system. 70

72 Summary Explain how system capacitance supplies MVARS to the system. Define Surge Impedance Loading and state its significance to system operation. 71

73 Distribution Factors and Generation Shift Factors TO1-3 72

74 Lesson Objectives Define a transmission line distribution factor. Briefly describe the application of distribution factors for system operation. Given appropriate distribution factors, analyze the impact of taking a line out of service. Define a generation shift factor and describe its application for system operation. 73

75 Lesson Objectives Given appropriate generation shift factors, analyze the impact of a shift in generation. Define the concept of $/MW effect and its application in the new operating environment. 74

76 Introduction to Distribution Factors Definition The percentage of flow currently on a line that will transfer to another line as a result of the loss of the first line Characteristics of Distribution Factors Determined by line impedances Computer generated Expressed as a decimal number of 1.0 or less Distribution factor for a line for the loss of itself is -1.0 if line flow is positive. 75

77 Introduction to Distribution Factors Characteristics of Distribution Factors (continued) Can be a positive or negative factor Sum of all distribution factors in a closed system is zero Formula: New flow on line = Previous flow + [(Dfax) (Flow on outaged facility)] 76

78 Example Simple Calculations For the loss of line C: Dfax b = 0.5 Dfax c = -1.0 Dfax d = 0.3 Dfax e =

79 Example Simple Calculations Let s do Exercise TO1_3.1! 78

80 Applications of Distribution Factors Line Outages Use distribution factors to estimate how power will flow and predict any flow problems which may result from a line outage. Generally performed by computer tool Flow Analysis Used to predict the results of losing a specific piece of equipment (Contingency analysis) 79

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82 PJM Distribution Factor Table Try Exercise TO1_

83 Generation Shift Factors Similar to Distribution Factors Decimal Fraction Used to analyze the effect of generation shifts on MW flow Does NOT add up to 0 Definition Fraction of change in generation MW output that will appear on a line or facility Used to predict the effect of generation changes on transmission line flow 82

84 Generation Shift Factors Formula New flow on line = Previous flow + [(Gen Shift Factor)(Amount of MW Shift)] 83

85 Generation Shift Factors Line 3 = 500 MW Increase Gen A by 100 MW. What is resultant flow on Line 3? New Flow = 500 MW + (.12)(+100MW) = 512 MW LINE 5 84

86 Generation Shift Factors Line 3 = 512 MW Now, Generator C is decreased by 100 MW. What is resultant flow on Line 3? LINE 5 New Flow = 512 MW + (-0.6)(-100MW) = 572 MW 85

87 Generation Shift Factors Try Exercise TO1_3.3! LINE 5 86

88 $/MW Effect Adjustment of Shift Factors due to Economics. Definition $/MW Effect = (Current Dispatch Rate - Unit Bid) / Unit Generator Shift Factor Unit with lowest $/MW effect is redispatched when system is constrained. Other unit operating constraints taken into account (I.e. min run time, time from bus, etc) In an emergency, economics takes the back seat to reliability. 87

89 $/MW Effect Line #1 is overloaded! Dispatch rate = $20 Unit D = $21 Unit B = $40 Which unit would you raise to alleviate the overload? 88

90 $/MW Effect Unit D = ($20-$21)/(-.12) = $8.33/MW Unit B = ($20-$40)/(-.2) = $100/MW Select Unit D even though effect is less! 89

91 $/MW Effect Let s do Exercise TO1_3.4 on $/MW Effect. 2 PowerWorld Simulations on Loop Flows and Power Transfer Distribution Factors (PDTF) 90

92 Summary Define a transmission line distribution factor. Briefly describe the application of distribution factors for system operation. Given appropriate distribution factors, analyze the impact of taking a line out of service. Define a generation shift factor and describe its application for system operation. 91

93 Summary Given appropriate generation shift factors, analyze the impact of a shift in generation. Define the concept of $/MW effect and its application in the new operating environment. 92

94 Module Summary Review the purpose and function of the transmission system. Review basic system voltage and VAR characteristics Demonstrate basic distribution factor theory. Determine power flows utilizing system distribution factors and generation shift factors Introduce the concept of $/MW effect. 93

95 Questions? 94

96 Disclaimer: PJM has made all efforts possible to accurately document all information in this presentation. The information seen here does not supersede the PJM Operating Agreement or the PJM Tariff both of which can be found by accessing: For additional detailed information on any of the topics discussed, please refer to the appropriate PJM manual which can be found by accessing: 95