1. Presentation For PSAST May 14, 2010

2. Outline Most Limiting N-1-X Events Voltage Limitations For Loss of Three Terminal Monroe- Echo Lake 500kV and Chief Jo-Monroe 500kV

3. Most Limiting N-1-X Events Studied Winter 1500 MW South to North, With 680 MW Puget Sound Area Generation Showing All Lines In Service, Followed By A Primary N-1 Event, And Then A Secondary Contingency (N-1 or Common Mode) For Each Condition, A Series of Power Flow Plots Are Shown Attempt To Relieve Overloads By Reducing Transfers Verify Adequacy of Proposed Solutions

4. 1500 MW Winter S-N, 680 MW Area Gen All lines in service

5. All Lines In Service

7. Primary Contingency Now Take Monroe 500/230 kV Transformer Out of Service

8. 1500 MW Winter S-N, 680 MW Area Gen N-1: Monroe 500/230 kV

9. Monroe 500/230 kV O/S

11. Secondary Contingency Monroe 500/230 kV Transformer is Out of Service Now Take SnoKing 230 kV South Bus Breaker Failure

12. 1500 MW Winter S-N, 680 MW Area Gen N-1-X: Monroe 500/230 kV And BF SnoKing 230 kV South Bus (No Bothell-SnoKing RAS)

13. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus No Bothell-SnoKing RAS

14. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus No Bothell-SnoKing RAS

15. 1500 MW Winter S-N, 680 MW Area Gen N-1-X: Monroe 500/230 kV And BF SnoKing 230 kV South Bus (with Bothell-SnoKing RAS)

16. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus Bothell-SnoKing RAS

17. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus Bothell-SnoKing RAS

18. Try to Resolve Overloads First Reduce Transfers to BC Then Test Proposed Projects

19. 1000 MW Winter S-N, 680 MW Area Gen N-1-X: Monroe 500/230 kV And BF SnoKing 230 kV South Bus (with Bothell-SnoKing RAS)

20. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus

21. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus

22. 500 MW Winter S-N, 680 MW Area Gen N-1-X: Monroe 500/230 kV And BF SnoKing 230 kV South Bus (with Bothell-SnoKing RAS)

23. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus

24. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus

25. 250 MW Winter S-N, 680 MW Area Gen N-1-X: Monroe 500/230 kV And BF SnoKing 230 kV South Bus (with Bothell-SnoKing RAS)

26. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus

27. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus

28. 0 MW Winter S-N, 680 MW Area Gen N-1-X: Monroe 500/230 kV And BF SnoKing 230 kV South Bus (with Bothell-SnoKing RAS)

29. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus

30. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus

31. Adding Projects First, SCL Series Cable Reactors Then, Bothell-SnoKing-Maple Valley Reconductor

32. 1500 MW Winter S-N, 680 MW Area Gen SCL Series Cable Reactors Added All lines in service

33. All Lines In Service SCL Series Cable Reactors Added

34. All Lines In Service SCL Series Cable Reactors Added

35. 1500 MW Winter S-N, 680 MW Area Gen SCL Series Cable Reactors Added N-1: Monroe 500/230 kV

36. Monroe 500/230 kV O/S SCL Series Cable Reactors Added

37. Monroe 500/230 kV O/S SCL Series Cable Reactors Added

38. 1500 MW Winter S-N, 680 MW Area Gen SCL Series Cable Reactors Added N-1-X: Monroe 500/230 kV And BF SnoKing 230 kV South Bus (with Bothell-SnoKing RAS)

39. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus SCL Series Cable Reactors Added

40. Monroe 500/230 kV O/S BF SnoKing 230kV South Bus SCL Series Cable Reactors Added

41. 1500 MW Winter S-N, 680 MW Area Gen SCL Series Cable Reactors Added Bothell-SnoKing-MapleValley Reconductor N-1-X: Monroe 500/230 kV And BF SnoKing 230 kV South Bus

42. Primary Contingency Take Tacoma 500/230 kV Transformer Out of Service

43. 1500 MW Winter S-N, 680 MW Area Gen N-1: Tacoma 500/230 kV

44. Tacoma 500/230 kV O/S

46. N-1-X Primary Outage: Tacoma 500/230 kV Transformer Secondary Outage: BF Maple Valley 230kV Bus Sections #1, 2

47. 1500 MW Winter S-N, 680 MW Area Gen N-1-X: Tacoma 500/230 kV And BF Maple Valley 230kV Bus Sections #1, 2

48. Tacoma 500/230 kV O/S BF Maple Valley 230kV #1,2

49. Tacoma 500/230 kV O/S BF Maple Valley 230kV #1,2

50. Try to Resolve Overloads First Reduce Transfers to BC Then Test Proposed Projects

51. 1000 MW Winter S-N, 680 MW Area Gen N-1-X: Tacoma 500/230 kV And BF Maple Valley 230kV Bus Sections #1, 2

52. Tacoma 500/230 kV O/S BF Maple Valley 230kV #1,2

53. Tacoma 500/230 kV O/S BF Maple Valley 230kV #1,2

54. 0 MW Winter S-N, 680 MW Area Gen N-1-X: Tacoma 500/230 kV And BF Maple Valley 230kV Bus Sections #1, 2

55. Tacoma 500/230 kV O/S BF Maple Valley 230kV #1,2

56. Tacoma 500/230 kV O/S BF Maple Valley 230kV #1,2

57. Adding Projects Third Covington 500/230kV Transformer Or Second Maple Valley 500/230 kV Transformer

58. 1500 MW Winter S-N, 680 MW Area Gen 3 rd Covington 500/230 kV Transformer Added N-1-X: Tacoma 500/230 kV And BF Maple Valley 230kV Bus Sections #1, 2

59. 3 rd Covington xfmr Tacoma 500/230 kV O/S BF Maple Valley 230kV #1,2

60. 1500 MW Winter S-N, 680 MW Area Gen 2 nd Maple Valley 500/230 kV Transformer Added N-1-X: Tacoma 500/230 kV And BF Maple Valley 230kV Bus Sections #1, 2

61. 2 nd Maple Valley xfmr Tacoma 500/230 kV O/S BF Maple Valley 230kV #1,2

62. Primary Outage Take Maple Valley 500/230 kV Transformer Out of Service

63. 1500 MW Winter S-N, 680 MW Area Gen N-1: Maple Valley 500/230 kV

64. Maple Valley 500/230 kV O/S

66. N-1-X Primary Outage: Maple Valley 500/230 kV transformer Secondary Outage: N-2: Raver - Covington #1&2 500kV

67. Maple Valley 500/230 kV O/S And N-2: Raver – Covington #1&2 500kV

68. Try to Resolve Overloads First Reduce Transfers to BC Then Test Proposed Projects

69. Maple Valley 500/230 kV O/S And N-2: Raver – Covington #1&2 500kV

70. Maple Valley 500/230 kV O/S And N-2: Raver – Covington #1&2 500kV

71. Adding Projects Third Covington 500/230kV transformer Or Second Maple Valley 500/230 kV transformer

72. Maple Valley 500/230 kV O/S And N-2: Raver – Covington #1&2 500kV 3 rd Covington 500/230 kV Transformer Added

73. Maple Valley 500/230 kV O/S And N-2: Raver – Covington #1&2 500kV 2 nd Maple Valley 500/230 kV Transformer Added

74. Primary Contingency Take Chief Jo-Snohomish 345 kV Out of Service

75. 1500 MW Winter S-N, 680 MW Area Gen N-1: Chief Jo-Snohomish 345 kV

76. Chief Jo-Snohomish 345kV O/S

77. N-1-X Primary Outage: Chief Jo-Snohomish 345 kV Out of Service Secondary Outage: BF 4526 Echo Lake-Monroe-Custer

78. 1500 MW Winter S-N, 680 MW Area Gen Chief Jo-Snohomish 345 kV O/S BF 4526 Echo Lake-Monroe-Custer

79. Chief Jo-Snohomish 345kV O/S BF 4526 Echo Lake-Monroe-Custer

80. Try to Resolve Overloads First Reduce Transfers to BC Then Test Proposed Projects

81. 1000 MW Winter S-N, 680 MW Area Gen Chief Jo-Snohomish 345 kV O/S BF 4526 Echo Lake-Monroe-Custer

82. Chief Jo-Snohomish 345kV O/S BF 4526 Echo Lake-Monroe-Custer

83. 0 MW Winter S-N, 680 MW Area Gen Chief Jo-Snohomish 345 kV O/S BF 4526 Echo Lake-Monroe-Custer

84. Chief Jo-Snohomish 345kV O/S BF 4526 Echo Lake-Monroe-Custer

85. Adding Projects First Add SCL Series Cable Reactors Then Add Bothell-SnoKing-Maple Valley Reconductor

86. 1500 MW Winter S-N, 680 MW Area Gen Chief Jo-Snohomish 345 kV O/S BF 4526 Echo Lake-Monroe-Custer SCL Series Cable Reactors Added

87. Chief Jo-Snohomish 345kV O/S BF 4526 Echo Lake-Monroe-Custer SCL Series Cable Reactors Added

88. 1500 MW Winter S-N, 680 MW Area Gen Chief Jo-Snohomish 345 kV O/S BF 4526 Echo Lake-Monroe-Custer SCL Series Cable Reactors Added Bothell-SnoKing-Maple Valley Reconductor

89. Chief Jo-Snohomish 345kV O/S BF 4526 Echo Lake-Monroe-Custer SCL Series Cable Reactors Added, Bothell-SnoKing-Maple Valley Reconductor

90. Primary Contingency Take Monroe-Echo Lake 500 kV Three Terminal Line Out of Service

91. 1500 MW Winter S-N, 680 MW Area Gen N-1: Monroe-Echo Lake 500 kV

92. Monroe-Echo Lake O/S

93. 850 MW Winter S-N, 680 MW Area Gen N-1: Monroe-Echo Lake 500 kV

94. Monroe-Echo Lake O/S

95. N-1-X Primary Outage: Monroe-Echo Lake 500 kV Three Terminal Line Secondary Outage: Chief Jo-Monroe 500 kV Unable to Solve Case Unless Transfers are Limited to 850 MW

96. 850 MW Winter S-N, 680 MW Area Gen N-1-X: Monroe-Echo Lake 500 kV And Chief Jo-Monroe 500 kV

97. Monroe-Echo Lake O/S N-1 Chief Jo-Monroe 500 kV

98. Try to Resolve Overloads First Reduce Transfers to BC Then Test Proposed Projects

99. 0 MW Winter S-N, 680 MW Area Gen N-1-X: Monroe-Echo Lake 500 kV And Chief Jo-Monroe 500 kV

100. Monroe-Echo Lake O/S N-1 Chief Jo-Monroe 500 kV

101. Adding Projects SCL Series Cable Reactors And Bothell-SnoKing-Maple Valley Reconductor Can Solve Case at 900 MW Transfer

102. 900 MW Winter S-N, 680 MW Area Gen Monroe-Echo Lake 500 kV O/S N-1 Chief Jo-Monroe 500 kV SCL Series Cable Reactors And Bothell-SnoKing-Maple Valley Reconductor Added

103. Monroe-Echo Lake O/S N-1 Chief Jo-Monroe 500 kV Projects Added

104. Voltage Limitations What Is Required For The Double Outage Of Monroe-Echo Lake 500 kV and Chief Jo-Monroe 500 kV?

105. All Lines In Service 1500 MW South to North North Puget Sound Area

107. Monroe-Echo Lake Out of Service 1500 MW South to North North Puget Sound Area

109. Open Chief Jo-Monroe 500kV 1500 MW South to North Does Not Converge Reduce Transfers to 1000 MW South to North

111. Open Chief Jo-Monroe 500kV 1000 MW South to North Does Not Converge Reduce Transfers to 500 MW South to North

113. Open Chief Jo-Monroe 500kV 500 MW South to North Voltage at Monroe 500kV Increases 2.5% from 525kV to 538kV (caps switching) Many Thermal Overloads, Including: 142% Mass Transformer 230/115kV (244 MVA) 139% Mass-Union 115kV (1656 amps) 138% Union-Broad 115kV (1654 amps) 129% Maple Valley-SnoKing 230kV (1667 amps)

115. PV Analysis

117. PV Analysis (With SCL Reactors and Bothell-SnoKing-Maple Valley ReConductor)