THE HISTORY OF THE PACI AND PDCI

1948 POST WAR POWER SHORTAGES IN CALIFORNIA CAUSED BY DROUGHT LEAD TO DISCUSSIONS ABOUT A 230 KV INTERCONNECTION BETWEEN THE NW AND CALIFORNIA. REGIONAL POLITICAL CONCERNS PREVENTED PROGRESS

1951 DEVELOPMENT OF A NW-CALIFORNIA INTERCONNECTION IS DEEMED TO BE IN THE INTEREST OF NATIONAL SECURITY BY THE NATIONAL DEFENSE ADMINISTRATION. BPA STARTS DESIGN OF REDMOND-KLAMATH FALLS 230 KV LINE THAT WOULD CONTINUE SOUTH TO CALIFORNIA.

1952 HOUSE APPROPRIATIONS COMMITTEE DIRECTS THAT INTERTIE SHOULD NOT BE BUILT UNTIL EXHAUSTIVE STUDY HAS BEEN COMPLETED. THIS KILLED THE INTERTIE. BPA WAS FORCE TO STOP CONSTRUCTION OF THE REDMOND-KLAMATH FALLS LINE AND SELL THE MATERIALS AND RIGHT OF WAY FOR THE LINE AT COST TO THE CALIFORNIA-OREGON POWER COMPANY (COPCO) WHICH LATER MERGED WITH PACIFIC POWER.

1958 THE RISING COST OF OIL AND A SLUMP IN THE ALUMINUM MARKET CREATE A NEW MOTIVATION FOR A NW-CA INTERTIE. SENATE REQUIRES INTERTIE FEASIBILITY STUDY. MUCH PUBLIC CONCERN OVER REGIONAL PREFERENCE RIGHTS TO POWER. FORMER BPA CHIEF ENGINEER SOL SCHULTZ HIRED TO REVIEW THE STUDY AND CONSIDERS IT TO BE TOO CONSERVATIVE.

1961 THE SECRETARY OF INTERIOR FORMS A TASK FORCE LED BY BPA ADMINISTRATOR CHARLES LUCE TO DEVELOP AN INTERTIE PLAN.

1961 Continued TASK FORCE IDENTIFIES 3 OPTIONS: THREE 750 KV DC LINES THREE 500 KV AC LINES THREE 345 KV AC LINES

1961 Continued THE DC LINE OPTION WAS CONTROVERSIAL BECAUSE IT WAS RELATIVELY NEW TECHNOLOGY. A DC LINE HAD BEEN IN OPERATION SINCE 1954 IN SWEDEN AND A DC LINK BETWEEN ENGLAND AND FRANCE HAD BEEN ENERGIZED IN 1961

1961 Continued COLUMBIA RIVER TREATY WITH CANADA IS SIGNED. THE TREATY FORMULATED A PLAN TO DEVELOP THE UPPER COLUMBIA FOR FLOOD CONTROL, INCREASED POWER PRODUCTION, AND ARRANGED TO SELL THE CANADIAN POWER ENTITLEMENT (CANADA’S NEGOTIATED SHARE OF THE DOWNSTREAM BENEFITS). THE ORIGINAL GOAL WAS TO CONTROL THE RECORD COLUMBIA RIVER FLOW OF 1240 KCFS (1894) TO 600 KCFS AT THE DALLES.

1961 Continued THE TREATY LED TO THE CONSTRUCTION OF THREE STORAGE DAMS IN CANADA (DUNCAN, KEENLEYSIDE (ARROW), AND MICA). TO INCREASE THE DOWNSTREAM BENEFITS, LIBBY DAM AND THE THIRD POWERHOUSE AT COULEE WERE BUILT. THE TREATY SENT $254 MILLION TO CANADA TO BUILD DAMS IN EXCHANGE FOR 30 YEARS OF DOWNSTREAM POWER BENEFITS.

1961 Continued SIGNING OF THE COLUMBIA RIVER TREATY BROUGHT MORE INTEREST IN A NW-CA INTERTIE BECAUSE MANY UTILITIES HAD AN INTEREST IN GAINING TRANSMISSION CAPABILITY TO ACCESS THE CANADIAN ENTITLEMENT WHICH CANADA DID NOT NEED.

1964 INTERTIE PLAN FINALIZED WITH DESIGN FOR TWO 500 KV LINES AND TWO 750 KV DC LINES. THE SECOND DC LINE TO PHOENIX WAS NEVER BUILT.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) 1966 - ONE 500 KV LINE OPERATED AT 230 KV BETWEEN MALIN AND ROUND MT. 12/1967 - 500 KV OPERATION OF ONE LINE FROM NW TO CALIFORNIA. SPRING 68 - COMMERCIAL OPERATION STARTED WITH 750 MW LIMIT SUMMER 1968 - 2ND 500 KV LINE FROM NW TO CALIFORNIA COMPLETED WITH 1400 MW LIMIT

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 1971 - LIMIT INCREASED TO 2000 MW WITH GENERATOR DROPPING RAS BUT WAS LATER REDUCED TO 1800 MW DUE TO SERIES CAPACITOR PROBLEMS ON PG&E’S PORTION OF THE PACI. 6/71 - FOUR CORNERS SEPARATION SCHEME IMPLEMENTED WITH 97 RC RELAY AT FOUR CORNERS.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 1972 - LIMIT RETURNED TO 2000 MW AFTER SERIES CAPACITOR PROTECTION CHANGED. 6/72 - TRANSFER TRIP SCHEME FROM GRIZZLY TO FOUR CORNERS FOR TOTAL PACI LOSS PLACED IN SERVICE. 97 RC RELAY WAS KEPT IN SERVICE AS A BACKUP SCHEME TO THE GRIZZLY TRANSFER TRIP SCHEME.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 1975 - PACI LIMIT INCREASED TO 2200 MW. PACI LIMITED BY 30 MINUTE RATING OF SERIES CAPACITORS (2400 A) AFTER THE LOSS OF ONE PACI LINE NORTH OF MALIN

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 1976 - MORE RAS ADDED TO INCREASE PACI LIMIT TO 2500 MW. RAS ADDED BAKEOVEN AND FORT ROCK SERIES CAPACITOR INSERTION VIA MALIN SLL RELAY NW GEN DROP FOR SINGLE LINE OUTAGES.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 1982 - ADDITION OF MIDPOINT-MALIN 500 KV LINE ALLOWS INCREASING PACI LIMIT TO 2800 MW. PACI LIMITED BY 1600 A STEADY STATE LIMIT OF WAPA’S MALIN SERIES CAPS ON ROUND MT. #1 LINE.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 12/22/82 - WIND STORM CAUSES LOSS OF PACI WHICH WAS CARRYING 2685 MW. ARIZONA-CA INTERTIES ALSO TRIPPED IN RESPONSE TO THE PACI OUTAGE. THE SEPARATION SCHEME WAS DELAYED OVER 2 SECONDS AND IS BELIEVED TO HAVE CONTRIBUTED TO THE ARIZONA-CA TIES TRIPPING. A NUMBER OF RAS FAILURES CONTRIBUTED TO THE SEVERITY OF THE DISTURBANCE. THE DISTURBANCE REPORT RECOMMENDED THAT FUTURE PACI UPRATES NEED TO CONSIDER THE RISKS CAUSED BY INCREASED POWER FLOWS.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 1983 - SIMULTANEOUS TRANSFER PROBLEMS FROM NW AND ARIZONA INTO CALIFORNIA WERE IDENTIFIED WHILE STUDYING THE UPRATE OF PACI TO 3200 MW.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 1985 - INCREASING THE STEADY STATE CAPACITY OF WAPA SERIES CAPS AT MALIN TO 2400 A AND ADDITION OF THE BUCKLEY-SUMMER LAKE LINE INCREASES PACI CAPACITY TO 3200 MW. THE PACI WAS LIMITED BY 1800 A STEADY STATE LIMIT OF PAC’S MALIN SERIES CAPS ON ROUND MT. #2 LINE.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 1986 - THE PACIFIC AC SIMULTANEOUS TRANSFER (PAST) COMMITTEE WAS FORMED BY WSCC TO PERFORM SEASONAL STUDIES TO DETERMINE SIMULTANEOUS TRANSFER LIMITS INTO CALIFORNIA FROM THE NW AND ARIZONA. NOMOGRAMS START BEING USED.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 1993 - ADDITION OF CAPTAIN JACK-OLINDA-TRACY LINE (CALIFORNIA-OREGON TRANSMISSION PROJECT) & ADDITION OF SERIES CAPACITORS ON BUCKLEY-SUMMER LAKE AND SUMMER LAKE-MALIN LINES ALLOWS INCREASING COI TO 4000 MW. BAKEOVEN SERIES CAPS REMOVED AND SERIES CAPS AT SAND SPRINGS, FORT ROCK, AND SYCAN ARE REPLACED WITH HIGHER RATED CAPS. COI LIMITED BY DOUBLE LINE OUTAGE NORTH OF MALIN. COI IS A CALIFORNIA TERM FOR THE COMBINED CAPABILITY OF THE PACI AND THE CALIFORNIA-OREGON TRANSMISSION PROJECT (COTP).

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 1994 - COMPLETION OF DIXONVILLE-MERIDIAN LINE CREATES FOURTH AC LINE NORTH OF MALIN AND ALLOWS INCREASING PACI TO 4800 MW.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 1996 - PDCI AT FULL 3100 MW CAPABILITY WITH 4800 MW CAPACITY ON COI. HIGHER INTERNAL LOADING ON THE BPA SYSTEM DUE TO THE INCREASED CAPABILITY OF THE PDCI AND COI CREATE PROBLEMS NOT SEEN BEFORE.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 6/96 - THE FOUR CORNERS SEPARATION SCHEME IS TAKEN OUT OF SERVICE FOR THE LAST YEAR OF A 3 YEAR TEST PERIOD SCHEME WILL BE RETIRED IF NO COI N-3 OUTAGE OCCURS IN THE NEXT YEAR.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 7/2/96 - DISTURBANCE IN IDAHO CASCADES INTO AN OUTAGE OF THE COI. SIMULTANEOUS LOSS OF ALL THREE COI LINES HAD PREVIOUSLY BEEN THOUGHT TO BE A HIGHLY UNLIKELY EVENT. THE COI WAS LIMITED TO 4000 MW N-S STUDIES DONE BY BPA OVER THE NEXT MONTH INCREASES THE COI CAPABILITY UP TO 4500 MW N-S.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 8/10/96 - AN OUTAGE OF THE KEELER-ALLSTON LINE CASCADES INTO ANOTHER COI OUTAGE. THE SOUTHERN ISLAND LOST APPROXIMATELY 7000 MW OF POWER FROM THE NW BUT LOST OVER 25,000 MW OF LOAD. WSCC LIMITS COI & PDCI TO 3200 MW & 2000 MW RESPECTIVELY AFTER THE SECOND CASCADING LOSS OF THE COI IN LITTLE MORE THAN A MONTH.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. THE WSCC BOARD OF TRUSTEES REQUIRES THAT STUDIES JUSTIFYING INCREASING THE COI AND PDCI TRANSFER CAPABILITIES MUST BE APPROVED BY REGIONAL CONSENSUS. BLUE RIBBON PANEL FORMED BY BPA TO RECOMMEND ACTION TO BE TAKEN BY BPA.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 3/97 - COI AND PDCI CAPABILITY INCREASED TO 3568 MW & 2682 MW N-S AS APPROVED BY THE WSCC BOARD OF TRUSTEES. STUDIES SUPPORTED 500 MW HIGHER TRANSFER CAPABILITY THAN APPROVED.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. LOTS OF CHANGES IN OPERATION STUDY ASSUMPTIONS CHANGED SHUNT CAPACITORS ADDED AT JOHN DAY AND HANFORD RAS ADDITIONS MONITOR REACTIVE RESERVES MONITOR EQUIVALENT UNITS DEFAULT CURTAILMENT FOR UNSTUDIED OUTAGES CONDENSOR CAPABILITY ADDED TO UNITS AT JOHN DAY & THE DALLES

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 4/98 - COI & PDCI OPERATING CAPABILITY RESTORED TO FULL 4800 MW AND 3100 MW N-S RATED CAPABILITY.

HISTORY OF THE PACIFIC AC INTERTIE (PACI) Cont. 12/98 - LATE 1998 THE RENO-ALTURAS PROJECT WAS COMPLETED WHICH ALLOWS 300 MW TO FLOW SOUTH TO RENO. THE COMBINED FLOW ON THE COI AND NW/SIERRA PATH CANNOT EXCEED THE OTC OF THE COI. SIERRA NEEDED PATH TO PROTECT AGAINST LOSS OF MIDPOINT-HUMBOLDT 345 KV LINE AND INCREASE IMPORT CAPABILITY. BPA NEEDED ANOTHER PATH TO SERVE GROWING LOAD IN WELLS AREA. CAPACITY TO SERVE WELLS LOAD VIA IPC’S SYSTEM WAS LIMITED.