The BC hydro/port Alice utility intertie

Western Pulp Limited Partnership's mill at Port Alice, British Columbia, operated as an island power system that generated all its own power. BC Hydro served only one isolated load of 2 or 3 MW for which the mill lacked generating capability. Upon the addition of an 8 MW load, customer (Western Pulp) and utility (BC Hydro) agreed that it was time for the two power systems to be interconnected. The 30 km, 25 kV line from Keogh substation was converted to 132 kV so it could transmit this much power. The 132 kV line was served by tapping into an existing line, making it a multi-terminal power transmission line served from the middle, with generation at both ends. Western Pulp built the 132/25 kV Jeune Landing substation to serve the pulp mill and provide 25 kV power to BC Hydro for other customers. In an emergency, the mill is capable of backfeeding Jeune Landing substation from its generators if the 132 kV line fails. This paper discusses the difficult problem of operating and protecting a multi-terminal power transmission line as well as problems associated with the utility/customer interface, and the solutions chosen to overcome such problems.