Transmission equipment reliability data from Canadian Electrical Association

Frequent forced outages of power transmission equipment can significantly affect the performance of industrial and commercial power systems and the processes they control. Historical transmission reliability data provides the ability to predict the performance of various transmission line configurations and assess the economic impact of forced outages on industrial and commercial power systems. The prediction methodologies are presented in IEEE Std, 493 (i.e., IEEE Gold Book). This paper presents a summary of the Canadian Electrical Association´s Equipment Reliability Information System statistics on the forced outage performance characteristics of power transmission equipment (i.e., transformers, circuit breakers, cables, etc.) for Canadian utilities for the period 1988-1992. The paper reveals the structure of the database and presents relevant summary data (i.e., the frequency and duration of forced outages) necessary for the application of these reliability methodologies. A knowledge of the primary causes of the major equipment forced outages as to whether the outages are primarily due to the subcomponents of the major equipment or to its terminal equipment is essential for designing, operating and maintaining a reliable transmission system. This paper discusses and identifies for each major equipment the primary subcomponent (e.g., transformer windings) and the terminal equipment (e.g., auxiliary equipment) which dominated the forced outage statistics of the major equipment for the five year period