A power system is normally composed of a large number of generators and transmission lines that are connected through switching stations and substations. The quality and availability of power supply to the customer is highly dependent on the performance of the station equipment. Research shows that station related outages can have considerable impact on the composite system reliability. The individual station components, the station configurations and the terminal connection topologies are important factors in bulk system reliability evaluation. The major components in a station are circuit breakers, bus bars and transformers and these elements are periodically removed from service in order to conduct preventive maintenance. The removal of equipment for maintenance creates a change in the station configuration and a more vulnerable system. The failure of a related major component during a station preventive maintenance outage can result in a system disturbance and customer load loss. The bulk of the existing infrastructure of most electric power systems has been installed over the last 30 to 50 years. Aging failures of system components are a growing issue in modern electric power systems. Station related preventive maintenance outages and aging failures are important factors that affect the system reliability. This thesis examines the reliability implications of station related outages, including maintenance outages and aging outages in basic station configurations using two practical test systems. Models and techniques are created to incorporate these outages in composite system reliability evaluation. The techniques presented and the quantitative analyses illustrated in this thesis provide valuable information for a wide range of system planning, design, reinforcement and maintenance applications, including design and modification of power stations and station maintenance planning.

A power system is normally composed of a large number of generators and transmission lines that are connected through switching stations and substations. The quality and availability of power supply to the customer is highly dependent on the performance of the station equipment. Research shows that station related outages can have considerable impact on the composite system reliability. The individual station components, the station configurations and the terminal connection topologies are important factors in bulk system reliability evaluation. The major components in a station are circuit breakers, bus bars and transformers and these elements are periodically removed from service in order to conduct preventive maintenance. The removal of equipment for maintenance creates a change in the station configuration and a more vulnerable system. The failure of a related major component during a station preventive maintenance outage can result in a system disturbance and customer load loss. The bulk of the existing infrastructure of most electric power systems has been installed over the last 30 to 50 years. Aging failures of system components are a growing issue in modern electric power systems. Station related preventive maintenance outages and aging failures are important factors that affect the system reliability. This thesis examines the reliability implications of station related outages, including maintenance outages and aging outages in basic station configurations using two practical test systems. Models and techniques are created to incorporate these outages in composite system reliability evaluation. The techniques presented and the quantitative analyses illustrated in this thesis provide valuable information for a wide range of system planning, design, reinforcement and maintenance applications, including design and modification of power stations and station maintenance planning.