Reliability and economic based analysis to determine an opportune rehabilitation and modernization schedule for hydroelectric facilities

Twenty-four synchronous generators and associated equipment are selected to represent hydroelectric equipment reliability and system availability. Fault data for the 24 generators are collected and filtered for only forced outage data, from which equipment reliabilities are determined. The eight major equipments in a hydropower plant are divided into two groups based on their reliability for calculation of rehabilitation and modernization timing. Considering reliability and economics, it appears that 20 to 23 years is a favorable time to rehabilitate equipment of group 2, which includes the switchyard circuit breaker (CB), excitation system, governor and main CB, and 40 to 45 years is an opportune time to modernize group 1 equipment, comprised of the rotor, stator, turbine and main transformer.