Reliability Modelling of Thermal Units for Peaking and Cycling Operations

The four-state Markov model for peaking units recommended in 1972 by an IEEE Task Group is modified to provide a more accurate representation of the operating history of thermal units in cycling operations. Two new models are also presented: one for identifying contributions to the calculated index from the various causes of outages, the other for incorporating the forced extensions of planned outages separately instead of lumping them with forced outages. Finally, a general method is proposed for estimating the transition rates of Markov models from recorded data.