Sensitivity of system operating considerations in generating capacity adequacy evaluation

Generating capacity adequacy assessment is an important activity in power system planning and development. This procedure usually involves the development of suitable generating capacity models and the convolution of these models with appropriate system load or demand models. Generating capacity models are usually assumed to be independent of the load models and use fixed generating unit capacity and reliability parameters determined from design and operating statistics. The basic model for a base load generating unit is a two-state model representation in which the unit is either in service or unavailable for service. This is a valid representation for a base load unit but does not adequately represent intermittent operating units used to meet peaking load conditions.The two-state model for a base load unit has been extended to a four state representation, which is widely used in practice. In this case, the conventional generating unit forced outage rate (FOR) is replaced by the utilization forced outage probability (UFOP), which is the probability of the generating unit being unavailable given that the system needs it. The calculated UFOP is not a fixed value but varies depending upon the operating role played by the unit. This paper illustrates the utilization of a sequential Monte Carlo simulation technique for generating system adequacy evaluation and examines the response of the reliability parameters associated with intermittent operating units to changes in the generating unit loading order, the required reserve, the system peak load and other system conditions.