IMPACTS OF ENERGY LIMITED UNITS ON GENERATING CAPACITY ADEQUACY ASSESSMENT

Abstract

This thesis investigates the effects of energy limitations of generating units on overall system reliability. A generating system may fail to supply the load demand due to a shortage of capacity associated with equipment outages or due to a shortage of basic energy resources or both. Traditional models usually ignore the effect of energy shortages on the basis that sufficient energy resources will be held in reserve for use in critical periods. The assumption of abundant energy may not, however, be valid and it is essential that in these cases, energy limitation problems of generating units should be included in conventional studies. The Load Modification method is used in this thesis to evaluate the impact of energy limited units on the system reliability indices and the energy production cost. This method is basically a combination of the existing Loss of Load and Loss of Energy techniques. This thesis presents a technique which uses the Frequency and Duration approach and a Customer Loss Function to eval ate a factor that relates the customer losses to the worth of electric service reliability. This factor is designated as the Interrupted Energy Assessment Rate (IEAR). This thesis also estimates the economic optimum service reliability level and illustrates how this level is affected by the energy limited units of the system. The concepts involved in the inclusion of energy limited units in conventional generating capacity reliability studies, the evaluation of the system IEAR and the estimation of the optimum service reliability level are illustrated by numerical system examples.