RELIABILITY MODELING FOR EXPANSION-PLANNING OF ELECTRIC-POWER PLANTS

This paper presents a simple analytic approach for solving the problem of expansion planning of electric power plants. The relationship between the long-range generation investment and the plant size is studied to determine generation capacity. The reliability level, as an important limiting factor of the expansion planning process, is discussed and the corresponding system costs are determined based on the reliability specification. The model has the following features: The reliability modeling of the power plant is accurately represented by a 6-state model instead of the currently used 2-state models of plant availability. The choice of the economic expansion alternative based on the probabilistic estimation of the investment and production cost is simple. It follows the steps usually done by the planning engineers but requires much less time because of its analytic nature. For strategic long-term expansion planning, the plant size strongly influences the annual cost. A higher reliability level appreciably increases the necessary power reserve and system cost. The model does not yet determine the optimal reliability level by accounting for the cost of unserved energy.