Reliability modeling for expansion-planning of electric-power plants

The author 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 systems costs are determined based on the reliability specification. The stochastic behavior of each plant is represented using a six-state model. The reliability level of the generation system is evaluated using a recursive convolution of the weekly load duration curve with the stochastic availability of the generating units. Central to the reliability calculation is the selection of the unit size; the relationships between plant size and the corresponding investment and production cost are calculated for each expansion alternative. The techniques are also applied to a practical power system and a comparative study is used to select the optimal plant size