Load modification: a unified approach for generating-capacity reliability evaluation and production-cost modelling

The paper illustrates a unified probability technique entitled the `load-modification method¿¿ to evaluate generating-capacity reliability. The method is essentially a process of modifying a given load-duration curve with a generating-capacity distribution to give an equivalent load model. The technique presented has the unique ability of maintaining the identity of each individual generating unit in the system throughout the calculation process. This makes the method capable of incorporating the limited energy characteristics of hydro stations or other facilities in the analysis. The technique developed has also been utilised to incorporate load-forecast uncertainty considerations and extended to include interconnected systems in the evaluation. The paper describes and illustrates the approach in single and interconnected systems by simple numerical system examples. Selected studies using the IEEE reliability test system are conducted to illustrate the application of the method.