Including a combined fuzzy and probabilistic load model in transmission energy loss evaluation: Experience at BC Hydro

The uncertainty of load forecast is a challenging issue for power and energy loss evaluation in transmission planning. Traditionally, a normal distribution is assumed to model the load uncertainty. However, many utilities provide the most probable load forecast with unequal upper and lower bounds which do not follow a normal probability distribution. This paper presents a method to incorporate a combined fuzzy and probabilistic load model in transmission energy loss evaluation. The BC Hydro system is used to demonstrate the application of the presented method. The results indicate that the membership functions of power and energy losses can provide a clear insight into the impacts of load forecast uncertainty on losses.