Impact of power wheeling on composite system adequacy evaluation

One of the many possible uses and benefits of interconnection between neighbouring electric power systems is the opportunity to wheel energy through the transmission facilities of one system in order to serve another system. Wheeling of energy can also occur within a system when an independent power producer serves a load located at some other point in the system. Power wheeling transactions are recognized to have a definite impact on the utility's system losses depending upon the system topology, the amount of power/energy wheeled and the wheeling distance involved. These factors currently form the basis for determining service charges associated with power wheeling. Quantification of the reliability impacts of power wheeling is also important in order to understand fully the impacts of wheeling options. This paper discusses the effects of power wheeling on the composite power system adequacy indices of two test systems. The impacts associated with both intra-system and inter-system power wheeling are illustrated. The results presented were obtained using a basic computational tool for composite power system adequacy assessment.