Consideration of an appropriate TTC by probabilistic approach

In a new competitive environment, it becomes possible for third parties to access transmission networks. Key information used to determine how much power can be transferred through the network is known as available transfer capability (ATC). Generally, ATC is calculated based on the severest case with some safety margin reserved for any uncertainty in the near future. However, without considering the probabilistic nature of the power system, it becomes a question whether ATC is reasonable in practice or not. This paper proposes a probabilistic approach to cope with this problem. By the probabilistic method, a characteristic of the transfer capability can be obtained through its probability density function. The objective of this research is to provide realistic information on the actual ability of the network that may be an alternative choice for system operators. The advantages of this proposed method are illustrated by an application to a modified IEEE 118-bus system.