Calculation of risk and statistical indices associated with available transfer capability

A complete evaluation of available transfer capability (ATC) involves the determination of total transfer capability (TTC), transmission reliability margin (TRM) and capacity benefit margin (CBM). Due to the stochastic nature of power system behaviour, which is considered by TRM, it is important to assess ATC from a statistical and risk analysis point of view. Based on a combination of repeated AC power flow and Monte Carlo methods, risk assessment of the ATC value is described and a set of statistical indices and plots is presented, which provides important information for transmission customers, system operators and power marketers. In addition, two methods of incorporating CBM into ATC are presented and compared. Case studies with the IEEE Reliability Test System (RTS) demonstrate the effectiveness of the proposed methods, indices and plots. The impact of uncertainty, CBM and methods of incorporating CBM on ATC are also investigated.