Fast Determination of Simultaneous Available Transfer Capability (ATC)

This paper proposes a novel fast computational method to determine the simultaneous power available transfer capability (ATC) in a power system. This method consists of a fast estimation algorithm and a constrained power flow iteration. The ATC limiting factors considered in the method are: line thermal limits, bus voltage limits, and generator reactive power limits. When combined with the first line contingency considerations, this method will give the fastest ATC computing. The feature of this method is that it uses only one steady state power flow result for the fast estimation algorithm. Without further time consuming power flow iterations, it is the fastest estimation algorithm available. Based on the fast estimation, with a few more constrained power flow iterations, precise ATC value can be obtained. This method can be used to improve the speed of many available ATC programs. Especially, it may be used in addition to the widely used DC power flow program or simply replace it to provide additional voltage and var information, since DC power flow generally ignore voltage or var problems. This method can help the independent system operator (ISO) to determine the validity of the bidding results in an open access deregulated electricity market when timely ATC information is very important. It can also help the power market participants to place bids strategically when congestion happens.