Development and Application of Software for ATC Calculation

In the environment of the power market, available transfer capability (ATC) is a measure of transfer capability remaining in the physical transmission network for future commercial activity over and above already committed uses, then it is an important parameter for all companies participating in the power transmission activities. Widely used ATC calculation software-Powerworld simulates power transfer increment through decreasing generation output in sink area (receiving-end) using the repeated power flow method, but this simulation model does not accord with the actual circumstances of electricity shortage in China. In this paper, a combined method including linear distribution factors and repeated power flow (RPF) is proposed to perform ATC calculation, meanwhile, two scenarios can be selected to simulate power transfer increment: One is to increase the total generation output in source area as the load in sink area increases; The other is to decrease the same amount of generation in sink area while the generation output in source area is to be increased. According to the tests applied in the Northwest China power network to perform ATC calculation and analysis, this method guarantees more exact results by simulating actual transfer increasing mode of the Northwest China power network.