Application of AC equivalent to total transfer capability evaluation using two-step method

This paper proposes a method for calculating TTC including many security limits. This method is based on two-step process. First, with linear estimation method, the active constraint that limits the power transfer is predicted. Then, after the active constraint is known, the augmented Newton-Raphson load flow is calculated to evaluate the accurate TTC. In addition, due to the network size problem, AC equivalent model is used in this paper. The TTC obtained from IEEE 118 buses and 300 buses systems with this method show that this proposed method provides satisfactory results with short computation time.