Available transfer capability calculation with small signal stability constraints

Small signal stability becomes one of the important factors influencing transmission capacity because low frequency oscillation in power systems is always caused by small interference. This article proposes a method for calculating available transfer capability (ATC) based on improved second order continuation taking small signal stability constraints into consideration. In this proposed method, the electric power output of the generators of the power systems are re-dispatched in order to improve small signal stability of the power system according to eigenvalue sensitivity index. An improved method of second order continuation power flow is proposed, in which the additional information of the first order index is made to overcome its linear weakness, and the searching range of second order continuation power flow is reduced by the variable sensitivity computation of the control variables. A simulation example is given to illustrate the proposed method in New England power systems with 10 units and 39 buses. The simulation results show that ATC calculation is effective and feasible using the proposed method.