A new operation strategy of series compensating device under line flow congestion using the linearized line flow sensitivity

This paper deals with a new operation strategy of FACTS (flexible AC transmission system) device, especially the series compensating device like TCSC (thyristor controlled series compensator) using the linearized sensitivity derived in this paper. In case of a line overflow under contingency state or line congestion at normal state, the FACTS device must change its operating point to relieve the flow congestion and eventually to increase the system security level. In this paper, line flow sensitivity to FACTS device is derived analytically. The sensitivity derivation is based on the DC flow model under the assumption that the generator dispatch is maintained. The power flow control algorithm based on the sensitivity analysis proposed in this paper has several advantages; it is easy to compute, its computation time is short, and its form is very simple etc. Each FACTS device installed in the power system changes its reactance according to the dynamic algorithm proposed in this paper. Its direction and the amount of reactance change depend on the sensitivity of each device. The proposed algorithm in this paper is tested and verified on the IEEE 39 system