Optimal active power flow incorporating power flow control needs in flexible AC transmission systems

This paper presents a new method to incorporate the power flow control needs of flexible AC transmission system (FACTS) in studying the optimal active power flow problem. The linearized (DC) network model is used in this paper. Three main types of FACTS devices, namely thyristor controlled series compensators (TCSC), thyristor controlled phase shifters (TCPS) and unified power flow controllers (UPFC), are considered. The proposed method decomposes the solution of such modified OPF problem into two problems' iteration. The first problem is a power flow control subproblem while the second problem is a normal OPF problem. It is shown that the modified active power OFF can be solved by a new iterative strategy where a conventional LP-based technique may be used. Digital simulation studies on the IEEE 30 bus test system are presented to show the effectiveness of the proposed method.