ENHANCEMENT OF POWER-SYSTEM STABILITY BY USING CONTROLLED SERIES COMPENSATION

This paper studies the application of controlled series compensator (C SC) to damp power swings in multimachine power systems. For the design of CSC damping controllers, a necessary step is the derivation of the linear state equation for the system. In order to consider the dynami cs of the CSC, it is important to present the change in the CSC reacta nce as one of the state variables. In this case, unlike the traditiona l network representation, the network admittance matrix is no longer a constant matrix. Under this situation, the conventional linearization method for obtaining the linear state equation for the system must be modified, In this paper, a linear dynamic model for a multi-machine p ower system equipped with controlled series compensators (CSCs) is der ived. Based on this linear dynamic model, a state feedback controller is designed for CSC control. The feedback control gains are obtained b y using the pole placement technique. Given that CSCs are to be instal led in a meshed system, the optimum location for installing CSCs is de termined by analyzing the mode controllability. The effectiveness of t his controller for damping the oscillations caused by power system dis turbances is verified by simulation studies. Copyright (C) 1996 Elsevi er Science Ltd.