Improvement of Dynamic Stability of Multi-Machine Power Systems using TCSC and Fuzzy Control Method

When an error occurs in a power system, stability and damping of fluctuations is an important factor on which needs to pay attention during the system design. The use of the Power System Stabilizer (PSS) can damp the fluctuations due to small disturbances. Also Flexible AC transmission Systems (FACTS) in a power system, can be effective in improvement of the dynamic stability and in damping of low-frequency fluctuations. One of the FACTS elements is TCSC that can help rapid damping of the oscillation by changing the reactance of the line. In this paper, a TCSC with properly designed fuzzy controller is used to improve the dynamic stability. The proposed method does not need to set the parameters and the on-line controller can help damping of the fluctuations. Simulation results show that the fuzzy based TCSC controller can damp the fluctuations effectively in a power system connected to a single machine infinite bus (SMIB) and also in a multi-machine system (9 BUS IEEE).