Fuzzy Controlled STATCOM for Improving the Power System Transient Stability

This paper presents the application of a fuzzy logic controlled Static Compensator (STATCOM) to improve the transient stability of the power system. The nonlinear fuzzy logic controller is used to overcome the problems generated by different uncertainties existing in power systems when designing electromechanical oscillation damping controllers. Generator speed and its derivative are used to design the controller. Proposed method is implemented in the 9 Bus IEEE network and simulation results are presented to confirm the performance of the controller to increase the damping of the system. stability [4]. STATCOM is one of the parallel FACTS devices that are usually used for voltage regulation. It is also used to improve power system stability by injecting or absorbing reactive power. This function of STACOM needs some more supplementary input signals [4]. Several controllers have been used to perform this control strategy such as conventional PI controller [5], rule based controller [6] and energy function based controller [7]. Uncertainty exists in almost every physical system. It can be the result of different phenomena according to system nature, lake of information or measurements. Power systems are large scale systems with high nonlinearity, so there is a considerable uncertainty in every part of them. Fuzzy logic performs as a powerful tool to confront these uncertainties [8]. This paper presents a fuzzy logic based control strategy for STATCOM to improve power system stability and performance. The fuzzy logic approach provides a model-free method for STATCOM control and can be effective over a wide range of power system changes. Fuzzy logic