Optimal SSSC-based power damping inter-area oscillations using firefly and harmony search algorithms

The static synchronous series compensator (SSSC) can add a series reactance to the transmission line, and when it is fed using auxiliary signals, it can participate in damping inter-area oscillations by changing the series reactance. In this paper, the effect of the SSSC on small-signal stability is investigated. The design of a controller for damping oscillations is designed and discussed. Moreover, using the firefly and the harmony search algorithms, the optimal parameters controlling SSSC are addressed. The effectiveness of these two algorithms and the rate of SSSC participation in damping inter-area oscillation are also discussed. MATLAB software was used to analyse the models and to perform simulations in the time domain. The simulation results on the sample system, in two areas, indicated the optimal accuracy and precision of the proposed controller

Optimal designing of static var compensator to improve voltage profile of power system using fuzzy logic control

The unbalanced and nonlinear characteristic of many loads connected to the power system can cause power quality problems, which in turn affects other consumers. Electric arc furnaces (EAF) are among the loads that cause major problems for system power quality. The use of static var compensator (SVC) is a way to reduce power quality problems caused by EAF. Since precise quantification of the SVC susceptance function can greatly influence the optimization of the reactive power, in this paper proposed using of a fuzzy logic controller to optimize the susceptance function to further improve the voltage profile and reduce SVC capacitance. The results from simulations show that the SVC based fuzzy method optimally determines the coefficient of the susceptance function. The results show that the proposed method with the proposed method has good performance in reduction of harmonic currents and improving the voltage profile of the system. So, the results clear that in case of EAF load, the SVC is capable of rapidly compensating its effect and improve the system power quality. By maintaining the bus voltage and eliminating voltage oscillations, the active power received is quickly stabilised and power oscillations are removed. Thus, power quality problems of EAF application is eliminated with application of optimized SVC based fuzzy method. In addition, the performance of the proposed method compared to mathematical methods in previous studies has been evaluated, which presents superiority of the proposed method in reducing voltage oscillations and reducing harmonic currents