English title

The application of Flexible AC Transmission System (FACTS) devices shows that they can control the power system technical parameters effectively. However, optimal placement and sizing of them are difficult problems and analytical methods cannot be used to solve these problems. To solve such problems, some evolutionary algorithms are employed. The efficiency of these algorithms is related to their objective function. In this paper, two multi objective optimization algorithms, namely: Non-dominated Sorting Genetic Algorithm (NSGA-II) and Multi Objective Particle Swarm Optimization (MOPSO) are used to solve the congestion problem in power system. To verify our proposed method, simulations are performed to modify IEEE 14-bus and modified IEEE 30-bus test systems. Firstly, load of the system is increased uniformly until congestion occurs. Then, optimization algorithms are used to find out the optimal location and size of FACTS devices, as well as the optimal amount of changes in active power generation. Two types of FACTS devices namely: Static VAr Compensator (SVC) and Thyristor Controlled Series Capacitor (TCSC) are used for congestion elimination. The obtained results show the effectiveness of the proposed objective functions.