Analysis of the current situation is one of the fundamental needs for modification and development of every physical system. This subject is more considerable for the electric grid of Mobarakeh Steel Factory, due to various heavy nonlinear loads and the effects of the resulting voltage and current harmonics. This gird is composed of two separate parts connected to bus bars named PP Bus and EAF Bus. A set of trap filters known as Fixed Capacitor Bank (FCB) protect PP Bus and network connected to it against various produced harmonics. In this thesis an overview of the plant electric system is presented. Computer simulations in time and frequency domain are used to investigate and verify the role of FCB filters in modifying harmonic characteristics of the plant power system connected to PP Bus. Various harmonic producing loads are exactly modeled and analyzed by computer simulation in time domain. The effects of network components and configuration are considered by evaluation of network impedance characteristics and harmonic spectrum, using frequency domain simulation. Variation of filters resistance, effect of power factor compensation capacitors and harmonic characteristics at various points of the factory network are evaluated and compared in this work.
