Minimization of Distribution System Harmonics : Case Study Sudanese Malaysian Steel Factory

Abstract

The Harmonics in Distribution Systems come from transformers or saturable reactors, arc furnace, welding machines, florescent lamps, rotating machines and power electronics devices. In general, the non linear loads in which the relationship between the voltage and current is not constant. It is considered that there is no risk of harmful perturbation from 5 to 10%. Above 10%, problems will certainly occur. Equipments can be affected by the harmonics like transformers with increase of losses, risk of overheating, noise and even insulation stress problems. Cables that can heat too much due to as Kelvin effect above 400 Hz. Induction relays and meters that are pertubated by harmonic torques giving incorrect trippings and readings. The solutions that can be used to improve the p.f. and to protect the capacitors are either de-rate the capacitors or using detuning reactors, and also by using harmonic filters. This thesis presents the definitions of harmonics, generation, causes, analysis and solutions due to IEEE 519 standard of harmonics. The basic aim of the study is how to minimize the Harmonics in Distribution Systems and applied the study in Sudanese Malaysian steel factory. It was found that the factory has been suffered from the damage of sensitive electronic control devices, poor power factor and tripping of circuit breaker. By the measuring the power ,current ,voltage ,power factor and the total harmonic distortion with aid of standard formulas and calculation the suitable solution was found that using capacitors with reactors in series for both minimization of harmonics and improving the power factor in the factor.