Harmonic Control In 33/11 three Phase Distribution Transformer

Abstract

The Harmonics in Distribution Systems come from transformers or saturation reactors, arc furnace, welding machines, florescent lamps, rotating machines and power electronics devices. In general, the nonlinear 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 potpale by harmonic torques giving incorrect tripping 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. thesis presents the definitions of harmonics, generation, causes, analysis and solutions due to IEEE 519 standard of harmonics. In this Research the sources of harmonics and their effects in distribution system equipment are illustrated with the methods that are used to analyze and mitigate it A case study of Sudanese Electricity Distribution Company (SEDC) network (AL OMERA Substation) was investigated using Network Analyzer (AR5) for the reading, and ETAP simulation program. The results of harmonic analysis were compared with IEEE519-1992 limits(5%VTHD). It was found that the total harmonic distortion limit for current in the simulated case study network exceeded the limits(9.55 %VTHD).hence harmonic mitigation solution chosen was the passive filter.