Harmonics Effects and their Elimination in Jebel Aulia Power Station

Abstract

Electrical power system has many changes such as; disturbances, perturbations and oscillations caused by many factors such as electrical faults and transients in voltages and currents. Also the network has a lot of losses, which results increasing heat lead to equipment damage. Harmonics generate that is produced in circuit elements circuits like diodes, thyristors, rectifiers, inverters, converters, power generation equipment, Variable Speed Drives of induction motors, transformers and magnetic-ballast fluorescent lamps. Electrical arc furnace also is a major source of harmonics because it draws very high currents estimated in kilo amperes, which result in increasing heat of steel and generate harmonic currents. These harmonic currents create heat after a period of time will raise the temperature of the neutral conductor causing nuisance and tripping of circuit breakers, over voltage problems, blinking of incandescent lights and computer malfunctions. Among the electrical devices that seem to cause harmonics are personal computer, Dimmers, Laser printers, Electronic Ballast, Stereos, Television, Radio, Fax machines and any other equipment powered by switched-mode power supply equipment. These problems can be reduced by using a dedicated circuit for electronic equipments. The more expensive way to reduce these problems filters the mains effectively removing all low frequency harmonics. This thesis, studied and analyzed the harmonics, it found that the harmonics in Jebel Aulia power station is not related to induction generators, but it due to compensation grid. According to study and analysis taken measurements and found that amount of harmonics 20.7 % to 37.1 % before filter installation, when it operates amount of harmonics reduce to 2.6 %. By using MATLAB/SIMULINK, active filter was designed to reduce harmonics to 0.84 % instead of 2.6 %. This filter has high efficiency and sensitivity for all system variations.