ABSTRACT
Power quality is generally evaluated in terms of harmonic content in both supply voltage and current. For an ideal system, harmonics are typically caused by the use of nonlinear loads found in domestic equipment such as switch-mode power electronics converters, ballast for ¹uorescent lamps, computers, televisions, and other nonlinear loads used in tertiary and industrial applications such as power electronics operated adjustable speed drives, arc furnaces, and welding equipment [1]. že nonlinear loads draw nonsinusoidal current from the network, an important harmonic content of the supply voltage with regards to the fundamental. že presence of such harmonics in the system can cause a number of unwanted e¦ects for sensitive electronic loads such as industrial process controllers, hospital monitoring equipments, and laboratory measurement devices, and computers malfunction or fail to operate when connected to an ac line that has high harmonic voltage content. Also, electric utility transmission and distribution equipment may be susceptible to ac line harmonics. Furthermore, transmission lines, motors, and transformers could have higher operating losses; capacitor banks may fail due to over current, protective relays may not operate properly.
