POWER QUALITY IMPROVEMENT USING MULTILEVEL INVERTERS – A REVIEW
Keywords:
Active power filter (APF); Harmonics; Multilevel Inverters; Power Quality; Pulse Width Modulation (PWM); Voltage source Inverters.Abstract
A conventional two-level voltage source converter has so far been the most widely used converter in active power filters, however it creates several harmonic components and has a high switching stress, leading to additional power quality and loss issues. In recent years, a new breed of voltage source converters capable of producing a desired voltage from several levels of dc voltage as inputs, commonly referred to as multilevel inverters, has made active filtering a mature technology for improvement of power quality. In comparison with a two-level converter, a multi-level converter has less harmonic distortion and less switching stress. The selection of switching technique to control the inverter plays an effective role on harmonic elimination while generating the ideal output voltage. Intensive studies have been performed on the selection of topology and control techniques, and the best control scheme is suggested by various authors, according to various application areas.
