Analysis of current harmonics produced by rectifiers used in uninterruptable power supplies

In this study,the harmonics which are formed in the input of an Uninterruptible PowerSupply(UPS) and given to the network were analyzed and also explained the methods whichare used to destroy these harmonics.These methods are compared with each other and theirsuperiorities are explained.In the introduction section the whole study is summaried. In chapter 2, the harmonics areanalyzed theorically and in chapter 3, the definitions which are related to harmonics are givenplace.The elements that are caused to harmonics are discussed in chapter 4 and the effects that arerevealed by harmonics are also discussed in chapter 5. The standards which are related toharmonics are explained in chapter 6.In chapter 7, after giving the information about the harmonics,the methods which are used fordecreasing the input current harmonic distortion in uninterruptible power supplies areexplained in detail.In chapter 8, input current harmonic values are compared according to rectifier types that areused in the uninrettuptible power supplies. Besides,the measurement results that were obtainedby power analyzer in factories and the situation of harmonics that are given to network byproposed uninterruptible power supplys which are proposed according to these results areexplained as tables.In chapter 9 and in the last chapter conclusions and proposals are discussed.Key Words: Harmonics, Uninterruptible Power Supplys and Input Current HarmonicDistortion.JURY:1. Prof. Dr. Asım KASAOĞLU (Supervisor) Date : **.**.20052. Doç. Dr. Hakan ÜNDİL Page: 1143. Y. Doç. Dr. M. Salih TACİ