The effects of voltage sags on electrical energy systems

According to constructional approach, this thesis consists of ten chapters. In theintroduction chapter, after a short summary related with the main theme , it?s beeninvestigated literaturely and told about the phenomenas and reasons of the thesis. Inthe second chapter the defination of voltage sag, existance reasons and frequencieswere given. In chapter three the power systems and their structures were observed.Here, it?s been taken up the asynchronous engine behaviours, generators andtransmission lines.In chapter four, the effects of voltage sags are investigated generally.Voltage sags ininduction engines, voltage sags in transformators, voltage sags in synchronousengines and generators and the voltage sag effects of domestic electricalpowerhouses were examined. Also, the problems which were occured by the suddenworking of the big-power asynchronous engines and the additional contrubition ofthe domestic powerhouses were examined.In the fifth chapter, a detailed theoretical background, mathematical equations andthe methods which were used in the analysis of the short-term voltage sags weregiven.The world wide examples of the voltage sags which were enrolled in severalcountries were presented in the chapter six.The situations faced in the examples andsolutions of the problems were the main subjects in that chapter.InIn the seventh chapter, the voltage sag reduction devices were showed and informed.The error reducer usage techniques of the devices were being told for the probableerrors.( voltage sags, harmonical distortions etc. ). In the eight chapter,ıt?s givenabout the transmission line in Turkey.In the ninth chapter, ıt?s shown voltage sags problem and solve a few example byPowerWorld Sımulator programme. In the final chapter,ıt?s given to information howto solve voltage sags problems.Keywords : Voltage Sags (Dips), Short-term Voltage Sags, Voltage Distortions,Energy Quality, Distribution Systems.