Evaluations of energy efficiency improvement

Abstract

In this master thesis evaluations of energy efficiency based on harmonic impacts and improvement methods in order to obtain better harmonic performance have been investigated. Here, the impact of harmonics at the PCCs according to IEEE is studied. This work is based on the simulations of industrial furnaces by means of simulation tool PSCAD/EMTDC in order to approach a reliable simulation method and have a better overview of industrial furnaces operational behaviours. By means of these simulation methods, the appropriate harmonic filters for the furnaces can be applied. Two main industrial furnaces which have been studied here are induction furnaces and resistive heating elements furnaces. In this case the study of industrial furnaces principle works is vital. The related wiring diagrams and actual measuring value are also needed. This work is focused on investigations and improvements of harmonic impacts at the Company’s intern PCCs more than harmonic impacts on the grid. These harmonics lead to the lower energy efficiency at the Company and cause damages on the electric devices. Then by reducing the harmonics under the standard limitations the economical benefits will be emerged. Evaluations of power factor values for verifying the existing phase compensation capacitors at the Company has been put into action. In this case the available measured and documented data and information have been used. In this master thesis four numbers induction furnaces and three numbers heating elements group furnaces have been studied. All furnaces had one or some harmonic components over the IEEE limitations. By using passive harmonic filters for induction furnaces and two numbers of heating elements group furnaces, the harmonic performance are improved and all harmonic components and total demand distortions are reduced under the IEEE limitations. One of the heating elements group furnaces (heating elements group furnace 6) is required structural amendment of its drive system, then applications of passive harmonic filters isn't a proper solution for its harmonic performance improvement. Since the PCCs are on the secondary side of Company’s feeding transformers (10.5(kV)), there were some limitations for doing actual measurements. So the studies of previous measurements which are prepared by consultant Companies were another part of this master thesis activities.