الفهرس | Only 14 pages are availabe for public view |
Abstract Power system harmonics cause many problems like equipment failures, malfunctions and plant shutdowns. Accordingly, mitigation of these harmonics is considered an important target especially for the industrial applications where any short downtime period may lead to great economic losses. In this thesis, power systems harmonics and their mitigation techniques in the industrial electrical systems are investigated and analyzed from both technical and economic aspects. Novel technical and economic studies are introduced to enable the design engineers and consultants of the industrial electrical power systems of selecting the optimal mitigation technique for their plants. The thesis starts with a review of the literatures on power system harmonics and its mitigation techniques in industrial electrical power systems, then the fundamentals of power system harmonics are introduced. Then a detailed case study for an existing oil processing plant suffering from harmonics problems is presented and various harmonic studies are performed using the electrical transient analyzer program (ETAP). The effect of using multi-pulse VFD on the harmonic distortion is tested. In addition, the effect of varying the harmonic filter insertion point in the power system is examined. When an engineering consultant or an industrial plant owner decides to mitigate the harmonics within his plant, he will find out that there are at least ten harmonic mitigation techniques, each having specific advantages and disadvantages, thus selection of the optimal mitigating technique will be a difficult task. This thesis provides novel technical and economic studies for most of the harmonics mitigation techniques available in the market to enable design engineers and consultants of selecting the optimal mitigation technique for their plants. Finally the harmonic analysis studies are discussed and a comprehensive novel procedure for the steps required to perform a harmonic study is presented in the form of a flowchart. In addition, the current and voltage harmonic limits used in the industrial systems are presented. |