Reza Vafamehr. Design of Electrical Power Supply System in an Oil and Gas refinery

Göteborg, Sweden, 2011 — 70 p. Department of Energy and Environment Division of Electric Power Engineering Chalmers University of Technology.
In this study, the power supply of one unit of a petroleum refinery in Iran, the criteria and the methods of designs of normal networks, electrical equipments and protections of the system have been discussed and investigated. A single line diagram will be presented as the outcome of the design. The above so called “single line diagram” includes 20kV, 6.3kV and 420V voltage levels. In the second phase, the designed single line diagram is consequently simulated by the power system analyzer software. The study will eventually cover the followings; load flow, short circuit current and motor starting.
The intention of the above research is to create solutions in different ways electrical loads should be categorized in this energy industry as well as energizing these loads by a stable power supplies. In addition, the key role of the short circuit impedance of the transformers in control of the short circuit current will be presented. Furthermore, the selection procedures of the electrical equipments and accessories including cables, transformers, circuit breakers, relays and etc. are presented. Then, the following factors such as the size of equipments, losses and voltage drops will be checked by load flow study. In the meantime, a comprehensive study of the short circuit current calculation is implemented and can be observed how the system can be checked by the results of this study. In the dynamic study of the system, the biggest motor starting is simulated and the impacts of the voltage dip due to starting of this motor on the other running motors are shown.