الفهرس Only 14 pages are availabe for public view
 |  | from | 137 |  |  |
| | | from | 137 | | |
Abstract
of
A voltage sag is a brief (0.5 cycle - 1 minute) DROP in voltage magnitude, usually caused by a fault somewhere on the power system transmission or distribution network. Voltage sags are the most important power quality problem facing many process industry companies. Equipment used in modem industrial plants (process controllers, programmable logic controllers, adjustable speed drives ... etc) is actually becoming more sensitive to voltage sags as the complexity of the equipment increases and the equipment is interconnected in sophisticated processes. Even relays and contactors in motor starters can be sensitive to voltage sags, resulting in shut down of a process.
This thesis presents a study to the power quality problem and custom power concept in general, then it presents another study to the characterization of voltage sag and its impact on industrial processes giving a special attention to the three-phase induction motors where the three-phase induction motors, indeed, are the workhorses of today’s industry.
The goal of this thesis is to provide a detailed assessment of the performance of different induction motor sizes when subjected to different voltage sag types of different characterizations. To achieve such goal, a transient induction motor model was built using MA TLAB/SIMULINK package, another model was built which is the voltage sag generator that provides the ability of generating almost any sag type with any customized characterizations.