الفهرس | Only 14 pages are availabe for public view |
Abstract Power qual ity is an issue that has generated much interest to both electric utilities and customers today. With the increased use of complex and sensitive electronic circuitry, any slight variation in magnitude, frequency or purity of the WaVef01TI1can often affect and lead to expensive failures of equipment. The performance and operation of this equipment may unavoidably cost customers in lost time and revenue. Efficient simulation tools are important to investigate the causes and effects of these power quality problems, possibly saving large amount of time and money especially in today’s challenging and competitive environment. In addition, through the development of technologies and instruments, highly developed power quality monitoring tools are available to meet local and international standards. The present thesis is concerned with the power quality problem especially when induction motors are concerned. It comprises a background review of induction motors and the type of induction motor modeled. Parameters are extracted from the selected induction motor by means of experimental methods while some are synthetic parameter values. In order to understand more on the effects of the power quality problems, we will make use of simulation methods. MATLAB is currently used by the industry intensively for simulation and is widely recognized [0 be reliable. The simulation in MATLAB comprises a high-performance language for technical computing that includes functions for numeric computation, data analysis, system simulation, and application. By using Sirnulink in MA TLAB, the power quality problems response in a controlled environment can be observed. In the process of simulation, the control settings can be changed and the power quality problems response are displayed in the graphical format with variable loading to ensure better understanding of the outcome. Power quality disturbances such as capacitor switching and voltage sags events with emphasis on system faults and induction motor starting are of particular interest. Computer simulation results indicate that the software can be utilized as an effective tool for simulating power quality problems. Identifying problems in an electrical network before any extensive damage occurs is advisable for any power system. Not only does monitoring of power quality necessary for maintaining accurate operation of sensitive equipment, it also ensures that unnecessary energy losses in a power system are kept at a minimum which leads to more profits. This thesis seeks to identify the effect of power quality problems m a small power system mainly containing induction motors. For the problems identified recommendations are suggested to improve the power quality. The lifetime shorting of the induction motor caused by the voltage sags and momentary interruption is investigated with measured data from the motor and simulated using MATLAB to observe the extent of the sag throughout the system. The extent of sags from faults is also simulated |