A VOLTAGE SAG SUPPORTER UTILIZING A PWM-SWITCHED AUTOTRANSFORMER-Thesis(doctoral)-- Georgia Institute of Technology : Electrical & Computer Engineering 2004-Dong-Myung Lee

 1.1 Background 

A power distribution system is similar to a vast network of rivers. It is important to remove any system faults so that the rest of the power distribution service is not interrupted or damaged. When a fault occurs somewhere in a power distribution system, the voltage is affected throughout the power system. Among various power quality problems, the majority of events are associated with either a voltage sag or a voltage swell, and they often cause serious power interruptions. A voltage sag condition implies that the voltage on one or more phases drops below the specified tolerance for a short period of time. A voltage swell condition occurs when the voltage of one or more phases rises above the specified tolerance for a short period of time. The causes of voltage sags and swells are associated with faults within the power distribution system. Users located a close distance to the fault experience voltage sags much greater in magnitude and duration than users located farther away, and as the electrical system recovers after removing the fault, voltage swells are produced throughout the system for short periods of time. Often all users who are served by the power distribution system have power interruptions during a fault because of the effects of a voltage sag or voltage swell produced in the system by the fault. The objective of this research is to develop a novel voltage control scheme that can compensate for voltage sag and swell conditions in three-phase power systems. Power systems supply power for a wide variety of different user applications, and sensitivity to voltage sags and swells varies widely for different applications. Some applications such as automated manufacturing processes are more sensitive to voltage sags and swells than other applications. For sensitive loads, even a voltage sag of short duration can cause serious problems in the manufacturing process. Normally, a voltage interruption triggers a protection device, which causes the entire branch of the system to shut down.

LINK PART OF THE THESIS:
https://copy.com/h2Lcmcqbsr7fYCwo

LINKS PAPERS IEEE

A voltage sag supporter utilizing a PWM-switched autotransformer
Dong-Myung Lee ; Habetler, T.G. ; Harley, R.G. ; Rostron, J. ; Keister, T. Power Electronics Specialists Conference, 2004. PESC 04. 2004 IEEE 35th Annual Volume: 6 DOI: 10.1109/PESC.2004.1354751 Publication Year: 2004 , Page(s): 4244 - 4250 Vol.6 Cited by: Papers (5) IEEE Conference Publications

A Voltage Sag Supporter Utilizing a PWM-Switched Autotransformer
Dong-Myung Lee ; Habetler, T.G. ; Harley, R.G. ; Keister, T.L. ; Rostron, J.R. Power Electronics, IEEE Transactions on
Volume: 22 , Issue: 2
DOI: 10.1109/TPEL.2006.890004
Publication Year: 2007 , Page(s): 626 - 635
Cited by:  Papers (28)
IEEE Journals & Magazines