الفهرس 
chapter 1Only 14 pages are availabe for public view
 |  | from | 181 |  |  |
| | | from | 181 | | |
Abstract
Medium voltage elctric drives and utility application require an advanced poewr electronics converter to meet the high power demands since power electronics are now the link between all power stage.
unfortunately, the operational capacities of two-level power converters are restricted by the switching devices which are limited by the physical charchteristics of the semiconductor materials. in this sence, large amounts of research are taking place arounf the development of new semiconductor switching devices with larger voltage withstanding capabilities. however, one of the biggest problems in electrical power system is the harmonic contents and power converters are the main source of harmonics in the electrical systems. harmonics can cause problems for power system networks, such as overheating in the magnetic cores of transformers and motors, electromagnetic interference, and pulsating torque in induction motors.