Power semiconductors in transmission and distribution applications

Triggered by rapidly changing market conditions in the utility sector and fueled by advances in high power semiconductors, a silent revolution is taking place in development of transmission and distribution (T&D) system technologies. Innovation in high power, high speed gate-controlled semiconductor switches is now making it possible to utilize state-of-the-art voltage source converters (VSC) for systems rated between a few MVA to a few 100s of MVA. The result has been nothing short of spectacular in terms of functionality of the new systems and the resulting application opportunities. The semiconductor contents of such systems have increased many folds in comparison to the traditional current source converters (CSC)-mostly at the expense of bulky passive components. One senses for the first time that the marriage between power electronics and T and D system is finally consummated.