Current Trends in dc: Voltage-Source Converters

High-power electronics have been employed in transmission and distribution systems for many years, using thyristor-based currentsource converters. This approach has seen approximately 200 high-voltage dc (HVdc) systems and more than 1,000 static VAR compensation systems installed worldwide. The introduction of voltagesource converters (VSCs) across the transmission and distribution voltage range has stimulated significant interest in exploring many previously inaccessible applications.