Enhancing of power quality and availability in distribution systems by means of voltage source converters

Voltage source power converters (VSCs) far into the tens of MVA range and based on IGBT technology are now a reality. This opens up new approaches for the improvement of power quality as well as availability in power distribution. Flicker mitigation as well as active harmonic filtering are readily attainable by means of pulse width modulation in the kHz range. As a means for asynchronous power exchange, VSCs in a back-to-back scheme offer means for the stable interconnection of weak AC power systems where active power flow and system voltages can be controlled independently of each other.