Unified Power Flow Controller (UPFC) is the most advanced FACTS solution which provides independent active power and reactive power control of the transmission system. The UPFC is a combination of static synchronous compensator (STATCOM) and a static synchronous series compensator (SSSC) coupled via a common DC voltage link.
Due to the dynamic and flexible control in both active and reactive power UPFC can bring a bunch of benefits to power transmission system:
1.Flexible power flow control
2.Dynamic voltage regulation
3.Improved system stability
4.Power oscillation damping
5.Regulation of loop current in meshed network to achieve optimal load flow
6.Increase of transmission capacity of existing network and avoid installation of new lines
UPFC solution from NR is based on state-of-art MMC converter. Through connection of sub-modules in series power regulation at various high voltage levels is achieved according to system requirement.
