Using novel unified power flow controller to implement two phases operating in extra-high-voltage transmission system

A conventional unified power flow controller (UPFC) is three-phase three-wire, which cannot deal with zero sequence current, so we must improve it in order to add a function of zero sequence and negative sequence currents compensation. The improved UPFC is called novel UPFC. If we use the parallel converter of novel UPFC to compensate zero sequence and negative sequence currents and use the series converter to improve transmission power when one of the transmission lines is cut off, we can implement two phase operation in extra-high-voltage transmission lines, which can improve stability and reliability for the transmission system. Theoretical analysis and the results of simulation confirm it.