An integrated H-infinity optimised fuzzy controller for UPFC in multimachine power systems

A detailed mathematical model of a multimachine power system with unified power flow controller (UPFC) has been developed with a view to control the active and reactive power flow in the transmission line and to improve transient stability performance. Thus, initial voltage and angles of the series and shunt voltage sources are computed and used during transient stability studies. After the power flow conditions are met, a simple non-linear controller based on input-output linearisation and two-rule-based fuzzy control scheme is developed in closed mathematical form. Further, the gains of this controller are optimised using an adaptive particle swarm optimisation (PSO) technique for improvement of damping to system oscillations.

Keywords: unified power flow controller, UPFC, power system control, H-infinity tracking control, fuzzy control, particle swarm optimisation, PSO, multimachine power systems, mathematical modelling