DISTRIBUTED POWER FLOW CONTROLLER - AN IMPROVEMENT OF UNIFIED POWER FLOW CONTROLLER

Abstract

A new component within the FACTS family( flexible ac-transmission system), called distributed power-flow controller
(DPFC) which is modification of the unified power-flow controller (UPFC) is presented in this paper .The DPFC have the same
control capability as the UPFC (unified power-flow controller) i.e the adjustment of the line impedance, the transmission angle, and
the bus voltage. Two modifications are made i.e the common dc link through which active power is exchanged between the shunt and
series converters in UPFC is now through the transmission lines at the third-harmonic frequency in DPFC and three-phase series
converter is divided to several single-phase series distributed converters which provides redundancy, thereby makes the system more
reliable. D-FACTS converters are single-phase and floating with respect to the ground, high-voltage isolation is no longer required
between the phases. Comparatively, the cost of the DPFC system is less than the UPFC. DPFC has advantages like improved voltage
profile and reduced power loss. In this paper performance analysis of UPFC and DPFC are compared and corresponding
experimental results are carried out by simulink model