Designing of multilevel DPFC to improve power quality

According to growth of electricity demand and the increased number of non-linear loads in power grids, providing a high quality electrical power should be considered. In this paper, Enhancement of power quality by using fuzzy based multilevel power flow controller (DPFC) is proposed. The DPFC is a new FACTS device, which its structure is similar to unified power flow controller (UPFC). In spite of UPFC, in DPFC the common dc-link between the shunt and series converters is eliminated and three-phase series converter is divided to several single-phase series distributed converters through the line. This eventually enables the DPFC to fully control all power system parameters. It, also, increases the reliability of the device and reduces its cost simultaneously. In recent years multi level inverters are used high power and high voltage applications. Multilevel inverter output voltage produce a staircase output waveform, this waveform look like a sinusoidal waveform leads to reduction in Harmonics. Fuzzy Logic is used for optimal designing of controller parameters. Application of Fuzzy Multilevel DPFC for reduction of Total Harmonic Distortion was presented. The simulation results show the improvement of power quality using DPFC with Fuzzy logic controller.