Analysis of Distributed Power Flow Controller...

Analysis of Distributed Power Flow Controller to Improve Power Quality in Power System

Author Name : Khushboo Nagar , Neha Nagar , Mayank Vishvakarma

ABSTRACT Modern power utilities have to respond to a number of challenges such as growth of electricity demand specially in non-linear loads in power grids. So, there is a great demand to control the power flow in the lines. Power Flow Controlling Devices (PFCDs) are required for such purposes because power flow over the lines mainly depends on the impedance of the line. Nowadays the trend is to replace mechanical PFCDs with Power Electronics PFCDs. Among all Power Electronics PFCDs, Unified Power Flow Controller (UPFC) is the most versatile one. But it is not applied widely in utility grids due to its high and low reliability. A new PFCD called Distributed Power Flow Controller (DPFC) that offers the same controlling capability as that of UPFC with reduced cost and increased reliability have been highlighted in this paper. DPFC can be thought of as emerged from UPFC with some modifications in it. The DPFC eliminates the common DC link within the UPFC to enable the independent operation of shunt and series converters. The D-FACTS concept is employed in the design of series converters. High rating three phase series converters are being replaced by multiple low rating single phase converters which greatly reduces cost thereby increasing reliability and stability. The active power exchange takes place through transmission line at third harmonic frequency which in UPFC was done through common DC link.