Design and Test of UPFC-FCL Prototype

Unified Power Flow Controller with Fault Current limiting(UPFC-FCL) which consists of the UPFC module and FCL module connected via the series coupling transformer is discussed from the points of topology, working principles and control strategies, as well as the analysis of simulation results. UPFC-FCL is equivalent to a normal UPFC resulting from FCL appearing as ´non-impedance´ in normal conditions when it flexibly controls power-flow and voltage etc. While short-circuits happen, the ´non-impedance´ FCL changes to ´large-impedance´ to secure UPFC from system high voltage and short-circuit current. Simulation and experimental results verify the reliability and feasibility of UPFC-FCL prototype designation and its control strategy.