Operational Characteristics of Fault Current Limiting Reactor Combined with Multi-Functional Invertor

This paper deals with the fault current limiting reactor (FCLR) combined with a multi-functional inverter system, which aims at the integration of power quality improvement, uninterruptible power supply (UPS) and fault current limitation. The system consists of a FCLR with a switch and the single-phase voltage source inverter (VSI). The FCLR, which has coil 1 and coil 2 wound in parallel through pure resistance with switch, can perform the fault current limiting operation during a fault period. The multi-functional inverter is connected between coil 3 and grid, which can be operated to compensate the reactive power demanded by nonlinear and variation loads, and be controlled to provide a sinusoidal voltage at the fundamental value (220 V/60 Hz) for load during a grid fails. It is shown through the simulation for the its operation that the proposed system could both protect the system from over-current by a line-ground fault and outages by a grid fail (abnormal utility power condition).