A model experiment of current limiting characteristics of superconducting fault current limiter in the demand side with distributed generator

Abstract

Superconducting Fault Current Limiters (SCFCLs) are expected to improve both reliability and stability of power systems. Specifications of SCFCLs, such as trigger current level, recovery characteristic and impedance must be considered precisely in introducing SCFCLs to a power system. In this paper, current limiting characteristics of SCFCL in the demand side, (that is, a customer who has distributed generators and loads), is studied and demonstrated experimentally by use of a small 18kVA synchronous test generator with a test three-phase SCFCL unit of a transformer type and an artificial transmission line. In general, a current limiting reactor of normal conductor is installed in order to reduce the large fault current from the generator, however, it also decreases the maximum output power of the generator to the grid. The current limiting tests were carried out by replacing the reactor with the SCFCL. It was experimentally confirmed that SCFCLs can suppress the fault current considerably and can improve the transient stability at a certain fault without reducing the steady state stability margin. © 2006 IOP Publishing Ltd.