Research on the improved fault current limiter based on high coupled split reactor

Abstract

As the short circuit current increases sharply, the application of fault current limiter (FCL) becomes more and more extensive. The FCL based on high coupled split reactor (HCSR) has many advantages compared with other types of FCL. As the key component of FCL based on HCSR, HCSR only exhibits a small leakage inductance to power system in the normal operation condition, and it will change role to a current limiting reactor once fault occurs. Due to the reverse coupling characteristics between two windings of HCSR, it puts big pressure on the insulation design of HCSR when FCL is applied in high voltage or ultra high voltage power system. In order to solve the above problems, an improved FCL topology is proposed and retains the advantages of HCSR, eliminating the need to transfer full-capacity fault currents, and on the other hand reducing the insulation requirements for HCSR. In this paper, focusing on the improved FCL topology, a simulation model is established to analyse the voltage and current changes under working condition, which can provide reference for the selection of HCSR and fast mechanical switch.