Analysis of key factors affecting the non-limiting state reactance of superconducting fault current limiter

Abstract

Abstract With the rapid development of the power grid, the voltage level is getting higher, and the degree of interconnection is becoming stronger. As a result, the level of the short-circuit fault current of the power grid keeps increasing, which seriously threatens the security of the power grid. The saturated-core superconducting fault current limiter (SCSFCL) is a new type of current limiting device, which can effectively limit the short-circuit current without influencing the flexibility of the power grid. The non-limiting state reactance is very important to the normal operation of the power line protected by the SCSFCL, but there is little detailed analysis of the key factors affecting its non-limiting state reactance so far. In this paper, the effects of the height of AC coil, the turns of AC coil, the cross-section area of the iron core and the excitation of the DC coil on the non-limiting state reactance are analysed and verified by simulation with ANSYS Maxwell. Finally, the design suggestions are put forward, including the method of designing the DC excitation value of the superconducting coil and how the key factors affect the non-limiting state reactance.