Abstract:
The rapid growth of power loads makes the fault current levels in the power system continue to rise, even exceeds the interrupting capacity of the existing circuit breakers. To effectively limit the fault current, the Superconducting Fault Current Limiters (SFCLs) are gradually being put into practice. The SFCL presents zero impedance during the normal operation but rapidly turns to high impedance when a fault occurs. This characteristic can be as an ideal choice to be used along with the circuit breakers to improve the operational safety of the power systems. By introducing a magneto-biased superconducting fault current limiter (MBSFCL), this paper proposes a design method of the MBSFCL considering the DC component of short-circuit current, which may have a certain guiding significance for the manufacture of an MBSFCL. The feasibility of the proposed method is verified by building a simulation model, and the current-limiting characteristics of the MBSFCL are analyzed in depth. The effects of different DC components on the interrupting of the circuit breaker, and the effects of the current-limiting effects of the variations of
L or
R parameters in the MBSFCL on the short-circuit current and its components are discussed. The analytical results show that the DC component must be considered in the proposed MBSFCL design method and that the variation of the
R parameter of the MBSFCL has a more significant effect on the short-circuit current suppression.