Modeling of the DC Inductive Superconducting Fault Current Limiter

DC fault current limiter is an important device for the dc system, because the action speed of the existing selective protection cannot match the dc fault developing speed. Due to its excellent capacity on limiting dc fault rising speed, the analyses of dc inductive type superconducting fault current limiter (I-SFCL) are attracting more attention. In this paper, a modeling method for dc I-SFCL is proposed to describe its nonlinear characteristic of inductance. Firstly, the structure and working principle of the dc I-SFCL is briefly introduced, and the magnetic equivalent circuit is established according to the magnetic field distribution. Then, the relationship between dc transient current and the current-limiting inductance of dc I-SFCL is discussed. By analyzing the equivalent magnetic circuit, a mathematical I-SFCL model is proposed in Matlab based on the actual geometric and electrical parameters. Finally, under the same dc test platform, the magnetic flux density, the voltage and the current of dc I-SFCL in Matlab model are compared with that in finite element method (FEM) model. Simulation results verifies the validity and the correctness of the model.