A Compact Saturated Core Fault Current Limiter Magnetically Integrated with Decoupling Windings

Traditional saturated core fault current limiters (SCFCLs) have fast rising fault state inductance that can limit faults automatically. However, the current limiting performance of traditional SCFCLs is insufficient. In order to improve this, some novel SCFCLs use additional air core reactors, resulting in a large volume and floor area. A compact saturated core fault current limiter magnetically integrated decoupling windings (CSFCL) is proposed in this study, which has the advantages of a smaller volume and floor area. The principle of the non-orthogonal decoupling method is firstly introduced. The core body of the CSFCL is then magnetically integrated with the decoupling windings in the form of non-orthogonal decoupling. Equivalent magnetic circuit and electric circuit analysis is carried out. An inductance calculation method for decoupling windings is proposed. Following this, a 220 kV simulation model is conducted based on the finite element method. Finally, a small-capacity prototype of the CSFCL and a test platform are designed to test it. The experimental results verify the correctness and feasibility of the proposed structure.