Abstract:
Installing a saturated core fault current limiter is an effective method to limit short-circuit current in high-voltage alternating current transmission (HVAC) systems; however, it requires the combination of an external air-core reactor, resulting in a large occupied area and volume for the entire current-limiting system. Therefore, this paper proposes a compact hybrid-biased three-phase saturated core fault current limiter (CTFCL) based on the principle of non-orthogonal decoupling, which has the advantages of small occupied area and volume. Firstly, the topology of CTFCL with non-orthogonal decoupling windings is proposed. Secondly, the equivalent electromagnetic circuit model of CTFCL is established, and its working principle is analyzed. Then, the parameter design guidelines for CTFCL are provided, and a finite element model at 220 kV level is built to verify the current-limiting effect and electromagnetic characteristics of CTFCL. Finally, a small-capacity prototype is designed and developed to conduct the experiments. The simulation and experiment results both demonstrate the effectiveness of the proposed CTFCL. The CTFCL exhibits excellent current-limiting effects for various short-circuits, and compared to traditional three-phase SCFCL current-limiting system, the occupied area and volume of the CTFCL current-limiting system are, respectively, decreased by 44% and 26%, which makes it suitable for installation and application in practical HVAC systems.