Hybrid HTS-FCL Configuration With Adaptive Voltage Compensation Capability

This paper introduces a new hybrid high-temperature superconducting (HTS) fault current limiter (FCL) for improving the transient response system recovery with minimum utilization of HTS material. The hybrid HTS-FCL comprises a reduced size of HTS material connected in series with multistep braking resistors. The presented hybrid HTS-FCL utilizes the fast quench phenomena of HTS materials to ensure fast current limiting action and the multistep braking resistors to provide an adaptive voltage compensation during voltage dips. This combination of HTS and braking resistors allows the HTS material to recover faster by lowering its operating time, mitigates the issue of slow response in conventional braking resistors, and keeps the system fault level below the maximum limit even during offline recovery of its HTS component. A dynamic model representing the hybrid HTS-FCL is developed in PSCAD/EMTDC using a current-dependent model for the HTS combined with dynamic braking resistors associated with a phase voltage control scheme and an HTS bypass scheme for each phase individually. The proposed configuration is tested in a single-machine-to-infinite-bus test system in response to symmetrical and asymmetrical fault conditions. A comprehensive simulation analysis demonstrated the effective performance of the hybrid HTS-FCL with capability of fast fault current limitation and voltage boosting.