Design, building up and testing of a 400 kV A hybrid FCL

In the framework of the BYFAULT EU contract, a 400 kV A Hybrid FCL has been designed, built up and tested. The system integrates a set of current driven switches (CDS) connected in parallel and a transformer which couples the CDS array to the grid. The compactness and modularity of the system allow us to adjust it to several configurations by trimming the triggering current and the working voltage to those required to the line protection up to a maximum of 1 kV and 400 A. Two kinds of HTS CDS have been mounted, both based on single domain YBCO bars. A first kind using single domain YBCO bars of 3 cm as active element and the second kind using short buttons of 3 mm in length cut out from the bars. Each CDS has been individually tested and can handle currents as large as 2500 A. Both configurations of the system have been tested for more than 20 times maintaining the fault for more than 500 ms. Quench behavior of both classes of CDS, when separately tested and when installed in the system is reported. Limiting performances of the system are also discussed. (C) 2002 Elsevier Science B.V. All rights reserved.