Field test results for a multi-shot 12.47 kV fault current limiter

During ten months of 1989, a prototype multishot 12.47 kV fault current limiter (FCL) was installed in a field test mode at a simulation in Lincoln, Nebraska. The authors present the principles of operation, computer simulations, and the results of the field test. Nineteen fault occurrences were successfully handled by the FCL. Examples of actual faults include currents of 3900 A reduced to 2140 A and bus voltage sags improved from 0.33 to 0.9 per unit. The FCL features tested and proven in this field test were the dynamic insertion of the resistive rail to limit the first one half cycle of fault current without causing voltage or current transients, limiting the remaining cycles of fault current with the limiting resistor, automatic resetting of the device during current zero, and the large continuous current rating with no additional losses