Luciano Martini – IT – RIF S1 – Paper 0339

1. Development and Testing of Innovative Fault Current Limiters for Distribution System Applications Luciano MARTINI*, Marco BOCCHI*, Cesare RAVETTA# * RSE – Italy # Electrical Networks A2A SpA – Italy Luciano Martini – IT – RIF S1 – Paper 0339

2. Development and Testing of Innovative Fault Current Limiters for Distribution System Applications • Introduction and general concepts about SFCL devices for MV application • SFCL Design: General criteria and fundamental parameters • Numerical simulations to support SFCL design choices • Construction and characterization of a MV single-phase SFCL device Luciano Martini – IT – RIF S1 – Paper 0339

3. Introduction and general concepts about SFCL devices for MV application Network Requirements • Rated voltage Vnom= 9 kV • Rated current Inom = 220 A • Nominal current power factor cosFnom = 0.92 • Short circuit current ISC = 12.3 kArms, ISC peak = 32 kA • Short circuit current power factor cosFSC = 0.1 • Ungrounded three-phase fault duration tfault = 400 ms • Limiting factor LF, 1.7 < LF < 2 Luciano Martini – IT – RIF S1 – Paper 0339

4. Introduction and general concepts about SFCL devices for MV applications HTS conductor Requirements • High critical current, to use the minimum number of conductors in parallel • Suitable Mechanical and Thermal properties to withstand fault transients; • Dielectric properties compatible with the application voltage level; • Commercial availability in useful quantities, piece length and at affordable cost. Luciano Martini – IT – RIF S1 – Paper 0339

5. First generation (1G) HTS Multifilamentary BSCCO-2223 tapes with silver matrix. Critical temperature Tc=110 K, Critical current in self field Ic=180 A at 77 K. Tape dimensions: Width 4.6 mm, Thickness 0.35 mm, laminated with stainless steel reinforcement strips (2x20 mm), Electrical insulation by Kapton overlapped ribbons Second generation (2G) HTS YBCO coated conductors. Critical temperature Tc=92 K, Critical current in self field Ic=360 A at 77 K. Tape dimensions: Width 12 mm, Thickness 0.11÷0.14 mm Luciano Martini – IT – RIF S1 – Paper 0339

6. Luciano Martini – IT – RIF S1 – Paper 0339

7. SFCL Design: General criteria and fundamental parameters • The HTS operating temperature under nominal conditions • The ratio between the peak value of the rated current and the HTS critical current value • The maximum allowable temperature of the HTS conductor at the end of a fault event • The length of HTS conductor for each phase • The impedance value of the air core reactor in parallel to each SFCL phase Luciano Martini – IT – RIF S1 – Paper 0339

8. Numerical simulations: General equivalent circuit Luciano Martini – IT – RIF S1 – Paper 0339

9. Numerical simulations: Summary of results Luciano Martini – IT – RIF S1 – Paper 0339

10. Assembly of the MV single-phase SFCL device Luciano Martini – IT – RIF S1 – Paper 0339

11. Short-circuit tests on 1-phase SFCL at Vnom= 5.4 kV Luciano Martini – IT – RIF S1 – Paper 0339

12. Comparison simulations and experimental results Luciano Martini – IT – RIF S1 – Paper 0339

13. Isc =32.7kAp Short-circuit testing results on the 3-phase SFCL ITALY Jan. 2011 at RSE Luciano Martini – IT – RIF S1 – Paper 0339

14. Short-circuit testing results on the 3-phase SFCL ITALY Jan. 2011 at RSE Luciano Martini – IT – RIF S1 – Paper 0339

15. Luciano Martini – IT – RIF S1 – Paper 0339