Frankfurt (Germany), 6-9 June 2011 Luciano Martini – IT – RIF S1 – Paper 0339 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

Frankfurt (Germany), 6-9 June 2011  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 Development and Testing of Innovative Fault Current Limiters for Distribution System Applications

Frankfurt (Germany), 6-9 June 2011 Network Requirements  Rated voltage V nom = 9 kV  Rated current I nom = 220 A  Nominal current power factor cos  nom = 0.92  Short circuit current I SC = 12.3 kA rms, I SC peak = 32 kA  Short circuit current power factor cos  SC = 0.1  Ungrounded three-phase fault duration t fault = 400 ms  Limiting factor LF, 1.7 < LF < 2 Luciano Martini – IT – RIF S1 – Paper 0339 Introduction and general concepts about SFCL devices for MV application

Frankfurt (Germany), 6-9 June 2011 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 Introduction and general concepts about SFCL devices for MV applications

Frankfurt (Germany), 6-9 June 2011 Luciano Martini – IT – RIF S1 – Paper 0339 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  m), 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

Frankfurt (Germany), 6-9 June 2011 Luciano Martini – IT – RIF S1 – Paper 0339

Frankfurt (Germany), 6-9 June 2011  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 SFCL Design: General criteria and fundamental parameters

Frankfurt (Germany), 6-9 June 2011 Luciano Martini – IT – RIF S1 – Paper 0339 Numerical simulations: General equivalent circuit

Frankfurt (Germany), 6-9 June 2011 Luciano Martini – IT – RIF S1 – Paper 0339 Numerical simulations: Summary of results

Frankfurt (Germany), 6-9 June 2011 Luciano Martini – IT – RIF S1 – Paper 0339 Assembly of the MV single-phase SFCL device

Frankfurt (Germany), 6-9 June 2011 Luciano Martini – IT – RIF S1 – Paper 0339 Short-circuit tests on 1-phase SFCL at V nom = 5.4 kV

Frankfurt (Germany), 6-9 June 2011 Luciano Martini – IT – RIF S1 – Paper 0339 Comparison simulations and experimental results

Frankfurt (Germany), 6-9 June 2011 Short-circuit testing results on the 3-phase SFCL ITALY I sc =32.7kA p Luciano Martini – IT – RIF S1 – Paper 0339 Jan at RSE

Frankfurt (Germany), 6-9 June 2011 ITALY Luciano Martini – IT – RIF S1 – Paper 0339 Short-circuit testing results on the 3-phase SFCL Jan at RSE

Frankfurt (Germany), 6-9 June 2011 Luciano Martini – IT – RIF S1 – Paper 0339