Development Of A 220 Kv/300 Mva Superconductive Fault Current Limiter

After we developed a saturated iron core type 35 kV/90 MVA superconductive fault current limiter and installed the device in a transmission network at Puji substation of China Southern Power Grid for live-grid operation in 2007, we continued our efforts in advancing this technology. A 220 kV/300 MVA device has been designed, manufactured and factory tested. This device differs from the 35 kV device in its form of electrical insulation even though the two devices have the same working principle and similar core structure. Improvements in the dc magnetization circuit and the cryogenic system were also achieved. This 220 kV/300 MVA superconductive fault current limiter has been installed and has passed all field tests at Shigezhuang substation in Tianjin, China. Trial operation is underway. This paper introduces the major design parameters, key functional specifications and some testing results of the device.