Study On The Control System And Experiments On A New Type Of High Temperature Superconducting Fault Current Limiter

Once the short circuit fault happens in the power system, the short circuit current level will become very large within a short time, which will cause great damage to the power system and users .so it requires to limit the short circuit current to a safe level as quickly as possible .In this paper, a new concept of bridge type high temperature superconducting fault current limiter(HTSFCL) with serial resistance is introduced ,which is especially on the control system ,and also the low-voltage short circuit experiments have been carried out.Based on the non-resistance character of superconducting carrying large current ,the bridge type high temperature superconducting fault current limiter is most promising for SFCL application .but it has the weakness of lacking the ability to limit the steady short circuit current after the peak value. Considering the DC in the superconducting limiter coil ,we can use a power electronic device ,such as IGBT, GTO, IGCT paralleled with a resistance .the combination of the superconducting coil limiter and the serial resistance can solve the problem of short circuit current limiting perfectly through the SFCL control system.Based on this, a 380V/60A SFCL system and the short circuit test platform are developed, which consist of electric source, reactance, inductance, the back-to-back connected thyristors and so on. T\MS320LF2407DSP is used to send a control signal to trigger the back-to-back connected thyristors when the phase angle of line currentis in the biggest short circuit current situation .Different kinds of short circuits are conducted and the theoretical predictions and simulations are validated by the experiment results ,which lay a sound foundation for the 10.5kV/1.5kA HTSFCL system that will be installed to a power grid in Hunan province.