Saturated Core High Temperature Superconducting Current Limiter Design And Simulation

With the power system capacity continues to increase, the short circuit current value keeps rising, it poses a grave threat to the equipment and the human's security. The high temperature superconducting fault current limiter (HTSFCL), produced by the use of high-temperature superconductor, is an ideal current limiting device with an innovative vision. It rolls detection, trigger and limiting current functions into one and can automatic recovery. If it can be used, not only can reduce the system protection equipment specifications and enhance the transmission capacity of existing power grid, can also improve the safety and reliability of the system and power supply quality.This paper firstly introduced the development of the power system, the developmental background of the short-circuit current limiting technology and the current research level about the HTSFCL both at home and aboard, and then made a detailed introduction to the basic structure and operation principle of the saturation iron core type HTSFCL, clearly define the dynamic equation and the processing parameter of the system and set design methods and action steps to finish the design of a model of 6.3kV/lkA HTSFCL. According to the capacity of the automatic comprehensive experiment platform of power system, the model of the designed current limiting device is converted into one kind with small capacity which matches the experiment platform and calculation of the equal circuit is made. On this basis, the paper analysis the impedance change, fling up circuit for short-circuit test and make a snapshot simulation test to the current limiting device when short circuit occurs.Secondly, on the basis of the analysis about the equivalent circuit and short-circuit current testing of the experiment platform of power system, the paper simplifies and pushes the real electric circuit and make different kinds of tests to show the short-circuit changes when short circuit occurs. Meanwhile, connect the small capacity limiting current device into circuit to simulate short-circuit wrongs, and compare the changes to confirm the validity of the designed model.Finally, after the validity of the model is verified, further analysis is made to clear the changes of the fault current and the properties of limiting current device when the fault occurs at deferent times. This model can be effect to limit current in short-circuit at deferent moments. Based on the simulation of the model, discuss the parameters which impact the properties of limiting current device and then put forward a design proposal to improve this device.