Design Of Controllable Bridge Type Current Limiter And Simulation Study Of Its Superconducting Application

With the continuous increase of power system capacity,the short-circuit current in power system fault or grounding fault,the corresponding increase,the traditional high current current limiting devices can't limit the short-circuit fault,which brings great hidden trouble to the safe operation of power system.The development of superconducting technology,superconducting current limiter(SFCL)application technology continues to mature,it just can carry high current,and does not affect the normal operation of the system,so it is considered as an ideal device for limiting fault current.With the development of power electronics technology,the voltage is higher and higher,and the combination of power electronic technology and superconducting technology has become the hot spot of current research.In this paper,the basic principle of bridge limiter based on power electronic technology,proposes a controllable bridge type superconducting current limiter,the circuit structure is symmetrical,change the circuit structure of the bridge circuit by controlling the power switch,the current limiting coil series into the power system,and realizes the current limit.Due to the short response time of power electronics,the response time of the limiter can be shortened to us power system;access to the FCL,the system short-circuit fault occurs,may not need to immediately cut off the electricity system,which ensure the continuity of power system;the current limiter can not only limit the fault transient current also,limited fault current;without DC bias power supply circuit makes the system more stable,the limiter has the advantages of simple structure,lower cost,smaller volume,lighter weight,and the bridge structure is symmetrical,leg can be modular,maintenance period for.The main contents of this paper are as follows:This paper introduces the history of the development of the superconductor technology,the development background of the superconducting current limiter,the classification of the superconducting current limiter,and the development of the bridge superconducting current limiter.The controllable bridge limiting analyses working principle and process analysis,the theoretical derivation controlled bridge limiter recovery in the normal working state,fault conditions and fault,the theoretical analysis of the controllable bridge current limiter advantage.Simulation model of controllable limiter,different working conditions controlled bridge limiter is simulated,the controllable limiter in different coil inductance,different fault phase angles,and different response delay under the current limiting characteristics are simulated;the simulation results summarized controlled bridge limit the limiting law.The comparison between the controllable bridge current limiter and other bridge-type current limiter.In this paper,the simulation results are analyzed by using the traditional coil in the low voltage environment.Simulation study of the controllable bridge superconducting current limiter in 10 kV power system.