Study On Bridge Type Superconducting Fault Current Limiter

With the expansion of the power system scale and capacity, capacity of short circuit and short-circuit current level is also rising, the demand of limiting the short circuit current is becoming more and more urgent. Because of the huge advantages, superconducting fault current limiter become the forefront of current limiting technology research in many countries in recent years. Bridge type superconducting fault current limiter has the advantages of small size, light weight, fast response and easy to cooperate with the auto-recloser, which has a very wide range of applications.Firstly, the current research status of superconducting material and superconducting fault current limiter are discussed in this paper. The basic physical properties of superconducting materials are introduced, the topology and operating principle of various types of superconducting fault current limiter are studied. The advantages and disadvantages of each type of superconducting fault current limiter are analyzed, and the evaluation index of superconducting fault current limiter is presented. The shortcomings of conventional bridge type superconducting fault current limiter are analyzed from two aspects, which are the DC bias voltage source and the system auto-recloser.Then, this paper has proposed a novel bridge type superconducting fault limiter, whose operating principle and working process are analyzed in detail, and the mathematical analysis of each work process are given. The control strategy and the methods for the selection of component parameters are also studied in this paper.Finally, this paper makes studies around the core component, which is the DC inductance coil, of the novel bridge type superconducting fault limiter, the studies include the design of the DC inductance coil, the design of the current leads and the design of quench protection. The feasibility of the novel bridge type superconducting fault limiter is verified by the simulation model. The simulation results show that the novel bridge type superconducting fault limiter has a good effect of short-current limiting, and it is also easier to cooperate with other relay protection equipment and system auto-recloser.