Application Of220kV High Temperature Superconducting Fault Current Limiter To The Shenzhen Power Grid

Shenzhen power grid load density, the relative concentration of each substation location,part of substation220kV short-circuit current exceed the standard, in order to avoid shortcircuit current exceeds the breaking capacity of the equipment, the whole operation mode ofShenzhen power grid is restricted to a certain extent reduces the ability to withstand risks ofShenzhen power grid. On the other hand, the Shenzhen power grid users are precisionmanufacturing industry, headquarters economy, high requirement on power supply reliability.High demand of power grid operation mode is limited and the reliability of power supply hasbecome a contradiction.The performance of resistive type high temperature superconducting (HTS) fault currentlimiter (SFCL) is mainly based on the zero resistance characteristics of superconductingmaterials and its fast changing ability. The SFCL is of zero resistance during the normaloperation of the power grid. However, a large impedance occurs when short-circuit happens,so that the SFCL could limit the short circuit current value. In this paper, the characteristics ofa220kV SFCL introduced, and the viability of its application in Shenzhen220kV isdiscussed.This paper first introduces the conventional grid fault current limiting methods and theiradvantages and disadvantages. Then, we point out that the superconducting fault currentlimiter technology seems to be an important method to solve the issue of short-circuits currentof high-voltage transmission grid. Comparison of structural features of various configurationsof fault current limiter and its advantages and disadvantages, the SFCL is chosen as theresearch target. In order to reduce the amount of superconducting tapes, reduce themanufacturing cost of SFCL, according to the characteristics of superconducting tapes, thecircuit topology of SFCL, the shunt circuit breaker, realize the quick disconnect currentlimiting unit, so as to improve the reliability of SFCL current limiting and recovery timedecreases the superconducting current limiting unit loss. The basic parameter of currentlimiter, and analyze the adverse effect of shunt circuit breaker action sequence not existingelectric grid relay protection circuit breaker action.Secondly, based on the operating characteristics of SFCL, the impact of the SFCL on thepower grid transient stability, automatic reclosing and current protection are discussed.Through the calculation and deduction, simulation of the resistance type SFCL, joint action ofthree-phase short circuit fault conditions in the power grid single-phase, and power gridstate.The results show that there will be no effect on the automatic reclosing, and it is conducive to the grid transient stability, but the grid current protection parameters need to bere-tuning.Finally, the status of short-circuit current in Shenzhen power grid is presented, and thenthe feasibility of applying the SFCL in Shenzhen220kV grid is analyzed. A simulation isbased on the parameters of220kV Ma Ao substation, and the results show that Short circuitfault distance bus closer, superconducting current limiter function more quickly, the shortcircuit current is more conducive to the rapid response current limiter, the main reason is thatthe high fault currents can be more quickly makes the superconducting winding generateslarge impedance the SFCL can effectively reduce the220kV Yuan Ma busbar short circuitcurrent and improve system reliability.