Parameters Design And Test Research Of 220kV Improved Saturated Iron Core Superconducting Fault Current Limiter

Along with the expanding of modern power grid,short-circuit current becomes more and more important problem for future grid.As a consequence,exorbitant short current would pose threat to the power equipments and their operators.In order to cut the short-current to the lower level when the control equipment of power system can break,during the last few years,a number of programs have been sponsored to investigate various techniques and devices applicable to limit fault currents in power systems.The most ideal one of such devices is the superconducting fault current limiter(SFCL).Under normal grid conditions,it is a good conductor with no influence on power system.However,in the case of a fault,its impedance abruptly increases to limit short current and short circuit breaking capacity.It works naturally and is self-examination,self-triggered,self-operation and self-restore.If we can make its products more applicable,it can not only upgrade the capability of the existing electrical transmission system,but also can improve the safety and dependability and power quality of the power system.Comparing with other types of SFCLs,the saturated iron core superconducting fault current limiter(SIC-SFCL)that was developed from current-limiting reactor principle and poewer transformer technology has proved to be a promising fault current limiter to be applied to high voltage(HV)and extra-high voltage(EHV)power grids,along with some other approaches,solving the short-circuit fault problems.In this paper,the significance of SFCL is briefly described.The classification,advantages,disacvantages and research status at home and abroad of SFCL and especially SIC-SFCL are more detailed summarized.Based on the principle of single-phase SIC-SFCL,the operation principle,the structural characteristics,the technical parameters,and the design method limitations of improved SIC-SFCL that was added dc control loop and designed unequal core section are emphasized.The limiting and steady-state performance of laboratory model simulation and test results are summaried and the relationship of key structural parameters-the ac winding turns,ac core cross-section,the cross-section ratio and excitation ampere-turns ratio,and the limiting and steady-state performance are obtained.Then,the design processes and methods of electromagnetic theory calculations are more in-depth researched by the limited fault current and the steady-state voltage drop as the design constraints,through using circuit simulation based on MATLAB/Simulink software and finite element analysis software-ANSOFT.In steady-state calculation with ANSOFT,an idea that a minimum composite magnetic field Bmin to replace the steady-state voltage drop AU as design specifications was proposed to improve the simulation efficiency.Combined with 220kV SIC-SFCL technical indicators completed a three-phase 220kV SIC-SFCL's limiting and steady-state simulation,and parameter optimization.Combined with the steady-state performance test results,verify the correctness of the steady-state simulation and communication ANSOFT minimum composite core saturation field Bmi,choice is reasonable.Finally,combined with the structural features,technical specifications,operating conditions of 220kV SIC-SFCL,the contents,requirements and evaluation criteria of test were studied.As a satandar that guide the factory test of 220kV SIC-SFCL prototype.