Research and analysis on insulation tolerance level and MOV setting principles of electrical equipment in 1000kV substation

In order to study the insulation withstand level and MOV setting principles of electrical equipment in a 1000kV substation. Using the ATP-EMTP1 program and auxiliary calculation program to calculate and analyze lightning induced surge overvoltage in a 1000kV substation, the maximum values of lightning induced surge overvoltage and shielding surge overvoltage on various electrical equipment in the substation are obtained under the two most severe operating modes. The insulation withstand voltage values of electrical equipment are verified and selected, and the setting principles and installation positions of metal oxide varistors (MOV) are determined. The 1000kV distribution device is simulated and calculated based on the most severe one line, one transformer, and single line operation mode. The calculated value of the lightning strike current is 250kA, and the winding strike current is 27kA. Verify and calculate the insulation withstand level of electrical equipment for 1000kV distribution equipment, as well as the principles and installation positions of MOVs, based on the verification and calculation of counterattack, winding overvoltage, maximum intrusion wave overvoltage, and MOV lightning current of each electrical equipment.