Study on Magnetic Field Generated by Simulated Disturbance Source of 110kV AIS Disconnecting Switch

In air insulated substation (AIS), the arc produced by the disconnecting switch operation is the most serious electromagnetic interference source. It can produce electromagnetic radiation in space with high frequency, which will couple to the secondary equipment and affect the normal operation of the secondary equipment. To study the transient magnetic field caused by disconnecting switch operation, a large number of repeated tests in AIS are required. However, repeated tests are not allowed in AIS because it will affect the normal running of power system. So a simulated disturbance source system which can simulate the actual disconnecting switch operation was designed in this paper. Then the influence on the magnetic field by the bus parameters, gap spacing of disconnecting switch and power capacity was studied. The results show that the disturbance source system can produce magnetic field of 1.1 MHz to 1.9 MHz in frequency and 569A/m in maximum strength, which is coincident with the existing measured data of the disconnecting switch operation in AIS.