Analysis of the electromagnetic environment under the lead-in after extending a new main transformer in high voltage substation

When extending a new main transformer within the radius of a high voltage substation, if there is a transient process in the primary system, the electromagnetic interference given by the lead-in of the new main transformer may result in abnormal operation of the secondary equipments, so it is important to analyze the electromagnetic environment under this condition. Based on the method of moment (MoM) associated with the fast Fourier transform (FFT) technique, this paper analyses the electromagnetic interference to the secondary equipments given by the lead-in of the new main transformer when there is a line to ground fault in primary system. The results indicate that itpsilas necessary to take measure to protect the secondary equipments.