Simulation Method for the Applications of Ferromagnetic Materials in Suppressing High-Frequency Transients Within GIS

Ferromagnetic rings can be utilized to effectively suppress the amplitude and steepness of very fast transient overvoltages (VFTO) generated within GIS, however, type selection of ferromagnetic materials is of extreme significance. Based on an equivalent description of the complex magnetic spectrum of ferromagnetic materials, as well as the application of transmission line theory, a simulation model is established in frequency domain to analyze the suppressing characteristics of ferromagnetic rings to VFTO, by which the high frequency suppressing effects of various ferromagnetic materials can be acquired conveniently. Simulation results to the VFTO within GIS produced by switching unloaded busbar demonstrates that, the proposed analyzing method is practicable, leading easily to the realization of optimal type selection of materials and saving experimental expenditure.