Protection of Overvoltage in Fuse Breaking Test System

To protect the impulse generator,which was the core of high voltage apparatus test system,a metal oxide arrester would be designed. When current-limiting fuses(CLFs) breaking in fuse breaking test system,fuse element melt and gasified,the arc voltage generated by CLFs will transfer arc energy into the inductive elements of the CLFs breaking test system,such as inductor and capacitor.The fuse elements melt so quick that the overvoltage was higher than other switch-operating overvoltage.The melting course of the CLFs was studied,and an electric-thermal model was established with the finite element method to obtain the resistance-time graph for CLFs,and a circuit model of fuse breaking test system was set up.With the calculation results of electric-thermal model,the overvoltage was calculated with EMTP/ATP.For the appointed device to be protected,the design included electric design and thermal design.Electric design could assure the device to run safely without insulation damage and thermal design should maintain the life time of MOA without thermal crash.Considering the electric and thermal demands,the MOA is picked.Guidelines of MOA was developed for selection and application of the non-electric power systems surge arresters.