An Inductive 700-MW High-Voltage Pulse Generator

A repetitive inductive 700-MW high-voltage pulse generator that delivers a 150-ns square pulse with 20-ns rise time at 150 kV has been constructed. The pulse generator has a 1:10 air core transformer connected to a 25-Omega pulse forming line (PFL). The transformer and the PFL are both constructed using high-voltage cables. The closing switch of the PFL is a spark gap that is in a water tank together with the cable endings of the PFL and transformer. The electric field at the cable endings is refractively graded by the high permittivity of the surrounding water. The PFL is charged in 2.5 mus to 170 kV, and the electric field in the closing switch of the PFL reaches 33 kV/mm until the threshold voltage is exceeded. The efficiency of the pulse generator is 40%. The authors believe that this concept can be up-scaled to a 25-GW generator operating at 500 kV. An electric circuit simulation of a 25-GW pulse generator and an electrostatic simulation for a refractive cable ending are presented