Relationship of pulsed permeability of magnetic cores with annealing Metglas and interlayer insulation films to applied voltage slope

Magnetic core is a crucial part of Inductive Voltage Adder, which the magnetization properties of the core at the voltage pulse with fast rise time directly influences the co-coupling effect between the primary and secondary. The characteristic parameter V_p/(S_e·t_r), that is the slope of the voltage pulse applied to per unit area core, is proposed for describing the condition of the applied voltage. The characteristic parameter V_p/(S_e·t_r) and the size of the cores on typical IVAs at aboard are summarized in detail. With the pulse voltage generator with the rise time of 15 ns and output amplitude of 100kV, the hysteresis and average pulsed relative permeability of magnetic core sample that made of annealing 25 μm Metglas 2605SA1 with 8 μm inter-layer insulation films are investigated at the operating V_p/(S_e·t_r) parameter for IVAs. The experimental results indicate that the characteristic parameter V_p/(S_e·t_r) has an important impact on pulsed relative permeability of magnetic core (μ_Δ) and hysteresis shape, while has little effect on magnetic flux density swing, and at the parameter of V_p/(S_e·t_r) is equal to about 100V/ns · cm²,the parameter of μ_Δ of magnetic core sample is equal to about from 200 to 400, when the parameter of V_p/(S_e·t_r) decreases to 10V/ns · cm², the parameter of μ_Δ of magnetic core sample increased to about 3000, while the magnetic flux density swing keeps about constant 2.2T.