Analyzing a noise suppression circuit for impulse dividers using Haar wavelets

Investigations on characteristics of dividers and adjustments of their structural parameters in order to measure impulse voltages play a key role in high voltage measurements. When considering resistive switching impulse dividers, in particular, it is difficult to measure precisely the unit step response (USR) because of noises and large-scale factor (several thousands). One efficient solution is to mount a cylindrical metal shield at the lower end of the main resistor. However, powerful numerical divider simulations fail to compute the USR of dividers when the RC distributed circuit, to be composed by the main resistor and the cylindrical shield. This article presents approximation models of the RC distributed circuit of a 700 kV resistive switching impulse divider based on theoretical and wavelet analyses, which can be used for USR simulations.