Development of inexpensive electrical probe for wideband voltage measurement up to 300 kV

It is necessary to measure DC and high frequency signals simultaneously in many high voltage electrical systems. We designed an electrical probe with combined resistive and capacitive characteristics that preserve the fast rise time while allowing the measurement of dc and low frequency high voltage signals. The approach involves a self - compensation RC circuit where parallel combinations of resistive and capacitive divider are used. It is required to maintain the compactness of the voltage probe to be used in the environment of transformer oil. This paper will present the circuit theory and the probe design realization for the pulsed voltage measurement up to 300 kV.