Patent ID: 8519698

Claim:
A presettable voltage sensor comprising: a sensor connected to a voltage source to be measured, the sensor comprising, an electrode electrically connected to the voltage source, an electric field probe facing the electrode, a screening conductive shell enclosing the probe and connected to a reference potential, a dielectric material housed within the shell and interposed between said probe and the electrode; and a conditioning circuit connected to an exit of the sensor and comprising a resistor of resistance R m interposed between the probe and a second reference potential, the conditioning circuit being configured to satisfy the following conditions: R m ⁢ <<  R p ⁢ ⁢ 2 1 + j ⁢ ⁢ ω ⁢ ⁢ C 2 ⁢ R p ⁢ ⁢ 2  R m >> ω ⁢ ⁢ L pm R m ⁢ <<  1 j ⁢ ⁢ ω ⁢ ⁢ C pm  R m ⁢ <<  R p ⁢ ⁢ 1 1 + j ⁢ ⁢ ω ⁢ ⁢ C 1 ⁢ R p ⁢ ⁢ 1  in which: C 1 indicates capacitance of a first capacitor having first plates formed by the electrode and the electric field probe, the first plates being immersed in the dielectric material, C 2 indicates capacitance of a second capacitor having second plates formed by the electric field probe and the conductive shell, the dielectric, material surrounding the second plates, R p1 indicates parasitic resistance of the first capacitor, R p2 indicates parasitic resistance of the second capacitor, L pm indicates parasitic inductance of the resistor of resistance R m , and C pm indicates parasitic capacitance of the resistor of resistance R m ; and an integrator circuit formed from an RC network, the integrator circuit being connected to the exit of the sensor and comprising a resistor of resistance R i , a capacitor of capacitance C i , and a loss factor which, at a frequency of interest, is of an order of 10 −4 , such to satisfy the following relationship: arctan ⁡ ( - ω ⁢ ⁢ C i ⁢ R i ) + arctan ⁢ ω ⁢ ⁢ R p ⁢ ⁢ 1 2 ⁢ R m ⁢ C 1 R m ⁢ R p ⁢ ⁢ 1 + R m 2 + ω 2 ⁢ R p ⁢ ⁢ 1 2 ⁢ R m 2 ⁢ C 1 2 = 0 in which: ω R i C i >>1.