Method of measurement of partial capacitances for tested objects with three electrodes

Abstract

The article is devoted to the development of a method of measuring partial capacitances between the electrically conductive structural elements of a capacitive tested object with three electrodes. The developed method involves the applying of resistive-capacitive grounding of the investigated insulation layer with subsequent gradual adjustment of the value of the auxiliary resistor, through which the investigated insulation layer is grounded, to the value at which the phase shift between the voltage on the investigated insulation layer and the auxiliary capacity will be equal to 0º. The results of the calculations showed that in this case the voltage between the electrodes depends only on the capacitive elements of the circuit, and does not depend on the electrical resistance caused by dielectric losses. After measuring the voltages on the elements of the substitution scheme followed by similar re-adjustment of the value of the auxiliary resistor, for a different value of the capacity of the auxiliary capacitor, it is possible to form a system of equations, the solution of which allows you to determine the unknown values of the partial capacities of the insulation layers. The developed method can be used to determine each partial capacitance of the object of control with three electrodes and does not require the use of 3-terminal immittance meters and the use of application-based cumulative measurement survey techniques