Zero-contact cable voltage measurement method

Abstract

The invention relates to a zero-contact cable voltage measurement method. The method specifically comprises the following steps that S1, the equivalent capacitance of an outer-layer insulating colloid of a three-phase cable is obtained; S2, whether the three-phase cable has ground wire connection or not is judged, if so, the step S3 is conducted, or otherwise, the step S4 is conducted; S3, an additional capacitor is additionally arranged on the ground wire of each phase of cable, the potential of the additional capacitor and the equivalent capacitor and the current flowing through the additional capacitor are calculated, the voltage to ground of the three-phase cable is obtained through calculation according to the potential and the current, and the voltage value of the three-phase cable is obtained through calculation according to the voltage to ground; and S4, additional capacitors and additional switches are additionally arranged among the three-phase cables, loop current among the three-phase cables is calculated by closing the corresponding switches, and voltage values of the three-phase cables are calculated according to the loop current, the equivalent capacitance and capacitance of the additional capacitors. Compared with the prior art, the method has the advantages of being safe and reliable, improving the accuracy of a measurement result and the like.

Description

technical field [0001] The invention relates to the technical field of line voltage monitoring, in particular to a zero-contact cable voltage measurement method. Background technique [0002] At present, the cable voltage collection technology is mostly to install the voltage transformer on the terminal side of the cable in advance to collect the voltage data; another way is to use the micro-hole technology at the place where the cable is to be tested, and put the measuring equipment through the small hole. Measurement; Another way is to generate an electric field through two metal plates and measure the voltage parameters of the cable through coil induction. [0003] However, the disadvantage of the measurement method at the terminal side is that the measurement point is fixed, and it is inconvenient to detect line faults on the non-terminal side; using the needle-pricked cable voltage detection technology will damage the cable insulation layer to a certain extent. The cab...

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Problems solved by technology

[0003]However, the disadvantage of the measurement method on the terminal side is that the measurement point is fixed, and it is inconvenient to detect the line fault on the non-terminal side; The detection technology will destroy the cable insulation layer to a certain extent, causing irreversible damage to the cable insulation; when the voltage parameters are obtained through the electrode plate, the waveform is seriously disturbed, and the obtained parameters do not necessarily belong to the voltage signal, and the accuracy is too low

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