True-root-mean-square capacitive current tester

Abstract

The invention relates to a true-root-mean-square capacitive current tester. After a power supply is plugged into a power socket, the power socket transmits power energy to a low-voltage side coil of a test transformer through a main power switch and a test switch, a high-voltage end on a high-voltage side of the test transformer is connected with a high-voltage test cable and is connected in parallel with a serial circuit composed of voltage dividing resistors R1 and R2, a low-voltage end on the high-voltage side of the test transformer is connected with the input end of a current sensor, and a node between the voltage dividing resistors R1 and R2 is connected with the input end of a voltage sensor. The input end of a switching power supply is connected with the output of the main power switch, the output of the switching power supply respectively powers a single chip microcomputer, the current sensor and the voltage sensor, the output ends of the current sensor and the voltage sensor are respectively connected with a signal acquisition end of the single chip microcomputer, and the output of the single chip microcomputer is respectively connected with a voltage display meter, a voltage display meter and a capacitive current display meter. True root mean square measurement on voltage and current is carried out by the sensors, data processing is carried out by the single chip microcomputer, and the true-root-mean-square capacitive current tester has the advantage of high precision, high isolation, broad frequency response and low drift.

Description

technical field [0001] The invention belongs to the technical field of electric cable capacitive current testing, and in particular relates to a true effective value capacitive current testing instrument. Background technique [0002] With the development of power system and modern science and technology, as well as the requirements of environmental protection and city appearance planning, power cables used for transmission and distribution of electric energy are gradually replacing traditional overhead transmission lines. [0003] For the neutral point ungrounded power grid, when the system has a large capacitance current to the ground, according to my country's "Technical Regulations for Design of Power Equipment Overvoltage Protection", if the capacitance current of 35kV and 10kV systems is greater than 30A and 10A, arc suppression coils should be installed compensation capacitor current. If there is no compensation, when the single-phase is grounded, the arc cannot be au...

AI Technical Summary

Problems solved by technology

[0004] The traditional measurement method of cable capacitive current needs to use a voltage regulator to boost the voltage, and the voltmeter and ammeter measure voltage, current and other parameters through voltage transformers and current transformers. The data has to be calculated through formula derivation, which leads to low work efficiency

Furthermore, the more complicated the intermediate links, the more uncertain factors will bring errors to the measurement results.

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