Partial discharge detection device and detection method for power cable withstand voltage test

Abstract

The invention provides a partial discharge detection device and detection method for a power cable withstand voltage test. The detection device includes a sensor and a data acquisition device. The sensor is composed of a parallel resistor, a saturable inductance and a protection gap. The outer shielding layer is connected, the other end of the sensor is grounded, and the data acquisition device is connected to the sensor. When partial discharge occurs in the cable, the partial discharge current passes through the sensor to generate a voltage drop on the resistance, which is collected and picked up by the data acquisition device, and the low-frequency signal is absorbed and filtered by a saturable inductor. In addition, it realizes high-sensitivity pickup of high-frequency signals of partial discharge of capacitive power equipment, low-frequency signals are absorbed and filtered by saturable inductors, and low-frequency interference signals are filtered out. Detect the insulation status of power cables, find insulation defects and deal with them in time.

Description

technical field [0001] The invention relates to a power cable test device, in particular to a partial discharge detection device and a detection method for a power cable withstand voltage test. Background technique [0002] With the continuous and rapid growth of urban electricity load, the requirements for power supply reliability are getting higher and higher, and the full realization of cable-based urban distribution network is the development direction to adapt to high reliability and save space. With the increase in the number of cable applications and the extension of running time, the detection and troubleshooting of cable faults are becoming more and more difficult. In order to ensure the safe and reliable operation of the cable, it is generally selected to perform a withstand voltage test on the power cable and use a sensor to detect partial discharge. The detection of partial discharge is based on various phenomena produced by partial discharge, and the state of p...

AI Technical Summary

Problems solved by technology

[0009] The main disadvantage of the ultrasonic method is that the transmission of the ultrasonic signal will have serious attenuation. The ultrasonic wave will produce reflection and refraction on the interface of different media, and attenuation will occur on the two interfaces where the wave characteristic impedance does not match. The greater the signal attenuation, it is precisely because of the attenuation that it is difficult to accurately quantify the relationship between the amplitude of the ultrasonic signal and the actual PD amount

[0010] To sum up, there are many kinds of partial discharge sensors for power cables, but they cannot achieve satisfactory results in terms of anti-interference ability and detection sensitivity.

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