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

Abstract

The invention provides a partial discharge detection device and detection method for a power cable voltage-withstand test. The detection device comprises a sensor and a data collection device. The sensor is composed of resistors connected in parallel, satiable inductors and protection gaps, one end of the sensor is connected with an outer shielding layer of a power cable, the other end of the sensor is grounded, and the data collection device is connected with the sensor. In the process of partial discharge of the cable, partial discharge current generates voltage drop on the resistors through the sensor, drop voltage is picked up by the data collection device, low-frequency signals are absorbed and filtered out by the satiable inductors, and then high-flexibility pick up on partial discharge high-frequency signals of capacitive type power equipment is achieved. The low-frequency signals are filtered out by the satiable inductors, low-frequency interference signals are filtered out, so the detection device has excellent grounding safety and low-frequency signal anti-interference capacity; thus, the state of insulation of the power cable can be detected accurately, and insulation defects can be found and treated 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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