CN103308744B - High-tension cable gauze screen ground wire leakage current detector - Google Patents

Abstract

The invention relates to a leakage current detector for grounding wires of high-voltage cable shielding nets, which includes an aluminum alloy housing, in which an AC/DC power supply device and a detection device are arranged, and the positive and negative poles of the AC/DC power supply device are respectively connected to a frequency selection circuit , the secondary side of the current sensor is connected to the I/V conversion circuit through the shielded wire, the I/V conversion circuit is connected to the bidirectional analog output port and the frequency selection circuit, the frequency selection circuit is connected to the filter circuit and the rectification circuit respectively, and the filter circuit It is connected with the rectification circuit, the rectification circuit is connected with the peak response time selection circuit, the peak response time selection circuit is connected with the input end of the peak hold circuit and the LCD drive circuit respectively, and the output end of the peak hold circuit 318 is connected with the voltage divider circuit, the LCD drive circuit and the input end of the LCD drive circuit. The LCD display is in turn electrically connected. The invention solves the problem of finding out in time the cable burnout caused by multi-point grounding of the grounding wires of the existing cable shielding network.

Description

High-voltage cable shielding network grounding wire leakage current detector

technical field

The invention relates to a detector, in particular to a detector for leakage current of a grounding wire of a high-voltage cable shielding network.

Background technique

At present, the known leakage current test of the grounding wire of the shielding network of high-voltage cables has not been included in the test procedures, and there is no such test instrument in China.

Contents of the invention

In order to solve the problems existing in the prior art, the present invention provides a high-voltage cable shielding network grounding wire leakage current detector, which can detect the grounding current of the power cable shielding network and judge whether there is a multi-point grounding problem in the cable shielding network grounding wire , which solves the problem of cable burnout caused by multi-point grounding of the grounding wire of the existing cable shielding network.

The technical scheme adopted in the present invention is:

The high-voltage cable shielding network grounding wire leakage current detector includes an aluminum alloy housing, and an AC and DC power supply device, a detection device and a current sensor are arranged in the aluminum alloy housing. The detection device is composed of an I/V conversion circuit, a bidirectional analog Quantity output port, frequency selection circuit, filter circuit, rectification circuit, peak response time selection circuit, peak hold circuit, voltage divider circuit, LCD drive circuit and LCD display screen, the positive and negative poles of the AC and DC power supply device are respectively Connected to the frequency selection circuit, the secondary side of the current sensor is connected to the input terminal of the I/V conversion circuit through a shielded wire, and the output terminal of the I/V conversion circuit is respectively connected to the bidirectional analog output port and the input of the frequency selection circuit The output end of the frequency selection circuit is connected with the input end of the filter circuit and the rectification circuit respectively, the output end of the filter circuit is connected with the input end of the rectification circuit, the output end of the rectification circuit is connected with the input end of the peak response time selection circuit, The output terminals of the peak response time selection circuit are respectively connected to the input terminals of the peak hold circuit and the LCD drive circuit, and the output terminals of the peak hold circuit 318 are electrically connected to the voltage divider circuit, the LCD drive circuit and the LCD display screen in sequence.

The grounding wire leakage current detector of the high-voltage cable shielding network is equipped with an intelligent tide-removing device.

The intelligent tide driving device is composed of a temperature and humidity controller, a fan, a heater and a temperature and humidity sensor. The input end of the temperature and humidity controller is electrically connected to the AC and DC power supply device, and the output end of the temperature and humidity controller is The fan and the heater are respectively electrically connected, and the temperature and humidity sensor is electrically connected to the signal input end of the temperature and humidity controller.

Advantage and effect that the present invention has are:

The leakage current detector of the grounding wire of the high-voltage cable shielding network of the present invention is provided with an aluminum alloy housing, and an AC/DC power supply device and a detection device are arranged in the aluminum alloy housing, which can detect the grounding current of the power cable shielding network and judge whether the grounding wire of the cable shielding network is There is a problem with multi-point grounding. The current sensor is connected to the display part with a shielded wire. Due to the shielding effect of the aluminum alloy shell, the whole set of equipment is in a shielded state, avoiding the interference of the complex electric field on the test site; because the current sensor and the detection device are separated, it is easy to read Values on the LCD display; with frequency selection function and peak hold function, and because of the addition of an intelligent tide-repelling device, it ensures that the instrument is always under ideal working conditions and the test data is more accurate. The problem of cable burning caused by multi-point grounding of the grounding wire of the existing cable shielding network is solved.

Description of drawings

Fig. 1 is a block diagram of a leakage current detector for a grounding wire of a high-voltage cable shielding network according to the present invention.

In the figure, AC and DC power supply device 1, intelligent tide driving device 2, detection device 3, current sensor 4, I/V conversion circuit 312, bidirectional analog output port 313, frequency selection circuit 314, filter circuit 315, rectification circuit 316, peak value Response time selection circuit 317, peak hold circuit 318, voltage divider circuit 319, LCD drive circuit 320, LCD display screen 321, temperature and humidity controller 207, fan 208, heater 209, temperature and humidity sensor 210, AC power socket 101, air Switch 102, fuse 103, transformer 104, bridge rectifier 105, rechargeable battery 106.

Detailed ways

Below in conjunction with accompanying drawing, the present invention is described in further detail:

As shown in Fig. 1, the high-voltage cable shielding network ground wire leakage current detector of the present invention includes an aluminum alloy housing, and an AC and DC power supply device 1, a detection device 3 and a current sensor 4 are arranged in the aluminum alloy housing, and the detection device 3 is composed of an I/V conversion circuit 312, a bidirectional analog output port 313, a frequency selection circuit 314, a filter circuit 315, a rectification circuit 316, a peak response time selection circuit 317, a peak hold circuit 318, a voltage divider circuit 319, and an LCD drive circuit 320 and LCD display screen 321, the AC and DC power supply device 1 is composed of AC power socket 101, air switch 102, fuse 103, transformer 104, bridge rectifier 105 and rechargeable battery 106. The positive and negative poles of the AC/DC power supply device 1 are respectively connected to the frequency selection circuit 314, and the secondary side of the current sensor 4 is connected to the input terminal of the I/V conversion circuit 312 through a shielded wire, and the I/V conversion circuit The output end of 312 is connected with the input end of bidirectional analog output port 313 and frequency selection circuit 314 respectively, the output end of frequency selection circuit 314 is connected with the input end of filter circuit 315 and rectification circuit 316 respectively, the output end of filter circuit 315 is connected with The input end of the rectification circuit 316 is connected, the output end of the rectification circuit 316 is connected with the input end of the peak response time selection circuit 317, the output end of the peak response time selection circuit 317 is connected with the input end of the peak hold circuit 318 and the LCD drive circuit 320 respectively , the output end of the peak hold circuit 318 is electrically connected to the voltage divider circuit 319 , the LCD drive circuit 320 and the LCD display screen 321 in sequence.

The high-voltage cable shielding network grounding wire leakage current detector is also provided with an intelligent tide-removing device 2 .

The intelligent tide repelling device 2 is composed of a temperature and humidity controller 207, a fan 208, a heater 209 and a temperature and humidity sensor 210, the input end of the temperature and humidity controller 207 is electrically connected to the AC and DC power supply device 1, The output terminals of the temperature and humidity controller 207 are electrically connected to the fan 208 and the heater 209 respectively, and the temperature and humidity sensor 210 is electrically connected to the signal input terminals of the temperature and humidity controller 207 .

Working process of the present invention is as follows:

The current sensor collects on-site data, and transmits the collected data to the I/V conversion circuit through the shielded wire. The I/V conversion circuit converts the current signal into a voltage signal and sends it to the subsequent circuit for processing, and finally outputs it to the LCD display to display the measured value. As a result, the analog quantity can be output at the same time for analysis by oscilloscope, digital multimeter or recorder. The device adopts AC and DC power supply. The temperature and humidity in the box are sent to the temperature and humidity controller, which intelligently performs dehumidification and heat preservation, so that the device is always under ideal working conditions. The whole set of devices is installed in an aluminum alloy box, which plays a role of shielding , avoiding the interference of the complex electric field at the test site.

Claims (1)

1. high-tension cable gauze screen ground wire leakage current detector, it is characterized in that including Al-alloy casing, supplied by AC/DC electricity device is provided with in Al-alloy casing, pick-up unit and current sensor, described pick-up unit is by I/V change-over circuit, bidirectional analog amount output port, frequency selection circuit, filtering circuit, commutating circuit, peak response time selection circuit, peak value keeps loop, pressure divider circuit, LCD drive circuit and LCD display form, described supplied by AC/DC electricity device is by AC Power supply socket, air switch, fuse, transformer, bridge rectifier and rechargeable battery form, the both positive and negative polarity of described supplied by AC/DC electricity device is connected with frequency selection circuit respectively, the secondary side of described current sensor is connected by the input end of shielding line with I/V change-over circuit, the output terminal of I/V change-over circuit is connected with the input end of frequency selection circuit with bidirectional analog amount output port respectively, the output terminal of frequency selection circuit is connected with the input end of commutating circuit with filtering circuit respectively, the output terminal of filtering circuit is connected with the input end of commutating circuit, the output terminal of commutating circuit is connected with the input end of peak response time selection circuit, the output terminal of peak response time selection circuit keeps loop to be connected with the input end of LCD drive circuit with peak value respectively, peak value keeps output terminal and the pressure divider circuit in loop, LCD drive circuit and LCD display are electrically connected successively, be provided with intelligent moisture separating device, described intelligent moisture separating device is made up of temperature and humidity controller, fan, well heater and Temperature Humidity Sensor, the input end of described temperature and humidity controller is electrically connected with supplied by AC/DC electricity device, the output terminal of temperature and humidity controller is electrically connected with fan and well heater respectively, and Temperature Humidity Sensor is electrically connected with the signal input part of temperature and humidity controller.