CN203825145U - Device for detecting partial discharge of terminal of on-site power cable - Google Patents

Abstract

A terminal partial discharge detection device for on-site power cables, which includes the electrical equipment in the substation such as the GIS cylinder connected by the cable terminal after the high-voltage cable of the external incoming line enters the substation, and the B-phase and C-phase cables of the return line A high-frequency current sensor is installed on each of the terminal grounding wires, and an ultra-high-frequency current sensor is installed near the joint between the cable terminal of phase C and the GIS. The two high-frequency current sensors and one ultra-high-frequency current sensor are respectively Connected to a signal converter, and connected to a data acquisition industrial computer through the signal converter; the data acquisition industrial computer has a waveform display, which is a kind of continuous data acquisition, and simultaneously acquires power frequency reference phase signals , and uses a portable detection device for power frequency phase trigger sampling; it has the characteristics of simple structure, convenient and reliable use, does not change the structure of the running cable and accessories, and is suitable for on-line detection of power cables that have been put into operation.

Description

A terminal partial discharge detection device for on-site power cables

technical field

The utility model relates to a terminal partial discharge detection device of an on-site power cable, which belongs to the technical field of power cable safety detection.

Background technique

At present, the insulation detection methods applied to power cables mainly include DC component method, DC voltage superposition method, AC superposition method, loss current measurement method and partial discharge method; in view of the development of cable partial discharge detection related technologies, it is now commonly used in cable partial discharge The discharge detection methods mainly include acoustic emission method and electromagnetic coupling method. The sensors used in the electromagnetic coupling method can be divided into capacitive, inductive, ultra-high frequency, directional coupling and metal film sensors. However, the above-mentioned various methods for on-site partial discharge detection of power cable terminals have different defects, mainly because of poor reliability of detection, insufficient precision, and easy to be affected by various external signals.

Contents of the invention

The purpose of the utility model is to overcome the deficiencies of the prior art, and provide a field power cable with simple structure, convenient and reliable use, without changing the structure of the running cable and accessories, and suitable for on-line detection of power cables that have been put into operation. terminal partial discharge detection device.

The purpose of this utility model is accomplished through the following technical scheme, which includes the electrical equipment in the substation such as the GIS cylinder connected by the cable terminal after the high-voltage cable of the external incoming line enters the substation, wherein the B phase and C phase of the return line A high-frequency current sensor is installed on the grounding wire of the cable terminal of each phase, and an ultra-high-frequency current sensor is installed near the joint between the cable terminal of phase C and the GIS. The two high-frequency current sensors and one ultra-high-frequency current sensor The sensors are respectively connected to a signal converter and connected to a data acquisition industrial computer through the signal converter.

The data acquisition industrial computer is equipped with a waveform display, and is a portable detection device capable of realizing continuous data acquisition, simultaneously collecting power frequency reference phase signals, and using power frequency phase to trigger sampling.

The portable detection device can collect data with a sampling frequency of 20MHz and a sampling depth of 2M, and realize a continuous data recording depth of up to 5 power frequency cycles.

The utility model is a combined detection method based on HF and UHF to realize the purpose of partial discharge detection at the high-voltage cable terminal on site. The high-frequency current sensor is used to detect the high-frequency partial discharge current signal flowing through the cable grounding wire. The ultra-high frequency sensor The electromagnetic wave signal radiated from the space is sensed, thereby realizing the continuous monitoring of the insulation condition of the cable terminal. Both the high-frequency current sensor and the ultra-high-frequency sensor used in the utility model are non-invasive detection methods, do not affect the state of the re-running system, and are suitable for online detection of cables.

The utility model has the characteristics of simple structure, convenient and reliable use, does not change the structure of running cables and accessories, and is suitable for on-line detection of power cables that have been put into operation.

Description of drawings

Fig. 1 is the structural composition schematic diagram of the present utility model.

Detailed ways

The utility model will be described in detail below in conjunction with the accompanying drawings: As shown in Figure 1, the terminal partial discharge detection device of the field power cable described in the utility model, after it includes the high-voltage cable of the external line entering the substation, passes through the cable terminal 1 Connected GIS cylinder 2 and other electrical equipment in the substation, in which a high-frequency current sensor 4 is installed on the ground wire 3 of the cable terminal of the B-phase and C-phase of the return line, and at the same time, the cable terminal 1 of the C-phase is combined with the GIS An ultra-high-frequency sensor 6 is installed near the position 5, and the two high-frequency current sensors 4 and an ultra-high-frequency current sensor 6 are respectively connected to a signal converter 7, and are connected to a data acquisition system through the signal converter 7. Industrial computer8.

The data acquisition industrial computer 8 has a waveform display 9, which is a portable detection device that can realize continuous data acquisition, simultaneously collect power frequency reference phase signals, and use power frequency phase trigger sampling, and is a prior art .

The portable detection device can collect data with a sampling frequency of 20MHz and a sampling depth of 2M, and realize a continuous data recording depth of up to 5 power frequency cycles.

The utility model is a combined detection method based on HF and UHF to realize the purpose of partial discharge detection at the high-voltage cable terminal on site. The high-frequency current sensor is used to detect the high-frequency partial discharge current signal flowing through the cable grounding wire. The ultra-high frequency sensor The electromagnetic wave signal radiated from the space is sensed, thereby realizing the continuous monitoring of the insulation condition of the cable terminal. Both the high-frequency current sensor and the ultra-high-frequency sensor used in the utility model are non-invasive detection methods, do not affect the state of the re-running system, and are suitable for online detection of cables.

Claims (3)

1. the terminal local discharge detection device of an on-the-spot power cable, it comprises that the high-tension cable of outside inlet wire enters after transformer station, electrical equipment in the GIS cylindrical shell transformer station connecting by cable termination, it is characterized in that: wherein on the B phase of return line and the cable termination ground wire of C phase, a High Frequency Current Sensor is respectively installed, cable termination and GIS binding site in C phase is attached with a ultrahigh-frequency current sensor simultaneously, described two High Frequency Current Sensor and a ultrahigh-frequency current sensor are connected to a signal converter, and be connected in a data acquisition industrial computer by this signal converter.

2. the terminal local discharge detection device of on-the-spot power cable according to claim 1, it is characterized in that: described data acquisition industrial computer is with waveform oscilloscope, a kind ofly can realize continuous data acquisition, gather power frequency reference phase signal simultaneously, and use operating frequency phase to trigger the portable checkout equipment of sampling.

3. the terminal local discharge detection device of on-the-spot power cable according to claim 2, it is characterized in that: described portable checkout equipment can carry out data acquisition with the sample frequency of 20MHz and the sampling depth of 2M, realize the continuous data recording degree of depth that reaches 5 power frequency periods.