CN210803634U - Cable buffer layer testing arrangement - Google Patents

Abstract

The utility model discloses a cable buffer layer testing device, which comprises a voltage testing unit for simulating a testing loop of voltage in a cable system; the current testing unit is used for simulating a testing loop of current in the cable system; the change-over switch is used for converting the voltage test loop and the current test loop; and an interface at one end of the change-over switch is connected with the voltage test unit or the current test unit, and the other end of the change-over switch is connected with one end of the cable core. The utility model discloses a set up the built-up connection of voltage test unit and current test unit, develop the test of cable buffer layer insulating state under the various operating mode conditions, through setting up open-close type adapter, realize the fast switch-over in voltage return circuit and current return circuit, can effectively shorten test time, improve cable buffer layer test efficiency.

Description

A cable buffer layer testing device

technical field

The utility model relates to the technical field of high-voltage power equipment insulation testing, in particular to a cable buffer layer testing device.

Background technique

Cables are playing an increasing role in accelerating grid development and enhancing urban power supply security. In recent years, there have been dozens of high-voltage XLPE insulated cables faults caused by defects in the buffer layer in Zhejiang, Guangzhou, Fujian, Beijing, Shanghai, Xinjiang and other regions. There are similar reports in Singapore and Australia abroad. The fault even occurs when the fault is serious The insulation shielding layer is completely penetrated, causing cable insulation breakdown and power outage accidents. Therefore, it is of great significance to ensure the safe and stable operation of cables.

In the prior art, there are no relevant provisions for the detection and evaluation indicators of the cable buffer layer, the laboratory evaluation technology for detecting the performance of the cable buffer layer is not yet mature, and there is a lack of quantitative measurement and evaluation standards for material properties.

SUMMARY OF THE INVENTION

In order to solve the problems raised in the above-mentioned background technology, the utility model provides a cable buffer layer testing device, which realizes the detection of indicators such as voltage and current by setting the combined connection of a voltage testing unit and a current testing unit, and at the same time, the testing platform is set and switched. The switch can effectively shorten the test time and improve the test efficiency of the cable buffer layer.

A first aspect of the present utility model provides a cable buffer layer testing device, a voltage testing unit for simulating a voltage testing loop in a cable system; a current testing unit for simulating a current testing loop in the cable system; a switch for simulating a current testing loop in a cable system A voltage test loop and a current test loop are converted; the interface at one end of the switch is connected with the voltage test unit or the current test unit, and the other end is connected with one end of the cable core.

As an optional solution, the voltage testing unit includes: a voltage generator, a voltage divider, a conductive rod and a connecting wire; the voltage divider is connected to the voltage generator through the conductive rod, and the voltage divider is connected to the voltage generator. The switch is connected to the first interface at one end of the switch through the connecting wire.

As an optional solution, the voltage generator includes a waveform selector, a measurement control system and a voltage output system; the waveform selector is connected to one end of the measurement control system; the other end of the measurement control system is connected to the voltage Output system connection.

As an optional solution, the current testing unit includes a rigid connecting rod, one end of the rigid connecting rod is connected to the second interface at one end of the switch, and the other end is electrically connected to the cable terminal; the other end of the cable core passes through A cable is electrically connected to the cable termination.

As an optional solution, the cable core and the other end are provided with a metal flange, and the cable core is connected with the cable through the metal flange; the metal flange is also connected with a ground wire.

As an optional solution, the test device further includes a state detection module, an off-line test module, a current booster and a sensor; the current booster is arranged on the cable; the sensor is arranged on the ground wire; The state monitoring module is connected to the sensor; the offline test module is connected to the voltage divider; the state detection module includes partial discharge test data, cable conductor temperature test data, leakage current test data, and dielectric loss test data ; The offline test module includes partial discharge test data, insulation resistance test data, and dielectric loss test data.

As an optional solution, the testing device further includes a metal shield, and the switch is arranged in the metal shield.

As an optional solution, the switch is an open-close adapter, and the open-close adapter includes a fixed part, a rotating part, a rotating shaft body, a cylindrical interface, a square interface, a cable interface and a bolt hole; the fixed part The part and the rotating part are movably connected through the rotating shaft body; the fixed part and the rotating part are fastened and connected by means of bolts adapted to the bolt holes.

A second aspect of the present utility model provides a cable buffer layer testing method, which determines a test type; sets the cable buffer layer testing device according to the test type; records test data, and obtains a test result according to the test data.

As an optional solution, the test types include voltage test or/and current test, offline test or/and online state test.

The advantages of the utility model are: the utility model can carry out the test of the insulation state of the cable buffer layer under various working conditions by setting the combined connection of the voltage test unit and the current test unit, and by setting the open-close type adapter, the voltage loop and the current can be realized. The fast switching of the loop can effectively shorten the test time and improve the test efficiency of the cable buffer layer.

Description of drawings

1 is a schematic diagram of the overall structure of a cable buffer layer testing device provided by an embodiment of the present invention;

Among them, 1-voltage generator, 2-voltage divider, 3-conductive rod, 4-connecting wire, 5-rigid connecting rod, 6-metal shield, 7A-opening and closing adapter, 7B-opening and closing adapter, 8 -Cable core, 9-metal flange, 10-cable, 11-cable terminal, 12-current riser, 13-ground wire, 14-state detection platform, 15-sensor, 16-off-line test platform;

2 is a schematic diagram of a voltage generator assembly provided by an embodiment of the present invention;

3 is a schematic structural diagram of an open-close adapter provided by an embodiment of the present invention;

Among them, 71-opening and closing adapter fixing parts, 72-opening and closing adapter rotating parts, 73-rotating shaft body, 74-cylindrical interface, 75-square interface, 76-cable interface, 77-bolt hole;

Figure 4 is a schematic diagram of the cable structure of the present invention;

Among them, 17-cable buffer layer, 18-corrugated aluminum sheath, 19-cable sheath

FIG. 5 is a flowchart of a method for testing the performance of a cable buffer layer provided by an embodiment of the present invention.

Detailed ways

The present utility model will be further described in detail below with reference to the accompanying drawings and in conjunction with specific embodiments.

Example 1

Please refer to FIG. 1 , an embodiment of the present invention provides a cable buffer layer testing device, the cable buffer layer testing device includes a voltage generator 1, a voltage divider 2, a conductive rod 3, a connecting wire 4, a rigid connecting rod 5, a metal Shield 6, split type adapter 7A, cable core 8, metal flange 9, cable 10, cable terminal 11, current booster 12, ground wire 13, state detection platform 14, sensor 15, offline test platform 16, this implementation In the example, the rigid connecting rod 5 is connected with the cable terminal 11 through a split-type adapter 7B.

The different test modes of the cable system are realized by setting the connection mode of the device, wherein the test loop device that simulates the voltage in the cable system is connected as follows:

The conductive rod 3 is respectively connected with the voltage generator 1 and the voltage divider 2. The voltage divider 2 is connected with the split-type adapter 7 through the connecting wire 4. The flange 9 and its connected ground wire 13, cable 10, and cable terminal 11 constitute a complete voltage test circuit.

Please refer to FIG. 2 , the voltage generator is composed of a waveform selector, a measurement control system and a voltage output system, and can output power frequency voltage, oscillating wave voltage, lightning wave voltage and operating wave voltage according to test requirements. Among them, the frequency of the power frequency voltage is 49~61Hz, and the waveform is basically a sine wave; the wave front time of the lightning wave is 1`5 microseconds, and the half-wave peak time is 50±10 microseconds.

Preferably, the test device is connected with an offline detection module of the cable buffer layer, which includes partial discharge partial discharge test data, insulation resistance test data, and dielectric loss test data.

Preferably, the test device is connected with a cable buffer layer insulation state detection module, and the cable buffer layer insulation state detection module includes detection partial discharge test data, cable conductor temperature test data, leakage current test data, and dielectric loss test data.

Preferably, the split-type adapter 7A and the split-type adapter 7B are placed inside the metal shield to prevent corona interference during the voltage test.

When the voltage test circuit is connected, open the split-type adapter fixing member 71 and the split-type adapter rotating member 72 through the bolt hole 77 and the rotating shaft body 73, install the connecting wire 4 in the square interface 75, and then connect the cable interface 76 to the cable The core 8 is turned on, and then the split-type adapter fixing member 71 and the split-type adapter rotating member 72 are closed and fixed with bolts.

The test loop device to simulate the current in the cable system is connected as follows:

The rigid connecting rod 5 is respectively connected with the split-type adapter 7A and the split-type adapter 7B at both ends of the cable loop under test, the other end of the split-type adapter 7A is connected with the cable core 8, and the other end of the split-type adapter 7B is rigidly connected to the cable terminal 11 It is electrically connected, and a complete current test loop is formed through the metal flange 9, the ground wire 13 and the cable 10 connected to it.

When the current test circuit is connected, open the split-type adapter fixing member 71 and the split-type adapter rotating member 72 through the bolt hole 77 and the rotating shaft body 73, keep the cable interface 76 connected with the cable core 8, remove the connecting wire 4, and make the rigid The connecting rod 5 is installed in the cylindrical interface 74, and then the split-type adapter fixing member 71 and the split-type adapter rotating member 72 are closed and fixed with bolts.

4 , the cable buffer layer 17 is located between the cable core 8 and the corrugated aluminum sheath 18 , and the cable sheath 19 is wrapped outside the corrugated aluminum sheath 18 .

Embodiment 2

Using the above cable buffer layer testing device, the specific working steps are: (1) Determine the type of cable buffer layer test, including voltage test or/and current test, offline test or/and live test; (2) Formulate cable buffer layer test plan , including test voltage/current value, offline/live test time, wiring method, etc.; (3) Wiring test loop and test platform; (4) Start cable buffer layer test work; (5) Evaluate test results, including validity, accuracy (6) End all testing work.

Taking the partial discharge test of measuring the power frequency voltage at different temperatures as an example, the test method and steps are as follows: the off-line detection equipment adopts the pulse current method partial discharge tester, firstly through the rigid connecting rod 5, the metal shield 6, the open-close adapter 7. The cable core 8, the metal flange 9, the cable 10, the cable terminal 11, the current booster 12 and the ground wire 13 form a current test loop, which simulates the current in the cable system, so that the temperature of the cable core reaches the preset temperature, and then through the opening Combined adapter 7, quickly remove the rigid connecting rod 5 to connect to the connecting wire 4, through the voltage generator 1, voltage divider 2, conductive rod 3, connecting wire 4, metal shield 6, open and close adapter 7A, cable core 8 , metal flange 9, cable 10, cable terminal 11 and grounding wire 13 form a voltage test loop, select and output the power frequency voltage through the voltage generator 1, and pass the partial discharge tester under the corresponding voltage to detect the buffer layer of the cable under test. of partial discharge.

Further, in the off-line partial discharge test, the test voltage should gradually rise to 1.75U ₀ and hold for 10s, and then slowly drop to 1.5U ₀ . At 1.5U ₀ , the partial discharge detected in the cable under test is lower than 10pC.

Further, in combination with the state detection module, during the off-line partial discharge test, the test data and waveforms of live partial discharge, leakage current, and dielectric loss are collected, and the insulation state of the tested cable buffer layer is analyzed from multiple angles.

Further, the off-line test method of the above-mentioned test device can be replaced by an insulation resistance test and a dielectric loss test. Among them, insulation resistance test can use power analyzer, multimeter and other insulation resistance test equipment, dielectric loss test can use insulation diagnostic analyzer IDAX-300D or other equipment with the same function.

The cable buffer layer test method given in this embodiment is an offline partial discharge test scenario. Other offline and state testing processes are as described above, and will not be repeated here.

The above-mentioned technical solutions and accompanying drawings provided by the embodiments of the present invention are used to further illustrate rather than limit the present invention. In addition, it should be noted that those of ordinary skill in the art should know that the technical solutions described in the preceding embodiments can still be used. Modifications are made to the solutions, or equivalent replacements are made to some or all of the technical features therein, and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the present invention.

The above are only examples of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model are included in the application pending approval. within the scope of the claims of the present invention.

Claims (7)

1. A cable buffer layer testing device, the testing device comprising:

the voltage testing unit is used for simulating a testing loop of voltage in the cable system;

the current testing unit is used for simulating a testing loop of current in the cable system;

the change-over switch is used for converting the voltage test loop and the current test loop;

an interface at one end of the change-over switch is connected with the voltage testing unit or the current testing unit, and the other end of the change-over switch is connected with one end of the cable core;

the voltage test unit includes:

the voltage generator, the voltage divider, the conducting rod and the connecting wire;

the voltage divider is connected with the voltage generator through the conducting rod, and the voltage divider is connected with a first interface at one end of the change-over switch through the connecting wire.

2. The cable buffer testing device of claim 1,

the voltage generator comprises a waveform selector, a measurement control system and a voltage output system;

the waveform selector is connected with one end of the measurement control system;

and the other end of the measurement control system is connected with the voltage output system.

3. The cable buffer layer testing device of claim 1 or 2, wherein the current testing unit comprises a rigid connecting rod, one end of the rigid connecting rod is connected with the second interface at one end of the switch, and the other end of the rigid connecting rod is electrically connected with a cable terminal;

the other end of the cable core is electrically connected with the cable terminal through a cable.

4. The cable buffer layer testing device according to claim 3, wherein a metal flange is provided at the other end of the cable core, and the cable core is connected with the cable through the metal flange;

the metal flange is also connected with a grounding wire.

5. The cable buffer layer testing device of claim 4, wherein the testing device further comprises a state detection module, an offline testing module, a current booster and a sensor;

the current booster is arranged on the cable;

the sensor is arranged on the grounding wire;

the state monitoring module is connected with the sensor;

the offline test module is connected with the voltage divider;

the state detection module comprises partial discharge test data, cable conductor temperature test data, leakage current test data and dielectric loss test data;

the off-line test module comprises partial discharge test data, insulation resistance test data and dielectric loss test data.

6. The cable buffer layer testing device according to claim 1 or 2, wherein the testing device further comprises a metal shielding case, and the switch is disposed in the metal shielding case.

7. The cable buffer layer testing device of claim 1 or 2, wherein the switch is an open-close type adapter, and the open-close type adapter comprises a fixing member, a rotating shaft body, a cylindrical interface, a square interface, a cable interface and a bolt hole;

the fixed piece is movably connected with the rotating piece through a rotating shaft body;

and the fixing piece and the rotating piece are tightly connected through a bolt matched with the bolt hole.

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