CN217278758U - Partial discharge test device of cable insulation layer - Google Patents

Abstract

The utility model discloses a cable insulation's partial discharge test device, this test device contains: the device comprises a vacuum container, a discharge module, a temperature monitoring module and a gas collection module; the glass plug and the glass cup with a valve on the side wall form a vacuum container, a cable sample placing pedestal is arranged in the vacuum container, a fiber grating temperature sensor is plugged into a central opening of the cable sample, and the two electrodes are coaxial with the fiber grating temperature sensor; the fiber grating temperature sensor is connected with the fiber grating demodulator through an optical fiber; the circuit is connected with the electrode, the voltage sensor, the current sensor and the step-up transformer; the side wall valve of the container is connected with a vacuum pump or an injector. Through the technical scheme of the utility model, can simulate real condition and discharge heat, the electric decomposition cable insulation layer releases volatility characteristic thing and collect and study for carry out the early warning to early conflagration.

Description

Partial discharge test device of cable insulation layer

Technical Field

The utility model relates to a technical field of high-pressure electrolysis particularly, relates to a partial discharge test device of cable insulation layer.

Background

The cable is a device for transmitting electric energy and electric signals, and the cable trench is an underground pipeline for transmitting power to the outside by a transformer substation and is used for laying cables and replacing power cable facilities. The layout of the cables of the transformer substation adopts a mode of laying in the same trench, once one cable suddenly catches fire, the nearby cable can be ignited, and the flame can quickly spread along the cable laying direction. And the cable trench is basically isolated from the external environment in the operation process, the number of the entrances and exits of the cable trench is small, cables are laid on two walls in the trench, the middle channel is narrow, and the overall position is in a relatively hidden area, so that the difficulty of finding and putting out a fire is increased.

The automatic fire alarm system of the existing cable trench detects various physical phenomena which are generated after a fire disaster occurs by arranging sensors for sensing smoke, flame, temperature and the like, and can not predict in advance to cause great damage and loss.

The cable in the cable trench consists of a protective layer, an insulating layer, a semi-conducting layer and a conductor, wherein the insulating layer and the protective layer belong to macromolecular combustible substances except a core conductor, and can generate the phenomena of combustion, thermal degradation, thermal decomposition, electrical degradation, electrical decomposition and the like at high temperature. Practical experience with the operation of power cables has shown that deterioration or failure of the insulation is the primary cause of insulation breakdown and hence fire. The transmission voltage of the high-voltage cable is higher, the insulation erosion caused to the cable is more serious, and the cable insulation material can generate larger damage when the cable insulation material fails. Therefore, if the volatile characteristic of the cable insulation material can be detected before the cable insulation material fails, early fire can be warned to avoid greater loss, but the characteristic of the volatile is not clear at present, and a testing device is needed for detection testing.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a: a volatility characteristic matter collecting test device for early fire early warning is provided.

The technical scheme of the utility model is that: there is provided a partial discharge test apparatus for a cable insulation layer, the apparatus comprising: the device comprises a vacuum container, a discharge module and a temperature monitoring module;

the vacuum vessel includes: the glass cup, the glass plug, the valve and the sample placing pedestal;

the opening of the glass cup is upward, the glass plug seals the opening of the glass cup, a gap between the glass plug and the opening of the glass cup is sealed by a sealing ring, a valve communicated with the inner cavity of the glass cup is arranged on the side surface of the glass cup and is used for connecting a vacuum pump, and a sample wafer placing pedestal is arranged in the glass cup;

the discharge module includes: two electrodes, a voltage sensor, a current sensor and a step-up transformer;

the two electrodes penetrate through the holes in the side wall of the glass cup and are oppositely arranged and coaxial with each other, and sealant is coated at the joint of the two electrodes and the glass cup; the cable sample wafer is arranged in the sample wafer placing pedestal, a small hole is formed in the middle of the cable sample wafer, the axes of the two electrodes penetrate through the small hole in the middle of the cable sample wafer, and a voltage sensor, a current sensor and a boosting transformer which are connected in series are respectively connected between the two electrodes, wherein the boosting transformer is externally connected with a power supply;

the temperature monitoring module includes: the fiber grating temperature sensor and the fiber grating demodulator;

the fiber bragg grating temperature sensor is connected with the fiber bragg grating demodulator, and a probe of the fiber bragg grating temperature sensor is positioned in a small hole in the middle of the cable sample wafer.

In any of the above technical solutions, further, the apparatus further includes: a gas collection module; the extraction equipment in the gas collection module is an injector and is connected with a valve when in use.

In any one of the above technical schemes, further, when the injector is connected with the valve for use, before the valve is opened, the joint is wrapped by the rubber sealing pipe, and the residual gas in the gap is extracted by using the vacuum pump to ensure sealing.

In any of the above technical solutions, further, the sample-placing stand is a u-shaped bracket, and the cable sample is inserted from the upper end opening between the two vertical sides of the u-shaped bracket.

In any of the above technical solutions, further, the cable sample is taken from the cable insulation layer and is a square cut piece.

The utility model has the advantages that:

according to the technical scheme of the utility model, the glass plug is arranged above the glass cup and can be installed and disassembled, so that the cable sample wafer can be conveniently replaced; the process of placing the sample piece on the bracket with the U-shaped design is simple and rapid, supporting force is formed on three sides of the square sample piece, the square sample piece is more stable, and the central part is not obstructed and does not influence the passing of electric arcs; the joints of the vacuum container and each part are sealed, so that the gas components finally collected by the device are more accurate.

Drawings

The above and additional aspects of the invention will be apparent from and readily appreciated by reference to the following description of the embodiments taken in conjunction with the accompanying drawings, in which:

fig. 1 is a schematic structural diagram of a partial discharge test device for a cable insulation layer according to an embodiment of the present invention;

fig. 2 is a schematic side view of a vacuum vessel of a partial discharge test apparatus for a cable insulation layer according to an embodiment of the present invention.

101-glass plug, 102-valve, 103-sample placing pedestal, 104-glass cup, 201-two electrodes, 202-voltage sensor, 203-current sensor, 204-step-up transformer, 301-fiber grating temperature sensor, 302-fiber grating demodulator and 401-cable sample.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail with reference to the accompanying drawings and detailed description. It should be noted that the embodiments and features of the embodiments of the present invention may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and thus the scope of the present invention is not limited by the specific embodiments disclosed below.

Research shows that different Volatile Organic gases (VOCs) can be generated when the cable insulating material is subjected to high-temperature thermal degradation and electrical degradation and is close to critical combustion, and the Organic gases can be used as combustion characteristics to identify fire disasters, so that the accuracy of fire detection can be effectively improved. Through the research on the partial discharge (release characteristic gas detection technology) of the XLPE cable, when the partial discharge occurs due to the defect in the cable joint, the insulation material around the partial discharge point can be decomposed and damaged, certain gas is released, the gas generated by the partial discharge under different discharge conditions is collected, and the working state of the intermediate joint of the XLPE cable can be evaluated through the detection of the gas.

The embodiment provides a partial discharge test device of cable insulation, and the device includes: the device comprises a vacuum container, a discharge module, a temperature monitoring module and a gas collection module.

As shown in FIG. 1, the vacuum container of the testing apparatus can be used for making a vacuum environment, and the vacuum container consists of a glass 104 and a glass stopper 101, the glass stopper 101 is arranged above the glass 104, and a valve 102 is arranged on the side surface of the glass 104 and is connected with a vacuum pump or a syringe; the glass cup 104 is internally provided with a sample placing pedestal 103 which is composed of two glass materials, a certain gap is arranged between the two glass materials, the upper part of the pedestal is provided with an opening and is fixed at the central line inside the glass cup 104,

as shown in fig. 2, the glass sheet is "U" shaped, so that the cable sample 401 can stand between the two sheets; the components of the system are sealed by using a sealing ring and a sealant, in addition, as shown in fig. 1, an electrode 201 and an optical fiber line connecting an optical fiber grating temperature sensor 301 and an optical fiber grating demodulator 302 penetrate through an opening on the side wall of a glass cup 104, and the sealant is used for sealing the gap between the optical fiber line and the hole.

The circuit of the discharge module includes: two electrodes 201, a voltage sensor 202, a current sensor 203 and a booster transformer 204 which are connected by using a lead; two ends of a voltage sensor 202 are respectively connected to the two electrodes 201, one end of a current sensor 203 is connected to the electrode 201, the other end of the current sensor is connected to a booster transformer 204, the booster transformer 204 internally comprises a fixed resistance load which can protect a circuit, the booster transformer 204 is externally connected with a power supply, and a vacuum arc is formed between the two electrodes 201 during use.

The temperature measuring module comprises a fiber bragg grating temperature sensor 301 and a fiber bragg grating demodulator 302 which are connected through optical fibers, the optical fibers penetrate through the side wall of the glass cup 104, and the fiber bragg grating temperature sensor 301 is fixed on the cable sample wafer 401; the temperature sensor 301 is an intrinsic type optical fiber sensor, replaces a traditional thermistor, is characterized by small size and electromagnetic insensitivity, and is particularly suitable for temperature measurement in a complex electromagnetic environment.

The gas collection method of the gas collection module adopts a mode of extracting by an injector, the injector is connected with the valve 102, and meanwhile, a rubber pipe is used for wrapping the joint to ensure the sealing property.

In this embodiment, the glass plug 101 can be mounted and dismounted, and the detachable structure facilitates replacement of different cable sample wafers 401; the glass plug 101 can be in different structures such as piston type or screw type, and the contact surfaces of the glass cup 104 and the glass plug 101 respectively comprise at least one sealing ring.

As shown in fig. 2, in this embodiment, the cable sample 401 is taken from the cable insulation layer, and should be cut into a square shape suitable for the sample placement pedestal 103, the side length should be equal to the inner diameter of the glass cup, and a small hole should be drilled in the center of the sample to simulate the actual situation of cable damage; the electrodes 201 penetrate through the side wall of the glass cup, the height is equal to the inner radius of the glass cup 104, at the height, the two electrodes 201 are coaxial with the central hole of the cable sample wafer 401, and an electric arc generated in the working process is opposite to the damaged position; in addition, the fiber grating temperature sensor 301 should be plugged at the small hole.

In this embodiment, the rubber tube connecting the valve 102 and the syringe should be short, before collecting the gas, the air in the gap between the syringe and the rubber tube is pumped by a vacuum pump under the condition of closing the valve 102, and then the valve 102 is opened to collect the gas by using the syringe.

In the present invention, the terms "fixing" and "connecting" should be understood broadly, for example, "fixing" may be fixing with an adhesive such as glue, or fixing it firmly by using a physical structure; "connected" may be a fixed connection, a removable connection, or an integral connection. The specific meaning of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

The shapes of the various elements in the drawings are illustrative and do not preclude the existence of certain differences from the actual shapes, and the drawings are used for the purpose of illustrating the principles of the present application and are not intended to limit the present application.

Although the present application has been disclosed in detail with reference to the accompanying drawings, it is to be understood that such description is merely illustrative and not restrictive of the application of the present application. The scope of the present application is defined by the appended claims and may include various modifications, adaptations, and equivalents of the subject application without departing from the scope and spirit of the present application.

Claims (5)

1. A partial discharge test apparatus for a cable insulation layer, the apparatus comprising: the device comprises a vacuum container, a discharge module and a temperature monitoring module;

the vacuum vessel includes: a glass (104), a glass plug (101), a valve (102) and a sample placing pedestal (103);

the opening of the glass (104) faces upwards, the glass plug (101) seals the opening of the glass (104), a gap between the glass plug (101) and the opening of the glass (104) is sealed by a sealing ring, a valve (102) communicated with the inner cavity of the glass (104) is arranged on the side surface of the glass (104), the valve (102) is used for connecting a vacuum pump, and a sample wafer placing pedestal (103) is arranged in the glass (104);

the discharge module includes: two electrodes (201), a voltage sensor (202), a current sensor (203) and a step-up transformer (204);

the two electrodes (201) penetrate through holes in the side wall of the glass cup (104) and are oppositely arranged and coaxial with each other, and sealant is coated at the joint of the two electrodes (201) and the glass cup (104); a cable sample wafer (401) is arranged in the sample wafer placing pedestal (103), a small hole is formed in the middle of the cable sample wafer (401), the axes of the two electrodes (201) penetrate through the small hole in the middle of the cable sample wafer (401), the voltage sensor (202), the current sensor (203) and the step-up transformer (204) which are connected in series are respectively connected between the two electrodes (201), and the step-up transformer (204) is externally connected with a power supply;

the temperature monitoring module includes: a fiber grating temperature sensor (301) and a fiber grating demodulator (302);

the fiber bragg grating temperature sensor (301) is connected with the fiber bragg grating demodulator (302), and a probe of the fiber bragg grating temperature sensor (301) is located at a small hole in the middle of the cable sample wafer (401).

2. The apparatus for testing partial discharge of an insulation layer of a cable according to claim 1, further comprising: a gas collection module; the extraction device in the gas collection module is a syringe, which is connected to the valve (102) in use.

3. The partial discharge test device for the cable insulation layer according to claim 2, wherein when the injector is connected with the valve (102) for use, a joint is wrapped by a rubber sealing tube before the valve (102) is opened, and a vacuum pump is used for pumping residual gas in a gap to ensure sealing.

4. A partial discharge test device of a cable insulation according to claim 1, characterized in that said sample-placing abutment (103) is a u-shaped bracket, said cable sample (401) being inserted from the upper end opening between the vertical edges of the u-shaped bracket.

5. The partial discharge test apparatus for cable insulation according to claim 4, wherein the cable sample (401) is taken from the cable insulation and is a square cut piece.

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