CN110535090A - A kind of cable intermediate joint water-proof protection device - Google Patents

Abstract

The invention relates to a waterproof protection device for cable intermediate joints. The device includes a receiver antenna, a sensor antenna, a passive humidity sensor, a waterproof protection box, and an RFID receiver; the receiver antenna is installed inside the RFID receiver; the passive humidity sensor adopts The adhesive method is fixed on the waterproof protective box to detect whether there is water in the waterproof protective box. The sensor antenna is built in the passive humidity sensor; the RFID receiver supplies power for the passive humidity sensor; the passive humidity sensor and the RFID receiver Data transmission is carried out through the sensor antenna and the receiver antenna respectively. The invention realizes the real-time monitoring of the water ingress of the cable by detecting the humidity in the cable, and can find the water ingress of the cable in time.

Description

A waterproof protection device for cable intermediate joints

technical field

The invention relates to the field of power cables, and more specifically relates to a waterproof protection device for cable intermediate joints.

Background technique

Compared with overhead lines, power cables are laid underground, have more insulation layers, and their state is less observable. Internal hidden dangers left by improper product quality and installation processes are difficult to be discovered and checked in time, that is, they have the characteristics of "latency". Some common potential hidden dangers include: water ingress, moisture ingress, impurities in accessories, internal damage to the body due to mechanical stress, cracking of the metal shield, scratches on the outer sheath, wrong installation dimensions of accessories, insufficient holding force on the interface of accessories, poor lead sealing, etc. When these hidden dangers accumulate and develop to a certain extent, they will quickly lead to cable failure. The main symptom is breakdown. In special cases, it will also cause combustion and explosion, especially where the cable accessories are located. Judging from the consequences of potential hidden dangers of cables, the most extensive impact is cable water ingress. Cables with latent hidden dangers, under the excitation of partial discharge or overvoltage, are easy to rapidly develop into defects and expand to cause faults, and faults often occur repeatedly on the same line, causing most cables to fail to meet their design requirements. service life. At present, power supply companies often adopt passive protection measures to solve hidden dangers of cables, such as installing joint waterproof casings, fireproof/explosion-proof sealing, etc. In extreme cases, personnel are required to guard and guard, lacking source and systematic technical solutions to timely discover and the ability to deal with hidden dangers is insufficient. The invention designs a cable intermediate joint waterproof protection device based on a wireless sensor, which can monitor the water ingress of the cable in real time, stifle the cable fault in the cradle, and improve the operation reliability of the cable.

Contents of the invention

(1) Technical problems to be solved

In order to solve the problems existing in the prior art, the present invention provides a cable intermediate joint waterproof protection device, which can monitor the water ingress of the cable in real time by detecting the humidity in the cable, and can detect the water ingress in the cable in time, and can pass through A hand-held device RFID receiver reads the measurement data, increasing the operational reliability of the cable.

(2) Technical solution

In order to achieve the above object, the main technical solutions adopted in the present invention include:

Design a kind of cable intermediate joint waterproof protection device, this device comprises receiver antenna, sensor antenna, passive humidity sensor, waterproof protection box, RFID receiver; Described receiver antenna is installed inside RFID receiver; Described passive humidity The sensor is fixed on the waterproof protective box by adhesive method, and is used to detect whether water enters the waterproof protective box. The sensor antenna is built in the passive humidity sensor; the RFID receiver supplies power to the passive humidity sensor; The passive humidity sensor and the RFID receiver perform data transmission with each other through the sensor antenna and the receiver antenna respectively.

In the above scheme, the RFID receiver is a handheld RFID receiver, including a baseband circuit and a radio frequency circuit; the baseband circuit module is used to control the radio frequency circuit and implement encoding and decoding of signals, and communicate with external devices; The radio frequency circuit module is used for signal modulation or demodulation, transmission or reception, and is a communication interface between the passive humidity sensor and the RFID receiver; the baseband circuit and the radio frequency circuit are connected through a DAC chip/ADC chip, and the baseband The circuit generates an analog baseband signal through the DAC chip, and sends it to the radio frequency circuit for modulation and amplification, and then sends it to the passive humidity sensor through the receiver antenna; after the passive humidity sensor sends the measurement result signal, the radio frequency circuit The measurement result signal is collected by the ADC chip and converted into a digital signal and sent to the FPGA chip for calculation and decoding processing.

In the above solution, the passive humidity sensor includes a sensor circuit and a humidity sensing layer made of a humidity sensitive material, the sensor circuit is connected to the humidity sensing layer, and the dielectric constant of the humidity sensitive material changes after absorbing moisture, The change in dielectric constant is converted into a directly measurable capacitance value by a sensor circuit.

In the above solution, the humidity sensitive material is polyimide.

In the above scheme, the sensor circuit includes a matching circuit, a rectification circuit, a voltage stabilizing circuit, an upper reset circuit, an interface circuit, and a modulation circuit, and the matching circuit, a rectification circuit, a voltage stabilizing circuit, an upper reset circuit, an interface circuit, and a modulation circuit The circuits are connected in sequence; the sensor antenna receives the wireless signal sent by the RFID receiver and sends it to the matching circuit, and the best receiving state is achieved through the matching circuit, and the received wireless signal is converted into an upper The reset circuit and the stable DC voltage signal required for the work of the interface circuit, the upper reset circuit provides a reset signal for the interface circuit, and the interface circuit converts the reset signal into a digital signal, and the digital signal is converted into a high voltage signal by the modulation circuit. HF or UHF modulated signal and sent to the RFID receiver through the sensor antenna.

In the above solution, the waterproof protection box includes an upper cover, a fastening groove, an upper lining, a sealing column, a sealing strip, a lower lining, a lower cover, a fastening hoop, bolts, nuts, and through holes; The upper cover and the lower cover are semi-cylindrical buttable structures, the upper cover and the lower cover are provided with internal grooves inside the shell, and fastening grooves are respectively provided at both ends and the middle of the external shell; The upper lining is embedded in the groove in the upper cover body, and the lower lining is embedded in the groove in the lower cover body; the sealing strip is located between the upper cover body and the lower cover body; the upper cover body and the lower cover body Both ends are provided with through holes for cables to pass through. The inner wall of the through hole is in the shape of a groove, and the sealing column is installed in the circumferential direction of the through hole; the fastening grooves at both ends and the middle of the upper cover and the lower cover Align and fix by fastening hoops, and the two ends of the fastening hoops are fixed by bolts and nuts.

In the above solution, the sealing strip and the sealing column are made of flame retardant materials, the fastening hoop, the upper cover and the lower cover are made of fiberglass composite materials, and the upper inner lining and lower inner lining are made of fireproof composite materials.

In the above solution, the signal transmission distance between the sensor antenna and the receiver antenna is more than 2m; the gain of the receiver antenna is 9dBi, the frequency range is 840-940MHz, and the impedance is 50Ω.

(3) Beneficial effects

The beneficial effect of the present invention is that: the present invention realizes the real-time monitoring of the water ingress of the cable by detecting the humidity in the cable, can detect the water ingress of the cable in time, and can read the measurement data through the RFID receiver of the handheld device, and improve the efficiency of the cable. operational reliability.

Description of drawings

Figure 1 is a schematic diagram of the working principle of a cable intermediate joint waterproof protection device;

Figure 2 is a schematic diagram of disassembly of the waterproof protective box;

Fig. 3 is a half-cut front view of the waterproof protective box;

Fig. 4 is a half-cut perspective view of the waterproof protective box;

Fig. 5 is a half-cut left view of the waterproof protective box;

Fig. 6 is a schematic diagram of the principle of the passive humidity sensor.

In the figure: 1-receiver antenna, 2-sensor antenna, 3-passive humidity sensor, 4-waterproof protection box, 5-RFID receiver, 6-radio frequency circuit, 7-baseband circuit, 8-upper cover, 9 -Fastening groove, 10-upper lining, 11-seal column, 12-sealing strip, 13-lower lining, 14-lower cover, 15-fastening hoop, 16-bolt, 17-nut, 18-pass Hole, 19-matching circuit, 20-rectification circuit, 21-voltage stabilizing circuit, 22-reset circuit, 23-interface circuit, 24-modulation circuit.

Detailed ways

In order to better explain the present invention and facilitate understanding, the present invention will be described in detail below through specific embodiments in conjunction with the accompanying drawings.

As shown in FIG. 1 , the present invention provides a cable intermediate joint waterproof protection device, which includes a receiver antenna 1 , a sensor antenna 2 , a passive humidity sensor 3 , a waterproof protection box 4 , and an RFID receiver 5 .

The receiver antenna 1 is installed inside the RFID receiver 5; the passive humidity sensor 3 is fixed on the waterproof protective box 4 by adhesive method, and is used to detect whether water enters the waterproof protective box 4; the RFID receiver 5 is a passive humidity sensor. The sensor 3 supplies power; the passive humidity sensor 3 and the RFID receiver 5 transmit data to each other through the sensor antenna 2 and the receiver antenna 1 respectively.

Among them, the signal transmission distance between the sensor antenna 2 and the receiver antenna 1 is more than 2m; the sensor antenna 2 is built in the passive humidity sensor 3; the gain of the receiver antenna 1 is 9dBi, the frequency range is 840-940MHz, and the impedance is 50Ω. It has the characteristics of fast reading speed, convenience, high data security, and long transmission distance.

The RFID receiver 5 is a handheld RFID receiver, including a baseband circuit 7 and a radio frequency circuit 6; the baseband circuit 7 module is used to control the radio frequency circuit 6 and realize encoding and decoding of signals, and also communicates with external equipment; the radio frequency circuit 6 module It is used for signal modulation or demodulation, transmission or reception, and is a communication interface between the passive humidity sensor 3 and the RFID receiver 5 . The baseband circuit 7 and the radio frequency circuit 6 are connected through a DAC/ADC. The baseband circuit 7 generates an analog baseband signal through the DAC chip, and sends it to the radio frequency circuit 6 for modulation and amplification, and then sends it out through the receiver antenna 1 . After the passive humidity sensor 3 sends the measurement result signal, the radio frequency circuit 6 collects the measurement result signal through the ADC chip and converts it into a digital signal and sends it to the FPGA chip for calculation and decoding processing. Wherein, the radio frequency circuit 6 adopts a zero-IF receiving mode, so its transmitting part and receiving part can share a frequency source.

The passive humidity sensor 3 includes a sensor circuit and a humidity sensing layer made of humidity sensitive material, and the sensor circuit is connected with the humidity sensing layer. The dielectric constant of humidity-sensitive materials will change significantly after moisture absorption, and the change in dielectric constant is reflected as a directly measurable capacitance value through the phase sensor. Since polyimide is a polymer material, it has the least impact on cables and intermediate joints. Therefore, in the embodiment of the present invention, polyimide is selected as the humidity sensitive material.

As shown in Figure 2-5, the waterproof protection box 4 includes an upper cover body 8, a fastening groove 9, an upper lining 10, a sealing column 11, a sealing strip 12, a lower lining 13, a lower cover body 14, and a fastening hoop 15 , bolts 16, nuts 17, through holes 18, the upper cover 8 and the lower cover 14 are semi-cylindrical buttable structures, the upper cover 8 and the lower cover 14 are provided with inner grooves inside the shell, and Fastening grooves 9 are respectively provided at both ends and the middle of the outer body. The upper inner liner 10 is embedded in the inner groove of the upper cover body 8 , and the lower inner liner 13 is embedded in the inner groove of the lower cover body 14 . The sealing strip 12 is located between the upper cover body 8 and the lower cover body 14 to play a role of sealing and waterproofing. The two ends of the upper cover body 8 and the lower cover body 14 are provided with a through hole 18 for cables to pass through. The inner wall of the through hole 18 is in the shape of a groove, and the sealing column 11 is installed in the circumferential direction of the through hole 18 to ensure the tightness of the waterproof protection box 4 . The upper cover body 8 is aligned with the fastening grooves 9 at the two ends and the middle part of the lower cover body 14 and fixed by a fastening hoop 15 , and the two ends of the fastening hoop 15 are fixed by bolts 16 and nuts 17 . Among them, the sealing strip 12 and the sealing column 11 are all made of flame-retardant materials, the fastening hoop 15, the upper cover body 8 and the lower cover body 14 are all made of glass fiber reinforced plastic composite materials, and the upper inner lining 10 and the lower inner lining 13 are made of fire-resistant composite materials, which can Prevent the waterproof protective box 4 from being burned when the cable catches fire. After the waterproof protection box 4 connects each section of cable, different numbers of passive humidity sensors 3 can be installed in different positions to form a sensor detection array. Through the data in the RFID receiver 5, distributed measurement of the water inlet point of the cable can be realized , Accurately judge the water inlet point of the cable.

As shown in Figure 6, the sensor circuit of passive humidity sensor 3 comprises matching circuit 19, rectification circuit 20, voltage stabilizing circuit 21, upper reset circuit 22, interface circuit 23, modulating circuit 24, matching circuit 19, rectifying circuit 20, stabilizing circuit The voltage circuit 21, the upper reset circuit 22, the interface circuit 23, and the modulation circuit 24 are connected in sequence; the signal received by the sensor antenna 2 is transmitted to the matching circuit 19, and then passes through the rectifier circuit 20, the voltage stabilizing circuit 21, the upper reset circuit 22, and the interface. The circuit 23 and the modulation circuit 24 process, and the processed signal is sent to the RFID receiver 5 by the sensor antenna 2 .

The sensor antenna 2 receives the wireless signal sent by the RFID receiver 5 and sends it to the passive humidity sensor 3. The passive humidity sensor 3 reaches the best receiving state through the matching circuit 19, and the received wireless signal passes through the rectifying circuit 20 and the voltage stabilizing circuit 21 Converted into the stable DC voltage signal required for the normal operation of the upper reset circuit 22 and the interface circuit 23, the upper reset circuit 22 provides a reset signal for the interface circuit 23, and the interface circuit 23 converts the reset signal into a digital signal, and the digital signal is passed through the modulation circuit 24 is converted into a high frequency or ultra high frequency modulation signal and sent back to the RFID receiver 5 through the sensor antenna 2 reflection. The RFID receiver 5 powers the passive humidity sensor 3 .

The cable intermediate joint waterproof protection device of the present invention is used to measure the moisture content of the cable joint, comprising the following steps:

Step 1: RFID receiver 5 sends instructions to passive humidity sensor 3;

Step 2: The passive humidity sensor 3 detects the moisture content of the cable joint and sends the detection result to the RFID receiver 5, and the RFID receiver 5 acquires the moisture content of the cable joint.

Accompanying drawing has described the embodiment of the present invention, but the present invention is not limited to above-mentioned specific implementation, and above-mentioned specific implementation is only illustrative, rather than restrictive, and those of ordinary skill in the art are in the present invention Under the enlightenment of the present invention, many forms can also be made without departing from the purpose of the present invention and the scope of protection of the claims, and these all belong to the protection of the present invention.

Claims (10)

1. a kind of cable middle joint waterproof protective device, it is characterized in that, this device comprises receiver antenna (1), sensor antenna (2), passive humidity sensor (3), waterproof protection box (4), RFID receiver ( 5); the receiver antenna (1) is installed inside the RFID receiver (5); the passive humidity sensor (3) is fixed on the waterproof protective box (4) by an adhesive method, and is used to detect the Whether water enters in waterproof protection box (4), described sensor antenna (2) is built in in the passive humidity sensor (3); Described RFID receiver (5) is the power supply of passive humidity sensor (3); The source humidity sensor (3) and the RFID receiver (5) perform mutual data transmission through the sensor antenna (2) and the receiver antenna (1) respectively. 2. A kind of cable intermediate joint waterproof protection device according to claim 1, is characterized in that, described RFID receiver (5) is a handheld RFID receiver, comprises baseband circuit (7) and radio frequency circuit (6); The baseband circuit (7) is used to control the radio frequency circuit (6) and implement encoding and decoding of signals, and communicate with external equipment; the radio frequency circuit (6) is used for signal modulation or demodulation, transmission or reception , the radio frequency circuit (6) is connected with the passive humidity sensor (3) and the RFID receiver (5); Described baseband circuit (7) and radio frequency circuit (6) are connected by DAC chip/ADC chip, and described baseband circuit (7) produces analog baseband signal by DAC chip, and sends to radio frequency circuit (6) and carries out modulation, amplification, then Send to the passive humidity sensor (3) through the receiver antenna (1); after the passive humidity sensor (3) sends the measurement result signal, the radio frequency circuit (6) collects the measurement result signal through the ADC chip And convert it into a digital signal and send it to the FPGA chip for calculation and decoding. 3. A waterproof protection device for cable intermediate joints according to claim 1, characterized in that, the passive humidity sensor (3) includes a sensor circuit and a humidity sensing layer made of humidity sensitive materials, and the sensor circuit Connected with the humidity sensing layer, the sensor circuit is used to convert the dielectric constant of the humidity sensing layer into a capacitance value. 4. A waterproof protection device for cable intermediate joints according to claim 3, characterized in that the moisture sensitive material is polyimide. 5. A kind of cable intermediate joint waterproof protection device according to claim 3, is characterized in that, described sensor circuit comprises matching circuit (19), rectification circuit (20), voltage stabilizing circuit (21), upper reset circuit ( 22), interface circuit (23), modulation circuit (24), described matching circuit (19), rectification circuit (20), voltage stabilizing circuit (21), upper reset circuit (22), interface circuit (23), modulation The circuits (24) are connected in turn; the sensor antenna (2) receives the wireless signal sent by the RFID receiver (5) and sends it to the matching circuit (19), and the best receiving state is reached by the matching circuit (19), and the receiving The wireless signal is converted into the stable DC voltage signal required by the upper reset circuit (22) and the interface circuit (23) through the rectification circuit (20) and the voltage stabilization circuit (21), and the upper reset circuit (22) is The interface circuit (23) provides a reset signal, and the interface circuit (23) converts the reset signal into a digital signal, and the digital signal is converted into a high-frequency or ultra-high-frequency modulation signal by the modulation circuit (24) and passed through the sensor antenna (2) Send to RFID receiver (5). 6. A cable intermediate joint waterproof protection device according to claim 1, characterized in that, the waterproof protection box (4) comprises an upper cover (8), a fastening groove (9), an upper lining (10 ), sealing post (11), sealing strip (12), lower lining (13) and lower cover (14); the upper cover (8) and lower cover (14) are semi-cylindrical Butt joint structure, the upper cover (8) and the lower cover (14) are provided with inner grooves inside the shell, and fastening grooves (9) are respectively provided at both ends and the middle of the outer shell; the upper inner lining (10) is embedded in the inner groove of the upper cover (8), and the lower lining (13) is embedded in the inner groove of the lower cover (14); the sealing strip (12) is located at the upper cover (8) and Between the lower cover (14). 7. A waterproof protection device for cable intermediate joints according to claim 6, characterized in that, the two ends of the upper cover (8) and the lower cover (14) are provided with through holes (18) for cables to pass through ), the inner wall of the through hole (18) is groove-shaped, and the sealing column (11) is installed in the circumferential direction of the through hole (18). 8. A cable intermediate joint waterproof protection device according to claim 6, characterized in that the upper cover (8) is aligned with the fastening grooves (9) at both ends and in the middle of the lower cover (14) and It is fixed by a fastening hoop (15), and the two ends of the fastening hoop (15) are fixed by bolts (16) and nuts (17). 9. A cable intermediate joint waterproof protection device according to claim 1, characterized in that the sealing strip (12) and the sealing column (11) are made of flame-retardant materials, and the fastening hoop (15), upper The cover body (8) and the lower cover body (14) are made of fiberglass composite material, and the upper inner lining (10) and the lower inner lining (13) are made of fireproof composite material. 10. A cable intermediate joint waterproof protection device according to claim 1, characterized in that the receiver antenna (1) has a gain of 9dBi, a frequency range of 840-940MHz, and an impedance of 50Ω.