CN114414086B - Fiber Bragg grating insulator temperature monitoring system and method based on VCSEL wavelength demodulation - Google Patents

Abstract

The present invention discloses a fiber grating insulator temperature monitoring system and method based on VCSEL wavelength demodulation, comprising: a composite insulator, a fiber grating arranged at the high-voltage end and the low-voltage end of the composite insulator, and a fiber grating temperature sensor for monitoring the ambient temperature; the fiber grating wavelength demodulation system based on VCSEL demodulates the wavelength change of the fiber grating at different temperatures to obtain the temperature of the high-voltage end and the low-voltage end of the composite insulator and the ambient temperature; in the self-organizing network communication system, the Lora module receives the temperature data, and after the conversion of the Lora protocol and the Beidou protocol, it is forwarded to the monitoring terminal through the Beidou module, and an early warning is issued according to the temperature difference between the high-voltage end and the low-voltage end and the ambient temperature. The temperature is obtained by wavelength demodulation through the fiber grating wavelength demodulation system based on VCSEL, and the temperature is transmitted through the self-organizing network communication system formed by Beidou and Lora networking, so as to realize the real-time online monitoring of the temperature of the composite insulator.

Description

Fiber Bragg grating insulator temperature monitoring system and method based on VCSEL wavelength demodulation

Technical Field

The present invention relates to the technical field of composite insulator detection, and in particular to a fiber grating insulator temperature monitoring system and method based on VCSEL wavelength demodulation.

Background technique

The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

During the operation of the power system, the interface defects between the core rod and the sheath of the composite insulator have an important impact on the insulation performance of the insulator and the safe and stable operation of the transmission line. Composite insulators work for a long time in a complex and harsh environment composed of strong electric fields, mechanical stress, dirt, temperature and humidity, and the interface process between the core rod and silicone rubber is poorly controlled. The probability of failure is very high, which seriously threatens the safe operation of the power system.

When a composite insulator is in normal operation, the internal voltage distribution changes with the change of its position in the composite insulator. The distributed voltage is higher near the high-voltage end, slightly lower in the middle, and the distributed voltage at the low-voltage end rises again. Therefore, under normal circumstances, the temperature rise at different positions of the composite insulator will also be reflected with the voltage distribution, and the temperature is continuously distributed.

When the composite insulator is damaged on the outside, cracks appear on the inside, the core rod itself is of poor material, or there is an air gap between the core rod and the insulating sheath, water vapor and impurities will slowly invade to form electrolyte bubbles. If electrolyte bubbles are formed at the high-voltage end of the composite insulator, due to the high field strength at the high-voltage end, the bubbles can easily be broken down and cause local discharge, leading to local heating, aging of the insulating sheath and cracking.

Under the combined effect of the external environment, the surface gradually carbonizes into a conductive state, causing the insulating sheath at the high-voltage end to be damaged. High field strength is applied to the next sheath, and local discharge develops step by step toward the low-voltage end, gradually reducing the effective insulation distance of the insulator, which will eventually lead to breakdown and damage of the entire insulator.

In addition, under normal circumstances, the insulation resistance of composite insulators is very large, and the internal leakage current is very small. However, when the insulation resistance at a certain point of the high-voltage end of the composite insulator decreases due to degradation or aging, the leakage current inside the insulator will flow through that point, causing excessive resistance loss at that point, resulting in local heating. Both local discharge and insulation resistance aging can cause local heating of the insulator. The abnormal operation of the insulator can be judged by detecting the different local temperatures of the insulator and the ambient temperature of the transmission tower.

The widely used method at present is infrared thermal imaging detection. The main disadvantage is that the detection result is easily affected by the observation angle. In addition, this detection method is inefficient and can only perform targeted tracking detection. It is not suitable for large-scale insulator temperature detection.

Summary of the invention

In order to solve the above problems, the present invention proposes a fiber grating insulator temperature monitoring system and method based on VCSEL wavelength demodulation. The wavelength is demodulated by the fiber grating wavelength demodulation system based on VCSEL to obtain temperature data. The temperature signal is transmitted through the Beidou and Lora networking to realize real-time online monitoring of the temperature of the composite insulator of the high-voltage transmission line.

In order to achieve the above object, the present invention adopts the following technical solution:

In a first aspect, the present invention provides a fiber Bragg grating insulator temperature monitoring system based on VCSEL wavelength demodulation, comprising: a fiber Bragg grating insulator, a fiber Bragg grating temperature sensor, a fiber Bragg grating wavelength demodulation system based on VCSEL, and a self-organizing network communication system;

The fiber grating insulator comprises a composite insulator and fiber gratings arranged at the high-voltage end and the low-voltage end of the composite insulator;

The fiber grating temperature sensor is arranged on both sides of the tower head of the transmission tower to monitor the ambient temperature;

The VCSEL-based fiber Bragg grating wavelength demodulation system includes a multi-channel VCSEL wavelength demodulation module and a first Lora module. The multi-channel VCSEL wavelength demodulation module is used to demodulate the wavelength changes of the fiber Bragg grating and the fiber Bragg grating temperature sensor of the composite insulator at different temperatures to obtain the high-voltage end temperature, low-voltage end temperature and ambient temperature of the composite insulator. The first Lora module is used to send the high-voltage end temperature, low-voltage end temperature and ambient temperature of the composite insulator.

The self-organizing network communication system includes a Lora+Beidou base station, a Beidou satellite system and a remote monitoring station. The Lora+Beidou base station includes a second Lora module and a Beidou module. The second Lora module receives the high-voltage end temperature, the low-voltage end temperature and the ambient temperature of the composite insulator, and after conversion between the Lora protocol and the Beidou protocol, forwards the temperature to the remote monitoring station through the Beidou module and the Beidou satellite system, so as to calibrate the high-voltage end temperature and the low-voltage end temperature of the composite insulator using the ambient temperature, and issue an early warning based on the temperature difference between the high-voltage end and the low-voltage end.

As an optional implementation, a groove is provided on the surface of the core rod of the composite insulator, and the optical fiber Bragg grating is pre-buried between the insulating sheath and the groove on the core rod.

As an optional implementation, the wavelength of the fiber Bragg grating is matched with the wavelength scanning range of the multi-channel VCSEL wavelength demodulation module, so that each channel of the multi-channel VCSEL wavelength demodulation module is allocated a fiber Bragg grating at the high-voltage end and a fiber Bragg grating at the low-voltage end, and the wavelength variation of the fiber Bragg grating meets the temperature variation range of the composite insulator temperature measurement.

As an optional implementation, the wavelength scanning range of the multi-channel VCSEL wavelength demodulation module is 1527nm-1531nm, the maximum number of channels is 8, two channels are connected to two fiber grating temperature sensors for monitoring ambient temperature, and are used to provide an ambient reference temperature for the temperature of the composite insulator.

As an optional implementation, the first Lora module and Beidou module periodically send temperature data via a radio frequency antenna.

As an optional implementation, the second Lora module converts the temperature into a standard instruction, the Beidou module receives the Beidou instruction in the standard instruction, and sends it to the Beidou satellite system through the radio frequency antenna, and then is transmitted to the remote monitoring station after being transferred by the Beidou satellite system.

As an optional implementation, the remote monitoring station includes a Beidou receiving terminal and a monitoring terminal. The Beidou receiving terminal is used to convert Beidou satellite data forwarded by the Beidou satellite system into standard data frames, and send them to the monitoring terminal through a serial port after protocol conversion.

As an optional implementation, the remote monitoring station uses the ambient temperature to calibrate the temperature of the high-voltage end and the low-voltage end of the composite insulator, and issues an early warning based on the temperature difference between the high-voltage end and the low-voltage end.

As an optional embodiment, the temperature monitoring system also includes a power supply system, which includes a battery, a solar charging panel and a charge and discharge controller; the solar charging panel is installed in the low-voltage area of the tower head and converts solar energy into electrical energy to charge the battery.

In a second aspect, the present invention provides a working method of the fiber grating insulator temperature monitoring system based on VCSEL wavelength demodulation according to the first aspect, comprising:

Fiber Bragg gratings are pre-buried at the high-voltage end and the low-voltage end of the composite insulator respectively;

Fiber Bragg grating sensors for monitoring ambient temperature are placed on both sides of the transmission tower head;

The multi-channel VCSEL wavelength demodulation module demodulates the wavelength change of the fiber Bragg grating at different temperatures to obtain the high-voltage end temperature, low-voltage end temperature and ambient temperature of the composite insulator, and the first Lora module periodically sends the temperature data to the Lora+Beidou communication base station;

The second Lora module receives the high-voltage end temperature, low-voltage end temperature and ambient temperature of the composite insulator, and after conversion between the Lora protocol and the Beidou protocol, the temperature is forwarded to the remote monitoring station through the Beidou module. The temperature of the high-voltage and low-voltage ends of the composite insulator is calibrated using the ambient temperature, and an early warning is issued based on the temperature difference between the high-voltage and low-voltage ends.

Compared with the prior art, the present invention has the following beneficial effects:

The fiber grating insulator temperature monitoring system based on VCSEL wavelength demodulation provided by the present invention has low cost, high detection accuracy, and a wide monitoring range, and can monitor the temperature of composite insulators in real time. By forming an ad hoc network communication system through Beidou and Lora networking, real-time online monitoring of the temperature of composite insulators on the entire high-voltage transmission line can be achieved.

The fiber grating wavelength demodulation system based on VCSEL insulator temperature monitoring system based on VCSEL wavelength demodulation provided by the present invention has a simple structure, reduces system power consumption and production cost, and can realize real-time, online monitoring of insulator temperature.

The fiber grating insulator temperature monitoring system and method based on VCSEL wavelength demodulation provided by the present invention can utilize a solar power supply system to transmit a composite insulator temperature signal through a self-organizing network communication system. Compared with an infrared thermal imaging detection method, the detection efficiency is high, and regular sampling inspections and manual inspections can be avoided. The system is suitable for insulator temperature monitoring of the entire high-voltage transmission system and is suitable for popularization and use.

Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

FIG1 is a schematic diagram of a fiber grating insulator temperature monitoring system based on VCSEL wavelength demodulation provided in Example 1 of the present invention;

FIG2 is a schematic diagram of a fiber Bragg grating insulator in a fiber Bragg grating insulator temperature monitoring system based on VCSEL wavelength demodulation provided in Example 1 of the present invention;

3 is a schematic diagram of a fiber Bragg grating wavelength demodulation system based on VCSEL in a fiber Bragg grating insulator temperature monitoring system based on VCSEL wavelength demodulation provided in Example 1 of the present invention;

4 is a schematic diagram of a Lora+Beidou communication base station in a fiber grating insulator temperature monitoring system based on VCSEL wavelength demodulation provided in Example 1 of the present invention;

5 is a schematic diagram of a BeiDou satellite system in a fiber grating insulator temperature monitoring system based on VCSEL wavelength demodulation provided in Example 1 of the present invention;

6 is a schematic diagram of a remote monitoring station in a fiber grating insulator temperature monitoring system based on VCSEL wavelength demodulation provided in Example 1 of the present invention;

Among them, 1. fiber grating at the high-voltage end, 2. optical fiber, 3. fiber grating at the low-voltage end, 4. white sleeve optical fiber, 5. optical cable, 6. fiber grating temperature sensor, 7. first power supply system, 8. multi-channel VCSEL wavelength demodulation module, 9. first Lora module, 10-1. first RF antenna, 10-2. second RF antenna, 10-3. third RF antenna, 10-4. fourth RF antenna, 11. second power supply system, 12. second Lora module, 13. Beidou module, 14. processing module, 15. Beidou receiving terminal, 16. monitoring terminal, 17. Beidou satellite system.

Detailed ways:

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that the terms "include" and "have" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

Example 1

As shown in FIG1 , this embodiment provides a fiber Bragg grating insulator temperature monitoring system based on VCSEL wavelength demodulation, comprising: a fiber Bragg grating insulator, a fiber Bragg grating temperature sensor, a fiber Bragg grating wavelength demodulation system based on VCSEL, and a self-organizing network communication system;

The fiber grating insulator comprises a composite insulator and fiber gratings arranged at the high-voltage end and the low-voltage end of the composite insulator;

The fiber grating temperature sensor is arranged on both sides of the tower head of the transmission tower to monitor the ambient temperature;

The VCSEL-based fiber Bragg grating wavelength demodulation system includes a multi-channel VCSEL wavelength demodulation module and a first Lora module. The multi-channel VCSEL wavelength demodulation module is used to demodulate the wavelength changes of the fiber Bragg grating and the fiber Bragg grating temperature sensor of the composite insulator at different temperatures to obtain the high-voltage end temperature, low-voltage end temperature and ambient temperature of the composite insulator. The first Lora module is used to send the high-voltage end temperature, low-voltage end temperature and ambient temperature of the composite insulator.

The self-organizing network communication system includes a Lora+Beidou base station, a Beidou satellite system and a remote monitoring station. The Lora+Beidou base station includes a second Lora module and a Beidou module. The second Lora module receives the high-voltage end temperature, the low-voltage end temperature and the ambient temperature of the composite insulator, and after conversion between the Lora protocol and the Beidou protocol, forwards the temperature to the remote monitoring station through the Beidou module and the Beidou satellite system, so as to calibrate the high-voltage end temperature and the low-voltage end temperature of the composite insulator using the ambient temperature, and issue an early warning based on the temperature difference between the high-voltage end and the low-voltage end.

As shown in FIG2 , the fiber grating insulator includes a composite insulator, a high-voltage end fiber grating 1, an optical fiber 2, a low-voltage end fiber grating 3, a white sleeve optical fiber 4 and an optical cable 5;

In this embodiment, a groove is provided on the surface of the core rod of the composite insulator, and a high-voltage end fiber Bragg grating 1 and a low-voltage end fiber Bragg grating 3 for temperature monitoring are pre-embedded at the high-voltage end and the low-voltage end of the composite insulator, respectively, so that the high-voltage end fiber Bragg grating 1 and the low-voltage end fiber Bragg grating 3 are placed between the insulating sheath and the groove on the core rod of the composite insulator.

As an optional implementation, the wavelength selection and pre-embedded position of the fiber grating include:

A high-voltage end fiber Bragg grating 1 is embedded at a specific position (according to the actual length of the insulator) between the high-voltage end insulation sheath and the core rod, with a wavelength of 1527.7nm at 30°C and a corresponding temperature measurement range of -40-140°C;

A low-voltage end fiber Bragg grating 3 is pre-buried between the low-voltage end insulation sheath and the core rod (according to the actual length of the insulator), with a wavelength of 1530.1nm at 30°C and a corresponding temperature measurement range of -40-60°C;

At the high-voltage end of the composite insulator, leave 5 cm of the fiber 2 pigtail to extend into the high-voltage end fitting to prevent background noise caused by reflection from the fiber 2 pigtail end.

A white sleeve is inserted into the optical fiber 2 at 10 cm at the low-voltage end of the composite insulator and extended to the outside. The white sleeve optical fiber 4 inserted outside is connected to the optical cable 5 inside the low-voltage end hardware, and is connected to the VCSEL-based fiber Bragg grating wavelength demodulation system at the low-voltage end of the transmission tower head through the optical cable 5.

According to a large number of actual operation tests, the temperature of the high-voltage end of the fiber grating insulator changes by about 0.5-2℃ compared with the low-voltage end during normal operation; when there is partial discharge at the high-voltage end of the insulator, the temperature of the high-voltage end changes by about 5-10℃ compared with the low-voltage end.

As shown in Figure 3, the VCSEL-based fiber grating wavelength demodulation system includes a first power supply system 7, a multi-channel VCSEL wavelength demodulation module 8, a first Lora module 9, and a first RF antenna 10-1; wherein, the multi-channel VCSEL wavelength demodulation module 8 has 8 data channels, the optical cable 5 is connected to the channels of the multi-channel VCSEL wavelength demodulation module 8, the first power supply system 7 provides power for the multi-channel VCSEL wavelength demodulation module 8 and the first Lora module 9, the multi-channel VCSEL wavelength demodulation module 8 has a data communication interface with the first Lora module 9, and the first Lora module 9 sends data through the first RF antenna 10-1.

In this embodiment, the VCSEL-based fiber Bragg grating wavelength demodulation system is powered by 12V and has an overall power consumption of 2.4W. It is placed in the low-voltage area of the head of a transmission tower and uses a multi-channel VCSEL wavelength demodulation module 8 to demodulate the fiber Bragg grating wavelengths at the high-voltage and low-voltage ends of the composite insulator on the transmission tower, as well as the wavelength of the fiber Bragg grating temperature sensor used to monitor the ambient temperature, to obtain the temperature data of the composite insulator, and to communicate with the second Lora module 12 of the ad hoc network communication system through the first Lora module 9 to periodically send the temperature data to the Lora+Beidou communication base station.

The wavelength scanning range of the multi-channel VCSEL wavelength demodulation module 8 is 1527nm-1531nm, and the maximum number of channels is 8, of which two channels are connected to two fiber grating temperature sensors 6 for monitoring the ambient temperature, which are placed on both sides of the tower head of the transmission tower to monitor the ambient temperature and provide an ambient reference temperature for the temperature sensor inside the composite insulator. In addition, a temperature pressure chip is integrated inside the multi-channel VCSEL wavelength demodulation module to measure the ambient temperature so as to correct the temperature value measured by the fiber grating.

In this embodiment, the wavelength of the temperature monitoring fiber Bragg grating is matched with the wavelength scanning range of the multi-channel VCSEL wavelength demodulation module, so that each channel of the multi-channel VCSEL wavelength demodulation module is allocated a high-voltage end fiber Bragg grating 1 and a low-voltage end fiber Bragg grating 3, and the wavelength change meets the temperature change range of the composite insulator temperature measurement, that is, meets the temperature monitoring range requirements.

In this embodiment, the first power supply system 7 is connected to a multi-channel VCSEL wavelength demodulation module 8 , which obtains the status of the solar charging panel and the battery in real time, and transmits the battery status data through the first Lora module 9 .

In this embodiment, temperature monitoring fiber Bragg gratings are pre-buried at the high-voltage end and the low-voltage end between the insulating sheath and the core rod of the composite insulator, and a fiber Bragg grating temperature sensor for monitoring the ambient temperature is placed on the top of the transmission tower. The temperature information monitored by the fiber Bragg grating at the high-voltage end and the low-voltage end of the composite insulator and the ambient temperature information are demodulated by a multi-channel VCSEL wavelength demodulation module. The thermal effect caused by partial discharge inside the insulator and the problem of reduced insulation performance of the insulator caused by the thermal effect and aging of the insulation resistance are effectively determined according to the temperature changes at the high-voltage end and the low-voltage end, so as to prevent the occurrence of insulator breakdown or thermal expansion explosion accidents.

As shown in Figure 4, the Lora+Beidou communication base station includes a second power supply system 11, a second Lora module 12, a Beidou module 13, a processing module 14, a second RF antenna 10-2 and a third RF antenna 10-3; the second Lora module 12 receives temperature data through the second RF antenna 10-2, the processing module 14 is used to convert the Lora protocol and the Beidou protocol, and the Beidou module 13 sends temperature data through the third RF antenna 10-3.

As shown in FIG5 , the BeiDou satellite system 17 acts as a relay station to transmit BeiDou satellite data.

As shown in Figure 6, the remote monitoring station includes a Beidou receiving terminal 15, a monitoring terminal 16 and a fourth RF antenna 10-4. The Beidou receiving terminal 15 receives Beidou satellite data through the fourth RF antenna 10-4, and converts the Beidou satellite data forwarded by the Beidou satellite system 17 into standard data frames, which are sent to the monitoring terminal 16 through the serial port after protocol conversion.

In this embodiment, the first Lora module 9 of the VCSEL-based fiber Bragg grating wavelength demodulation system is connected to the second Lora module 12 of the Lora+Beidou communication base station through an antenna, and the Beidou module 13 of the Lora+Beidou communication base station communicates with the Beidou satellite system 17 via satellite; the first Lora modules 9 on the 14-70 towers are grouped together, and the temperature data obtained by the multi-channel VCSEL wavelength demodulation module is transmitted to the Beidou satellite system 17 through the Lora+Beidou communication base station, and then transmitted to the remote monitoring station after being transferred by the Beidou satellite system 17. The specific communication steps are:

1) The first Lora module 9 periodically sends temperature data to the Lora+Beidou communication base station through the first radio frequency antenna 10-1;

2) The second Lora module 12 inside the Lora+Beidou communication base station converts the temperature data into standard instructions, the processing module 14 controls the conversion between the Lora protocol and the Beidou protocol, and then the Beidou module 13 receives the Beidou instructions in the standard instructions from the processing module 14, and sends them to the Beidou satellite system 17 through the third RF antenna 10-3, and then transmits them to the remote monitoring station after being transferred by the Beidou satellite system 17;

3) The Beidou receiving terminal 15 inside the remote monitoring station converts the Beidou satellite data into standard data frames, and sends them to the monitoring terminal 16 through the serial port after protocol conversion. The monitoring terminal 16 receives all the Beidou satellite data, processes the data and opens the network interface to provide more services to users.

In this embodiment, the first power supply system 7 and the second power supply system 11 both include a storage battery, a solar charging battery panel and a charge and discharge controller;

Among them, the battery is used to power the entire monitoring and early warning system. The capacity meets the needs of 6 consecutive rainy days, the reserved capacity for charging and discharging, and the loss during operation. The required capacity is 12V, 44AH. The specific calculation is: 0.2A×24h×6 days÷80%×120%≈44AH;

Solar panels convert sunlight into electrical energy. The peak demand meets the average daily effective light time of 4.5 hours, panel reserve, working loss, etc. The peak demand (WP) is 161W, which is calculated as follows: 17.4V×(0.2A×24h×6)÷4.5h×120%×120%≈161W;

Solar charging panels convert solar energy into electrical energy to charge batteries; solar charging panels are installed in the low-voltage area on the tower head to convert solar energy into electrical energy and store it in batteries. Each power supply unit can support the normal operation of an independent monitoring and early warning system on each transmission tower.

In this embodiment, the temperature monitoring system is driven by a rechargeable battery, and uses fiber Bragg grating to monitor the temperature changes of the high-voltage and low-voltage ends of the composite insulator in real time. The temperature changes of the high-voltage and low-voltage ends are used as one of the parameters for judging the partial discharge inside the composite insulator and the aging of the insulation resistance, thereby realizing accurate online temperature monitoring of the working state and environment of the composite insulator on the transmission tower, providing accurate information for abnormal temperature conditions that may occur in the composite insulator, and providing early warning for possible failures of the high-voltage composite insulator.

In this embodiment, the temperature monitoring system is deployed on high towers in areas where manual maintenance is difficult, such as outdoor and mountainous areas. The first Lora modules on 14-70 high towers are grouped together, and 286 Lora+Beidou communication base stations are deployed along the 2000km transmission line to transmit the temperature data of all composite insulators monitored on the entire high-voltage transmission line to the monitoring terminal, thereby realizing real-time online monitoring of the internal temperature of the composite insulators of the entire high-voltage transmission line.

Example 2

This embodiment provides a working method of the fiber grating insulator temperature monitoring system based on VCSEL wavelength demodulation as described in Embodiment 1, comprising the following steps:

Fiber Bragg gratings are pre-buried at the high-voltage end and the low-voltage end of the composite insulator respectively;

Fiber Bragg grating sensors for monitoring ambient temperature are placed on both sides of the transmission tower head;

The multi-channel VCSEL wavelength demodulation module demodulates the wavelength change of the fiber Bragg grating at different temperatures to obtain the high-voltage end temperature, low-voltage end temperature and ambient temperature of the composite insulator, and the first Lora module periodically sends the temperature data to the Lora+Beidou communication base station;

The VCSEL-based fiber Bragg grating wavelength demodulation system uses the Lora channel to determine the tower position of the composite insulator, and uses the number of channels accessed by the composite insulator's fiber Bragg grating to determine the specific position of the composite insulator on the tower. The acquired temperature data is transmitted to the Lora+ Beidou communication base station through the second Lora module.

The Lora+ Beidou communication base station sends the received temperature data to the Beidou satellite through the Beidou module, and then transmits it to the remote monitoring station after being relayed by the Beidou satellite;

The Beidou receiving terminal inside the remote monitoring station converts Beidou satellite data into standard data frames, and sends them to the monitoring terminal through the serial port after protocol conversion. The monitoring terminal receives all Beidou satellite data;

The temperature difference threshold is preset, and 85% of the temperature difference between the high-pressure end and the low-pressure end is used as the first-level temperature warning, and 60% of the temperature difference is used as the second-level temperature warning threshold. At the same time, the relative threshold warning method is adopted. When the temperature difference change per minute is greater than the temperature difference threshold, the temperature change rate alarm is triggered.

Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Technical personnel in the relevant field should understand that various modifications or variations that can be made by technical personnel in the field without creative work on the basis of the technical solution of the present invention are still within the scope of protection of the present invention.

Claims (10)

1. Fiber bragg grating insulator temperature monitoring system based on VCSEL wavelength demodulation, characterized by comprising: the system comprises a fiber bragg grating insulator, a fiber bragg grating sensor, a fiber bragg grating wavelength demodulation system based on VCSEL and an ad hoc network communication system;

the fiber grating insulator comprises a composite insulator and fiber gratings arranged at a high-voltage end and a low-voltage end of the composite insulator;

the fiber bragg grating temperature sensors are arranged on two sides of the tower head of the power transmission high tower and are used for monitoring the environmental temperature;

the VCSEL-based fiber bragg grating wavelength demodulation system comprises a multichannel VCSEL wavelength demodulation module and a first Lora module, wherein the multichannel VCSEL wavelength demodulation module is used for demodulating wavelength changes of the fiber bragg grating at different temperatures to obtain a high-voltage end temperature, a low-voltage end temperature and an environment temperature of the composite insulator, and the first Lora module is used for sending the high-voltage end temperature, the low-voltage end temperature and the environment temperature of the composite insulator;

the self-organizing network communication system comprises a Lora+ Beidou communication base station, a Beidou satellite system and a remote monitoring station, wherein the Lora+ Beidou communication base station comprises a second Lora module and a Beidou module, the second Lora module receives the high-voltage end temperature, the low-voltage end temperature and the environment temperature of the composite insulator, and after conversion of a Lora protocol and a Beidou protocol, the temperature is forwarded to the remote monitoring station through the Beidou module and the Beidou satellite system, and early warning is carried out according to the temperature difference between the high-voltage end and the low-voltage end and the environment temperature.

2. The fiber grating insulator temperature monitoring system based on VCSEL wavelength demodulation according to claim 1 wherein grooves are formed in the surface of the core rod of the composite insulator, and the fiber grating is pre-buried between the insulation sheath and the grooves on the core rod.

3. The fiber grating insulator temperature monitoring system based on VCSEL wavelength demodulation according to claim 1, wherein the wavelength of the fiber grating is matched with the wavelength scanning range of the multichannel VCSEL wavelength demodulation module, so that each channel of the multichannel VCSEL wavelength demodulation module is respectively distributed with the fiber grating at one high-voltage end and the fiber grating at one low-voltage end, and the wavelength change of the fiber grating meets the temperature change range of the composite insulator temperature measurement.

4. The fiber grating insulator temperature monitoring system based on VCSEL wavelength demodulation according to claim 1, wherein the wavelength scanning range of the multichannel VCSEL wavelength demodulation module is 1527nm-1531nm, the maximum channel number is 8, and two channels are connected with two fiber grating temperature sensors for monitoring the ambient temperature and are used for providing the ambient reference temperature for the temperature of the composite insulator.

5. The VCSEL wavelength demodulation based fiber grating insulator temperature monitoring system of claim 1, wherein the first Lora module and the beidou module periodically transmit temperature data through a radio frequency antenna.

6. The fiber bragg grating insulator temperature monitoring system based on VCSEL wavelength demodulation of claim 1, wherein the second Lora module converts the temperature into a standard command, and the beidou module receives the beidou command in the standard command and sends the beidou command to a beidou satellite system through a radio frequency antenna, and the beidou satellite system transfers the beidou command to a remote monitoring station.

7. The fiber bragg grating insulator temperature monitoring system based on VCSEL wavelength demodulation according to claim 1, wherein the remote monitoring station comprises a Beidou receiving terminal and a monitoring terminal, the Beidou receiving terminal is used for converting Beidou satellite data forwarded by a Beidou satellite system into standard data frames, and the standard data frames are transmitted to the monitoring terminal through a serial port after protocol conversion.

8. The fiber grating insulator temperature monitoring system based on VCSEL wavelength demodulation according to claim 1, wherein the remote monitoring station uses the ambient temperature to calibrate the temperature of the high voltage end and the low voltage end of the composite insulator, and pre-warns according to the temperature difference between the high voltage end and the low voltage end.

9. The fiber bragg grating insulator temperature monitoring system based on VCSEL wavelength demodulation of claim 1, further comprising a power supply system including a storage battery, a solar charging panel, and a charge-discharge controller; the solar charging battery panel is arranged in a low-voltage area of the tower head and converts solar energy into electric energy to charge the storage battery.

10. A method of operating a fiber grating insulator temperature monitoring system based on VCSEL wavelength demodulation according to any of claims 1-9, comprising:

respectively pre-embedding fiber bragg gratings at a high-voltage end and a low-voltage end of the composite insulator;

fiber bragg grating temperature sensors for monitoring the ambient temperature are respectively arranged at two sides of the tower head of the power transmission high tower;

demodulating the wavelength changes of the fiber bragg grating at different temperatures by a multichannel VCSEL wavelength demodulation module to obtain the high-voltage end temperature, the low-voltage end temperature and the environment temperature of the composite insulator, and periodically sending temperature data to a Lora+ Beidou communication base station by a first Lora module;

the second Lora module receives the high-voltage end temperature, the low-voltage end temperature and the environment temperature of the composite insulator, and after the conversion of the Lora protocol and the Beidou protocol, the temperature is forwarded to a remote monitoring station through the Beidou module so as to perform early warning according to the temperature difference between the high-voltage end and the low-voltage end and the environment temperature.