CN114894340A - Power transmission cable multiplexing distributed temperature sensing method based on Internet of things - Google Patents

Abstract

The invention discloses a power transmission cable multiplexing distributed temperature sensing method based on the Internet of things, and relates to the technical field of cable detection. The invention comprises a temperature measurement host, a temperature measurement optical fiber and a background monitoring host; the temperature measurement host is arranged in the monitoring room and comprises a laser transmitter, a filter, a photoelectric conversion module, a signal acquisition module and a processing module; the temperature measurement host is used for acquiring, processing and transmitting the operating temperature information of the cable in real time; the temperature measuring optical fiber is arranged on the surface of the optical fiber needing temperature measurement; and the background monitoring host is used for displaying the temperature of the cable in real time, displaying the temperature in an imaging manner, and predicting the change trend of the temperature of the cable to perform overtemperature early warning. According to the invention, the power transmission cable temperature sensing system is constructed, the influence degree of each influence factor on the cable is classified, the cable temperature is measured by using the Raman scattering effect, and the danger level of the temperature is judged for notification, so that the on-line supervision strength of the cable is improved, and the occurrence of power accidents is reduced.

Description

Distributed temperature sensing method for power transmission cable reuse based on Internet of Things

technical field

The invention belongs to the technical field of cable detection, and in particular relates to a distributed temperature sensing method for power transmission cable multiplexing based on the Internet of Things.

Background technique

With the gradual development of information technology and the improvement of network technology, mobile Internet and Internet of Things technologies have gradually entered all aspects of people's lives. In the era of mobile Internet, the traditional operation mode of information industry is being broken, and new operation mode Formed, the traditional electrical safety monitoring system is also moving closer to the direction of smart electrical safety monitoring. With the rapid development of diversification of life, the safety problems of power supply systems are becoming more and more serious, and the application of various electrical collection and alarm devices is becoming more and more common. With the sharp increase in residential electricity consumption, the over-temperature situation in power distribution cabinets is becoming more and more serious. , the temperature monitoring of electrical cables is particularly important.

At present, there is no real-time monitoring system for the status of power transmission cables in the power industry, and it is impossible to monitor the swing amplitude of the cables, whether they are disconnected, and the temperature. In the power industry, the maintenance of power transmission cables is generally performed in a hollow operation. After the erosion of disasters such as typhoons, ice disasters, and fires, the power transmission cables in the power industry need to be repaired one by one. The amount of work is large and the efficiency is low. Can not be dealt with in time, resulting in power supply problems. For example, when there is a fire around a high-voltage line, it is impossible to quickly monitor the temperature of the cable, so as to judge the hidden danger and deal with it in time. Carry out material dispatch and repair in time to prolong the failure time.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a multiplexed distributed temperature sensing method for power transmission cables based on the Internet of Things. It can measure and judge the danger level of the temperature for notification, which solves the problems of imperfect existing power transmission cable monitoring system, untimely fault detection and great potential safety hazard.

In order to solve the above-mentioned technical problems, the present invention is achieved through the following technical solutions:

The present invention is a distributed temperature sensing method for power transmission cable multiplexing based on the Internet of Things, comprising the following steps:

Step S1: using the fully distributed Raman fiber sensing technology to construct a power transmission cable temperature sensing system;

Step S2: collecting environmental state data and power transmission cable state data in real time;

Step S3: assigning weights to the environmental state quantity data set and the influence factors of the transmission cable state quantity set;

Step S4: classify the influence degree on the cable of each influence factor in the state quantity set;

Step S5: using the Raman scattering effect of the optical fiber to measure the temperature of the cable at different distances;

Step S6: comparing the measured temperature with the data in the state quantity set to judge the danger level of the temperature;

Step S7: the background monitoring host notifies and alarms the abnormal risk level.

As a preferred technical solution, the power transmission cable temperature sensing system includes a temperature measurement host, a temperature measurement optical fiber and a background monitoring host;

The temperature measuring host is installed in the monitoring room and includes a laser transmitter, a filter, a photoelectric conversion module, a signal acquisition module and a processing module; the temperature measuring host is used for real-time collection, processing and transmission of the operating temperature information of the cable;

The temperature-measuring optical fiber is installed on the surface of the optical fiber to be temperature-measured;

The background monitoring host is used to display the temperature of the cable in real time and display it graphically, to predict the change trend of the cable temperature and to give an over-temperature warning.

As a preferred technical solution, the processing module is a DSP processor, which is used to send out control pulses, start the laser transmitter to start working, and at the same time send an instruction to start the signal acquisition module for data collection and processing; After the laser passes through the filter, the Stokes light and the Anti-Stokes light are respectively filtered out; the Stokes light and the Anti-Stokes light are converted in the photoelectric conversion module; the Stokes light and the Anti-Stokes light are converted by the photoelectric conversion module into The electrical signal is then input to the processing module through the amplifying circuit; the processing module is used to process the amplified electrical signal into temperature information and send the result to the background monitoring host.

As a preferred technical solution, in the step S3, the weights are divided into 4 grades from light to heavy, and the coefficients are 1, 2, 3, and 4 respectively, and the sum of all weights is 10; the weight of 4 is particularly important The characteristic quantity refers to the need for timely maintenance or even stop operation to ensure the safe operation of the transmission cable; the weight 3 is an important characteristic quantity, which means that the unfavorable factors of the safe operation of the transmission cable can be eliminated through maintenance; the weight 2 is a relatively important characteristic quantity , which means that no emergency treatment is required for the safe operation of the power transmission cable; the weight of 1 is a general important feature quantity, which means that it basically has no effect on the safe operation of the power transmission cable.

As a preferred technical solution, in the step S4, the influence degree of the influence factors on the cable deterioration is classified according to the actual situation of each type of influence factors, and is divided into 4 grades from light to heavy, namely I, II, For grades III and IV, the corresponding basic deductions are 2, 4, 8, and 10 points.

As a preferred technical solution, in the step S5, when the external ambient temperature where the temperature measuring fiber is located is T, the Stokes scattered light power at the temperature measuring fiber L is P _s , and the anti-Stokes light power is P s . The power of the scattered light is P _a . Comparing P _s with P _a , the function of temperature T can be obtained. The formula for deriving the temperature value T at the distance L on the fiber is:

where h is Planck's constant and k is Boltzmann's constant.

As a preferred technical solution, in the step S6, the temperature value T at the distance L on the optical fiber is derived to obtain a temperature threshold function, and the monitored Raman temperature of the cable is monitored under multiple input pulses. The data curves are compared and analyzed; when the temperature curve is greater than the temperature threshold curve, the monitoring time can be recorded and the fault point can be found by inverting the fault point through the propagation time of the pulse in the fiber.

The present invention has the following beneficial effects:

By constructing a power transmission cable temperature sensing system, the invention classifies the influence degree of each influencing factor in the state quantity set on the cable, uses the Raman scattering effect of the optical fiber to measure the temperature of the cable at different distances, and judges the temperature The danger level is notified, which improves the online supervision of cables and reduces the occurrence of power accidents.

Of course, it is not necessary for any product embodying the present invention to achieve all of the above-described advantages simultaneously.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1 is a flowchart of a distributed temperature sensing method for multiplexing power transmission cables based on the Internet of Things according to the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Referring to FIG. 1, the present invention is a distributed temperature sensing method for power transmission cable multiplexing based on the Internet of Things, including the following steps:

Step S1: using the fully distributed Raman fiber sensing technology to construct a power transmission cable temperature sensing system;

Step S2: collecting environmental status data and power transmission cable status data in real time; the environmental status information includes humidity information, temperature information, smoke concentration information, rainfall information and video monitoring information;

Step S3: assigning weights to the environmental state quantity data set and the influence factors of the transmission cable state quantity set;

Step S4: classify the influence degree on the cable of each influence factor in the state quantity set;

Step S5: using the Raman scattering effect of the optical fiber to measure the temperature of the cable at different distances;

Step S6: comparing the measured temperature with the data in the state quantity set to judge the danger level of the temperature;

Step S7: the background monitoring host notifies and alarms the abnormal risk level.

The power transmission cable temperature sensing system includes a temperature measurement host, a temperature measurement optical fiber and a background monitoring host;

The temperature measuring host is installed in the monitoring room, including laser transmitter, filter, photoelectric conversion module, signal acquisition module and processing module; the temperature measuring host is used to collect, process and transmit the operating temperature information of the cable in real time;

The temperature measuring fiber is installed on the surface of the fiber that needs to be measured;

The background monitoring host is used to display the cable temperature in real time and display it graphically, and predict the change trend of the cable temperature for over-temperature warning.

(1) Alarm information monitoring and processing: The functions of the power transmission cable temperature sensing system include: for the monitoring information of abnormal alarms, the system accurately locates the fault segment, reminds or rings through the monitoring screen window, and connects to the SMS platform. Remind relevant personnel through text messages, and the system provides the recording function of abnormal information and processing results and stores them as the basis for operation inspection, inspection, maintenance and overhaul.

(2) Combination monitoring of monitoring information: It mainly provides the flexible combination function of state monitoring, which can carry out multi-dimensional self-combination of multiple devices and multiple monitoring types, and display various cross-monitoring points and cross-monitoring types on one monitoring interface. information to provide users with more targeted status monitoring functions in different application scenarios. For example, monitoring the cables in the construction area, monitoring the cables in the power protection area, monitoring the cables just put into operation, monitoring the cables in special areas such as floods and earthquakes; for high temperature weather, you can focus on monitoring the temperature attributes of the equipment.

(3) Comprehensive display of equipment monitoring information: On the GS map, you can click on specific equipment (cable segments, intermediate joints, terminal heads, cable branch boxes, grounding boxes, cross-connect boxes, etc.) to locate the configuration diagrams, tables, etc. It can display the detailed status monitoring information of the single cable equipment, and can display the status monitoring information and other production information in the PMS (account information, defect information, fault information, maintenance information, etc.) Status evaluation, diagnosis and other functions of physical equipment.

(4) Comprehensive display of monitoring information: Through the integration of GIS, relying on GS graphics, the state monitoring situation of the entire power grid cable equipment is displayed macroscopically in the form of "business theme". It can be displayed in layers according to the monitoring type, and alarms can be issued by highlighting, bubbling reminders or ringing reminders for abnormal cable segments.

(5) Monitoring report: This type of application provides conventional state monitoring report functions, including the failure rate statistical report, false alarm rate statistical report, coverage ratio statistical report, and status alarm distribution and processing statistical report of monitoring devices. Export and print functions.

The processing module is a DSP processor, which is used to send out control pulses, start the laser transmitter to start working, and at the same time send an instruction to start the signal acquisition module for data acquisition and processing; Anti-Stokes light; Stokes light and Anti-Stokes light are converted in the photoelectric conversion module; Stokes light and Anti-Stokes light are converted into electrical signals by the photoelectric conversion module and then input to the processing module through the amplifying circuit; the processing module is used for The amplified electrical signal is processed into temperature information and the result is sent to the background monitoring host.

In step S3, the weights are divided into 4 grades from light to heavy, and the coefficients are 1, 2, 3, and 4 respectively, and the sum of all weights is 10; the weight 4 is a particularly important feature quantity, which means that it needs to be repaired in time or even stop running. In order to ensure the safe operation of the transmission cable; the weight 3 is an important feature quantity, which means that the unfavorable factors of the safe operation of the power transmission cable can be eliminated through maintenance; the weight 2 is a relatively important feature quantity, which means that there is no need for the safe operation of the transmission cable. Emergency treatment; weight 1 is a general important feature quantity, which basically has no effect on the safe operation of the transmission cable.

In step S4, the degree of influence of the influencing factors on the cable deterioration is classified according to the actual situation of each type of influencing factors, and is divided into 4 grades from light to heavy, which are I, II, III and IV respectively. Scores are 2, 4, 8, and 10.

In step S5, when the light generated by the laser transmitter is transmitted in the optical fiber, the light pulse interacts with the molecules in the optical fiber and is scattered, and the scattered light generated includes various types. Among them, Raman scattering is generated due to the energy exchange between the thermal vibration of the molecules in the fiber and the light pulse interaction. Therefore, the intensity of the Raman scattered light is related to temperature and is sensitive to temperature changes. Using the Stokes in Raman scattering The light and anti-Stokes light can deduce the external temperature of the fiber. When the external ambient temperature of the temperature measuring fiber is T, the Stokes scattered light power at the temperature measuring fiber L is P _s , and the anti- _Stokes scattered light power is P _{a .} By comparison, the function of temperature T can be obtained, and the formula for deriving the temperature value T at the distance L on the fiber is:

In the formula, h is Planck's constant, k is Boltzmann's constant, through which the temperature value of the fiber can be calculated.

In step S6, the temperature value T at the distance L on the deduced optical fiber is derived to obtain a temperature threshold function, and the monitored cable Raman temperature data curves are compared and analyzed under multiple input pulses; when the temperature curve is greater than When the temperature threshold curve is established, the exact location of the fault point can be found by recording the monitoring time and inverting the fault point through the propagation time of the pulse in the optical fiber.

It is worth noting that, in the above system embodiment, the units included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be realized; in addition, the specific names of the functional units It is only for the convenience of distinguishing from each other, and is not used to limit the protection scope of the present invention.

In addition, those skilled in the art can understand that all or part of the steps in the methods of the above embodiments can be completed by instructing relevant hardware through a program, and the corresponding program can be stored in a computer-readable storage medium.

The above-disclosed preferred embodiments of the present invention are provided only to help illustrate the present invention. The preferred embodiments do not exhaust all the details, nor do they limit the invention to only the described embodiments. Obviously, many modifications and variations are possible in light of the content of this specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is to be limited only by the claims and their full scope and equivalents.

Claims (7)

1. A power transmission cable multiplexing distributed temperature sensing method based on the Internet of things is characterized by comprising the following steps:

step S1: constructing a power transmission cable temperature sensing system by using a fully distributed Raman fiber sensing technology;

step S2: collecting environmental state data and power transmission cable state data in real time;

step S3: carrying out weight distribution on the environmental state quantity data set and the influence factors of the power transmission cable state quantity set;

step S4: classifying the influence degree of each influence factor in the state quantity set on the cable;

step S5: measuring the temperature of the cable at different distances by using the Raman scattering effect of the optical fiber;

step S6: comparing the measured temperature with data in the state quantity set, and judging the danger level of the temperature;

step S7: the background monitoring host machine carries out notification and alarm on abnormal danger levels.

2. The Internet of things-based power transmission cable multiplexing distributed temperature sensing method according to claim 1, wherein the power transmission cable temperature sensing system comprises a temperature measurement host, a temperature measurement optical fiber and a background monitoring host;

the temperature measurement host is arranged in the monitoring room and comprises a laser transmitter, a filter, a photoelectric conversion module, a signal acquisition module and a processing module; the temperature measurement host is used for acquiring, processing and transmitting the operating temperature information of the cable in real time;

the temperature measuring optical fiber is arranged on the surface of the optical fiber needing temperature measurement;

the background monitoring host is used for displaying the temperature of the cable in real time, displaying the temperature in an imaging mode, and predicting the change trend of the temperature of the cable to perform overtemperature early warning.

3. The Internet of things-based electric power transmission cable multiplexing distributed temperature sensing method according to claim 2, wherein the processing module is a DSP (digital signal processor) and is used for sending a control pulse, starting a laser transmitter to start working and sending an instruction to start a signal acquisition module to acquire and process data; the laser emitted by the laser emitter is filtered out Stokes light and Anti-Stokes light respectively after passing through the filter; the Stokes light and the Anti-Stokes light are converted in the photoelectric conversion module; the Stokes light and the Anti-Stokes light are converted into electric signals by the photoelectric conversion module and then are input into the processing module through the amplifying circuit; the processing module is used for processing the amplified electric signals into temperature information and sending the result to the background monitoring host.

4. The Internet of things-based electric power transmission cable multiplexing distributed temperature sensing method according to claim 1, wherein in the step S3, the weights are divided into 4 grades from light to heavy, the coefficients are 1, 2, 3 and 4 respectively, and the sum of all weights is 10; the weight 4 is a particularly important characteristic quantity, and means that the cable needs to be overhauled in time and even stops running to ensure the safe running of the transmission cable; the weight 3 is an important characteristic quantity, and means that adverse factors of safe operation of the power transmission cable can be eliminated through maintenance; the weight 2 is a relatively important characteristic quantity, which means that emergency treatment on safe operation of the power transmission cable is not needed; the weight 1 is a general important characteristic quantity, and basically has no influence on the safe operation of the power transmission cable.

5. The method according to claim 1, wherein in step S4, the influence degree of the influencing factors on the cable degradation is classified according to the actual situation of each influencing factor, and the influence degree is classified into 4 grades from light to heavy, I, ii, iii and iv, and the corresponding basic deduction values are 2, 4, 8 and 10.

6. The Internet of things-based power transmission cable multiplexing distributed temperature sensing method according to claim 1, wherein in step S5, when the external environment temperature of the temperature measurement optical fiber is T, the Stokes scattered light power at the temperature measurement optical fiber L is P _s The power of the anti-Stokes scattered light is P _a A 1 is to P _s And P _a The comparison is carried out to obtain a function of the temperature T, and the formula for deducing the temperature value T at the position with the distance L on the optical fiber is as follows:

in the formula, h is Planck constant, and k is Boltzmann constant.

7. The Internet of things-based electric power transmission cable multiplexing distributed temperature sensing method according to claim 1, wherein in step S6, a temperature value T at a distance L on an optical fiber is derived to obtain a temperature threshold function, and a monitored cable Raman temperature data curve is subjected to comparative analysis under a plurality of input pulses; when the temperature curve is larger than the temperature threshold curve, the monitoring time is recorded, and the fault point is inverted through the propagation time of the pulse in the optical fiber, so that the accurate position of the fault point can be searched.

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