A self-powered lightning arrester on-line monitoring system

Abstract

The present application relates to the technical field of power equipment monitoring, in particular to a lightning arrester online monitoring system based on self-power supply; the system obtains electric energy from the leakage current of the lightning arrester through a power taking module, realizes self-power supply operation of the system, and comprises the power taking module, a power management module, a lightning stroke counting module, a leakage current collecting module, a temperature monitoring module, a display and communication module and a SOC control module; the system uses temperature capacity as an aging state evaluation index of the lightning arrester, calculates the corrected temperature capacity by collecting the temperature of the lightning arrester and the ambient temperature in real time, combining the leakage current and the lightning current correction coefficient and dynamic weight adjustment, and realizes accurate aging state judgment. The system has the functions of periodic collection, event triggered detection, data correction, wireless communication and local display, supports long-term online monitoring and remote alarm, and effectively improves the accuracy and reliability of lightning arrester state monitoring.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power equipment monitoring, and particularly relates to a lightning arrester online monitoring system based on self-power supply. BACKGROUND

[0002] As a key equipment for overvoltage protection of power systems, the aging state of the lightning arrester during long-term operation is directly related to the safety of the power grid. Traditional monitoring methods rely on manual periodic inspection or external power supply online monitoring devices, which have challenges such as insufficient real-time performance, strong power dependence, and limited data accuracy. Especially in remote areas or passive scenarios, power supply difficulties make it difficult for the monitoring system to operate stably for a long time.

[0003] The existing technology for evaluating the aging state of the lightning arrester relies on a single parameter such as leakage current or lightning strike times, lacks a comprehensive judgment method with multiple factors, and is difficult to fully reflect the cumulative aging effect. Therefore, there is an urgent need for an online monitoring system that can be self-powered, real-time monitored, and multi-parameter fusion judged to improve the reliability and accuracy of lightning arrester state monitoring. SUMMARY

[0004] The present application aims to solve the problems in the background art and proposes a lightning arrester online monitoring system based on self-power supply.

[0005] The technical scheme of the present application is a lightning arrester online monitoring system based on self-power supply, which comprises:

[0006] A power taking module is used to obtain electrical energy from the leakage current of the lightning arrester.

[0007] A power management module is connected to the power taking module and is used to convert the electrical energy obtained by the power taking module into a stable system voltage and supply power to other modules of the system.

[0008] A lightning strike counting module is used to detect and record the number of lightning strike events suffered by the lightning arrester.

[0009] A leakage current acquisition module is used to acquire the leakage current value of the lightning arrester.

[0010] A temperature monitoring module is used to acquire the body temperature and ambient temperature of the lightning arrester in real time.

[0011] A display and communication module is used to display monitoring data locally and send data to a remote monitoring center.

[0012] An SOC control module is connected to the power management module, the lightning strike counting module, the leakage current acquisition module, the temperature monitoring module, and the display and communication module.

[0013] The SOC control module is configured to:

[0014] The temperature capacity increment is calculated based on the body temperature of the surge arrester and the ambient temperature collected by the temperature monitoring module;

[0015] The leakage current correction coefficient determined by the current leakage current value and the lightning current correction coefficient determined by the lightning event and the lightning current value are obtained;

[0016] The influence factor is calculated by using the leakage current correction coefficient and the lightning current correction coefficient, combined with the dynamically adjusted leakage current weight and lightning current weight, and the temperature capacity increment is corrected;

[0017] The cumulative temperature capacity is obtained by accumulating the corrected temperature capacity increment, and the aging state of the surge arrester is evaluated according to the cumulative temperature capacity, and an alarm is triggered when the threshold is exceeded.

[0018] Preferably, the power taking module includes a voltage-dependent resistor and a power taking bypass;

[0019] The power taking bypass is composed of a plurality of resistors in series;

[0020] When the surge arrester is in normal operation, the voltage-dependent resistor is in a high resistance state, and the leakage current flows through the power taking bypass to provide power for the system.

[0021] Preferably, the power management module internally integrates a plurality of tantalum capacitors for providing instantaneous energy when the system performs wireless data transmission and leakage current collection.

[0022] Preferably, the lightning stroke counting module uses an optical coupler for lightning detection;

[0023] When the system is in normal operation, the optical coupler outputs a high level; when lightning occurs, the optical coupler is turned on and outputs a low level to the SOC control module, and the SOC control module counts the number of lightning actions after detecting the falling edge signal.

[0024] Preferably, the leakage current collection module includes a solid-state relay, an operational amplifier and a signal conditioning circuit;

[0025] The SOC control module controls the conduction and shutdown of the solid-state relay to switch the leakage current collection state and the power taking state of the system;

[0026] In the leakage current collection state, the operational amplifier works, and the collected leakage current signal is processed by the signal conditioning circuit and sent to the analog-to-digital converter of the SOC control module.

[0027] Preferably, the display and communication module includes a fault code display screen and a wireless communication module;

[0028] The fault code display screen is used for local display of the leakage current value, the number of lightning events, the cumulative temperature capacity and the system operation state;

[0029] The wireless communication module is used for sending the monitoring data and the alarm information to a remote monitoring center.

[0030] Preferably, the SOC control module periodically wakes up the system through its internal timer, controls the temperature monitoring module and the leakage current acquisition module to sequentially perform data acquisition tasks, and controls the system to enter a sleep state during a non-acquisition period.

[0031] Preferably, the SOC control module calculates the temperature capacity for evaluating the aging state of the surge arrester in the following manner:

[0032] The body temperature and the ambient temperature of the surge arrester at several continuous time points are acquired, and the temperature capacity increment at adjacent time points is calculated ;

[0033] Wherein, is the temperature of the surge arrester at time t i ; is the ambient temperature at time t i ;

[0034] According to the currently acquired leakage current value, a preset leakage current level and correction coefficient table is queried to determine the corresponding leakage current correction coefficient λ ci ;

[0035] According to whether a lightning strike event occurs and a lightning current value, a preset lightning current level and correction coefficient table is queried to determine the corresponding lightning current correction coefficient λ Ii ;

[0036] Based on the leakage current correction coefficient and the lightning current correction coefficient, combined with the dynamically adjusted leakage current weight WC i and the lightning current weight WI i , the influence factor at the current time is calculated ;

[0037] The temperature capacity increment is corrected using the influence factor to obtain the corrected temperature capacity :

[0038] ;

[0039] The corrected temperature capacity increment is added to the total temperature capacity, that is:

[0040] ;

[0041] Wherein, n is the total number of set acquisition time points;

[0042] The system compares the cumulative temperature capacity (TC) with a preset threshold in real time. When the TC exceeds the threshold, it determines that the aging state of the surge arrester has reached the critical point. The system immediately displays the alarm information on the local fault code display screen and sends the alarm data to the remote monitoring center via the wireless communication module.

[0043] Preferably, the corresponding leakage current correction coefficient is determined based on the currently collected leakage current value, including: dividing the monitored leakage current value into several preset leakage current intervals, each leakage current interval corresponding to a leakage current correction coefficient; wherein, the division of the leakage current interval adopts a non-linear method, the larger the leakage current value, the smaller the corresponding interval range.

[0044] The corresponding lightning current correction coefficient is determined based on whether a lightning strike event has occurred and the lightning current value. This includes dividing the monitored lightning current impact value into several preset lightning current intervals, with each lightning current interval corresponding to a lightning current correction coefficient. The larger the lightning current value, the larger the corresponding lightning current correction coefficient.

[0045] Compared with the prior art, the above-mentioned technical solution of the present invention has the following beneficial technical effects:

[0046] This invention designs a self-powered online monitoring system for surge arresters. By directly extracting electrical energy from the leakage current of the surge arrester through its self-powered design, it eliminates dependence on external power sources and achieves uninterrupted online monitoring around the clock. The system employs multi-module collaborative operation, combined with high-precision data acquisition and dynamic correction methods, significantly improving the accuracy and reliability of surge arrester aging status assessment. By introducing temperature capacity as a core evaluation indicator and weighting the temperature capacity correction based on real-time leakage current and lightning current data, it can more comprehensively reflect the actual operating status and cumulative aging effects of the surge arrester. The system features low-power operation, event-triggered data acquisition, remote communication, and local display functions, supports long-term stable operation, and can issue timely warnings, effectively preventing power system failures caused by surge arrester aging. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the hardware architecture of an online monitoring system for surge arresters based on self-powered power supply proposed in this invention. Detailed Implementation

[0048] Example 1: The hardware structure of the online monitoring system for surge arresters based on self-powered power supply proposed in this invention is as follows: Figure 1 As shown, it includes: a power bypass, a varistor, a lightning strike counting module, a solid-state relay module, an operational amplifier, a signal conditioning circuit, a SOC (system-on-a-chip) control module, a power management module, a code break display, a temperature monitoring module, and a wireless communication module.

[0049] The above system mainly includes the following modules:

[0050] Power module: using a piezoresistance (1mA voltage is 620V) and power bypass (6 12kΩ / 2W resistor in series) to constitute, when the arrester is in normal operation, the piezoresistance is in high resistance state, the impedance is much larger than the power bypass, the leakage current flows to the ground through the bypass, thereby providing power for the system;

[0051] Power management module: convert the power bypass voltage into 5V system voltage, internally integrate 5 1000μF tantalum capacitors, used to provide instantaneous energy when collecting leakage current and wireless transmission, prevent voltage drop from causing system reset;

[0052] Lightning strike counting module: using an optocoupler to realize lightning detection, normally the optocoupler outputs high level; when lightning strikes, the optocoupler is turned on, outputting low level, the SOC control module detects the falling edge and accumulates the count of the number of actions;

[0053] Leakage current acquisition module: including solid state relay, operational amplifier and signal conditioning circuit; the SOC controls the solid state relay to turn on / off, switching the leakage current acquisition state: pause power when collecting, accurately measure the leakage current; turn off the relay after collecting to reduce power consumption; the operational amplifier output signal is sent to the ADC module of the SOC after conditioning, through software filtering, average value taking and standard source calibration, the accurate leakage current value is obtained;

[0054] Temperature monitoring module: built-in temperature sensor, real-time acquisition of arrester temperature (denoted as TMOV) and environmental temperature (denoted as TEV), used for calculating temperature capacity and correction;

[0055] Display and communication module: using ultra-low power dot-matrix display, bidirectionally connected with the SOC control module, displaying monitoring data; the wireless communication module is responsible for sending data to the remote monitoring center;

[0056] SOC control module: as the core of the system, integrating timer, analog-to-digital converter (ADC) and communication interface; the system is woken up by the timer (such as 500ms period) to collect temperature and leakage current; lightning current is collected when lightning strikes; realizing data storage, processing and communication control.

[0057] In embodiment two, the self-powered arrester online monitoring system proposed by the application further includes a temperature capacity calculation and correction method, and the implementation process is as follows:

[0058] The system evaluates the aging state of the arrester through "temperature capacity", and the temperature capacity TC is defined as the integral of the difference between the operating temperature and the environmental temperature and time, that is:

[0059] ;

[0060] Wherein, TMOV is the temperature of the surge arrester; TEV is the ambient temperature; TC is the temperature capacity (referred to as temperature capacity for short).

[0061] Specifically:

[0062] A1, set n collection time points: t1, t2, …, t i , …, t n , the temperature and ambient temperature of the surge arrester corresponding to each collection time point;

[0063] denoted as ;

[0064] Calculate the temperature capacity increment of any adjacent time point:

[0065] ;

[0066] Wherein, is the temperature capacity increment at t i ;

[0067] A2, according to the monitored leakage current value, it is divided into a plurality of intervals, each interval corresponds to a leakage current correction coefficient λ ci ; The interval is divided in a nonlinear way, and the interval range is smaller when the leakage current is larger, so as to improve the accuracy of state judgment;

[0068] Exemplarily, taking a 110kV surge arrester as an example, 10 levels (C1~C10) are divided according to the size of leakage current, each level corresponds to a leakage current correction coefficient , and the leakage current correction coefficient division rule is shown in table 1:

[0069] Table 1 leakage current correction coefficient division rule table

[0070] ;

[0071] A3, according to the monitored lightning current impulse value, it is divided into a plurality of intervals, each interval corresponds to a lightning current correction coefficient λ Ii , the larger the lightning current value, the larger the corresponding correction coefficient λ Ii , which reflects the accelerated effect of lightning current impulse on the aging of the surge arrester;

[0072] Exemplarily, 10 levels (I1~I10) are divided according to the size of lightning current, each level corresponds to a lightning current correction coefficient ; The lightning current correction coefficient division rule is shown in table 2:

[0073] Table 2 lightning current correction coefficient division rule table

[0074] ;

[0075] A4、define leakage current weight WC i , lightning current weight WI i (meet WC i + WI i =1), the weight is dynamically adjusted according to the level, corresponding to WC1~WC n , WI1~WI n ;

[0076] Influence factor ψ of current time i :

[0077] ;

[0078] Accordingly, the corrected temperature capacity :

[0079] ;

[0080] Accordingly: the corrected temperature capacity increment is accumulated into the total temperature capacity, that is ;

[0081] Wherein, n is the total number of set collection time;

[0082] It should be noted that the cumulative temperature capacity TC obtained by real-time comparison is compared with the preset threshold value, when TC exceeds the threshold value, it is determined that the aging state of the lightning arrester reaches the critical point, and immediately displays the alarm information through the local break code display screen and sends the alarm data to the remote monitoring center through the wireless communication module.

[0083] Example three, the lightning arrester online monitoring system based on self-powered proposed by the application, its system working mode is as follows:

[0084] S1, the system starts running immediately after accessing the lightning arrester, the power module obtains power from the leakage current of the lightning arrester, the power management module converts the power voltage into stable 5V system voltage, and each module of the system completes self-checking and parameter initialization process;

[0085] S2, the SOC control module realizes periodic collection through the internal timer, the timer wakes up the SOC control module in the sleep state, and executes the collection task in order;

[0086] The temperature collection stage reads the lightning arrester body temperature TMOV and the environment temperature TEV and stores the temperature data and the corresponding time stamp;

[0087] The leakage current collection stage is a stage of collecting leakage current. The SOC control solid-state relay is turned on and the power taking function is suspended. The operational amplifier starts to work and collects the leakage current signal. The signal is sent to the ADC module of the SOC through the conditioning circuit. After the collection is completed, the SOC closes the solid-state relay to reduce the power consumption of the operational amplifier.

[0088] The collected data is subjected to software filtering, average value processing and comparison and calibration with a standard source to obtain an accurate leakage current value.

[0089] S3, in the lightning event detection process, the light coupling output end remains high during normal operation. When lightning occurs, the light coupling is turned on and the output end becomes low. The SOC detects the falling edge signal and immediately records the lightning action and makes the counter accumulate once. At the same time, the current lightning current impulse value is collected, and the lightning time and lightning current data are stored.

[0090] S4, according to the temperature data of adjacent sampling time, the discretized temperature capacity increment TCt is calculated i ; the leakage current correction coefficient λc is determined according to the current collected leakage current value i ; when lightning event occurs, the lightning current correction coefficient λI is determined according to the lightning current value i , and the default lightning current correction coefficient is used when there is no lightning event;

[0091] The influence factor calculation uses the formula , then the corrected temperature capacity is calculated , and finally the corrected TCt i is added to the total temperature capacity TC to complete the accumulation process, that is ;

[0092] It should be noted that the dynamic weight adjustment determines the leakage current weight WC i and the lightning current weight WI i according to the current operating state, and maintains the constraint condition that WC i + WI i =1, and the weight value is adjusted in real time according to the leakage current level and the lightning current impulse condition;

[0093] S5, real-time comparison of accumulated temperature capacity TC and preset threshold value, when TC exceeds threshold value, determine that the arrester aging state reaches critical point, immediately display alarm information through local break code display screen and send alarm data to monitoring center through 433MHz wireless module;

[0094] S6, the break code display screen displays the current leakage current value, lightning action times, accumulated temperature capacity and system operating state and other key parameters in real time. The 433MHz module sends monitoring data at a set period and actively uploads alarm information when an alarm occurs.

[0095] S7. In the non-acquisition period, the SOC control module automatically enters a dormant state, the display screen maintains a minimum power consumption display mode, only the timer and necessary interrupt sources remain in working state, and when the next timer expires, the system is re-awakened and a new acquisition cycle begins;

[0096] S8. The system continuously performs the above steps S1-S7, adaptively adjusts the weight distribution according to long-term operation data, and updates the arrester health state assessment in real time, to ensure accurate monitoring throughout the arrester life cycle.

[0097] The embodiments of the present application are described in detail above with reference to the accompanying drawings, but the present application is not limited thereto, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application.

Claims

1. An online monitoring system for surge arresters based on self-powered power supply, characterized in that, include: The power extraction module is used to extract electrical energy from the leakage current of the surge arrester; The power management module connects to the power acquisition module and is used to convert the electrical energy obtained by the power acquisition module into a stable system voltage and supply power to other modules in the system. The lightning strike counting module is used to detect and record the number of lightning strikes suffered by the surge arrester. Leakage current acquisition module is used to acquire the leakage current value of the surge arrester; Temperature monitoring module is used to collect the temperature of the surge arrester body and the ambient temperature in real time; The display and communication module is used to display monitoring data locally and send data to a remote monitoring center. The SOC control module is connected to the power management module, lightning strike counting module, leakage current acquisition module, temperature monitoring module, and display and communication module, respectively. The SOC control module is configured as follows: The temperature capacity increment is calculated based on the surge arrester body temperature and ambient temperature collected by the temperature monitoring module. Obtain the leakage current correction factor determined by the current leakage current value, and the lightning current correction factor determined by the lightning strike event and the lightning current value; Using the leakage current correction coefficient and the lightning current correction coefficient, combined with the dynamically adjusted leakage current weight and lightning current weight, the influence factor is calculated, and the temperature capacity increment is corrected. The cumulative temperature capacity is obtained by accumulating the corrected temperature capacity increment, and the aging status of the surge arrester is evaluated based on the cumulative temperature capacity. An alarm is triggered when the threshold is exceeded. The SOC control module calculates the temperature capacity used to assess the aging condition of the surge arrester in the following manner: Obtain the surge arrester body temperature and ambient temperature at several consecutive time points, and calculate the temperature capacity increment between adjacent time points. ; in, For t i The temperature of the surge arrester at all times; For t i Ambient temperature at all times; Based on the currently collected leakage current value, consult the preset leakage current level and correction coefficient comparison table to determine the corresponding leakage current correction coefficient λ. ci ; Based on whether a lightning strike occurred and the lightning current value, consult the preset lightning current level and correction factor table to determine the corresponding lightning current correction factor λ. Ii ; Based on the leakage current correction coefficient and the lightning current correction coefficient, combined with the dynamically adjusted leakage current weight WC i Lightning current weight WI i Calculate the influence factor at the current moment. ; The temperature capacity increment is corrected using an influencing factor to obtain the corrected temperature capacity. : ； The corrected temperature capacity increment is added to the total temperature capacity, i.e.: ； Where n is the total number of data collection times set; The system compares the cumulative temperature capacity (TC) with a preset threshold in real time. When the TC exceeds the threshold, it determines that the aging state of the surge arrester has reached the critical point. The system immediately displays the alarm information on the local fault code display screen and sends the alarm data to the remote monitoring center via the wireless communication module.

2. The online monitoring system for surge arresters based on self-powered power supply according to claim 1, characterized in that, The power supply module includes a varistor and a power supply bypass; The power bypass consists of several resistors connected in series; When the surge arrester is operating normally, the varistor is in a high-resistance state, and the leakage current flows through the power bypass to provide power to the system.

3. The online monitoring system for surge arresters based on self-powered power supply according to claim 1, characterized in that, The power management module integrates several tantalum capacitors to provide instantaneous power when the system is transmitting wireless data and collecting leakage current.

4. The online monitoring system for surge arresters based on self-powered power supply according to claim 1, characterized in that, The lightning strike counting module uses an optocoupler for lightning strike detection; When the system is running normally, the optocoupler outputs a high level; when a lightning strike occurs, the optocoupler turns on and outputs a low level to the SOC control module. After detecting the falling edge signal, the SOC control module accumulates and counts the number of lightning strikes.

5. The online monitoring system for surge arresters based on self-powered power supply according to claim 1, characterized in that, The leakage current acquisition module includes a solid-state relay, an operational amplifier, and a signal conditioning circuit. The SOC control module switches between the system's leakage current acquisition state and power supply state by controlling the on and off states of the solid-state relays. In the leakage current acquisition state, the operational amplifier works, and the acquired leakage current signal is processed by the signal conditioning circuit and then sent to the analog-to-digital converter of the SOC control module.

6. The online monitoring system for surge arresters based on self-powered power supply according to claim 1, characterized in that, The display and communication module includes a broken code display screen and a wireless communication module; The fault code display screen is used to locally display leakage current value, number of lightning strikes, cumulative temperature capacity, and system operating status; The wireless communication module is used to send monitoring data and alarm information to the remote monitoring center.

7. The online monitoring system for surge arresters based on self-powered power supply according to claim 1, characterized in that, The SOC control module periodically wakes up the system through its internal timer, controls the temperature monitoring module and leakage current acquisition module to sequentially execute data acquisition tasks, and controls the system to enter sleep mode during non-acquisition periods.

8. The online monitoring system for surge arresters based on self-powered power supply according to claim 7, characterized in that, The corresponding leakage current correction coefficient is determined based on the currently collected leakage current value, including: dividing the monitored leakage current value into several preset leakage current intervals, each leakage current interval corresponding to a leakage current correction coefficient; wherein, the division of leakage current intervals adopts a non-linear method, the larger the leakage current value, the smaller the corresponding interval range. The corresponding lightning current correction coefficient is determined based on whether a lightning strike event has occurred and the lightning current value. This includes dividing the monitored lightning current impact value into several preset lightning current intervals, with each lightning current interval corresponding to a lightning current correction coefficient. The larger the lightning current value, the larger the corresponding lightning current correction coefficient.

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