A method and apparatus for accelerated aging and on-line evaluation of a sealed defective surge arrester

Abstract

The application discloses a sealed defective lightning arrester accelerated dampening and online evaluation method and equipment, and belongs to the technical field of lightning arrester evaluation. The sealed defective lightning arrester accelerated dampening and online evaluation method can be suitable for the whole lightning arrester, and can quantitatively evaluate the dampening aging degree of the whole lightning arrester by constructing a defective lightning arrester manufacturing model, an accelerated dampening processing model, a defective data acquisition model, a structure equal proportion model, a voltage detection model, a characteristic electrical quantity calculation model, a humidity monitoring model and an evaluation model. The accelerated dampening processing model and the structure equal proportion model can simulate the same scene and environment as the dampening mode and process of the on-site lightning arrester, and the test data can be obtained through the voltage detection model and the humidity monitoring model, so that the accuracy and reliability of the evaluation result are ensured, and the maintenance work efficiency is improved, and the safe and stable operation of the power grid is ensured.

Description

Technical Field

[0001] This invention relates to a method and device for accelerating moisture absorption and online evaluation of surge arresters with sealing defects, belonging to the field of surge arrester evaluation technology. Background Technology

[0002] A surge arrester is a "switch" with specific electrical characteristics. When subjected to overvoltage, the "switch closes," discharging the charge accumulated on equipment and lines, reducing the voltage amplitude, and preventing overvoltage from damaging the insulation of electrical equipment, thereby ensuring the safe operation of electrical equipment and the power grid system. With the continuous improvement of power grid levels and power system protection levels, surge arresters play an increasingly important role in power systems.

[0003] Currently, researchers both domestically and internationally are paying close attention to the research direction of surge arrester insulation condition assessment, and have conducted extensive experimental and research work on methods for assessing the insulation condition of zinc oxide surge arresters. Existing methods for assessing surge arrester moisture absorption are all based on the electrical quantities described in GB11032-2020, mainly including the DC 1mA voltage U1mA of the surge arrester (or resistor), the current at 0.75 times U1mA, insulation resistance, etc. While these electrical quantities do provide some assistance to personnel in judging the moisture condition of surge arresters, they often exhibit an "inflection point effect," meaning that these parameters only show significant changes after the moisture level reaches a certain point. Before this "inflection point," the parameters meet the requirements of relevant testing standards, which makes online assessment of the moisture condition of surge arresters difficult.

[0004] Furthermore, patent document CN 112904118A discloses a performance evaluation method for moisture aging of zinc oxide surge arrester resistor valve sheets, including: using hot steam to moisten the sample resistor valve sheet, simulating different degrees of moisture absorption based on different placement times in the steam; placing the moistened sample at room temperature to allow it to cool down sufficiently, and wiping the surface moisture dry; using an electronic balance to measure the mass before and after moisture absorption, and using the change in mass to specifically measure the degree of moisture absorption; conducting a simulated aging experiment on the moisture-affected resistor valve sheet under a constant temperature of 135°C for 16 hours, and testing the DC volt-ampere characteristics and dielectric response parameters of the moisture-aged resistor valve sheet; and analyzing the degree of moisture aging based on the DC volt-ampere characteristic curve and dielectric response parameters.

[0005] Patent document CN 114839438 A discloses a method for assessing the condition of zinc oxide surge arresters based on the harmonic components of leakage current. The method includes: real-time monitoring of the operating status of zinc oxide surge arresters, real-time analysis of the resistive component and harmonic components of leakage current, analysis of the operating status of surge arresters based on the harmonic and resistive components, and the ability to distinguish between valve plate aging and valve plate moisture defects, and to provide a preliminary location judgment for valve plate moisture.

[0006] Therefore, most current technologies simulate different degrees of moisture absorption based on hot steam tests of individual resistor elements. However, the results of such studies based on individual resistor elements are difficult to generalize to the entire surge arrester. Additionally, some methods involve injecting water into the surge arrester using a syringe to induce moisture absorption, which differs significantly from the actual moisture absorption patterns and processes of surge arresters in the field. Therefore, the reliability of test data obtained using these methods is questionable. Furthermore, existing technologies cannot quantitatively assess the degree of moisture aging in the entire surge arrester, thus failing to address the aforementioned technical problems. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a scientific, reasonable, and feasible method for accelerating moisture absorption and conducting online evaluation of the moisture absorption degree of a defective surge arrester. This method involves constructing a defective surge arrester manufacturing model, an accelerated moisture absorption treatment model, a defect data acquisition model, a structural scale model, a voltage detection model, a characteristic electrical quantity calculation model, a humidity monitoring model, and an evaluation model. Based on these sealing defect variables, the temperature and humidity of the surge arrester's test environment are determined, and test parameters are set to obtain the permanent compression deformation (K) of the main sealing ring after aging, as well as the corrosion data of the surge arrester cover and explosion-proof plate. Simultaneously, the required number of zinc oxide resistance sheets and / or epoxy insulation rods and / or aluminum pad diameter for the defective surge arrester are calculated. Then, the total current and reference voltage information of the defective surge arrester are acquired. This information is then processed to calculate several characteristic electrical quantities. Finally, the most sensitive electrical quantity is selected from these characteristic electrical quantities and correlated with the relative humidity measurement results to achieve online evaluation of the surge arrester's moisture absorption degree. This method is scientific, reasonable, and feasible for accelerating moisture absorption and conducting online evaluation of sealed defective surge arresters.

[0008] The second objective of this invention is to provide a method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects. This method can be applied to the entire surge arrester and can quantitatively assess the degree of moisture aging of the entire surge arrester. By using an accelerated moisture absorption treatment model and a proportional structural model, it can simulate the same scenario and environment as the moisture absorption mode and process of the surge arrester in the field. Experimental data can be obtained through a voltage detection model and a humidity monitoring model to ensure the accuracy and reliability of the evaluation results.

[0009] The third objective of this invention is to provide a method and equipment for the accelerated moisture absorption and online evaluation of a surge arrester that can be applied to the entire arrester. This method and equipment can be used to quantitatively assess the degree of moisture absorption and aging of the entire arrester. It can simulate the same scenario and environment as the moisture absorption mode and process of the arrester in the field by using several zinc oxide resistance sheets, several aluminum pads, several epoxy insulating rods, the arrester insulating cylinder, and a complex multi-factor environmental climate chamber. The test data is obtained by using capacitive humidity sensing elements, a full current online monitoring platform, and a voltage wireless monitoring device to ensure the accuracy and reliability of the evaluation results.

[0010] The fourth objective of this invention is to provide a method and equipment for online monitoring of the total current change trend during the gradual moisture absorption process of a surge arrester, and based on this, to calculate characteristic electrical quantities such as resistive current, reference phase angle, and resistance-capacitance ratio. By selecting the most sensitive electrical quantity and correlating it with the relative humidity measurement results, an online assessment of the moisture aging degree of the surge arrester can be achieved. The solution is simple, highly practical, and can assist maintenance personnel in easily, quickly, and accurately judging the moisture absorption degree of the surge arrester without interfering with the normal operation of the equipment, thereby improving maintenance efficiency and ensuring the safe and stable operation of the power grid.

[0011] To achieve one of the above objectives, the first technical solution of the present invention is as follows:

[0012] A method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects.

[0013] Includes the following:

[0014] By using a pre-built model of a defective surge arrester, the defect data of the surge arrester is processed to determine the sealing defect variables of the defective surge arrester.

[0015] Sealing defect variables include the compression permanent deformation K of the main sealing ring and / or corrosion data of the surge arrester cover and explosion-proof plate;

[0016] Using a pre-built accelerated moisture treatment model, the sealing defect variables of the surge arrester are analyzed to determine the temperature and humidity of the surge arrester test environment;

[0017] The model is obtained by pre-constructing defect data, and test parameters are set according to the characteristics of sealing defect variables to obtain the compression permanent deformation K of the main sealing ring after aging, as well as the corrosion data of the surge arrester cover and explosion-proof plate.

[0018] Using a pre-built proportional structural model, calculate the number of zinc oxide resistors and / or the number of epoxy insulating rods and / or the diameter of aluminum pads required for the defective surge arrester;

[0019] The full current and reference voltage information of the defective surge arrester are obtained by using a pre-built voltage detection model;

[0020] Based on the pre-built characteristic electrical quantity calculation model, the total current and reference voltage information are processed to calculate several characteristic electrical quantities;

[0021] Several characteristic electrical quantities include at least the resistive current component, the reference phase angle, and the resistance-capacitance ratio;

[0022] By using a pre-built humidity monitoring model, the relative humidity measurement value and change trend inside the defective surge arrester during the accelerated moisture absorption process were obtained;

[0023] By using a pre-built evaluation model, the most sensitive electrical quantity is selected from several characteristic electrical quantities and correlated with the relative humidity measurement results to achieve online evaluation of the moisture level of the surge arrester.

[0024] This invention, through continuous exploration and experimentation, establishes a defective surge arrester manufacturing model, an accelerated moisture treatment model, a defect data acquisition model, a structural scale model, a voltage detection model, a characteristic electrical quantity calculation model, a humidity monitoring model, and an evaluation model. This model determines the sealing defect variables of the defective surge arrester. Based on these sealing defect variables, the temperature and humidity of the surge arrester's test environment are determined, and test parameters are set to obtain the compression permanent deformation K of the main sealing ring after aging, as well as the corrosion data of the surge arrester cover and explosion-proof plate. Simultaneously, the required number of zinc oxide resistance sheets and / or epoxy insulation rods and / or aluminum pad diameter for the defective surge arrester are calculated. Then, the total current and reference voltage information of the defective surge arrester are acquired. This information is then processed to calculate several characteristic electrical quantities. Finally, by selecting the most sensitive electrical quantity from these characteristic electrical quantities and correlating it with the relative humidity measurement results, an online assessment of the surge arrester's moisture level is achieved. The solution is scientific, reasonable, and feasible.

[0025] Furthermore, this invention is applicable to the entire surge arrester, enabling quantitative assessment of the degree of moisture aging. The accelerated moisture treatment model and proportional structural model of this invention can simulate the same scenario and environment as the moisture absorption mode and process of the surge arrester in the field, and obtain experimental data through voltage detection models and humidity monitoring models, ensuring the accuracy and reliability of the assessment results.

[0026] Furthermore, this invention can monitor the trend of total current change during the gradual moisture absorption of a surge arrester online and calculate characteristic electrical quantities such as resistive current, reference phase angle, and resistance-capacitance ratio based on this. By selecting the most sensitive electrical quantity and correlating it with the relative humidity measurement results, the online assessment of the moisture aging degree of the surge arrester can be achieved. The solution is simple and highly practical, and can assist maintenance personnel in easily, quickly, and accurately judging the moisture level of the surge arrester without interfering with the normal operation of the equipment, thereby improving maintenance efficiency and ensuring the safe and stable operation of the power grid.

[0027] As a preferred technical measure:

[0028] The test parameters include accelerated compression set test parameters and corrosion test parameters;

[0029] The compression set K was obtained by conducting an accelerated compression set test on the main sealing ring.

[0030] Corrosion data were obtained by corroding the surge arrester cover and explosion-proof plate in a high-temperature and high-salinity environment.

[0031] As a preferred technical measure:

[0032] Accelerated compression set test parameters include compression set test temperature, compression ratio, and compression time.

[0033] The formula for calculating the permanent compressive deformation is as follows:

[0034] K = (h0 - h2) / (h0 - h1),

[0035] Where h0 is the initial height of the sealing ring before compression, h1 is the height of the sealing ring when the compression rate is 30%, and h2 is the recovery height of the sealing ring after compression.

[0036] The parameters for the rust test include high temperature, high salinity environment, spraying method, and rusting time.

[0037] As a preferred technical measure:

[0038] The surge arrester test environment is a high temperature and high humidity environment, with the high temperature being 40℃-60℃ and the high humidity being 90%-99% relative humidity;

[0039] The most sensitive electrical quantity is determined by the relative rate of change of the relevant electrical quantity per unit time of moisture absorption, and its resistive current I. r , resistance-capacitance ratio R c The functional relationship between relative humidity (RH) and accelerated moisture absorption time (h) is as follows:

[0040] I r =-0.06*exp(-h / 51.07)+0.113 (1)

[0041] R c =-0.087*exp(-h / 33.38)+0.205 (2)

[0042] RH=-73.49*exp(-h / 26.91)+104.74 (3).

[0043] To achieve one of the above objectives, the second technical solution of the present invention is as follows:

[0044] A method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects includes the following steps:

[0045] Step 1: Calculate the number of zinc oxide resistors required for the surge arrester. Place one aluminum pad between every two zinc oxide resistors, fix them with an epoxy insulating rod, and then place them inside the surge arrester's insulating cylinder.

[0046] Step 2: Conduct an accelerated compression set test on the main sealing ring and test its compression set K after aging;

[0047] Step 3: Corrode the surge arrester cover and explosion-proof plate in a high-temperature and high-salinity environment;

[0048] Step 4: Based on Step 1, assemble the main sealing ring and / or the corroded cover plate and explosion-proof plate from Step 2 respectively. With other components in good condition and the installation process correct, fabricate a surge arrester with sealing defects.

[0049] Meanwhile, a capacitive humidity-sensitive element is pre-installed near the grounding inside the surge arrester's insulating cylinder to monitor the relative humidity inside the surge arrester and obtain the relative humidity measurement results;

[0050] Step 5: Place the defective surge arrester from Step 4 into a complex multi-factor environmental climate chamber. The complex multi-factor environmental climate chamber is set with a high temperature and high humidity environment to accelerate the moisture absorption process.

[0051] Step 6: Apply a long-term continuous operating voltage to the defective surge arrester in Step 5. Based on the full current online monitoring platform and the voltage wireless monitoring device, monitor the full current and reference voltage information in real time. The monitoring results are uploaded to the host IED via wireless transmission.

[0052] Step 7: The host IED processes the total current and reference voltage information from Step 6 based on the fundamental current method to calculate the characteristic electrical quantities.

[0053] Characteristic electrical quantities include at least the resistive current component, the reference phase angle, and the resistance-capacitance ratio;

[0054] Step 8: By selecting the most sensitive electrical quantity from the characteristic electrical quantities in Step 7 and correlating it with the relative humidity measurement results, the online assessment of the moisture level of the surge arrester can be achieved.

[0055] The method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects of the present invention can be applied to the entire surge arrester, and can quantitatively evaluate the degree of moisture aging of the entire surge arrester. The present invention uses several zinc oxide resistive elements, several aluminum pads, several epoxy insulating rods, a surge arrester insulating cylinder, and a complex multi-factor environmental climate chamber to simulate a scenario and environment identical to the moisture absorption mode and process of surge arresters in the field. Test data is obtained through capacitive humidity sensors, a full-current online monitoring platform, and a wireless voltage monitoring device, ensuring the accuracy and reliability of the evaluation results.

[0056] Furthermore, this invention can monitor the trend of total current change during the gradual moisture absorption of a surge arrester online and calculate characteristic electrical quantities such as resistive current, reference phase angle, and resistance-capacitance ratio based on this. By selecting the most sensitive electrical quantity and correlating it with the relative humidity measurement results, the online assessment of the moisture aging degree of the surge arrester can be achieved. The solution is simple and highly practical, and can assist maintenance personnel in easily, quickly, and accurately judging the moisture absorption degree of the surge arrester without interfering with the normal operation of the equipment, thereby improving maintenance efficiency and ensuring the safe and stable operation of the power grid.

[0057] As a preferred technical measure:

[0058] The number of zinc oxide resistors required for a 17kV surge arrester is 5, the diameter of the aluminum pad is the same as the diameter of the resistor, and the number of epoxy insulating rods used for fixing is 3.

[0059] As a preferred technical measure:

[0060] The main sealing ring is located between the upper cover plate and the top of the surge arrester, or between the lower cover plate and the bottom, to prevent outside air from entering the surge arrester;

[0061] The accelerated compression set test was conducted at a temperature of 125℃, a compression rate of 30%, and a compression time of 168 hours.

[0062] The formula for calculating the compressive permanent deformation according to the standard is as follows:

[0063] K = (h0-h2) / (h0-h1), where h0 is the initial height of the sealing ring before compression, h1 is the height of the sealing ring when the compression rate is 30%, and h2 is the recovery height of the sealing ring after compression.

[0064] Before corrosion, the zinc plating layer on the surge arrester cover should be removed using an angle grinder to ensure effective corrosion.

[0065] The high temperature and high salinity environment refers to a temperature of 50℃, a NaCl salt concentration of 13.6%, a corrosive environment created by uniform spraying, and a rusting time of 240 hours.

[0066] As a preferred technical measure:

[0067] The defective surge arrester refers to a surge arrester assembled by assembling a rusted cover plate and explosion-proof plate or an aged sealing ring according to normal installation procedures.

[0068] If the cover plate and explosion-proof plate are corroded, a new sealing ring shall be used during the assembly process;

[0069] If the sealing ring is aged, a new cover plate and explosion-proof plate shall be used during the assembly process; other unmentioned parts shall be qualified and installed normally.

[0070] Capacitive humidity sensor is used to monitor the relative humidity and its trend inside the surge arrester during accelerated moisture absorption; its measurement range is 1% to 99% RH, and its capacitance is 180pF at 55% RH.

[0071] When the relative humidity changes from 0 to 100%, the capacitance ranges from 163 pF to 202 pF.

[0072] The temperature coefficient is 0.04 pF / ℃;

[0073] The complex multi-factor environmental climate chamber provides a temperature range of -20 to 150°C and a relative humidity of 20% to 98%.

[0074] Set a high temperature and high humidity environment, with the high temperature being 50℃ and the high humidity being 98% relative humidity.

[0075] As a preferred technical measure:

[0076] The long-term continuous operating voltage is 0.8 times the rated voltage of the surge arrester, where 0.8 is the load factor;

[0077] The long-term continuous operating voltage is applied through a test transformer with a rated capacity of 50kVA, a maximum output voltage of 50kV, and finely controllable output voltage.

[0078] The full-current online monitoring platform uses an active zero-flux current transformer to collect the full-current signal on the grounding wire of the surge arrester; the voltage wireless monitoring device collects signals from the measuring coil terminal of the test transformer; the reference voltage and full-current information are uploaded to the host IED via wireless transmission.

[0079] To achieve one of the above objectives, the third technical solution of the present invention is as follows:

[0080] A device for accelerating moisture absorption and online evaluation of surge arresters with sealing defects, employing the aforementioned method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects.

[0081] It includes several zinc oxide resistors, several aluminum pads, several epoxy insulating rods, surge arrester insulating cylinders, capacitive humidity-sensitive elements, complex multi-factor environmental climate chambers, full current online monitoring platform, voltage wireless monitoring device, main unit IED and online evaluation system;

[0082] Place one aluminum pad between every two zinc oxide resistor pieces;

[0083] The defective surge arrester to be evaluated is placed inside the surge arrester insulation cylinder after being fixed with an epoxy insulating rod;

[0084] A capacitive humidity sensor is pre-installed near the grounding inside the surge arrester's insulating cylinder to monitor the relative humidity inside the surge arrester.

[0085] The complex multi-factor environment climate chamber is set up with high temperature and high humidity environment to accelerate the moisture absorption process;

[0086] The online monitoring platform for total current and the wireless voltage monitoring device monitor the total current and reference voltage information in real time, respectively, and the monitoring results are uploaded to the host IED via wireless transmission.

[0087] The host IED is based on the fundamental current method principle, which processes the total current and reference voltage information to calculate several characteristic electrical quantities;

[0088] The online assessment system selects the most sensitive electrical quantity from several characteristic electrical quantities and correlates it with the relative humidity measurement results to achieve online assessment of the moisture content of surge arresters.

[0089] The method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects of the present invention can be applied to the entire surge arrester, and can quantitatively evaluate the degree of moisture aging of the entire surge arrester. The present invention uses several zinc oxide resistive elements, several aluminum pads, several epoxy insulating rods, a surge arrester insulating cylinder, and a complex multi-factor environmental climate chamber to simulate a scenario and environment identical to the moisture absorption mode and process of surge arresters in the field. Test data is obtained through capacitive humidity sensors, a full-current online monitoring platform, and a wireless voltage monitoring device, ensuring the accuracy and reliability of the evaluation results.

[0090] Furthermore, this invention can monitor the trend of total current change during the gradual moisture absorption of a surge arrester online and calculate characteristic electrical quantities such as resistive current, reference phase angle, and resistance-capacitance ratio based on this. By selecting the most sensitive electrical quantity and correlating it with the relative humidity measurement results, the online assessment of the moisture aging degree of the surge arrester can be achieved. The solution is simple and highly practical, and can assist maintenance personnel in easily, quickly, and accurately judging the moisture absorption degree of the surge arrester without interfering with the normal operation of the equipment, thereby improving maintenance efficiency and ensuring the safe and stable operation of the power grid.

[0091] Compared with the prior art, the present invention has the following beneficial effects:

[0092] This invention, through continuous exploration and experimentation, establishes a defective surge arrester manufacturing model, an accelerated moisture treatment model, a defect data acquisition model, a structural scale model, a voltage detection model, a characteristic electrical quantity calculation model, a humidity monitoring model, and an evaluation model. This model determines the sealing defect variables of the defective surge arrester. Based on these sealing defect variables, the temperature and humidity of the surge arrester's test environment are determined, and test parameters are set to obtain the compression permanent deformation K of the main sealing ring after aging, as well as the corrosion data of the surge arrester cover and explosion-proof plate. Simultaneously, the required number of zinc oxide resistance sheets and / or epoxy insulation rods and / or aluminum pad diameter for the defective surge arrester are calculated. Then, the total current and reference voltage information of the defective surge arrester are acquired. This information is then processed to calculate several characteristic electrical quantities. Finally, by selecting the most sensitive electrical quantity from these characteristic electrical quantities and correlating it with the relative humidity measurement results, an online assessment of the surge arrester's moisture level is achieved. The solution is scientific, reasonable, and feasible.

[0093] Furthermore, this invention is applicable to the entire surge arrester, enabling quantitative assessment of the degree of moisture aging. The accelerated moisture treatment model and proportional structural model of this invention can simulate the same scenario and environment as the moisture absorption mode and process of the surge arrester in the field, and obtain experimental data through voltage detection models and humidity monitoring models, ensuring the accuracy and reliability of the assessment results.

[0094] Furthermore, this invention can monitor the trend of total current change during the gradual moisture absorption of a surge arrester online and calculate characteristic electrical quantities such as resistive current, reference phase angle, and resistance-capacitance ratio based on this. By selecting the most sensitive electrical quantity and correlating it with the relative humidity measurement results, the online assessment of the moisture aging degree of the surge arrester can be achieved. The solution is simple and highly practical, and can assist maintenance personnel in easily, quickly, and accurately judging the moisture level of the surge arrester without interfering with the normal operation of the equipment, thereby improving maintenance efficiency and ensuring the safe and stable operation of the power grid.

[0095] Furthermore, the method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects in this invention can be applied to the entire surge arrester, enabling a quantitative assessment of the degree of moisture aging. This invention, through several zinc oxide resistive elements, several aluminum pads, several epoxy insulating rods, the surge arrester insulating cylinder, and a complex multi-factor environmental climate chamber, can simulate a scenario and environment identical to the moisture absorption mode and process of surge arresters in the field. Test data is obtained through capacitive humidity sensors, a full-current online monitoring platform, and a wireless voltage monitoring device, ensuring the accuracy and reliability of the evaluation results. Attached Figure Description

[0096] Figure 1 This is a flowchart of the method for accelerating moisture absorption and online evaluation of the sealing defect surge arrester of the present invention;

[0097] Figure 2 This is a schematic diagram of a surge arrester structure.

[0098] Figure 3 This is a framework diagram of the experimental part of the present invention;

[0099] Figure 4 This is a schematic diagram showing the real-time humidity measurement results inside the surge arrester of the present invention;

[0100] Figure 5 This is a schematic diagram illustrating the reference voltage measurement principle of the present invention;

[0101] Figure 6 This is a schematic diagram illustrating the principle of the fundamental current method of this invention;

[0102] Figure 7 This is a schematic diagram illustrating the online monitoring results of total current and resistive current during the accelerated moisture absorption process of the surge arrester with sealing defects according to the present invention.

[0103] Figure 8 This is a schematic diagram showing the online monitoring results of the phase angle and resistance-capacity ratio of the surge arrester with sealing defects during the accelerated moisture absorption process of the present invention.

[0104] Explanation of reference numerals in the attached figures:

[0105] 1. Main sealing ring; 2. Explosion-proof plate; 3. Top cover plate; 4. Resistance element; 5. Aluminum pad; 6. Insulating cylinder. Detailed Implementation

[0106] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0107] Conversely, this invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the invention as defined in the claims. Furthermore, to provide a better understanding of the invention, certain specific details are described in detail below. However, those skilled in the art will fully understand the invention even without these detailed descriptions.

[0108] It should be noted that when two components are "fixedly connected," the two components can be directly connected or there may be an intermediate component. Conversely, when an component is said to be "directly on" another component, there is no intermediate component. The terms "on," "below," and similar expressions used in this document are for illustrative purposes only.

[0109] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0110] A first specific embodiment of the method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects of the present invention:

[0111] A method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects includes the following:

[0112] By using a pre-built model of a defective surge arrester, the defect data of the surge arrester is processed to determine the sealing defect variables of the defective surge arrester.

[0113] This invention examines the general operating conditions of surge arresters, identifying that arrester deterioration primarily manifests as aging and moisture absorption. If a surge arrester has been in use for an extended period, the sealing rings may become brittle due to harsh external environments, or the design during manufacturing may be flawed. This can lead to moisture absorption of internal components, increasing the resistive leakage current flowing through the resistor elements, resulting in increased active power and consequently, a continuous rise in arrester temperature. In the early stages of moisture absorption, a thermal balance can be maintained. However, if the fault becomes severe, the thermal stability operating point continuously shifts, eventually leading to thermal collapse or even explosion of the arrester. Moisture-induced accidents account for over 60% of all surge arrester accidents. Moisture-induced accidents are mainly caused by sealing problems, specifically poor sealing between the top cover and the upper part of the arrester, as well as aging and improper installation of the sealing rings.

[0114] Therefore, the sealing defect variables of this invention mainly include the compression permanent deformation K of the main sealing ring and / or the corrosion data of the surge arrester cover and explosion-proof plate;

[0115] Using a pre-built accelerated moisture treatment model, the sealing defect variables of the surge arrester are analyzed to determine the temperature and humidity of the surge arrester test environment;

[0116] The model is obtained by pre-constructing defect data, and test parameters are set according to the characteristics of sealing defect variables to obtain the compression permanent deformation K of the main sealing ring after aging, as well as the corrosion data of the surge arrester cover and explosion-proof plate.

[0117] Using a pre-built proportional structural model, calculate the number of zinc oxide resistors and / or the number of epoxy insulating rods and / or the diameter of aluminum pads required for the defective surge arrester;

[0118] The full current and reference voltage information of the defective surge arrester are obtained by using a pre-built voltage detection model;

[0119] Based on the pre-built characteristic electrical quantity calculation model, the total current and reference voltage information are processed to calculate several characteristic electrical quantities;

[0120] Several characteristic electrical quantities include at least the resistive current component, the reference phase angle, and the resistance-capacitance ratio;

[0121] By using a pre-built humidity monitoring model, the relative humidity measurement value and change trend inside the defective surge arrester during the accelerated moisture absorption process were obtained;

[0122] By using a pre-built evaluation model, the most sensitive electrical quantity is selected from several characteristic electrical quantities and correlated with the relative humidity measurement results to achieve online evaluation of the moisture level of the surge arrester.

[0123] like Figure 1 As shown, this invention provides a second specific embodiment of the method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects:

[0124] A method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects includes the following steps:

[0125] Step 1: Calculate the number of zinc oxide resistor sheets 4 required for a 17kV surge arrester. Place one aluminum pad 5 between every two resistor sheets 4, fix it with an epoxy insulating rod, and then place it inside the surge arrester insulating cylinder 6.

[0126] Step 2: Conduct an accelerated compression set test on the main sealing ring 1 and test its compression set K after aging;

[0127] Step 3: Corrode the surge arrester cover and explosion-proof plate 2 in a high-temperature and high-salinity environment;

[0128] Step 4: Based on Step 1, assemble the surge arrester with sealing defects using the deformed sealing ring from Step 2 and / or the corroded cover plate and explosion-proof plate 2 from Step 3, ensuring other components are normal and the installation process is correct. Simultaneously, pre-install a capacitive humidity sensor near the grounding inside the surge arrester's insulating cylinder 6 to monitor the relative humidity inside the surge arrester.

[0129] Step 5: Place the defective surge arrester into a complex multi-factor environmental climate chamber, where a high temperature and high humidity environment is set up to accelerate the moisture absorption process.

[0130] Step 6: Apply a long-term continuous operating voltage to the defective surge arrester. Based on the full current online monitoring platform and the voltage wireless monitoring device, monitor the full current and reference voltage information in real time. The monitoring results are uploaded to the host IED via wireless transmission.

[0131] Step 7: The host IED calculates the resistive current component, reference phase angle, and resistance-capacitance ratio based on the fundamental current method.

[0132] Step 8: By selecting the most sensitive electrical quantity (resistive current and resistance-capacitance ratio) from the above characteristic electrical quantities and correlating it with the relative humidity measurement results, the online assessment of the moisture level of the surge arrester can be achieved.

[0133] like Figure 2 As shown, a specific embodiment of the surge arrester oxidation structure of the present invention is as follows:

[0134] In step 1, the number of zinc oxide resistor sheets 4 required for the 17kV surge arrester is 5, the diameter of the aluminum pad 5 is the same as the diameter of the resistor sheet 4, and the number of epoxy insulating rods used for fixing is 3.

[0135] A specific embodiment of the assembly position of the main sealing ring 1 of the present invention:

[0136] In step 2, the main sealing ring 1 is located between the upper cover plate 3 and the top of the surge arrester, or between the lower cover plate and the bottom, effectively preventing outside air from entering the surge arrester.

[0137] A specific embodiment of the accelerated compression set test of the present invention:

[0138] The accelerated compression set test was conducted at a temperature of 125°C, a compression ratio of 30%, and a compression time of 168 hours. The compression set rate K was calculated according to the standard as K = (h0 - h2) / (h0 - h1), where h0 is the initial height of the sealing ring before compression, h1 is the height of the sealing ring at a compression ratio of 30%, and h2 is the recovery height of the sealing ring after compression.

[0139] The compression set K, under the same aging temperature, compression amount and test time, is mainly related to the material of the sealing ring.

[0140] A specific embodiment of the corrosion test of the present invention:

[0141] In step 3, the galvanized layer on the surface of the surge arrester cover is removed using an angle grinder before corrosion is carried out, so as to facilitate effective corrosion.

[0142] The high temperature and high salinity environment refers to a temperature of 50℃, a NaCl salt concentration of 13.6%, a corrosive environment created by uniform spraying, and a rusting time of 240 hours.

[0143] A specific embodiment of the surge arrester assembly method of the present invention:

[0144] In step 4, the surge arrester with sealing defects refers to a surge arrester assembled using rusted cover plates and explosion-proof plates or aged sealing rings according to normal installation procedures. If the cover plate and explosion-proof plate are rusted, a new sealing ring should be used during assembly; if the sealing ring is aged, a new cover plate and explosion-proof plate should be used during assembly. Other unmentioned components are qualified and installed normally.

[0145] like Figure 3 As shown, a specific embodiment of the operating voltage setting of the present invention is as follows:

[0146] The long-term continuous operating voltage is 0.8 times (13.6kV) of the rated voltage of the surge arrester, which is 17kV. The value of 0.8 is the load factor, which is provided by the DL / T 474.5-2018 Guidelines for Field Insulation Testing of Surge Arresters.

[0147] The long-term continuous operating voltage is applied through a test transformer with a rated capacity of 50kVA and a maximum output voltage of 50kV. The output voltage is finely controllable.

[0148] like Figure 4 As shown, a specific embodiment of the present invention with an added detection element is as follows:

[0149] The aforementioned capacitive humidity sensor is used to monitor the relative humidity and its changing trend inside the surge arrester during accelerated moisture absorption. Its measurement range is (1%–99%) RH, and its capacitance at 55% RH is 180 pF (typical value). When the relative humidity changes from 0 to 100%, the capacitance ranges from 163 pF to 202 pF. The temperature coefficient is 0.04 pF / ℃.

[0150] A specific embodiment of the present invention is a complex multi-factor environmental climate chamber:

[0151] In step 5, the complex multi-factor environmental climate chamber can provide a temperature range of -20 to 150°C and a relative humidity of 20% to 98%.

[0152] The system is designed to provide a high-temperature and high-humidity environment, with the high temperature being 50°C and the high humidity being 98% relative humidity.

[0153] like Figure 5 As shown, this invention provides a specific embodiment of a full-current online monitoring platform:

[0154] The aforementioned online full-current monitoring platform uses a zero-flux current transformer to collect the full-current signal on the grounding wire of the surge arrester. The aforementioned wireless voltage monitoring device collects signals from the measuring coil terminal of the test transformer. The reference voltage signal passes through a protection circuit and is converted via V / I signal conversion and then isolated by a current sensor to achieve high-precision voltage phase measurement.

[0155] The phase angle information of voltage and current, as well as the total current, are uploaded to the IED host via wireless transmission. The IED, acting as a data concentrator, manages the various monitoring nodes in the field via wireless communication, primarily including the total current I... s With the reference voltage signal U, phase synchronous acquisition, data collection and uploading are achieved.

[0156] like Figure 6 As shown, a specific embodiment of the fundamental current method of the present invention is as follows:

[0157] Under alternating current, the total current signal I of the metal oxide surge arrester s Includes resistive current I r and capacitive current I c Under normal operating conditions, the current flowing through the surge arrester is mainly capacitive current, with resistive current accounting for only a small portion, approximately 10% to 20%. However, when the surge arrester becomes damp, I... c The changes are not significant, while I r However, it increases significantly. Therefore, by monitoring the I of metal oxide surge arresters... r The component can effectively determine the operating status of the surge arrester. The IED host calculates the reference phase angle φ by analyzing the angle difference between the total current and the reference voltage, based on I... s I r and I c Calculation of vector relationships I r =I s *cosφ、I c =I s *sinφ and resistance-capacitance ratio R c =I r / I c The calculation results, along with the total current, are displayed on the screen in real time.

[0158] A specific embodiment of the most sensitive electrical quantity selection method of the present invention:

[0159] The most sensitive electrical quantity mentioned in step 8 is obtained through... Figure 6 and Figure 7 The relative rates of change of relevant electrical quantities within a unit of time under moisture were compared. Resistive current and resistance-capacitance ratio were selected as the most sensitive electrical quantities, and the values ​​of resistive current, resistance-capacitance ratio, and relative humidity were given. Figure 8 The functional relationship between the acceleration time to moisture absorption (h) and the acceleration time to moisture absorption (h) is as follows:

[0160] I r =-0.06*exp(-h / 51.07)+0.113 (1)

[0161] R c =-0.087*exp(-h / 33.38)+0.205 (2)

[0162] RH=-73.49*exp(-h / 26.91)+104.74 (3)

[0163] By solving equations (1) to (3), the relative humidity inside the surge arrester and the corresponding resistive current and resistance-capacitance ratio under a certain accelerated moisture absorption time h can be obtained. In addition, by changing the external relative humidity, such as decreasing it from 98% to 80%, the accelerated moisture absorption rate and the corresponding rate of change of resistive current and resistance-capacitance ratio can be changed.

[0164] According to the Condition-Based Maintenance Test Procedure for Transmission and Transformation Equipment Q / GDW 1168-2013, operators should pay attention when the resistive current of surge arresters in a substation increases by 50% relative to its initial value.

[0165] An embodiment of a device applying the method of the present invention:

[0166] A device for accelerating moisture absorption and online evaluation of surge arresters with sealing defects, employing the aforementioned method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects.

[0167] It includes several zinc oxide resistors, several aluminum pads, several epoxy insulating rods, surge arrester insulating cylinders, capacitive humidity-sensitive elements, complex multi-factor environmental climate chambers, full current online monitoring platform, voltage wireless monitoring device, main unit IED and online evaluation system;

[0168] Place one aluminum pad between every two zinc oxide resistor pieces;

[0169] The defective surge arrester to be evaluated is placed inside the surge arrester insulation cylinder after being fixed with an epoxy insulating rod;

[0170] A capacitive humidity sensor is pre-installed near the grounding inside the surge arrester's insulating cylinder to monitor the relative humidity inside the surge arrester.

[0171] The complex multi-factor environment climate chamber is set up with high temperature and high humidity environment to accelerate the moisture absorption process;

[0172] The online monitoring platform for total current and the wireless voltage monitoring device monitor the total current and reference voltage information in real time, respectively, and the monitoring results are uploaded to the host IED via wireless transmission.

[0173] The host IED is based on the fundamental current method principle, which processes the total current and reference voltage information to calculate several characteristic electrical quantities;

[0174] The online assessment system selects the most sensitive electrical quantity from several characteristic electrical quantities and correlates it with the relative humidity measurement results to achieve online assessment of the moisture content of surge arresters.

[0175] An embodiment of an apparatus for applying the method of the present invention:

[0176] A computer device comprising:

[0177] One or more processors;

[0178] Storage device for storing one or more programs;

[0179] When the one or more programs are executed by the one or more processors, the one or more processors implement the above-described method for accelerating moisture absorption and online evaluation of a surge arrester with sealing defects.

[0180] An embodiment of a computer medium applying the method of the present invention:

[0181] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described method for accelerating moisture absorption and online evaluation of a surge arrester with sealing defects.

[0182] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0183] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0184] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0185] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0186] In this application, the fixed connection method can be screwed, riveted, plugged, or connected through a third component, and those skilled in the art can choose according to the actual situation.

[0187] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects, characterized in that, Includes the following steps: Step 1: Calculate the number of zinc oxide resistors (4) required for the surge arrester. Place one aluminum pad (5) between every two zinc oxide resistors (4), and after fixing with an epoxy insulating rod, place it into the surge arrester insulating cylinder (6). Step 2: The main sealing ring (1) is subjected to an accelerated compression set test, and its compression set K after aging is tested; Step 3: Corrode the surge arrester cover and explosion-proof plate (2) in a high temperature and high salinity environment; Step 4: Based on Step 1, use the main sealing ring (1) from Step 2 and / or the corroded cover plate and explosion-proof plate (2) to assemble the equipment. Other components are normal and the installation process is correct. Make a defective surge arrester with sealing defects. Meanwhile, a capacitive humidity-sensitive element is pre-installed near the ground inside the surge arrester insulation cylinder (6) to monitor the relative humidity inside the surge arrester and obtain the relative humidity measurement result; Step 5: Place the defective surge arrester from Step 4 into a complex multi-factor environmental climate chamber. The complex multi-factor environmental climate chamber is set with a high temperature and high humidity environment to accelerate the moisture absorption process. Step 6: Apply a long-term continuous operating voltage to the defective surge arrester in Step 5. Based on the full current online monitoring platform and the voltage wireless monitoring device, monitor the full current and reference voltage information in real time. The monitoring results are uploaded to the host IED via wireless transmission. Step 7: The host IED processes the total current and reference voltage information from Step 6 based on the fundamental current method to calculate the characteristic electrical quantities. Characteristic electrical quantities include at least the resistive current component, the reference phase angle, and the resistance-capacitance ratio; Step 8: By selecting the most sensitive electrical quantity from the characteristic electrical quantities in Step 7 and correlating it with the relative humidity measurement results, the online assessment of the moisture level of the surge arrester can be achieved.

2. The method for accelerating moisture absorption and online evaluation of a surge arrester with sealing defects according to claim 1, characterized in that, The number of zinc oxide resistors required for a 17kV surge arrester is 5, the diameter of the aluminum pad is the same as the diameter of the resistor, and the number of epoxy insulating rods used for fixing is 3.

3. The method for accelerating moisture absorption and online evaluation of a surge arrester with sealing defects according to claim 1, characterized in that, The main sealing ring is located between the upper cover plate and the top of the surge arrester, or between the lower cover plate and the bottom, to prevent outside air from entering the surge arrester; The accelerated compression set test was conducted at a temperature of 125℃, a compression rate of 30%, and a compression time of 168 hours. The formula for calculating the compressive permanent deformation according to the standard is as follows: K =( h 0- h 2) / ( h 0- h 1), of which h 0 represents the initial height of the sealing ring before compression. h 1 represents the height of the sealing ring when the compression rate is 30%. h 2 represents the recovery height of the sealing ring after compression; Before corrosion, the zinc plating layer on the surge arrester cover should be removed using an angle grinder to ensure effective corrosion. The high temperature and high salinity environment refers to a temperature of 50℃, a NaCl salt concentration of 13.6%, a corrosive environment created by uniform spraying, and a rusting time of 240 hours.

4. The method for accelerating moisture absorption and online evaluation of a surge arrester with sealing defects according to claim 1, characterized in that, The defective surge arrester refers to a surge arrester assembled by assembling a rusted cover plate and explosion-proof plate or an aged sealing ring according to normal installation procedures. If the cover plate and explosion-proof plate are corroded, a new sealing ring shall be used during the assembly process; If the sealing ring is aged, a new cover plate and explosion-proof plate shall be used during the assembly process; other unmentioned parts shall be qualified and installed normally. Capacitive humidity sensor is used to monitor the relative humidity and its trend inside the surge arrester during accelerated moisture absorption; its measurement range is 1% to 99%RH, and its capacitance is 180pF at 55%RH. When the relative humidity changes from 0 to 100%, the capacitance ranges from 163 pF to 202 pF. The temperature coefficient is 0.04 pF / ℃; The complex multi-factor environmental climate chamber provides a temperature range of -20 to 150°C and a relative humidity of 20% to 98%. Set a high temperature and high humidity environment, with the high temperature being 50℃ and the high humidity being 98% relative humidity.

5. A method for accelerating moisture absorption and online evaluation of a surge arrester with sealing defects according to any one of claims 1-4, characterized in that, The long-term continuous operating voltage is 0.8 times the rated voltage of the surge arrester, where 0.8 is the load factor; The long-term continuous operating voltage is applied through a test transformer with a rated capacity of 50kVA, a maximum output voltage of 50kV, and finely controllable output voltage. The full-current online monitoring platform uses an active zero-flux current transformer to collect the full-current signal on the grounding wire of the surge arrester; the voltage wireless monitoring device collects signals from the measuring coil terminal of the test transformer; the reference voltage and full-current information are uploaded to the host IED via wireless transmission.

6. A device for accelerating moisture absorption and online evaluation of surge arresters with sealing defects, characterized in that, The method for accelerating moisture absorption and online evaluation of surge arresters with sealing defects as described in any one of claims 1-5 is adopted. It includes several zinc oxide resistors, several aluminum pads, several epoxy insulating rods, surge arrester insulating cylinders, capacitive humidity-sensitive elements, complex multi-factor environmental climate chambers, full current online monitoring platform, voltage wireless monitoring device, main unit IED and online evaluation system; Place one aluminum pad between every two zinc oxide resistor pieces; The defective surge arrester to be evaluated is placed inside the surge arrester insulation cylinder after being fixed with an epoxy insulating rod; A capacitive humidity sensor is pre-installed near the grounding inside the surge arrester's insulating cylinder to monitor the relative humidity inside the surge arrester. The complex multi-factor environment climate chamber is set up with high temperature and high humidity environment to accelerate the moisture absorption process; The online monitoring platform for total current and the wireless voltage monitoring device monitor the total current and reference voltage information in real time, respectively, and the monitoring results are uploaded to the host IED via wireless transmission. The host IED is based on the fundamental current method principle, which processes the total current and reference voltage information to calculate several characteristic electrical quantities; The online assessment system selects the most sensitive electrical quantity from several characteristic electrical quantities and correlates it with the relative humidity measurement results to achieve online assessment of the moisture content of surge arresters.

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