Arrester defect diagnosis method based on engineering application criterion
By constructing a lightning arrester model with alternating valve-sensor distribution and combining it with engineering application criteria of multiple characteristic quantities, the problems of insufficient sensitivity and low accuracy in lightning arrester status assessment are solved, and fast and accurate defect diagnosis is achieved.
Patent Information
- Application Number
- CN202510834905.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-20
- Publication Date
- 2025-09-05
AI Technical Summary
Existing arrester status assessment methods have problems such as insufficient sensitivity, hysteresis and high cost, making it difficult to achieve real-time monitoring and precise control. Traditional characteristic quantity measurements are susceptible to interference and have low accuracy.
A lightning arrester model with a topological architecture of alternating valve-sensor distribution is constructed. By measuring the internal leakage current and temperature distribution of the lightning arrester, and comprehensively considering the sensor non-uniformity coefficient, the maximum sensor-ambient temperature difference and the fundamental component of the full current, a new engineering diagnostic criterion is proposed for defect diagnosis.
It achieves fast and accurate arrester defect diagnosis, can distinguish between contaminated and faulty conditions, improves diagnostic accuracy, and reduces computational complexity and resource waste.
Smart Images
Figure CN120594987A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of high voltage engineering, and in particular relates to a lightning arrester defect diagnosis method based on engineering application criteria. Background Art
[0002] With the high-quality development of my country's economy, the power system has ushered in a new era of large-scale clean transformation. As the core device for overvoltage protection of the power system, the performance of the zinc oxide arrester (Metal Oxide Arrester, MOA) directly affects the insulation safety of the main equipment. In actual operation, the performance degradation of the arrester deepens over time. Changes in ambient temperature and humidity and the accumulation of dirt will cause abnormal increases in valve plate temperature and degradation of insulation performance. Extreme working conditions may cause serious faults such as cracking, breakdown or explosion. Studies have shown that the main causes of arrester failure are dampness of the valve plate caused by sealing failure, material aging, cumulative damage from lightning strikes, dirt discharge and thermal runaway of leakage current. Among them, moisture on the zinc oxide valve plate caused by degradation of the arrester's sealing performance is the main factor leading to arrester failure, while the thermal effect of leakage current is the key inducement to accelerate the aging of the arrester.
[0003] Existing methods for assessing the condition of lightning arresters are developing in a diversified manner. The traditional periodic power outage maintenance model has several problems. First, the aging process of zinc oxide valve plates has nonlinear cumulative characteristics. Conventional detection methods are insufficiently sensitive in the early stages of degradation, resulting in a lag in condition assessment. Second, the long-term and high-cost maintenance model makes it difficult to achieve real-time monitoring and precise control of lightning arresters, which can easily lead to mismatches in operation and maintenance resources.
[0004] To address the shortcomings of traditional methods, researchers have established an evaluation system based on multiple characteristic quantities, primarily total current, resistive current, and compensation methods. Resistive current is widely used due to its high measurement accuracy and strong diagnostic reliability. However, other characteristic quantities have significant limitations: total current lacks sensitivity and is susceptible to surface contamination, while capacitive current interference can cause a 40%-60% inaccuracy. Traditional resistive current detection methods can result in a 30% measurement error with a ±2° phase error. The third harmonic component has a weak amplitude and is susceptible to grid harmonic interference, resulting in low measurement stability. Compensation methods are constrained by the phase angle error of the voltage transformer, with a 0.5° error resulting in a 12% calculation error. Furthermore, external interference such as temperature and humidity, surface contamination, and phase-to-phase coupling capacitance further increase the uncertainty of characteristic quantity measurement.
[0005] By conducting experimental research on the leakage current and temperature distribution characteristics of arresters in different states, the aim is to provide an arrester defect diagnosis method based on engineering application criteria to improve the accuracy of arrester defect diagnosis. Summary of the Invention
[0006] The purpose of the present invention is to address the gaps and deficiencies in the prior art and to provide a lightning arrester defect diagnosis method based on engineering application criteria. The method constructs a lightning arrester model with a topological architecture of alternating valve plate and sensor distribution to measure the internal leakage current and temperature distribution of the lightning arrester. By conducting a series of lightning arrester tests, the leakage current measured by the sensor is obtained, and a sensor non-uniformity coefficient is proposed to describe the characteristics of the sensor leakage current distribution. At the same time, the advantages of the sensor non-uniformity coefficient, the maximum sensor-environmental temperature difference and the full current fundamental component are integrated to propose a new engineering diagnostic criterion to realize lightning arrester defect diagnosis.
[0007] Specifically, the arrester defect diagnosis method based on engineering application criteria consists of three parts: an arrester model, an arrester test, and engineering application criteria. The iron arrester model consists of valve plates and sensors. Eight sets of embedded sensors are deployed equidistantly along the axial direction of the arrester valve plate column. The sensor system consists of a built-in data acquisition terminal, a wireless receiving module, and a status monitoring platform. Wireless communication between the acquisition terminal and the receiving module is achieved via the 2.4GHz ISM band. The RS485 protocol is used between the receiving module and the monitoring platform. The acquisition terminal uses a parallel high-energy resistor design to construct a current source by collecting the operating current of the arrester. After rectification and conversion to DC, the current is stored in a supercapacitor, achieving self-powered power supply for the system. The arrester tests were conducted under normal operating conditions, surface contamination conditions, and internal valve plate failure conditions.
[0008] The present invention can diagnose arrester defects by utilizing the advantages of sensor non-uniformity coefficient, maximum sensor-ambient temperature difference, and full current fundamental component in arrester defect diagnosis. The device has the characteristics of simple calculation, can distinguish between contaminated and faulty arrester conditions, and is fast and accurate.
[0009] To achieve the above-mentioned purpose, the technical solution of the present invention is: a lightning arrester defect diagnosis method based on engineering application criteria, constructing a lightning arrester model with a valve plate-sensor alternating distribution topology architecture, which is used to measure the internal leakage current and temperature distribution of the lightning arrester. By conducting a series of lightning arrester tests, the leakage current measured by the sensor is obtained, and a sensor non-uniformity coefficient is proposed to describe the characteristics of the sensor current distribution; by integrating the advantages of the sensor non-uniformity coefficient, the maximum sensor-environmental temperature difference and the full current fundamental component, a new engineering diagnostic criterion is proposed to realize lightning arrester defect diagnosis.
[0010] Furthermore, the interior of the lightning arrester model is composed of valve plates and sensors; among them, 8 groups of embedded sensors are deployed at equal intervals along the axial direction of the valve plate column; the sensors include an acquisition terminal; among them, the acquisition terminal adopts a parallel high-energy resistor design, and constructs a current source by collecting the operating current of the lightning arrester, and after rectification and conversion into DC, it stores energy in the supercapacitor to achieve self-energy power supply.
[0011] Furthermore, the acquisition terminal communicates with the status monitoring platform via a wireless receiving module, and the acquisition terminal and the wireless receiving module communicate with each other via 2.4 GHz ISM band wireless communication; the wireless receiving module and the status monitoring platform use RS485 protocol.
[0012] Furthermore, the series of arrester tests include arrester tests under normal operating conditions, surface contamination conditions, and internal valve failure conditions.
[0013] Furthermore, the maximum sensor non-uniformity coefficient is calculated as follows:
[0014]
[0015] Where: n i is the non-uniformity coefficient of the i-th sensor, I i is the leakage current measured by the i-th sensor.
[0016] Furthermore, the sensor-environment temperature difference is:
[0017] maxΔT=max(T ci -T0)
[0018] Where: T ci is the temperature measured by the i-th sensor, and T0 is the ambient temperature.
[0019] Furthermore, the full current fundamental component is the fundamental component after Fourier decomposition of the full current.
[0020] Furthermore, the engineering diagnosis criteria are:
[0021] P=100*(max(n1,n8)-min(n1,n8))+I x +maxΔT
[0022] Where: n1-n8 are the non-uniformity coefficients of each sensor, I x is the fundamental component of the arrester full current, and maxΔT is the maximum sensor-ambient temperature difference.
[0023] Furthermore, the engineering application criterion under fault conditions is >635, the engineering application criterion under polluted conditions is between 600-635, and the engineering application criterion under normal conditions is <600.
[0024] The present invention also provides a computer-readable storage medium on which computer program instructions that can be executed by a processor are stored. When the processor executes the computer program instructions, any of the method steps described above can be implemented.
[0025] Compared with the prior art, the present invention has the following beneficial effects:
[0026] 1. The constructed arrester model with a valve plate-sensor alternating distribution topology can measure the current and temperature of the valve plate inside the arrester.
[0027] 2. The arrester defect diagnosis method based on engineering application criteria is simple and fast to calculate, and the response time is short when diagnosing arrester defects.
[0028] 3. The arrester defect diagnosis method based on engineering application criteria combines the advantages of multiple characteristic quantities and has a high judgment accuracy. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 Schematic diagram of a multi-parameter online monitoring system for lightning arresters based on embedded sensors according to an embodiment of the present invention.
[0030] Figure 2 4 is a distribution diagram of the uneven coefficient span according to an embodiment of the present invention.
[0031] Figure 3 Schematic diagram of a lightning arrester model with a topological architecture in which valve plates and sensors are alternately distributed according to an embodiment of the present invention.
[0032] Figure 4 Schematic diagram of the sensor structure; wherein, (a) is the main view of the sensor structure, (b) is the left view of the sensor structure, and c is the top view of the sensor structure.
[0033] Figure 5 This is the circuit schematic diagram of the acquisition terminal.
[0034] Figure 6 This is the software interface diagram. DETAILED DESCRIPTION
[0035] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.
[0036] It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the art to which this application belongs.
[0037] like Figure 1 As shown in FIG, the embodiment of the present invention is a multi-parameter online monitoring system for lightning arresters based on embedded sensors. Figure 3 A lightning arrester model with a topology architecture in which valve plates and sensors are alternately distributed is constructed for an embodiment of the present invention.
[0038] Its working principle is as follows: by constructing a lightning arrester model with a topological architecture of alternating valve plate and sensor distribution, it is used to measure the internal leakage current and temperature distribution of the lightning arrester. By conducting a series of lightning arrester tests, the leakage current measured by the sensor is obtained, and the sensor non-uniformity coefficient is proposed to describe the characteristics of the sensor leakage current distribution; at the same time, by integrating the advantages of the sensor non-uniformity coefficient, the maximum sensor-environmental temperature difference and the full current fundamental component, a new engineering diagnostic criterion is proposed to realize the diagnosis of lightning arrester defects.
[0039] The arrester model is composed of valve plates and sensors. Eight sets of embedded sensors are deployed at equal intervals along the axial direction of the arrester valve plate column. The sensor system consists of a built-in data acquisition terminal (sensor body), a wireless receiving module and a status monitoring platform ( Figure 6 The software interface diagram on the status monitoring platform consists of three parts; among them, the acquisition terminal and the wireless receiving module communicate with each other through the 2.4GHz ISM frequency band; the wireless receiving module and the status monitoring platform use the RS485 protocol. Figure 4 As shown, the sensor body, i.e., the acquisition terminal, adopts a parallel high-energy resistor design ( Figure 4 Smart board base setting Figure 5 (corresponding AC-DC rectifier, DC-DC buck, capacitor and other hardware circuits in the ), see Figure 5 The acquisition terminal builds a current source by collecting the operating current of the lightning arrester, and then rectifies and steps down the current ( Figure 5 The AC-DC rectifier realizes the rectification function and the DC-DC buck realizes the buck function) is a DC backward supercapacitor ( Figure 5 The collected current and temperature are converted into digital signals and communicate with the wireless receiving module through the RoLa communication transmitter module to transmit the digital signals to the status monitoring platform.
[0040] like Figure 1 As shown, the arrester and the small resistor are connected in series and form a loop with the test transformer. The voltage of the small resistor is measured by an oscilloscope to obtain the full current.
[0041] The following takes the test results of a 110kV lightning arrester as an example to further illustrate the beneficial effects of the present invention.
[0042] Calculate the unevenness coefficient under various working conditions. The span of each unevenness coefficient is as follows: Figure 2 The comparison of the unevenness coefficient data of each working condition is shown in Table 1.
[0043] Table 1 Non-uniformity coefficient table
[0044]
[0045] As can be seen from the data in Table 1, the non-uniformity coefficient of the leakage current measured by the sensor inside the lightning arrester shows significant differences under different operating conditions: the coefficient fluctuates the most under fault conditions (0.78-1.1), is most concentrated under normal operation (0.97-1.04), and the value under contaminated conditions is somewhere in between. The mechanism is that the sudden change in the local conductive channel caused by internal faults will produce strong nonlinear current distortion, while surface contamination causes the sensor measurement consistency to deteriorate through the uniformly distributed surface leakage current. The degree of impact is positively correlated with the conductivity of the contaminant. Research shows that combining the statistical characteristics of the non-uniformity coefficient with other characteristic parameters can effectively identify internal faults and external environmental interference in lightning arresters, providing a new criterion for multi-dimensional parameter fusion diagnosis.
[0046] Then the engineering application criteria are calculated, and the accuracy comparison of various diagnostic methods is shown in Table 2.
[0047] Table 2 Comparison of the accuracy of various diagnostic methods
[0048]
[0049] The arrester defect diagnosis accuracy rate based on engineering application criteria reached 98.53%, significantly outperforming traditional algorithms. Specifically, the engineering application criteria for fault conditions is >635, the engineering application criteria for contaminated conditions is between 600-635, and the engineering application criteria for normal conditions is <600. It should be noted that this criterion was proposed for the 110kV arrester used in this experiment, and its effectiveness for other arresters needs further verification. If its applicability is widely verified, this criterion has promising prospects for engineering application, as it not only possesses high-precision diagnostic capabilities but also requires no complex model training process and is computationally efficient.
[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other manner. Any person skilled in the art may utilize the above-disclosed technical content to modify or modify the present invention into equivalent embodiments. However, any simple modifications, equivalent variations, and modifications to the above embodiments that do not depart from the technical content of the present invention and are based on the technical essence of the present invention remain within the scope of protection of the present invention.
[0051] The above are preferred embodiments of the present invention. Any changes made according to the technical solution of the present invention, as long as the resulting functions and effects do not exceed the scope of the technical solution of the present invention, shall fall within the scope of protection of the present invention.
Claims
1. A lightning arrester defect diagnosis method based on engineering application criteria, characterized in that: A lightning arrester model with an alternating valve-sensor topology was constructed to measure the arrester's internal leakage current and temperature distribution. Through a series of arrester tests, the sensor-measured leakage current was obtained, and a sensor nonuniformity coefficient was proposed to characterize the sensor current distribution. Taking into account the advantages of sensor non-uniformity coefficient, maximum sensor-ambient temperature difference and full current fundamental component, a new engineering diagnostic criterion is proposed to realize arrester defect diagnosis.
2. The method for diagnosing arrester defects based on engineering application criteria according to claim 1, characterized in that: The interior of the lightning arrester model is composed of valve plates and sensors; among them, 8 groups of embedded sensors are deployed at equal intervals along the axial direction of the valve plate column; the sensors include an acquisition terminal; among them, the acquisition terminal adopts a parallel high-energy resistor design, which constructs a current source by collecting the operating current of the lightning arrester, and stores energy in the supercapacitor after rectification and conversion to DC, thereby realizing self-energy power supply.
3. The method for diagnosing arrester defects based on engineering application criteria according to claim 2, characterized in that: The acquisition terminal communicates with the status monitoring platform via a wireless receiving module. Wireless communication between the acquisition terminal and the wireless receiving module is performed via 2.4 GHz ISM frequency band. RS485 protocol is used between the wireless receiving module and the status monitoring platform.
4. The method for diagnosing arrester defects based on engineering application criteria according to claim 1, characterized in that: The series of arrester tests include arrester tests under normal operating conditions, surface contamination conditions and internal valve failure conditions.
5. The method for diagnosing arrester defects based on engineering application criteria according to claim 1, characterized in that: The maximum sensor non-uniformity coefficient is calculated as follows: Where: n i is the non-uniformity coefficient of the i-th sensor, I i is the leakage current measured by the i-th sensor.
6. The method for diagnosing arrester defects based on engineering application criteria according to claim 1, characterized in that: The sensor-environment temperature difference is: maxΔT=max(T ci -T0) Where: T ci is the temperature measured by the i-th sensor, and T0 is the ambient temperature.
7. The method for diagnosing arrester defects based on engineering application criteria according to claim 1, characterized in that: The full current fundamental component is the fundamental component after Fourier decomposition of the full current.
8. The method for diagnosing arrester defects based on engineering application criteria according to claim 1, characterized in that: The engineering diagnosis criteria are: P=100*(max(n1,n8)-min(n1,n8))+I x +maxΔT Where: n1-n8 are the non-uniformity coefficients of each sensor, I x is the fundamental component of the arrester full current, and maxΔT is the maximum sensor-ambient temperature difference.
9. The method for diagnosing arrester defects based on engineering application criteria according to claim 4, characterized in that: The engineering application criterion under fault conditions is >635, the engineering application criterion under polluted conditions is between 600-635, and the engineering application criterion under normal conditions is <600.
10. A computer-readable storage medium storing computer program instructions that can be executed by a processor, wherein when the processor executes the computer program instructions, the method steps according to any one of claims 1 to 9 can be implemented.