Porcelain insulator zero value detection method based on voltage distribution and related device

Abstract

The invention discloses a porcelain insulator zero value detection method based on voltage distribution and a related device. The method comprises the following steps: acquiring voltage effective value data of each insulator to be detected; drawing a curve according to the acquired voltage data of each insulator to be detected by taking the serial number of the insulator as a horizontal coordinate and taking the effective value of the voltage as a vertical coordinate; and analyzing whether a zero-value insulator exists in the to-be-detected insulator string according to the waveform trend of the curve. The step-down circuit with the core device being the capacitor is arranged in front of the input end of the voltage detection device, and the capacitor is connected to the porcelain insulator to be detected in parallel, so that the input voltage is effectively reduced, and the voltage detection device is protected from being damaged by overhigh voltage; the effective value of the measured voltage is obtained, the actual effect of the measured voltage can be reflected more accurately, the calculation process is simplified, and the efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the field of zero-value insulator detection, and relates to a porcelain insulator zero-value detection method based on voltage distribution and a related device. Background Art

[0002] As an important part of power equipment, insulators play a key role in ensuring the safe and stable operation of power lines. The main function of insulators is to provide electrical insulation and mechanical support. However, during long-term use, insulators may be affected by environmental factors, mechanical stress, and electrical stress, and their electromechanical strength may decrease, resulting in insulator degradation and damage, especially porcelain insulators, which may have zero-value insulators, posing a serious threat to the safety and reliability of the power system.

[0003] At present, with the rapid development of drone technology, drone-based infrared detection, ultraviolet detection, electric field detection, and electrical performance detection are being used. The infrared detection method determines whether there is a zero-value insulator based on the temperature rise of the porcelain insulator. It is easily affected by environmental factors during actual detection, resulting in misjudgment; the ultraviolet detection method mainly detects flashover on the surface of the porcelain insulator, and cannot identify porcelain insulators with internal degradation; although the electric field detection can identify the internal degradation of the porcelain insulator, it must strictly ensure that the detection distance is consistent during the detection. If there is a slight deviation, it will be impossible to make a clear judgment on the quality of the porcelain insulator.

[0004] Electrical performance testing is one of the more effective methods. By measuring the voltage distribution of the porcelain insulator string, it is determined whether there are zero-value insulators. However, since the voltage borne by the porcelain insulator itself is usually high, there is a certain technical difficulty in directly measuring its voltage; the traditional voltage measurement method requires the use of a voltage divider to reduce the voltage entering the measurement circuit, but the commonly used voltage divider is large in size and heavy in weight, which is difficult to adapt to the application requirements of mobile detection equipment such as drones. In addition, for AC transmission lines, the instantaneous value of the voltage borne by the insulator is constantly changing, making it difficult for the measurement results to be stable and accurately reflect the voltage level borne by the insulator. Summary of the invention

[0005] The purpose of the present invention is to provide a porcelain insulator zero value detection method and related device based on voltage distribution, which solves the technical problems that the porcelain insulator bearing voltage is difficult to measure directly and the instantaneous value change of AC voltage leads to unstable measurement results.

[0006] To achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a method for detecting a zero value of a porcelain insulator based on voltage distribution, comprising: Obtain voltage RMS data of each insulator to be tested; The collected voltage data on each insulator to be tested are plotted with the insulator number as the horizontal axis and the voltage effective value as the vertical axis; According to the waveform trend of the curve, it is analyzed whether there are zero-value insulators in the insulator string to be tested.

[0007] Furthermore, the voltage effective value data of each insulator to be tested is obtained, including: The calibrated measuring equipment connects the capacitor to the step-down circuit. Starting from the first insulator on the cross-arm side of the tower, the voltage of the insulator to be measured is applied to the step-down circuit. The voltage to be measured is reduced by the principle of impedance reduction after nF-class capacitors are connected in parallel, and the voltage effective value data is obtained by sampling.

[0008] Furthermore, all the sampled values ​​are squared and summed to find the mean, and then the mean is squared to obtain the effective value of the voltage to be measured:

[0009] in is the sampling value of each insulator, and N is the number of sampling times.

[0010] Furthermore, the collected voltage data on each insulator to be tested is plotted with the insulator serial number as the horizontal axis and the voltage effective value as the vertical axis, including: According to the simulation software, an insulator string of 220kV voltage level is constructed through the insulator string equivalent circuit, and the insulator serial number is numbered from the conductor side to the cross arm side; Perform several simulations on the insulator string, respectively simulating the situation where the insulator string and the nth insulator are zero-value insulators; For each group of simulations, an nF capacitor is connected in parallel to each insulator in sequence and its effective voltage is measured; based on the measurement results, several curves are drawn with the insulator number as the horizontal axis and the effective voltage value on the capacitor as the vertical axis.

[0011] Further, analyzing whether there are zero-value insulators in the insulator string to be tested according to the waveform trend of the curve includes: Find the image sinking point on the curve. If there is a sinking point, the horizontal coordinate corresponding to the sinking point position is a zero-value insulator.

[0012] Furthermore, if there is no dip point on the curve, the insulator string under test has no zero-value insulator.

[0013] In a second aspect, the present invention provides a porcelain insulator zero value detection system based on voltage distribution, comprising: A data acquisition module is used to obtain voltage effective value data of each insulator to be tested; A curve drawing module is used to draw a curve with the collected voltage data on each insulator to be tested as the horizontal coordinate and the voltage effective value as the vertical coordinate; The judgment output module is used to analyze whether there are zero-value insulators in the insulator string to be tested according to the waveform trend of the curve.

[0014] Furthermore, the voltage effective value data of each insulator to be tested is obtained, including: The calibrated measuring equipment connects the capacitor to the step-down circuit. Starting from the first insulator on the cross-arm side of the tower, the voltage of the insulator to be measured is applied to the step-down circuit. The voltage to be measured is reduced by the principle of impedance reduction after nF-class capacitors are connected in parallel, and the voltage effective value data is obtained by sampling.

[0015] In a third aspect, the present invention provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, steps of a method for detecting zero value of a porcelain insulator based on voltage distribution are implemented.

[0016] In a fourth aspect, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of a method for detecting zero value of a porcelain insulator based on voltage distribution are implemented.

[0017] Compared with the prior art, the present invention has the following technical effects: 1) A step-down circuit with a capacitor as the core device is set before the input end of the voltage detection device. The capacitor is connected in parallel to the porcelain insulator to be tested, which effectively reduces the input voltage and protects the voltage detection device from being damaged by excessive voltage; 2) Obtaining the effective value of the measured voltage can more accurately reflect the actual effectiveness of the measured voltage, simplify the calculation process and improve efficiency; 3) Plotting the test data into a voltage distribution curve of the porcelain insulator string allows intuitive observation of the data change trend without the need to compare with other results; 4) Find the “sinking point” of the image to determine the position of the zero-value insulator, avoiding the tedious data comparison process and improving the analysis efficiency and recognition accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a detection flow chart of the method of the present invention; Figure 2 It is a flow chart of the test result analysis of the method of the present invention; Figure 3 It is the equivalent circuit diagram of the insulator string.

[0019] Figure 4This is the waveform diagram of the third insulator in Example 1.

[0020] Figure 5 This is the waveform diagram of the 6th insulator in Example 1.

[0021] Figure 6 This is a curve diagram of Example 2.

[0022] Figure 7 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with the accompanying drawings: Example 1, please refer to Figure 7 The present invention provides a porcelain insulator zero value detection method based on voltage distribution, comprising: Obtain voltage RMS data of each insulator to be tested; The collected voltage data on each insulator to be tested are plotted with the insulator number as the horizontal axis and the voltage effective value as the vertical axis; According to the waveform trend of the curve, it is analyzed whether there are zero-value insulators in the insulator string to be tested.

[0024] In the process of analyzing the voltage distribution curve image, a method of finding the "sinking point" of the image is proposed to determine the location of the zero-value insulator. As one of the key factors affecting the safe operation of the power system, the accurate identification of the zero-value insulator is crucial. By observing the voltage distribution curve, the "sinking points" where the voltage drops abnormally due to the loss of insulation performance are found. These points correspond to the location of the zero-value insulator. The application of this method not only avoids the complexity and uncertainty in the traditional data comparison process, but also greatly improves the analysis efficiency and recognition accuracy, which wins valuable time for the timely maintenance and fault handling of the power system.

[0025] Embodiment 2, the present invention provides a porcelain insulator zero value detection method based on voltage distribution, specifically comprising: S1. Ensure that the measuring equipment is in good working condition and has been calibrated as necessary. Prepare a nF capacitor and ensure that its voltage level is suitable for the voltage range of the insulator to be tested. Connect the capacitor to the step-down circuit and ensure that the circuit connection is correct. S2, starting from the first insulator on the cross arm side of the tower, the voltage of the insulator to be tested is applied to the step-down circuit, and the voltage to be tested is reduced by the principle of impedance reduction after capacitors are connected in parallel; S3, move the detection equipment to the second insulator and repeat the detection process of S2; S4, repeat the above-mentioned process of S2 and S3, move to each insulator in turn, and perform the same measurement operation, ensuring that the corresponding voltage effective value data is recorded after each measurement; S5. Use data analysis software to draw a curve with the voltage data collected on each insulator as the horizontal axis and the voltage effective value as the vertical axis; S6. Analyze whether there are zero-value insulators in the insulator string to be tested based on the waveform trend of the curve.

[0026] The core component of the step-down circuit is a capacitor with a capacitance value of nF. From the circuit principle, it is equivalent to connecting this capacitor in parallel with the porcelain insulator to be tested. According to actual measurements, the capacitance value of a piece of porcelain insulator is in the range of 35~50pF. The equivalent circuit of a single piece of porcelain insulator can be regarded as the parallel connection of insulation resistance and capacitance. The insulation resistance of a good porcelain insulator is greater than 10 , the capacitance value of the porcelain insulator body is taken as 40pF, and the insulation resistance can be regarded as infinite, so the impedance value of the single-piece porcelain insulator is approximately its capacitive reactance value. The impedance value of a capacitor with a capacitance of 40nF is: ; Then the total capacitive reactance of the porcelain insulator and capacitor in parallel is: It can be seen that after the porcelain insulator is connected in parallel with the capacitor, the total capacitive reactance is much smaller than the capacitive reactance of the porcelain insulator itself, and the distributed voltage is reduced, which is convenient for measurement.

[0027] Assume that the insulation resistance of a good porcelain insulator is 20 , the body capacitance value is still taken as 40pF, then the admittance of the porcelain insulator is , its admittance angle When connected in parallel with a capacitor with a capacitance of 40nF, the combined admittance of the porcelain insulator and the capacitor is , admittance angle , the relative deviation of the admittance angle caused by the parallel capacitor before and after is , that is, the relative deviation of the voltage phase is 0.2536%. The influence of the parallel capacitor on the voltage phase of the porcelain insulator itself is extremely small.

[0028] The method of measuring the effective value of voltage is to first sample the voltage to be measured within a certain period, square all the sampled values ​​and sum them to find the mean, then square the mean to get the effective value of the voltage to be measured, that is, .

[0029] A step-down circuit is installed before the input end of the voltage detection device. This step-down circuit cleverly connects the capacitor in parallel to the porcelain insulator to be tested. Through the voltage-dividing characteristics of the capacitor, the voltage value input to the voltage detection device can be effectively reduced. This design not only ensures that the voltage detection device can operate within a safe voltage range, avoiding the risk of equipment damage caused by excessive voltage, but also greatly improves the stability and reliability of the entire detection system.

[0030] The method of obtaining the effective value of the measured voltage is adopted. As an important parameter of voltage, the effective value can truly reflect the equivalent DC effect of the voltage on the resistive load, thereby more accurately reflecting the actual effect of the measured voltage. Compared with other complex voltage parameters, the calculation of the effective value is more concise and clear, which not only simplifies the data processing process, but also significantly improves the detection efficiency and can obtain key information faster.

[0031] In order to further display the detection data intuitively, the collected voltage data was carefully plotted into a voltage distribution curve image of the porcelain insulator string. This graphical representation method makes the changing trend of the voltage data clear at a glance, without the need for cumbersome text descriptions or one-to-one comparisons with other data results. By observing this curve, technicians can quickly grasp the voltage distribution of the entire porcelain insulator string, providing strong visual support for subsequent troubleshooting and performance evaluation.

[0032] The method of finding the "sinking point" of the image is used to determine the location of the zero-value insulator. By observing the voltage distribution curve, the "sinking points" where the voltage drops abnormally due to the loss of insulation performance are found. These points correspond to the location of the zero-value insulator. The use of this method not only avoids the complexity and uncertainty in the traditional data comparison process, but also greatly improves the analysis efficiency and recognition accuracy.

[0033] Example 3 Use Simulink simulation software to simulate the circuit. Figure 3 The insulator string equivalent circuit shown is a 7-piece insulator string of 110kV voltage level, and the insulator serial numbers are numbered from the conductor side to the cross arm side; The insulator body capacitance is set to 40pF in the circuit, the capacitance of the capacitor connected in parallel to the insulator is 40nF, the stray capacitance of the insulator to the conductor is 2pF, and the stray capacitance to the ground is 6pF. According to GB 50150-2016 "Electrical Equipment Handover Test Standard for Electrical Installation Engineering", the insulation resistance value of a good suspension insulator should not be less than 300 MΩ. The measured insulation resistance is greater than 11GΩ, and it is set to 20 GΩ in the circuit; Do two sets of simulations: 1) Compare the instantaneous values ​​of the line phase voltage with the voltages of the third and sixth insulators; 2) Compare the instantaneous value of the line phase voltage with the voltage of the third insulator connected in parallel with the capacitor; Use the oscilloscope in the software to collect the instantaneous value of the voltage and draw waveform images, such as Figure 4 and Figure 5 As shown, the following conclusions can be drawn: 1) The voltage on each insulator in the insulator string is in phase with the line phase voltage; 2) When a capacitor is connected in parallel to an insulator, the phase of the voltage on it remains the same as the phase of the line phase voltage.

[0034] Example 4 Use Simulink simulation software to simulate the circuit. Figure 5 The insulator string equivalent circuit shown is a 13-piece insulator string of 220 kV voltage level, and the insulator serial numbers are numbered from the conductor side to the cross arm side; In the circuit, the capacitance of the insulator body is set to 40pF, the capacitance of the capacitor connected in parallel to the insulator is 40nF, the stray capacitance of the insulator to the conductor is 1pF, and the stray capacitance to the ground is 3pF. According to GB 50150-2016 "Electrical Equipment Handover Test Standard for Electrical Installation Engineering", the insulation resistance value of a good suspension insulator should not be less than 300MΩ. The measured insulation resistance is greater than 11GΩ, which is set to 20GΩ in the circuit, and the insulation resistance of the zero-value insulator is set to 2MΩ.

[0035] Perform 8 sets of simulations, simulating the good insulator string and the situation where the 1st, 3rd, 5th, 7th, 9th, 11th and 13th insulators are zero-value insulators respectively; For each simulation, 40nF capacitors were placed in sequence. Connect to each insulator in parallel and measure its effective voltage ; According to the measurement results, with the insulator number as the horizontal axis, the capacitor The effective value of the voltage on Draw 8 curves for the vertical axis, and the result is as follows Figure 6 As shown, the following conclusions can be drawn: 1) When there is a zero-value insulator in the insulator string, the effective value of the voltage measured at the zero-value insulator is significantly lower than that of the insulators on the adjacent two sides; 2) When the voltage distribution curve is drawn as a smooth "U"-shaped curve, the case where there is no zero value is considered; 3) When the voltage distribution curve is drawn and an obvious "sinking point" appears on the basis of the "U"-shaped curve, the insulator at the corresponding position is considered to be zero value when compared with the horizontal axis.

[0036] In yet another embodiment of the present invention, a porcelain insulator zero value detection system based on voltage distribution is provided, which can be used to implement the above-mentioned porcelain insulator zero value detection method based on voltage distribution. Specifically, the system includes: A data acquisition module is used to obtain voltage effective value data of each insulator to be tested; A curve drawing module is used to draw a curve with the collected voltage data on each insulator to be tested as the horizontal coordinate and the voltage effective value as the vertical coordinate; The judgment output module is used to analyze whether there are zero-value insulators in the insulator string to be tested according to the waveform trend of the curve.

[0037] The division of modules in the embodiments of the present invention is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional module in each embodiment of the present invention may be integrated into one processor, or may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated modules may be implemented in the form of hardware or in the form of software functional modules.

[0038] In another embodiment of the present invention, a computer device is provided, the computer device includes a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc., which is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of a porcelain insulator zero value detection method based on voltage distribution.

[0039] In another embodiment of the present invention, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both built-in storage media in the computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the above-mentioned embodiment regarding a method for detecting a porcelain insulator zero value based on voltage distribution.

[0040] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented 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.

[0041] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0042] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0043] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does 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 detecting zero value of porcelain insulator based on voltage distribution, characterized in that: include: Obtain voltage RMS data of each insulator to be tested; The collected voltage data on each insulator to be tested are plotted with the insulator number as the horizontal axis and the voltage effective value as the vertical axis; According to the waveform trend of the curve, it is analyzed whether there are zero-value insulators in the insulator string to be tested.

2. A porcelain insulator zero value detection method based on voltage distribution according to claim 1, characterized in that: Obtain the voltage RMS data of each insulator to be tested, including: The calibrated measuring equipment connects the capacitor to the step-down circuit. Starting from the first insulator on the cross-arm side of the tower, the voltage of the insulator to be measured is applied to the step-down circuit. The voltage to be measured is reduced by the principle of impedance reduction after nF-class capacitors are connected in parallel, and the voltage effective value data is obtained by sampling.

3. A porcelain insulator zero value detection method based on voltage distribution according to claim 2, characterized in that: All sampled values ​​are squared and summed to find the mean value, and then the square root of the mean value is taken to obtain the effective value of the voltage to be measured: in is the sampling value of each insulator, and N is the number of sampling times.

4. The method for detecting zero value of porcelain insulator based on voltage distribution according to claim 1, characterized in that: The collected voltage data on each insulator to be tested is plotted with the insulator number as the horizontal axis and the voltage effective value as the vertical axis, including: According to the simulation software, an insulator string of 220kV voltage level is constructed through the insulator string equivalent circuit, and the insulator serial number is numbered from the conductor side to the cross arm side; Perform several simulations on the insulator string, respectively simulating the situation where the insulator string and the nth insulator are zero-value insulators; For each group of simulations, an nF capacitor is connected in parallel to each insulator in sequence and its effective voltage is measured; based on the measurement results, several curves are drawn with the insulator number as the horizontal axis and the effective voltage value on the capacitor as the vertical axis.

5. The method for detecting zero value of porcelain insulator based on voltage distribution according to claim 1, characterized in that: Analyze whether there are zero-value insulators in the insulator string to be tested based on the waveform trend of the curve, including: Find the image sinking point on the curve. If there is a sinking point, the horizontal coordinate corresponding to the sinking point position is a zero-value insulator.

6. A method for detecting zero value of porcelain insulator based on voltage distribution according to claim 5, characterized in that: If there is no dip on the curve, there is no zero-value insulator in the insulator string being tested.

7. A porcelain insulator zero value detection system based on voltage distribution, characterized in that: include: A data acquisition module is used to obtain voltage effective value data of each insulator to be tested; A curve drawing module is used to draw a curve with the collected voltage data on each insulator to be tested as the horizontal coordinate and the voltage effective value as the vertical coordinate; The judgment output module is used to analyze whether there are zero-value insulators in the insulator string to be tested according to the waveform trend of the curve.

8. The porcelain insulator zero value detection system based on voltage distribution according to claim 7 is characterized in that: Obtain the voltage RMS data of each insulator to be tested, including: The calibrated measuring equipment connects the capacitor to the step-down circuit. Starting from the first insulator on the cross-arm side of the tower, the voltage of the insulator to be measured is applied to the step-down circuit. The voltage to be measured is reduced by the principle of impedance reduction after nF-class capacitors are connected in parallel, and the voltage effective value data is obtained by sampling.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the porcelain insulator zero value detection method based on voltage distribution as described in any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of a porcelain insulator zero value detection method based on voltage distribution as claimed in any one of claims 1 to 6 are implemented.

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