Multi-band signal filtering method and system for partial discharge monitoring equipment

Abstract

The present application relates to the technical field of partial discharge detection, and discloses a multi-band signal filtering method and system for partial discharge monitoring equipment. First, a corresponding first filter channel is set according to the first analog instruction obtained, and the first analog impedance and the first analog capacitive reactance are matched and configured accordingly, and then the corresponding first analog signal received by the detection terminal is controlled to be filtered, and the first filtered signal is output. Then, after obtaining the second analog instruction, the first filter channel is closed, and the discharge is continuously preset for a first time length, and then it is configured as a second filter channel corresponding to the second analog instruction. When configuring, the second analog impedance and the second analog capacitive reactance are first matched, and then the configuration is completed accordingly, and finally the second filter channel is controlled to filter the corresponding second analog signal received by the detection terminal, and the second filtered signal is output. The filtering processing of multi-band signals is realized in this way. The present application can use software for dynamic control to achieve dynamic filtering.

Description

Technical Field

[0001] The present application relates to the technical field of partial discharge detection, and in particular to a multi-band signal filtering method and system for partial discharge monitoring equipment. Background Art

[0002] For any insulation structure, it is inevitable to have bubbles, oil gaps and insulation weaknesses inside. These bubbles, oil gaps and insulation weaknesses are usually formed during the equipment manufacturing process. Since the dielectric constant of gas is smaller than that of insulating materials such as oil and paper, the electric field strength on the air gap is higher than that on the oil-paper insulation material. When the external applied voltage reaches a certain value, these air gaps will first cause partial discharge.

[0003] The partial discharge monitoring equipment is specially used for partial discharge measurement of electrical equipment such as transformers, motors, mutual inductors, cables, GIS, switches, lightning arresters, etc. It is an essential test equipment for electrical equipment manufacturers, power generation and supply operation departments, and power construction, installation and commissioning departments.

[0004] The main function of partial discharge monitoring equipment is to monitor the insulation status of power equipment in real time. Partial discharge sensors correspond to multiple types of signals such as ultrasonic waves, transient ground voltage, ultra-high frequency, high frequency, vibration, etc., and the measurement frequency bands of different types of signals are different. Partial discharge monitoring equipment is easily affected by electromagnetic waves or interference signals in other frequency bands. The traditional method is to use a combination of capacitors and resistors to form a filter to achieve the filtering function. The hardware cost is high, and sensors in different frequency bands need to adjust parameters and replace electrical components each time. The implementation steps are cumbersome. It is not easy to easily power off and replace equipment for the delivered product. Therefore, a partial discharge detection device that can be dynamically controlled by software to achieve dynamic filtering is needed. Summary of the invention

[0005] In order to use software for dynamic control to achieve dynamic filtering, the present application provides a multi-band signal filtering method and system for partial discharge monitoring equipment.

[0006] In a first aspect, the present application provides a multi-band signal filtering method for a partial discharge monitoring device, which adopts the following technical solution:

[0007] A multi-band signal filtering method for a partial discharge monitoring device comprises the following steps:

[0008] Based on the acquired first simulation instruction, setting a first filtering channel corresponding to the first simulation instruction;

[0009] According to the first simulation instruction, a first simulation impedance and a first simulation capacitive reactance are matched;

[0010] configuring the first filtering channel according to the first simulated impedance and the first simulated capacitive reactance;

[0011] Controlling the first filtering channel to filter the first analog signal received by the detection terminal, the first filtering channel outputting a first filtered signal after filtering, wherein the first analog signal corresponds to the first analog instruction;

[0012] Based on the acquired second simulation instruction, closing the first filter channel, and discharging the first filter channel for a preset first time period;

[0013] The first filtering channel is configured as a second filtering channel corresponding to the second simulation instruction, the configuring step comprising:

[0014] According to the second simulation instruction, a second simulation impedance and a second simulation capacitive reactance are matched;

[0015] configuring the second filtering channel according to the second simulated impedance and the second simulated capacitive reactance;

[0016] The second filtering channel is controlled to filter the second analog signal received by the detection terminal, and the second filtering channel outputs a second filtered signal after filtering, wherein the second analog signal corresponds to the second analog instruction.

[0017] By adopting the above technical solution, this solution configures the filter channel for filtering through software control, reduces the dependence on the combination of complex hardware filter components, and can effectively reduce the cost investment in hardware. It is superior to the traditional method of using a capacitor and a resistor to form a filter to achieve the filtering function, and the traditional method has a high hardware cost. In the past, sensors of different frequency bands needed to adjust parameters and replace electrical components every time, and the implementation steps were relatively cumbersome. However, this technical solution uses software to match impedance, capacitance and configure corresponding filter channels according to different analog instructions, without frequent manual replacement of electrical components and complex parameter adjustment, making the operation easier and improving work efficiency. It can flexibly switch the filter channel based on the different analog instructions obtained, such as setting the first filter channel for filtering first, and then closing the channel according to the new instruction and setting the second filter channel to continue filtering, realizing dynamic control of multi-band signal filtering, which can better adapt to the detection and filtering needs of signals in different frequency bands, especially suitable for the situation where the partial discharge monitoring equipment is easily affected by electromagnetic waves or interference signals in other frequency bands, enhancing the pertinence and effectiveness of filtering, and ensuring the accuracy of insulation status monitoring of power equipment. The software-controlled filtering channel approach of this solution avoids the inconvenience caused by frequent power outages to replace hardware equipment, is more in line with the requirements for equipment stability and continuous operation in actual application scenarios, and improves the practicality and reliability of partial discharge monitoring equipment in actual use.

[0018] Optionally, the method further comprises the following steps:

[0019] Using a calibrated device to detect a first analog signal, and obtaining the first filtered signal corresponding to the first analog signal;

[0020] analyzing a difference between the first filtered signal and the first analog signal, and outputting first corrected data;

[0021] If the first correction data is greater than a preset first reference index, the first analog impedance and the first analog capacitive reactance are corrected and calibrated according to the first correction data; otherwise, the first correction data is accumulated to the first accumulated data;

[0022] If the first cumulative data is greater than the preset first cumulative index, the time difference between the current time and the last time the first cumulative data was greater than the first cumulative index is calculated; if the time difference is less than the preset first time difference, the first reference index is reduced; if the time difference is less than the preset second time difference, a filter component replacement prompt is issued; wherein the first time difference is greater than the second time difference.

[0023] By adopting the above technical solution, since the filter developed by the software may filter out part of the original signal data, the second step needs to add a correction and calibration algorithm to restore the filtered real signal data, so as to filter out the clutter and restore the real and effective partial discharge data. By analyzing the difference between the filtered signal and the original signal in real time and correcting and calibrating accordingly, the accuracy of the filter can be significantly improved. By accumulating the correction data and adjusting the reference index in time, the long-term stability of the filter channel can be maintained. Through time difference analysis and filter component replacement prompts, the trend of equipment performance degradation can be discovered in advance, and preventive maintenance can be carried out to avoid monitoring interruptions caused by equipment failures. Reference indicators can be adjusted according to actual conditions to adapt to changes in different working environments and monitoring needs.

[0024] Optionally, the method of analyzing the difference between the first filtered signal and the first analog signal and outputting first correction data comprises the following steps:

[0025] Performing spectrum analysis on the first filtered signal and the first analog signal respectively, converting the time domain signal into a frequency domain signal, and obtaining a corresponding spectrum diagram;

[0026] Calculating the area enclosed by the frequency spectra of the first filtered signal and the first analog signal within the effective frequency range;

[0027] The value of the first correction data is a value of an area.

[0028] Optionally, the method further comprises the following steps:

[0029] Using a calibrated device to detect a second analog signal, and obtaining the second filtered signal corresponding to the second analog signal;

[0030] analyzing a difference between the second filtered signal and the second analog signal, and outputting second corrected data;

[0031] If the second corrected data is greater than a preset second reference index, the second simulated impedance, the second simulated capacitive reactance and the line impedance are corrected and calibrated according to the second corrected data; otherwise, the second corrected data is accumulated to the second accumulated data;

[0032] If the second accumulated data is greater than the preset second accumulated index, the time difference between the current time and the last time the second accumulated data was greater than the second accumulated index is calculated; if the time difference is less than the preset third time difference, a line type change prompt is issued; if the time difference is less than the preset fourth time difference, a filter device replacement prompt is issued; wherein the third time difference is greater than the fourth time difference.

[0033] By adopting the above technical solution, the accuracy and stability of the entire monitoring system can be ensured by simultaneously monitoring and analyzing the performance of the two filter channels. The accuracy of the filtering can be further improved by analyzing the difference between the filtered signal and the original signal in real time and correcting and calibrating accordingly. By accumulating the correction data and time difference analysis, the trend of equipment performance degradation can be discovered in advance, and preventive maintenance can be carried out to avoid monitoring interruptions caused by equipment failure. Not only the performance changes of the filter channel itself are taken into account, but also the influence of line impedance is taken into account, and prompts for line type replacement and filter component replacement are provided to adapt to changes in different working environments and monitoring needs. This extended multi-band signal filtering method not only improves the accuracy and stability of filtering, but also realizes long-term monitoring and preventive maintenance of filter channel and line performance through a comprehensive monitoring and feedback mechanism, further improving the reliability and service life of partial discharge monitoring equipment.

[0034] Optionally, the method of analyzing the difference between the second filtered signal and the second analog signal and outputting second correction data comprises the following steps:

[0035] Performing spectrum analysis on the second filtered signal and the second analog signal respectively, converting the time domain signal into a frequency domain signal, and obtaining a corresponding spectrum diagram;

[0036] Calculate the area enclosed by the frequency spectra of the second filtered signal and the second analog signal within the effective frequency range;

[0037] The value of the second correction data is a value of an area.

[0038] Optionally, the method further comprises the following steps:

[0039] If the time difference is less than a preset fifth time difference, the second reference indicator is adjusted according to the size of the time difference; the larger the time difference is, the lower the second reference indicator is; the smaller the time difference is, the higher the second reference indicator is.

[0040] By adopting the above technical solution, a certain buffer time is given to the system to avoid frequent triggering of maintenance prompts due to minor performance fluctuations, thereby reducing maintenance costs and improving the overall stability of the system.

[0041] Optionally, the method further comprises the following steps:

[0042] adjusting the first duration according to the time difference;

[0043] The larger the time difference is, the shorter the first duration is; the smaller the time difference is, the longer the first duration is.

[0044] By adopting the above technical solution, the larger the time difference is, the greater the interference in the last acquisition result is, and the first time length may need to be adjusted to better avoid or reduce the impact of interference in the next signal detection process.

[0045] Optionally, the method further comprises the following steps:

[0046] Based on the acquired stop monitoring instruction, the second filter channel is closed, and the second filter channel is discharged for a preset second time period.

[0047] By adopting the above technical solution, through discharge processing, it can be ensured that no dangerous charge remains in the second filter channel after monitoring is stopped, thereby improving the safety of the system or equipment. Discharge can prevent the charge from accumulating in the channel and possibly causing damage to the equipment or performance degradation. This is essential for extending the life of the equipment and maintaining its good performance. Discharge can remove the electrostatic interference that may exist in the channel, which helps to maintain the clarity and accuracy of the signal in subsequent operations. By ensuring that the channel is properly closed and discharged after monitoring is stopped, the system can respond more reliably to subsequent monitoring instructions, thereby improving the reliability of the entire system.

[0048] Optionally, the method further comprises the following steps:

[0049] Calculate an average value as an average deviation value according to the first corrected data and the second corrected data;

[0050] The second duration is adjusted according to the average deviation value. The larger the average deviation value is, the longer the second duration is; and the smaller the average deviation value is, the shorter the second duration is.

[0051] By adopting the above technical solution, if the interference is strong, the discharge time needs to be extended to ensure that the residual charge is completely removed; if the interference is weak, the discharge time can be shortened to improve efficiency. By adjusting the second duration according to the interference feedback, it can be ensured that the discharge process is neither too long nor too short, thereby improving the discharge efficiency. The appropriate discharge time can effectively remove the residual charge in the channel, thereby reducing the interference that may be generated in subsequent operations. The system can automatically adjust the discharge time according to different interference conditions, which enhances the adaptability and flexibility of the system. By avoiding unnecessary long-term discharge, energy can be saved and resource utilization can be optimized.

[0052] In a second aspect, the present application provides a multi-band signal filtering system for a partial discharge monitoring device, which adopts the following technical solution:

[0053] A multi-band signal filtering system for a partial discharge monitoring device comprises a processor, wherein the processor executes the steps of any one of the multi-band signal filtering methods for a partial discharge monitoring device as described above.

[0054] In summary, the present application includes at least one of the following beneficial technical effects:

[0055] The software filter of this application has powerful functions and many advantages. It can realize low-pass, high-pass and band-pass filtering. Based on the software algorithm of the band-pass filter, the real discharge data of the equipment is simulated by software parameter adjustment to achieve filtering. No additional hardware is required, saving development costs and hardware costs. The code is highly reusable and can be applied to various products. The filtering is achieved through the software algorithm, which can effectively restore the real discharge signal, with high reliability, small data distortion and simple implementation steps. In addition, the subsequent program replacement can adopt the OTA software upgrade method, without the need for technical personnel to go to the site, which not only saves manpower and material resources, but also improves the convenience and flexibility of operation, showing unique value and efficiency in the field of filtering technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 The present invention is a step-by-step diagram of a multi-band signal filtering method for partial discharge monitoring equipment.

[0057] Figure 2 It is a step diagram of using a calibrated device to detect a first analog signal and then compare and analyze and correct a first filtered signal corresponding thereto.

[0058] Figure 3 It is a step diagram of using a calibrated device to detect a second analog signal and then compare, analyze and correct a corresponding second filtered signal. DETAILED DESCRIPTION

[0059] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings.

[0060] In the description of this specification, the description with reference to the terms "certain embodiments", "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0061] The present application embodiment discloses a multi-band signal filtering method for a partial discharge monitoring device, referring to Figure 1 , including the following steps:

[0062] Based on the acquired first simulation instruction, a first filtering channel corresponding to the first simulation instruction is set; this channel is used for subsequent filtering of signals in a specific frequency band.

[0063] According to the first simulation instruction, a first simulation impedance and a first simulation capacitive reactance are matched;

[0064] The first filter channel is configured according to the first simulated impedance and the first simulated capacitive reactance. Using these impedance and capacitive reactance parameters, the system configures the first filter channel so that it can filter for a specific signal frequency band.

[0065] The first filter channel is controlled to filter the first analog signal received by the detection terminal, and the first filter channel outputs a first filtered signal after filtering, wherein the first analog signal corresponds to the first analog instruction.

[0066] Based on the acquired second simulation instruction, the first filter channel is closed, and the first filter channel is discharged for a preset first time period to discharge it. The first filter channel is discharged for a preset "first time period" to ensure that the charge in the channel is fully released to avoid affecting subsequent filtering.

[0067] The first filtering channel is configured to be a second filtering channel corresponding to the second simulation instruction, the configuring step comprising:

[0068] According to the second simulation instruction, a second simulation impedance and a second simulation capacitive reactance are matched;

[0069] configuring a second filtering channel according to a second simulated impedance and a second simulated capacitive reactance;

[0070] The second filter channel is controlled to filter the second analog signal received by the detection terminal, and the second filter channel outputs a second filtered signal after filtering, wherein the second analog signal corresponds to the second analog instruction.

[0071] The partial discharge monitoring equipment can dynamically adjust the configuration of its filter channel according to different simulation instructions, thereby achieving accurate filtering of signals in different frequency bands. This method improves the flexibility and adaptability of the equipment, enabling it to more effectively monitor and analyze partial discharge phenomena.

[0072] Reference Figure 2 , the method further comprises the steps of:

[0073] The first analog signal is detected using a calibrated device, and a first filtered signal corresponding to the first analog signal is obtained.

[0074] The difference between the first filtered signal and the first analog signal is analyzed, and first correction data is output.

[0075] If the first corrected data is greater than the preset first reference index, it means that the current filtering effect has a large deviation from the expectation, and the first analog impedance and the first analog capacitive reactance need to be corrected and calibrated according to the first corrected data to improve the filtering accuracy. If the first corrected data is not greater than the first reference index, the first corrected data is accumulated to the first accumulated data.

[0076] If the first cumulative data is greater than the preset first cumulative index, the time difference between the current time and the last time when the first cumulative data was greater than the first cumulative index is calculated; if the time difference is less than the preset first time difference, it means that the filtering performance has failed to meet the standard for many times in a short period of time, then the first reference index is reduced and the filtering effect is evaluated with stricter standards. If the time difference is less than the preset second time difference, and the second time difference is less than the first time difference, it means that the filtering performance has continued to fail to meet the standard for a longer period of time, then a filter replacement prompt is issued, indicating that the filter may be aged or damaged. Among them, the first time difference is greater than the second time difference.

[0077] This enhanced multi-band signal filtering method not only improves the accuracy and stability of filtering, but also realizes long-term monitoring and preventive maintenance of filter channel performance by introducing feedback and adjustment mechanisms, further improving the reliability and service life of partial discharge monitoring equipment.

[0078] The method of analyzing the difference between the first filtered signal and the first analog signal and outputting the first correction data comprises the following steps:

[0079] Perform spectrum analysis on the first filtered signal and the first analog signal respectively, convert the time domain signal into a frequency domain signal, and obtain a corresponding spectrum diagram; obtain the spectrum diagram of the first filtered signal and the first analog signal through Fourier transform or other spectrum analysis methods.

[0080] Calculate the area of ​​the spectrum of the first filtered signal and the first analog signal within the effective frequency range; the effective frequency range is defined according to actual application requirements and signal characteristics, and includes important frequency components in the signal. The area is a quantitative representation of the difference between the two in the frequency domain.

[0081] The value of the first correction data is an area value, which reflects the difference between the first filtered signal and the first analog signal in the frequency domain.

[0082] Reference Figure 3 , the method further comprises the steps of:

[0083] The second analog signal is detected using a calibrated device, and a second filtered signal corresponding to the second analog signal is obtained.

[0084] The difference between the second filtered signal and the second analog signal is analyzed, and second correction data is output.

[0085] If the second correction data is greater than the preset second reference index, the second analog impedance, the second analog capacitive reactance and the line impedance are corrected and calibrated according to the second correction data; wherein the correction and calibration method is the template matching method; otherwise, the second correction data is accumulated to the second accumulated data. If the second correction data exceeds the preset "second reference index", it means that the distortion or other problems of the signal are serious and need to be adjusted. At this time, the "second analog impedance" (electrical impedance), "second analog capacitive reactance" (capacitive reactance) and "line impedance" will be corrected and calibrated according to the second correction data to improve the signal quality. If the second correction data does not exceed the second reference index, this correction data will be accumulated in the "second accumulated data" for subsequent analysis and judgment.

[0086] If the second cumulative data is greater than the preset second cumulative index, the time difference between the current time and the last time the second cumulative data was greater than the second cumulative index is calculated; if the time difference is less than the preset third time difference, a line type change prompt is issued; if the time difference is less than the preset fourth time difference, a filter device replacement prompt is issued; wherein the third time difference is greater than the fourth time difference.

[0087] When the second cumulative data exceeds the preset "second cumulative index", it indicates that signal distortion or other problems persist for a period of time. At this time, the time difference between the current time and the last time the second cumulative data exceeded the second cumulative index will be calculated. If this time difference is less than the preset "third time difference", it means that the problem occurs frequently in a short period of time, and it is prompted that the line type needs to be changed, because the signal quality may be degraded due to problems with the line itself. If this time difference is even less than the preset "fourth time difference" and is shorter than the third time difference, it means that the problem is more serious or frequent, and it is prompted that the filter device needs to be replaced, because the signal quality may be degraded due to performance degradation or damage of the filter device.

[0088] By simultaneously monitoring and analyzing the performance of the two filter channels, the accuracy and stability of the entire monitoring system can be ensured. By analyzing the difference between the filtered signal and the original signal in real time and making corrections and calibrations accordingly, the accuracy of the filtering can be further improved. By accumulating correction data and time difference analysis, the trend of equipment performance degradation can be discovered in advance, and preventive maintenance can be performed to avoid monitoring interruptions caused by equipment failures. Not only the performance changes of the filter channel itself are taken into account, but also the influence of line impedance is taken into account, and prompts for line type replacement and filter component replacement are provided to adapt to changes in different working environments and monitoring needs. This extended multi-band signal filtering method not only improves the accuracy and stability of filtering, but also realizes long-term monitoring and preventive maintenance of filter channel and line performance through a comprehensive monitoring and feedback mechanism, further improving the reliability and service life of partial discharge monitoring equipment.

[0089] The method of analyzing the difference between the second filtered signal and the second analog signal and outputting the second correction data comprises the following steps:

[0090] The second filtered signal and the second analog signal are subjected to spectrum analysis respectively, and the time domain signal is converted into a frequency domain signal to obtain a corresponding spectrum diagram, wherein the signal is subjected to Fourier transform, such as fast Fourier transform FFT, to obtain the spectrum diagram of the signal.

[0091] Calculate the area of ​​the spectrum of the second filtered signal and the second analog signal within the effective frequency interval; the effective frequency interval refers to the frequency range that is important for analysis purposes and can be determined based on the characteristics of the signal and the analysis requirements. The area can be achieved by integrating the spectrum, and the result of the integration represents the total energy or power of the signal within the frequency interval.

[0092] The value of the second corrected data is the value of the area. The second corrected data is defined as the difference value of the area enclosed by the two signal spectrograms within the effective frequency interval. This value can be used as an indicator to quantify the difference between the two signals. If the two signals are very similar, the areas enclosed by their spectrograms within the effective frequency interval should be very close, so the second corrected data will be small. On the contrary, if the two signals are very different, the areas enclosed by their spectrograms within the effective frequency interval will be significantly different, so the second corrected data will be large.

[0093] The method further comprises the steps of:

[0094] If the time difference is less than the preset fifth time difference, the second reference index is adjusted according to the size of the time difference; the larger the time difference, the lower the second reference index; the smaller the time difference, the higher the second reference index. For example, assuming that in an actual partial discharge monitoring scenario, the preset fifth time difference is 10 minutes, the third time difference is 15 minutes, and the fourth time difference is 5 minutes. When a calculation shows that the time difference between the current time and the last time when the second cumulative data is greater than the second cumulative index is 8 minutes, this time difference is less than the fifth time difference but greater than the fourth time difference, indicating that although the signal has a certain performance degradation, it is not serious enough to directly prompt the replacement of the filter device or line type.

[0095] At this time, it is necessary to adjust the second reference index appropriately according to this time difference. The original value set for the second reference index may be 10% corresponding to the signal distortion degree. 10% is just an example to illustrate the specific value. Since the time difference is 8 minutes, which is relatively small, it means that the performance declines relatively quickly, so the second reference index can be appropriately increased, such as to 12%. The purpose of this is to give the system a certain buffer time to avoid frequent maintenance prompts due to relatively small performance fluctuations like this. After all, if maintenance prompts are given immediately every time there is a slight performance change, the maintenance cost will increase significantly, and it will not be conducive to the overall stable operation of the system. On the contrary, if the time difference is large, such as 12 minutes, close to the upper limit of the fifth time difference, it means that the performance decline is relatively not so rapid, and the second reference index can be appropriately lowered, such as to 8%, to monitor the subsequent signal conditions with stricter standards to ensure that more serious problems that may arise can be discovered in time.

[0096] The method further comprises the steps of:

[0097] Adjusting the first duration according to the time difference;

[0098] The greater the time difference, the shorter the first duration; the smaller the time difference, the longer the first duration.

[0099] For example, during a partial discharge monitoring process, we found that there was a large interference in the last acquisition result. After calculation, it was found that the time difference between the current time and the last time when the first cumulative data was greater than the first cumulative index was 18 minutes. Assuming that the first time difference was 20 minutes and the second time difference was 10 minutes, this time difference is relatively large, which means that the previous interference has a more obvious impact on the filter channel, and the risk of subsequent interference continuing is relatively low. Therefore, in order to better avoid or reduce the impact of interference during the next signal detection process, the first duration can be appropriately shortened. The original first duration was set to 5 seconds, and now it can be shortened to 3 seconds based on this large time difference, so that the system can perform the next round of filtering operations faster and reduce the possibility of continued interference.

[0100] If the time difference is smaller, such as only 8 minutes (less than the first time difference), it means that the interference occurs more frequently and at short intervals. Then it may be necessary to extend the first time length appropriately, such as to 7 seconds, so that the system has more time to fully eliminate possible interference factors during operations such as switching filter channels, ensuring that the subsequent detected signals are of higher quality.

[0101] The method further comprises the steps of:

[0102] Based on the acquired stop monitoring instruction, the second filter channel is closed, and the second filter channel is discharged for a preset second time period.

[0103] For example, in a factory electrical equipment partial discharge monitoring project, after a day's production, the staff issued a stop monitoring instruction. At this time, after receiving the instruction, the system will immediately close the second filter channel. Then the discharge operation of the second filter channel will begin, assuming that the preset second time length was originally set to 10 seconds. The discharge process is very important, which can ensure that no dangerous charge will remain in the second filter channel after the monitoring is stopped.

[0104] If there is residual charge in the channel, on the one hand, it may cause damage to the equipment. For example, these residual charges may form an excessively high electric field in the channel, causing breakdown and other damage to some sensitive electronic components in the channel, affecting the subsequent service life of the equipment; on the other hand, it will also affect the performance of the equipment. For example, the electrostatic interference generated by the residual charge may cause the initial signal received to be biased when the monitoring is started next time, and the clarity and accuracy of the signal cannot be guaranteed. By continuously discharging for 10 seconds, all the charges that may have accumulated in the channel can be released, eliminating these potential hidden dangers, allowing the system to respond to monitoring instructions more reliably when it is started again for monitoring, ensuring the stable and reliable operation of the entire monitoring system.

[0105] The method further comprises the steps of:

[0106] Calculate an average value as an average deviation value according to the first corrected data and the second corrected data;

[0107] The size of the second duration is adjusted according to the average deviation value. The larger the average deviation value is, the longer the second duration is; the smaller the average deviation value is, the shorter the second duration is.

[0108] For example, during a period of partial discharge monitoring, the first corrected data is calculated through analysis to obtain an area value of 15 corresponding to the signal frequency domain difference. 15 is just a quantitative value for example; the second corrected data is 18, so their average value, that is, the average deviation value, is (15 + 18) ÷ 2 = 16.5. If the average deviation value is set to be less than 10, it corresponds to a smaller interference situation. At this time, 16.5 is greater than 10, indicating that the interference is relatively strong. In this case, in order to ensure that the residual charge is completely removed and to avoid interference caused by the residual charge in subsequent operations, it is necessary to extend the discharge time. If the originally preset second duration is 8 seconds, it can be appropriately extended to 12 seconds.

[0109] On the contrary, if the average deviation value is calculated to be 8, which is less than 10, it means that the interference is weak. At this time, the discharge time can be shortened, for example, the second duration can be shortened from 8 seconds to 6 seconds. This can not only effectively remove the residual charge in the channel and reduce the subsequent interference that may occur, but also improve the discharge efficiency, avoid unnecessary long-term discharge, save energy and optimize the utilization of the entire system resources. At the same time, it also reflects that the system can automatically adjust the discharge time according to different interference conditions, enhancing the adaptability and flexibility of the system.

[0110] Through the combined effect of the above steps, the multi-band signal filtering method of the entire partial discharge monitoring equipment can operate more accurately, stably and flexibly, and comprehensively improves the performance of the partial discharge monitoring equipment in terms of reliability, accuracy and service life.

[0111] An embodiment of the present application also discloses a multi-band signal filtering method and system for a partial discharge monitoring device, including a processor, wherein the processor executes the steps of the multi-band signal filtering method for a partial discharge monitoring device as described in any one of the above.

[0112] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A multi-band signal filtering method for partial discharge monitoring equipment, characterized in that: The steps include: Based on the acquired first simulation instruction, setting a first filtering channel corresponding to the first simulation instruction; According to the first simulation instruction, a first simulation impedance and a first simulation capacitive reactance are matched; configuring the first filtering channel according to the first simulated impedance and the first simulated capacitive reactance; Controlling the first filtering channel to filter the first analog signal received by the detection terminal, the first filtering channel outputting a first filtered signal after filtering, wherein the first analog signal corresponds to the first analog instruction; Based on the acquired second simulation instruction, closing the first filter channel, and discharging the first filter channel for a preset first time period; The first filtering channel is configured as a second filtering channel corresponding to the second simulation instruction, the configuring step comprising: According to the second simulation instruction, a second simulation impedance and a second simulation capacitive reactance are matched; configuring the second filtering channel according to the second simulated impedance and the second simulated capacitive reactance; Controlling the second filtering channel to filter the second analog signal received by the detection terminal, the second filtering channel outputting a second filtered signal after filtering, wherein the second analog signal corresponds to the second analog instruction; The step of matching the first simulated impedance and the first simulated capacitive reactance according to the first simulation instruction further includes the following sub-steps: Using a calibrated device to detect a first analog signal, and obtaining the first filtered signal corresponding to the first analog signal; analyzing a difference between the first filtered signal and the first analog signal, and outputting first correction data; If the first correction data is greater than a preset first reference index, the first analog impedance and the first analog capacitive reactance are corrected and calibrated according to the first correction data; otherwise, the first correction data is accumulated to the first accumulated data; If the first cumulative data is greater than the preset first cumulative index, the time difference between the current time and the last time the first cumulative data was greater than the first cumulative index is calculated; if the time difference is less than the preset first time difference, the first reference index is reduced; if the time difference is less than the preset second time difference, a filter component replacement prompt is issued; wherein the first time difference is greater than the second time difference.

2. The multi-band signal filtering method of partial discharge monitoring equipment according to claim 1, characterized in that: The method of analyzing the difference between the first filtered signal and the first analog signal and outputting first correction data comprises the following steps: Performing spectrum analysis on the first filtered signal and the first analog signal respectively, converting the time domain signal into a frequency domain signal, and obtaining a corresponding spectrum diagram; Calculating the area enclosed by the frequency spectra of the first filtered signal and the first analog signal within the effective frequency range; The value of the first correction data is a value of an area.

3. The multi-band signal filtering method of the partial discharge monitoring device according to claim 2, characterized in that: The step of matching the second simulated impedance and the second simulated capacitive reactance according to the second simulation instruction further includes the following sub-steps: Using a calibrated device to detect a second analog signal, and obtaining the second filtered signal corresponding to the second analog signal; analyzing a difference between the second filtered signal and the second analog signal, and outputting second corrected data; If the second correction data is greater than a preset second reference index, correcting and calibrating the second simulated impedance, the second simulated capacitive reactance and the line impedance according to the second correction data; otherwise, accumulating the second corrected data to second accumulated data; If the second accumulated data is greater than the preset second accumulated index, the time difference between the current time and the last time the second accumulated data was greater than the second accumulated index is calculated; if the time difference is less than the preset third time difference, a line type change prompt is issued; if the time difference is less than the preset fourth time difference, a filter device replacement prompt is issued; wherein the third time difference is greater than the fourth time difference.

4. The multi-band signal filtering method for partial discharge monitoring equipment according to claim 3, characterized in that: The method of analyzing the difference between the second filtered signal and the second analog signal and outputting second correction data comprises the following steps: Performing spectrum analysis on the second filtered signal and the second analog signal respectively, converting the time domain signal into a frequency domain signal, and obtaining a corresponding spectrum diagram; Calculate the area enclosed by the frequency spectra of the second filtered signal and the second analog signal within the effective frequency range; The value of the second correction data is a value of an area.

5. The multi-band signal filtering method for partial discharge monitoring equipment according to claim 3, characterized in that: If the second correction data is greater than a preset second reference index, the step of correcting and calibrating the second simulated impedance, the second simulated capacitive reactance and the line impedance according to the second correction data further includes the following sub-steps: If the time difference is less than a preset fifth time difference, the second reference indicator is adjusted according to the size of the time difference; the larger the time difference is, the lower the second reference indicator is; the smaller the time difference is, the higher the second reference indicator is.

6. The multi-band signal filtering method for partial discharge monitoring equipment according to claim 3, characterized in that: The step of discharging the first filter channel for a preset first time period further includes the following sub-steps: adjusting the first duration according to the time difference; The larger the time difference is, the shorter the first duration is; the smaller the time difference is, the longer the first duration is.

7. The multi-band signal filtering method of partial discharge monitoring equipment according to claim 3, characterized in that: The step of matching the second simulated impedance and the second simulated capacitive reactance according to the second simulation instruction further includes the following sub-steps: Based on the acquired stop monitoring instruction, the second filter channel is closed, and the second filter channel is discharged for a preset second time period.

8. The multi-band signal filtering method for partial discharge monitoring equipment according to claim 7, characterized in that: The step of discharging the second filter channel for a preset second time period further includes the following sub-steps: Calculate an average value as an average deviation value according to the first corrected data and the second corrected data; The second duration is adjusted according to the average deviation value. The larger the average deviation value is, the longer the second duration is; and the smaller the average deviation value is, the shorter the second duration is.

9. A multi-band signal filtering system for partial discharge monitoring equipment, characterized in that: It comprises a processor, in which the steps of the multi-band signal filtering method of the partial discharge monitoring device as described in any one of claims 1 to 8 are executed.

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