Dynamic range detection method for GIS ultrahigh frequency partial discharge online detection equipment

Abstract

The invention provides a method for detecting the dynamic range of GIS ultrahigh frequency partial discharge online detection equipment, and the method comprises the steps: carrying out the signal processing of a real partial discharge signal through a statistical method, and generating a representative partial discharge signal as an injection signal; testing whether each output signal of the arbitrary waveform generator for the injection signal is distorted or not; building a GIS ultrahigh frequency partial discharge on-line monitoring system so as to carry out dynamic range measurement on GIS ultrahigh frequency partial discharge on-line monitoring equipment by using undistorted injection signals; background noise of the built GIS ultrahigh frequency partial discharge online monitoring system is determined; and determining the dynamic range of the GIS ultrahigh frequency partial discharge on-line monitoring equipment under the specified frequency point until the dynamic ranges of the GIS ultrahigh frequency partial discharge on-line monitoring equipment under different frequencies are obtained. The operation is simple and convenient, and the practicability is high.

Description

Technical Field

[0001] The invention relates to the technical field of electrical information measurement, and in particular to a dynamic range detection method for GIS ultra-high frequency partial discharge online detection equipment. Background Art

[0002] Gas Insulated Switchgear (GIS) is a key equipment in the power system. Partial discharge inside GIS will pose a great threat to the safe operation of the power grid.

[0003] The UHF method is currently a commonly used GIS partial discharge detection method. At present, some manufacturers have produced GIS UHF partial discharge online monitoring equipment (or UHF partial discharge online monitoring equipment). Its dynamic range reflects the accurate range of the system's discharge amplitude detection and is an important parameter of equipment performance.

[0004] Carrying out dynamic range calibration on UHF PD online monitoring equipment and proposing a technical solution for dynamic range calibration are of great significance in engineering applications. Summary of the invention

[0005] In view of this, the present application provides a dynamic range detection method for GIS ultra-high frequency partial discharge online detection equipment, aiming to solve the problem of lack of dynamic range detection and inspection method for ultra-high frequency partial discharge online monitoring equipment in the prior art.

[0006] The present application provides a method for detecting the dynamic range of a GIS ultra-high frequency partial discharge online detection device, comprising:

[0007] The real partial discharge signal is processed by statistical method to generate a representative partial discharge signal as the injection signal;

[0008] Testing whether each output signal of the arbitrary waveform generator for the injection signal is distorted;

[0009] Build a GIS UHF partial discharge online monitoring system to measure the dynamic range of the GIS UHF partial discharge online monitoring equipment using undistorted injection signals;

[0010] Determine the background noise of the constructed GIS UHF partial discharge online monitoring system;

[0011] Determine the dynamic range of the GIS UHF partial discharge online monitoring equipment at the specified frequency point until the dynamic range of the GIS UHF partial discharge online monitoring equipment at different frequencies is obtained.

[0012] Furthermore, the method of processing the real partial discharge signal by a statistical method to generate a representative partial discharge signal as an injection signal includes:

[0013] Multiple groups of GIS ultra-high frequency partial discharge signals with different defect types are collected at the GIS site; their interference signals are eliminated respectively, and the multiple groups of effective signals are averaged to obtain representative partial discharge signals as injection signals.

[0014] Furthermore, the collecting of multiple groups of GIS UHF partial discharge signals of different defect types at the GIS site includes:

[0015] Arrange multiple built-in UHF sensors to detect internal discharge signals of GIS;

[0016] Arrange at least one external space UHF sensor to detect discharge signals in the external space of GIS;

[0017] Defect types include any of the following: tip defects, suspension defects, air gap defects, particle defects, and poor contact current type defects.

[0018] Further, the test of whether each output signal of the arbitrary waveform generator for the injection signal is distorted includes:

[0019] An arbitrary waveform generator is used as a signal output source, the injection signal is introduced into the arbitrary waveform generator and output by the arbitrary waveform generator, and the output signal of the arbitrary waveform generator is measured by an oscilloscope;

[0020] The operating parameters of the arbitrary waveform generator are set to different amplitudes and frequencies, and an oscilloscope is used to check whether the output signals of the arbitrary waveform generator are distorted.

[0021] Furthermore, the construction of the GIS ultra-high frequency partial discharge online monitoring system includes:

[0022] Disconnect the coaxial cable of the designated channel of the GIS ultra-high frequency partial discharge online monitoring equipment from its built-in sensor, connect the coaxial cable of the designated channel to the arbitrary waveform generator, and use the program to record the amplitude displayed by the online monitoring equipment.

[0023] Furthermore, the background noise of the established GIS ultra-high frequency partial discharge online monitoring system is determined, including:

[0024] When the program determines that the online monitoring device has no background noise display, the arbitrary waveform generator is turned on and the amplitude of the arbitrary waveform generator output signal is gradually increased so that the monitoring system has a stable acquisition signal display. The program records the data amplitude monitored by the monitoring system at this time as background noise.

[0025] Furthermore, the determination of the dynamic range of the GIS UHF partial discharge online monitoring device at a specified frequency point includes:

[0026] After determining the background noise, set the arbitrary waveform generator to operate at the specified frequency;

[0027] Increase the output signal amplitude of the arbitrary waveform generator so that the monitoring system has a stable acquisition signal display. When the program detects that the data amplitude displayed by the monitoring system is 3dBm greater than the background noise at this time, determine that the displayed data amplitude is the sensitivity of the online monitoring device at the specified frequency point;

[0028] After determining the sensitivity at the specified frequency point, continue to increase the output signal amplitude, output signal amplitude every 10dB, record a set of arbitrary waveform generator output signal amplitude and online monitoring equipment display amplitude; when the GIS UHF partial discharge online monitoring equipment displays amplitude approaching saturation, record a set of amplitude data every 1dBm;

[0029] Compare the two latest sets of amplitude data until it is determined that the online monitoring device displays amplitude saturation, and use the amplitude collected by the online monitoring device at the specified frequency point in the latest set of amplitude data as the upper limit of the amplitude collected by the online monitoring device at the specified frequency point;

[0030] The difference between the upper limit of the amplitude collected by the UHF partial discharge online monitoring device and the sensitivity is taken as the dynamic range of the online monitoring device at the specified frequency point.

[0031] Furthermore, it also includes:

[0032] The frequency of the output signal of the arbitrary waveform generator is gradually increased and used as the updated designated frequencies respectively; for each updated designated frequency, the dynamic range of the GIS ultra-high frequency partial discharge online monitoring equipment at the designated frequency point is determined until the dynamic range of the GIS ultra-high frequency partial discharge online monitoring equipment at different frequencies is obtained.

[0033] Furthermore, the method of processing the real partial discharge signal by a statistical method to generate a representative partial discharge signal as an injection signal includes:

[0034] By comparing the output signals of the built-in sensor channel and the external sensor channel, the interference signal in the GIS UHF partial discharge signal collected on site can be eliminated.

[0035] Furthermore, the built-in UHF sensor or the external space UHF sensor is a broadband UHF sensor of 300MHz to 1500MHz.

[0036] The dynamic range detection method of GIS ultra-high frequency partial discharge online detection equipment provided by the present invention is based on the statistics of real partial discharge signals, collects multiple groups of GIS ultra-high frequency partial discharge signals of different defect types on site, excludes their interference signals, takes average of the effective signals as injection signals, injects them into the online monitoring system, gradually increases the output amplitude of the arbitrary waveform generator, obtains the sensitivity of the online monitoring equipment under the ultra-high frequency real partial discharge signal and the upper limit of the acquisition amplitude, and then calculates the dynamic range of the online monitoring equipment at the specified frequency point.

[0037] The dynamic range detection method of the UHF partial discharge online detection equipment based on the statistics of real partial discharge signals is easy to implement on site, simple to operate, and highly practical, and can be widely used in the detection and inspection of the dynamic range of UHF partial discharge online monitoring equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0039] Figure 1 A schematic diagram of the flow of a dynamic range detection method for a GIS UHF partial discharge online detection device according to an embodiment of the present application;

[0040] Figure 2 It is a schematic diagram of the on-site arrangement method of UHF sensor signal acquisition in the dynamic range detection method of the GIS UHF partial discharge online detection equipment in the embodiment of the present application;

[0041] Figure 3A This is a schematic diagram of typical original signals of a UHF sensor with different amplitudes displayed by an oscilloscope in an embodiment of the present application;

[0042] Figure 3B This is a schematic diagram of typical original signals of a UHF sensor with different amplitudes displayed by an oscilloscope in an embodiment of the present application;

[0043] Figure 4A This is a dynamic range output curve of a UHF partial discharge online monitoring device at a frequency of 600 MHz in an embodiment of the present application;

[0044] Figure 4B This is a dynamic range output curve of another UHF partial discharge online monitoring device at a frequency of 600 MHz in an embodiment of the present application. DETAILED DESCRIPTION

[0045] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other.

[0046] For GIS ultra-high frequency partial discharge online monitoring equipment, such as Figure 1 As shown, the dynamic range detection method of ultra-high frequency online detection equipment based on real partial discharge signal statistics according to an embodiment of the present invention includes the following steps S100 to S500.

[0047] S100: performing signal processing on the real partial discharge signal by using a statistical method to generate a representative partial discharge signal as an injection signal;

[0048] Specifically, collecting real partial discharge signals includes collecting multiple groups of GIS ultra-high frequency partial discharge signals of different defect types at the GIS site; eliminating their interference signals respectively, averaging the multiple groups of effective signals to obtain representative partial discharge signals and use them as injection signals. Figure 2 As shown in the on-site layout diagram, sensors 1, 2, and 3 are built-in UHF sensors, which are used to detect the internal discharge signal of GIS. Sensor 4 is an external space UHF sensor, which is used to detect the discharge signal of the external space of GIS; the external space UHF sensor is installed at the edge of the pot insulator, and if the pot insulator has a metal shield, it is installed at the pouring mouth.

[0049] Specifically, by comparing the output signals of the built-in sensor channel and the external sensor channel, interference signals in the GIS UHF partial discharge signals collected on-site can be eliminated.

[0050] Specifically, the built-in UHF sensor or the external space UHF sensor is a broadband UHF sensor of 300MHz-1500MHz.

[0051] Specifically, the defect type includes any of the following: voltage defects such as tip defects, suspension defects, air gap defects, particle defects, and poor contact current type defects.

[0052] In some embodiments, 100 groups of ultra-high frequency real partial discharge signals are sampled on-site and processed by statistical methods to obtain a representative partial discharge signal, which is an ultra-high frequency single-pulse partial discharge signal. The signal is used as an injection signal of an arbitrary waveform generator. By adjusting the arbitrary waveform generator, the amplitude and / or frequency of the injection signal can be adjusted.

[0053] Specifically, the statistical methods include: mean, standard deviation, peak-to-peak value, and DC effective value of the statistical amplitude.

[0054] S200: testing whether each output signal of the arbitrary waveform generator for the injection signal is distorted;

[0055] Specifically, an arbitrary waveform generator is used as a signal output source; each representative ultra-high frequency single pulse partial discharge signal generated is introduced into the arbitrary waveform generator and output by the arbitrary waveform generator, and the output signal of the arbitrary waveform generator is measured by an oscilloscope;

[0056] Specifically, the working parameters of the arbitrary waveform generator are set to different amplitudes and different frequencies, and an oscilloscope is used to check whether each output signal of the arbitrary waveform generator is distorted;

[0057] In some embodiments, Figure 3A The amplitudes of the real UHF partial discharge signals shown in the figure include: peak-to-peak value of 15.7mV, DC effective value of 2.77mV; ACRMS of 1.666mV; frequency of 420MHz; Figure 3B The amplitudes of the real UHF partial discharge signals shown in the figure include: peak-to-peak value of 1.48V, DC effective value of 163mV, ACRMS of 162.4mV, and frequency of 420560MHz. Usually, RMS is the true effective value, or effective value or root mean square value; DC is the simple average value or DC component.

[0058] S300: Build a GIS UHF partial discharge online monitoring system to measure the dynamic range of the GIS UHF partial discharge online monitoring equipment using undistorted injection signals;

[0059] When setting up the monitoring system, disconnect the coaxial cable of the designated channel of the GIS ultra-high frequency partial discharge online monitoring equipment from its built-in sensor, connect the coaxial cable of the designated channel to the arbitrary waveform generator, and use the program to record the amplitude displayed by the online monitoring equipment.

[0060] S400: Determine the background noise of the GIS UHF partial discharge online monitoring system;

[0061] When the program determines that there is no background noise displayed by the online monitoring device, the arbitrary waveform generator is turned on and the output signal amplitude of the arbitrary waveform generator is gradually increased (such as by turning a knob or pressing a button) so that the monitoring system has a stable acquisition signal display. The program records the data amplitude monitored by the monitoring system at this time as background noise or background noise floor, recorded as A0.

[0062] It should be understood that GIS UHF partial discharge online monitoring equipment usually has a built-in data processing program that can determine whether the background amplitude is lower than the acquisition threshold of the monitoring system.

[0063] S500: Determine the dynamic range of the GIS UHF PD online monitoring equipment at the specified frequency point;

[0064] After determining the background noise, set the arbitrary waveform generator to work at the specified frequency; increase (such as turning a knob or pressing a button) the output signal amplitude of the arbitrary waveform generator so that the monitoring system has a stable acquisition signal display. When the program detects that the data amplitude displayed by the monitoring system is 3dBm greater than the background noise A0 at this time, it is the sensitivity Sen0 of the online monitoring device at the specified frequency point;

[0065] After determining the sensitivity at the specified frequency point, continue to increase the output signal amplitude, output signal amplitude every 10dB, and record a set of arbitrary waveform generator output signal amplitudes and online monitoring equipment display amplitudes;

[0066] When the GIS UHF PD online monitoring device shows that the amplitude is approaching saturation, a set of amplitude data is recorded every 1dBm;

[0067] Compare the latest two sets of amplitude data (x i-1 ,y i-1 ) and (x i ,y i ), if (x i -x i-1 ) / (y i -y i-1 )>2, it is considered that the online monitoring equipment shows saturation amplitude, x i-1 It is the upper limit of the amplitude collected by the online monitoring equipment at the specified frequency point; where x i is the amplitude collected by the i-th group of online monitoring equipment at the specified frequency point, y i is the output signal amplitude of the i-th group of arbitrary waveform generators; x i-1 is the amplitude collected by the i-1th group of online monitoring equipment at the specified frequency point, y i-1 The output signal amplitude of the arbitrary waveform generator of the i-1th group, and first record the i-1th group amplitude array, and then record the i-th group amplitude array; i is a natural number greater than 1;

[0068] The difference between the upper limit of the amplitude Senup collected by the UHF partial discharge online monitoring device and the sensitivity Sen0 is taken as the dynamic range of the online monitoring device at the specified frequency point.

[0069] S600: gradually increase the frequency of the arbitrary waveform generator output signal and use it as the updated designated frequency respectively; for each updated designated frequency, repeat the above step S500 until the dynamic range of the GIS ultra-high frequency partial discharge online monitoring device at different frequencies is obtained.

[0070] In summary, the present invention proposes a dynamic range detection method for GIS ultra-high frequency partial discharge online monitoring equipment. By sampling multiple groups of ultra-high frequency real partial discharge signals on-site, the signals are processed by statistical methods to obtain representative partial discharge signals with adjustable signal amplitude and frequency. The signal is injected into the GIS ultra-high frequency partial discharge online monitoring equipment by an arbitrary waveform generator, and the dynamic range of the online monitoring equipment is tested.

[0071] The dynamic range detection method of the UHF partial discharge online detection equipment based on the statistics of real partial discharge signals is easy to implement on site, simple to operate, and highly practical, and can be widely used in the inspection of the dynamic range of UHF partial discharge online monitoring equipment.

[0072] Based on the above test method, dynamic range test was carried out on the UHF partial discharge online monitoring equipment of two manufacturers.

[0073] Using the designated acquisition channel of the UHF partial discharge online monitoring device as a standard, 100 groups of single pulse signals containing different partial discharge types measured on site were processed into representative pulse signals through the statistical method of the above embodiment. The signal was output to an oscilloscope, and the output signal frequency was measured to be within the frequency range of 300MHz to 1.5GHz, the peak of the spectrum curve was concentrated at 600MHz, and the effective output amplitude range of the signal was obtained to be 4.4mV-740mV.

[0074] The waveform generator outputs the tested injection signal to the UHF PD online monitoring equipment of the two manufacturers to form an UHF PD online monitoring system. The above method is used to test the dynamic range of the online monitoring system, and a dynamic range calibration curve is drawn as shown in the figure. Figure 4A , Figure 4B As shown in the figure, the online monitoring equipment of these two manufacturers have a dynamic range of 40dBm (horizontal axis is -10-(-50)=40) and 65dbm (horizontal axis is -10-(-75)=65) respectively at the frequency of this UHF real signal (600MHz).

[0075] In summary, the above method for detecting the dynamic range of the GIS ultra-high frequency partial discharge online detection equipment provided by the present invention is based on the statistics of real partial discharge signals, and multiple groups of GIS ultra-high frequency partial discharge signals of different defect types are collected on site, and their interference signals are excluded. The effective signals are averaged as injection signals, which are injected into the online monitoring system, and the output amplitude of the arbitrary waveform generator is gradually increased. The sensitivity of the online monitoring equipment under the ultra-high frequency real partial discharge signal and the upper limit of the acquisition amplitude are obtained, and then the dynamic range of the online monitoring equipment at the specified frequency point is calculated. The operation is simple and practical.

[0076] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these adjustments and modifications of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these changes and modifications.

Claims

1. A dynamic range detection method for GIS ultra-high frequency partial discharge online detection equipment, characterized in that: include: The real partial discharge signal is processed by statistical method to generate a representative partial discharge signal as the injection signal; Testing whether each output signal of the arbitrary waveform generator for the injection signal is distorted; Build a GIS UHF partial discharge online monitoring system to measure the dynamic range of the GIS UHF partial discharge online monitoring equipment using undistorted injection signals; Determine the background noise of the constructed GIS UHF partial discharge online monitoring system; Determine the dynamic range of the GIS UHF partial discharge online monitoring equipment at the specified frequency point until the dynamic range of the GIS UHF partial discharge online monitoring equipment at different frequencies is obtained.

2. The dynamic range detection method of GIS UHF partial discharge online detection equipment according to claim 1, characterized in that: The method of processing the real partial discharge signal by a statistical method to generate a representative partial discharge signal as an injection signal includes: Multiple groups of GIS ultra-high frequency partial discharge signals with different defect types are collected at the GIS site; their interference signals are eliminated respectively, and the multiple groups of effective signals are averaged to obtain representative partial discharge signals as injection signals.

3. The dynamic range detection method of GIS UHF partial discharge online detection equipment according to claim 2, characterized in that: The method of collecting multiple groups of GIS UHF partial discharge signals of different defect types at the GIS site includes: Arrange multiple built-in UHF sensors to detect internal discharge signals of GIS; Arrange at least one external space UHF sensor to detect discharge signals in the external space of GIS; Defect types include any of the following: tip defects, suspension defects, air gap defects, particle defects, and poor contact current type defects.

4. The dynamic range detection method of GIS UHF partial discharge online detection equipment according to claim 1, characterized in that: The testing of whether each output signal of the arbitrary waveform generator for the injection signal is distorted comprises: An arbitrary waveform generator is used as a signal output source, the injection signal is introduced into the arbitrary waveform generator and output by the arbitrary waveform generator, and the output signal of the arbitrary waveform generator is measured by an oscilloscope; The operating parameters of the arbitrary waveform generator are set to different amplitudes and frequencies, and an oscilloscope is used to check whether the output signals of the arbitrary waveform generator are distorted.

5. The dynamic range detection method of GIS UHF partial discharge online detection equipment according to claim 1, characterized in that: The construction of the GIS ultra-high frequency partial discharge online monitoring system comprises: Disconnect the coaxial cable of the designated channel of the GIS ultra-high frequency partial discharge online monitoring equipment from its built-in sensor, connect the coaxial cable of the designated channel to the arbitrary waveform generator, and use the program to record the amplitude displayed by the online monitoring equipment.

6. The dynamic range detection method of GIS UHF partial discharge online detection equipment according to claim 5, characterized in that: The background noise of the GIS ultra-high frequency partial discharge online monitoring system determined to be built includes: When the program determines that the online monitoring device has no background noise display, the arbitrary waveform generator is turned on and the amplitude of the arbitrary waveform generator output signal is gradually increased so that the monitoring system has a stable acquisition signal display. The program records the data amplitude monitored by the monitoring system at this time as background noise.

7. The dynamic range detection method of GIS UHF partial discharge online detection equipment according to claim 6, characterized in that: Determining the dynamic range of the GIS UHF partial discharge online monitoring device at a specified frequency point includes: After determining the background noise, set the arbitrary waveform generator to operate at the specified frequency; Increase the output signal amplitude of the arbitrary waveform generator so that the monitoring system has a stable acquisition signal display. When the program detects that the data amplitude displayed by the monitoring system is 3dBm greater than the background noise at this time, determine that the displayed data amplitude is the sensitivity of the online monitoring device at the specified frequency point; After determining the sensitivity at the specified frequency point, continue to increase the output signal amplitude, output signal amplitude every 10dB, record a set of arbitrary waveform generator output signal amplitude and online monitoring equipment display amplitude; when the GIS UHF partial discharge online monitoring equipment displays amplitude approaching saturation, record a set of amplitude data every 1dBm; Compare the two latest sets of amplitude data until it is determined that the online monitoring device displays amplitude saturation, and use the amplitude collected by the online monitoring device at the specified frequency point in the latest set of amplitude data as the upper limit of the amplitude collected by the online monitoring device at the specified frequency point; The difference between the upper limit of the amplitude collected by the UHF partial discharge online monitoring device and the sensitivity is taken as the dynamic range of the online monitoring device at the specified frequency point.

8. The method according to claim 7, characterized in that Also includes: The frequency of the output signal of the arbitrary waveform generator is gradually increased and used as the updated designated frequencies respectively; for each updated designated frequency, the dynamic range of the GIS ultra-high frequency partial discharge online monitoring equipment at the designated frequency point is determined until the dynamic range of the GIS ultra-high frequency partial discharge online monitoring equipment at different frequencies is obtained.

9. The dynamic range detection method of GIS UHF partial discharge online detection equipment according to claim 2, characterized in that: The method of processing the real partial discharge signal by a statistical method to generate a representative partial discharge signal as an injection signal includes: By comparing the output signals of the built-in sensor channel and the external sensor channel, the interference signal in the GIS UHF partial discharge signal collected on site can be eliminated.

10. The dynamic range detection method of GIS UHF partial discharge online detection equipment according to claim 3, characterized in that: The built-in UHF sensor or the external space UHF sensor is a broadband UHF sensor of 300MHz to 1500MHz.

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