Gas discharge electrical property monitoring method and device and computer program product

Abstract

The invention discloses a gas discharge electrical property monitoring method and device and a computer program product, and the method comprises the steps: constructing a combined electrode system comprising a pin electrode and a planar electrode; applying a controllable voltage on the composite electrode system to generate a gradient discharge condition; continuously capturing a brightness change event stream in the discharge process through a dynamic vision sensor, wherein the brightness change event stream comprises a brightening event data channel and a darkening event data channel; respectively executing time sequence window integration on the dual-channel brightness change event stream to generate a lightening event number time sequence and a darkening event number time sequence, and extracting a lightening event maximum number and a darkening event maximum number corresponding to each voltage gradient from the lightening event number time sequence and the darkening event number time sequence; establishing a mapping relation model of the event maximum number and the voltage characteristics; and substituting the maximum number of events collected in real time into the established mapping relation model to carry out inversion calculation, and obtaining equivalent electrical parameters in the discharge process. According to the invention, non-contact high-precision electrical property monitoring is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular, to a method, device, and computer program product for monitoring the electrical characteristics of gas discharges. Background Art

[0002] As a key research object in the fields of power systems, plasma physics, and environmental science, the real-time monitoring of the electrical characteristics during the gas discharge process is of great significance for equipment status evaluation and discharge mechanism research. The current mainstream detection methods can be divided into two major technical paths: contact measurement and non-contact detection:

[0003] The contact measurement method can accurately obtain electrical characteristic parameters such as voltage and current during the discharge process by directly accessing the measured circuit, and its measurement results have high time resolution and amplitude accuracy. However, this method has significant limitations: on the one hand, it is necessary to install electrodes or sensors on the measured equipment, which may disturb the original electric field distribution and affect the authenticity of the discharge characteristics; on the other hand, it is difficult to realize the on-line monitoring of equipment with complex structures, and safety hazards may be introduced especially in high-voltage insulation equipment.

[0004] The non-contact detection technology uses means such as ultra-high frequency (UHF) electromagnetic wave detection, ultraviolet imaging, and ultrasonic signal analysis to indirectly observe by capturing the secondary physical effects generated by the discharge. Such methods have the advantage of non-invasiveness, but there are the following technical bottlenecks: First, the UHF method is easily affected by environmental electromagnetic noise and cannot directly obtain the discharge current waveform; second, the ultraviolet imaging method can only detect surface discharges and is insensitive to internal discharges; third, the ultrasonic detection method is significantly affected by the propagation distance and medium attenuation, and it is difficult to realize long-distance positioning. The above technologies cannot directly reflect the electrical essential characteristics of the discharge process, and there is a lack of effective multi-physical field coupling characteristic analysis means among the methods. Summary of the Invention

[0005] The technical problem to be solved by the embodiments of the present invention is to provide a method, device, and computer program product for monitoring the electrical characteristics of gas discharges to achieve non-contact high-precision electrical characteristic monitoring.

[0006] To solve the above technical problem, the present invention provides a method for monitoring the electrical characteristics of gas discharges, including:

[0007] Step S1, constructing a composite electrode system including a needle electrode and a planar electrode;

[0008] Step S2, applying a controllable voltage to the composite electrode system to generate a gradient discharge condition;

[0009] Step S3: Continuously capture the stream of brightness change events during the discharge process through a dynamic vision sensor. The stream of brightness change events includes a channel for brightening event data and a channel for dimming event data;

[0010] Step S4: Perform temporal window integration on the dual-channel brightness change event stream respectively to generate a temporal sequence of the number of brightening events and a temporal sequence of the number of dimming events, and extract the maximum number of brightening events and the maximum number of dimming events corresponding to each voltage gradient therefrom;

[0011] Step S5: Establish a mapping relationship model between the maximum number of events and the voltage characteristics through time-frequency dual-domain analysis;

[0012] Step S6: Substitute the maximum number of events collected in real time into the established mapping relationship model for inversion calculation to obtain the equivalent electrical parameters during the discharge process.

[0013] Preferably, the composite electrode system includes two parallel planar electrodes, and the needle electrode is vertically installed at the center of the lower planar electrode and insulated from the planar electrode through a polytetrafluoroethylene insulating layer.

[0014] Preferably, the controllable voltage applied to the needle electrode is specifically a pulsed DC voltage of 15 KV, and the voltage adjustment range of the planar electrode is 10 - 20 KV, with an adjustment gradient of 2 KV.

[0015] Preferably, in step S3, the event detection threshold of the dynamic vision sensor is set to a relative brightness change of 15%; the brightening event data channel corresponds to the event stream with a polarity code p = +1, and the dimming event data channel corresponds to the event stream with a polarity code p = -1.

[0016] Preferably, in step S4, the window length of the temporal window integration is 100 μs, and the event stream is processed in a non-overlapping sliding window manner; the maximum number of brightening events and the maximum number of dimming events are respectively extracted from the global extreme values of the sequences under each voltage gradient.

[0017] Preferably, the time-frequency dual-domain analysis in step S5 includes: aligning and verifying the duration of the temporal sequence of the number of brightening events with the duration of the discharge voltage dropping to zero potential, and the duration is determined by the time window corresponding to the maximum number of events.

[0018] Preferably, the time-frequency dual-domain analysis in step S5 includes: in the frequency-domain correlation analysis, the fast Fourier transform is used to calculate the spectrum, and the linear relationship between the event spectrum and the voltage spectrum is verified through the Pearson correlation coefficient.

[0019] Preferably, in step S6, the mapping relationship model is constructed based on the positive correlation between the maximum number of brightening events and the discharge voltage, and the positive correlation between the maximum number of darkening events and the electric field strength, and the equivalent electrical parameter inversion is performed through the linear mapping relationship determined by the time-frequency double-domain analysis.

[0020] The present invention also provides a gas discharge electrical property monitoring device, including:

[0021] One or more processors;

[0022] A memory;

[0023] One or more applications, wherein the one or more applications are stored in the memory and are configured to be executed by the one or more processors, and the one or more applications are configured to execute the gas discharge electrical property monitoring method described above.

[0024] The present invention also provides a computer program product, including computer instructions, and the computer instructions instruct a computer device to perform the operations corresponding to the method.

[0025] Implementing the present invention has the following beneficial effects: The present invention breaks through the interference and safety hazards of the traditional contact measurement to the electric field, and uses the optical event stream characteristics to realize non-invasive monitoring; through the high spatio-temporal resolution and electromagnetic interference resistance of the dynamic vision sensor, the dynamic characteristics of photon generation and dissipation during the discharge process are synchronously captured, overcoming the spatial limitations and signal attenuation defects of methods such as ultraviolet imaging and ultrasonic detection; based on the time-frequency double-domain correlation analysis of the polarity classification event stream, the technical bottleneck that the traditional indirect detection method cannot directly reflect the electrical essential characteristics is solved; the constructed mapping relationship model has strong generalization ability, can adapt to discharge scenarios with different voltage conditions and electrode structures, provides a high-precision and real-time solution for on-line monitoring and fault diagnosis of power equipment, and at the same time provides a new characterization means for the research of multi-physical field coupling mechanisms. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Figure 1 It is a schematic flow chart of a gas discharge electrical property monitoring method according to Embodiment 1 of the present invention.

[0028] Figure 2 It is a schematic structural diagram of a three-electrode system established in the embodiment of the present invention.

[0029] Figure 3 It is a schematic diagram showing the variation of the maximum number of brightening events and the maximum number of dimming events with voltage in the embodiments of the present invention.

[0030] Figure 4 It is a schematic diagram of the comparative analysis of the number of events and voltage characteristics through the time domain and frequency domain in the embodiments of the present invention. Specific Embodiments

[0031] The following descriptions of the embodiments are with reference to the accompanying drawings, which are used to exemplify specific embodiments in which the present invention can be implemented.

[0032] Please refer to Figure 1 As shown, Embodiment 1 of the present invention provides a method for monitoring the electrical characteristics of gas discharge, including:

[0033] Step S1, constructing a composite electrode system including a needle electrode and a planar electrode;

[0034] Step S2, applying a controllable voltage to the composite electrode system to generate a gradient discharge condition;

[0035] Step S3, continuously capturing the stream of brightness change events during the discharge process through a dynamic vision sensor, where the stream of brightness change events includes a brightening event data channel and a dimming event data channel;

[0036] Step S4, respectively performing time series window integration on the two-channel brightness change event stream to generate a time series of the number of brightening events and a time series of the number of dimming events, and extracting the maximum number of brightening events and the maximum number of dimming events corresponding to each voltage gradient therefrom;

[0037] Step S5, establishing a mapping relationship model between the maximum number of events and voltage characteristics through time-frequency double-domain analysis;

[0038] Step S6, substituting the maximum number of events collected in real time into the established mapping relationship model for inversion calculation to obtain the equivalent electrical parameters during the discharge process.

[0039] From the above steps, it can be seen that the present invention constructs a gradient discharge environment through a composite electrode system, combines a dynamic vision sensor to capture the event stream of polarity classification, and innovatively uses time series integration processing to extract the peak event number characteristics, and establishes a mapping model between event characteristics and electrical parameters through time-frequency double-domain composite verification, realizing non-contact high-precision electrical characteristic monitoring.

[0040] Specifically, the dynamic vision sensing technology is a bionic vision technology formed by imitating the actions of the human eye. Instead of capturing images at a fixed rate, it measures the brightness changes of each pixel point asynchronously and outputs an event stream encoded with the time, position, and sign of the brightness changes. Using the brightness change information to reflect the characteristic physical quantities of the discharge process is a brand-new idea.

[0041] To obtain electrical property information, the present invention first constructs a DC "three-electrode" structure. As Figure 2 shown, the "three-electrode" structure consists of two parallel planar electrodes (diameter 250 mm) and a needle electrode. The gap between the two planes is 30 mm. The needle electrode is located at the center of the lower planar electrode and is insulated from the planar electrode by a layer of polytetrafluoroethylene. As an example, the planar electrodes are made of copper, and the needle electrode is made of tungsten steel with a tip curvature radius of 50 μm to ensure discharge concentration.

[0042] A 15 KV pulsed DC high voltage is applied to the needle electrode and its voltage is kept constant; the DC voltages of the two planar electrodes are respectively adjusted by a high-voltage power supply, starting from 10 KV and increasing by 2 KV each time up to 20 KV, to form discharge conditions under multiple voltage gradients. After each voltage adjustment, the actual voltage value of the planar electrode is recorded, and the dynamic vision sensor is synchronously triggered to start data acquisition.

[0043] A dynamic vision sensor (DVS) is arranged facing the discharge gap, and the event detection threshold is set at 15% relative brightness change. When a discharge occurs, the DVS asynchronously outputs event stream data composed of pixel coordinates, timestamps, and polarity encoding. Among them, when the polarity dimension p = +1, it is classified as the brightening event data channel, and when p = -1, it is classified as the darkening event data channel.

[0044] As Figure 3 shown, the two-channel event stream is processed by time-series window integration, specifically using the sliding time window cumulative counting method: for the brightening event channel, with an integration window length of 100 μs, the number of events within the window is statistically generated in chronological order to form the ON sequence; the same parameters are used for the darkening event channel to generate the OFF sequence. The maximum value ON max is extracted from the ON sequences under each voltage gradient, and the maximum value OFF max is extracted from the OFF sequences, which respectively represent the peak intensities of photon generation and dissipation during the discharge process.

[0045] It can be found that the maximum number of brightening events ON max shows a gradually increasing trend as the voltage increases. ON max represents the moment when the light intensity changes fastest during the process from streamer development to discharge stabilization. ON maxThe increase in the number of events with the increase in voltage indicates that as the electric field strength increases, when the length of the region occupied by space charge in the gap reaches the flat electrode, more intense and powerful streamer pulses penetrate the entire gap, resulting in the maximum number of brightening events ON max Gradually increases as the voltage increases.

[0046] In addition, the maximum number of darkening events OFF at different voltages max Also increases as the voltage increases. When the plate distance remains unchanged, as the voltage increases, the electric field strength also increases, and the velocity of charged particles flowing into the electrode under the action of the electric field force speeds up. The density of positive ion and electron space charge particles rapidly decreases, and the dissipation rate of the number of photons is greater than the generation rate. That is, as the electric field strength increases, the arc dissipates more, so OFF max Shows an upward trend with the increase in voltage.

[0047] Please refer to again Figure 4 As shown, in the embodiment of the present invention, time-frequency dual-domain analysis compares and analyzes the number of events and voltage characteristics from the time domain and the frequency domain. By changing the integration time, the variation of the number of events with time under a 100 μs integration time, the variation of the number of events with time under a 1 ms integration time, and the variation of voltage with time are obtained. From the time-domain waveform, the duration of the maximum value of the DVS event number is almost the same as the duration when the voltage drops to 0 during flashover. Specifically:

[0048] 1. Time-domain comparison: Align the durations at the corresponding moments of ON max and OFF max with the duration when the voltage drops to zero in the discharge voltage waveform to verify the synchronism between the two in the time domain;

[0049] 2. Frequency-domain correlation: Perform fast Fourier transform (FFT) on the ON sequence, OFF sequence, and voltage signal respectively to obtain the frequency spectra of the DVS and flashover processes, and compare the relationship between the number of events and the voltage signal. Use the Pearson correlation coefficient (Pearson Correlation Coefficient, PCC) to characterize the relationship between the two. PCC measures the linear relationship between two variables, and its value ranges from -1 to 1. The closer the value is to 1 or -1, the stronger the linear relationship between the two variables. Calculate the Pearson correlation coefficient (Pearson Correlation Coefficient, PCC) between the ON max frequency spectrum and the voltage spectrum: PCC = 0.9655; OFF maxPearson correlation coefficient between the spectrum and the voltage spectrum: PCC = 0.955, and the PCC between the ON event spectrum and the OFF event spectrum is 0.958. The correlation coefficients are all greater than 0.95, showing a linear correlation. A linear mapping relationship model between the maximum number of events and the voltage amplitude and frequency components is established.

[0050] In actual monitoring, the real-time collected ON max and OFF max data are input into the linear mapping relationship model, and the equivalent voltage amplitude, discharge duration, and arc dissipation rate parameters during the discharge process are directly output through inversion calculation, realizing non-contact quantitative monitoring of electrical characteristics.

[0051] By studying the relationship between the number of ON and OFF events and the test voltage, the correlation between the characteristic physical quantities in the discharge process and the number of events is found. The maximum number of brightening events ON max is related to the generation of photons and is affected by the discharge intensity. OFF max is related to the dissipation of photons and is affected by the electric field intensity. They are all positively correlated with the voltage applied between the plates. By relating the number of events to the electrical characteristics, new ideas and solutions can be provided for discharge observation and feature extraction.

[0052] Corresponding to the gas discharge electrical characteristic monitoring method described in the foregoing Embodiment 1 of the present invention, Embodiment 2 of the present invention further provides a gas discharge electrical characteristic monitoring device, including:

[0053] One or more processors;

[0054] A memory;

[0055] One or more applications, wherein the one or more applications are stored in the memory and are configured to be executed by the one or more processors. The one or more applications are configured to execute the gas discharge electrical characteristic monitoring method described in the foregoing Embodiment 1 of the present invention.

[0056] Corresponding to the gas discharge electrical characteristic monitoring method described in the foregoing Embodiment 1 of the present invention, Embodiment 3 of the present invention further provides a computer program product, including computer instructions, and the computer instructions instruct a computer device to execute the operations corresponding to the gas discharge electrical characteristic monitoring method described in the foregoing Embodiment 1 of the present invention.

[0057] Preferably, the processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor, or the processor may also be any conventional processor. The processor is the control center of the device, connecting various parts of the device through various interfaces and circuits.

[0058] The memory mainly includes a program storage area and a data storage area. Among them, the program storage area can store an operating system, application programs required for at least one function, etc., and the data storage area can store relevant data, etc. In addition, the memory may be a high-speed random access memory, or may also be a non-volatile memory, such as a plug-in hard disk, a SmartMedia Card (SMC), a Secure Digital (SD) card, a Flash Card, etc., or the memory may also be other volatile solid-state storage devices.

[0059] It should be noted that the above device may include, but is not limited to, a processor and a memory, which can be understood by those skilled in the art.

[0060] For the working principles and processes of the above embodiments, refer to the description of Embodiment 1 of the present invention above, and details will not be repeated here.

[0061] From the above description, it can be seen that compared with the prior art, the beneficial effects of the present invention are as follows: The present invention breaks through the interference and safety hazards of traditional contact measurement to the electric field, and realizes non-invasive monitoring by using the characteristics of optical event streams; through the high spatio-temporal resolution and electromagnetic interference resistance of the dynamic vision sensor, it synchronously captures the dynamic characteristics of photon generation and dissipation during the discharge process, overcoming the spatial limitations and signal attenuation defects of methods such as ultraviolet imaging and ultrasonic detection; based on the time-frequency dual-domain correlation analysis of the polarity classification event stream, it solves the technical bottleneck that the traditional indirect detection method cannot directly reflect the electrical essential characteristics; the constructed mapping relationship model has strong generalization ability, can adapt to discharge scenarios with different voltage conditions and electrode structures, provides a high-precision and real-time solution for on-line monitoring and fault diagnosis of power equipment, and at the same time provides a new characterization means for the research of multi-physical field coupling mechanisms.

[0062] The above-disclosed is only the preferred embodiment of the present invention, and of course, it cannot be used to limit the scope of the rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A method for monitoring the electrical characteristics of gas discharge, characterized in that, Comprising: Step S1, constructing a composite electrode system including a needle electrode and a planar electrode; Step S2, applying a controllable voltage to the composite electrode system to generate a gradient discharge condition; Step S3, continuously capturing an event stream of brightness changes during the discharge process through a dynamic vision sensor, the event stream of brightness changes including a brightening event data channel and a dimming event data channel; Step S4, respectively performing time-series window integration on the dual-channel event stream of brightness changes to generate a time-series sequence of the number of brightening events and a time-series sequence of the number of dimming events, and extracting the maximum number of brightening events and the maximum number of dimming events corresponding to each voltage gradient therefrom; Step S5, establishing a mapping relationship model between the maximum number of events and voltage characteristics through time-frequency dual-domain analysis; Step S6, substituting the maximum number of events collected in real time into the established mapping relationship model for inversion calculation to obtain the equivalent electrical parameters during the discharge process.

2. The method according to claim 1, wherein The composite electrode system includes two parallel planar electrodes, the needle electrode is vertically installed at the center of the lower planar electrode, and is insulated from the planar electrode through a polytetrafluoroethylene insulating layer.

3. The method according to claim 1, characterized in that, The controllable voltage applied to the needle electrode is specifically a pulsed DC voltage of 15 KV, and the voltage adjustment range of the planar electrode is 10 - 20 KV, with an adjustment gradient of 2 KV.

4. The method according to claim 1, wherein In the step S3, the event detection threshold of the dynamic vision sensor is set to 15% relative brightness change; the brightening event data channel corresponds to an event stream with a polarity encoding p = +1, and the dimming event data channel corresponds to an event stream with a polarity encoding p = -1.

5. The method according to claim 1, wherein In the step S4, the window length of the time-series window integration is 100 μs, and the event stream is processed in a non-overlapping sliding window manner; the maximum number of brightening events and the maximum number of dimming events are respectively extracted from the global extrema of the sequences under each voltage gradient.

6. The method according to claim 1, wherein The time-frequency dual-domain analysis in the step S5 includes: aligning and verifying the duration of the time-series sequence of the number of brightening events with the duration of the discharge voltage dropping to zero potential, and the duration is determined by the time window corresponding to the maximum number of events.

7. The method according to claim 1, wherein The time-frequency dual-domain analysis in the step S5 includes: in the frequency-domain correlation analysis, the spectrum is calculated using the fast Fourier transform, and the linear relationship between the event spectrum and the voltage spectrum is verified through the Pearson correlation coefficient.

8. The method according to claim 1, characterized in that, In the step S6, the mapping relationship model is constructed based on the positive correlation between the maximum number of brightening events and the discharge voltage, and the positive correlation between the maximum number of dimming events and the electric field strength, and the equivalent electrical parameter inversion is performed through the linear mapping relationship determined by the time-frequency dual-domain analysis.

9. A gas discharge electrical property monitoring device, characterized in that, Comprising: One or more processors; A memory; One or more applications, wherein the one or more applications are stored in the memory and are configured to be executed by the one or more processors, and the one or more applications are configured to execute the gas discharge electrical characteristic monitoring method according to any one of claims 1 to 8.

10. A computer program product, characterized in that, Including computer instructions, the computer instructions instructing the computer device to perform the operations corresponding to the method according to any one of claims 1 to 8.

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