Partial discharge optical detection system and method based on pulse width and amplitude cooperative discrimination

Abstract

The invention discloses a partial discharge optical detection system and method based on pulse width and amplitude cooperative discrimination, and the system is characterized in that an optical detection module is used for capturing an optical signal generated in a partial discharge process, and converting the optical signal into an electric signal; the signal processing module is used for respectively transmitting the electric signals to an analog signal processing unit and a digital signal processing unit for shunt processing; the post-processing module is used for collecting and processing data generated by the analog signal processing unit and data generated by the digital signal processing unit; the optical detection module captures an optical signal generated in the partial discharge process and converts the optical signal into an electric signal, the analog signal processing unit and the digital signal processing unit carry out shunt processing, and the post-processing module collects data generated by the analog signal processing unit and data generated by the digital signal processing unit. And the type of partial discharge is identified by performing fusion analysis on the acquired data.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of discharge detection, and in particular to a partial discharge optical detection system and method based on pulse width and amplitude cooperation. BACKGROUND

[0002] Partial discharge detection is a key technology in power equipment state monitoring, used for early detection of insulation defects and prevention of equipment failure. Traditional detection methods mainly rely on electrical signal measurement, such as pulse current method and ultra-high frequency detection method, but these methods are susceptible to electromagnetic interference and difficult to accurately capture discharge characteristics. In recent years, optical signal measurement technology has gradually attracted attention due to its advantages such as anti-electromagnetic interference and high sensitivity, and can effectively detect ultraviolet or visible light signals generated by partial discharge.

[0003] Patent document "System and method for calibrating and evaluating optical performance of partial discharge optical sensor based on integrating photometry" (publication number: CN119439025A) proposes a system that uses an integrating sphere system to evaluate the optical performance of a partial discharge optical sensor based on integrating photometry. Signal amplifiers and filters are used to reduce noise interference to some extent. However, this method measures standardized light signals generated artificially and does not consider the capture of weak light signals under electromagnetic interference.

[0004] Patent document "Multi-channel optical detection system for partial discharge of power equipment based on emission spectrum method" (publication number: CN111624449A) proposes a multi-channel spectral measurement system equipped with filters of different wavelengths, which can diagnose different characteristic spectral band signals in partial discharge. However, this system does not consider the capture of weak light signals under electromagnetic interference.

[0005] Patent document "GIL partial discharge detection device and method based on emission spectrum" (publication number: CN115436764A) proposes a partial discharge spectral diagnosis system containing a light collection assembly, suitable for weak partial discharge scenarios with weak light signals. However, this system only amplifies the input signal, improving the signal-to-noise ratio of system noise, and cannot handle the noise carried by the light signal itself.

[0006] Patent document "GIS partial discharge combined detection device and GIS with the device" (publication number: CN116699320A) proposes a partial discharge combined detection device that combines ultra-high frequency signal detection and spectral diagnosis system, using spectral diagnosis to compensate for the problem of ultra-high frequency signal detection being susceptible to electromagnetic interference. However, this system does not consider the capture of weak light signals under electromagnetic interference.

[0007] The patent document "A kind of power automatic seamless switching device" (publication number: CN118040867A) proposes a technical means of double-path measurement voltage, one signal mode for determining whether there is voltage, and another AD sampling for displaying actual voltage. However, this method is not applied to spectral signal acquisition.

[0008] In summary, how to capture weak optical signals in a complex electromagnetic environment and further distinguish partial discharge is a direction worthy of research. Therefore, we propose a partial discharge optical detection system and method based on pulse width and amplitude cooperative discrimination. SUMMARY

[0009] The problem to be solved by the present application is how to solve the problem of capturing weak optical signals in a complex electromagnetic environment and further distinguishing partial discharge.

[0010] To solve the above technical problems, the present application provides the following technical solutions: a partial discharge optical detection system and method based on pulse width and amplitude cooperative discrimination.

[0011] The technical solutions of the present application are as follows: On the one hand, the present application provides a partial discharge optical detection system based on pulse width and amplitude cooperative discrimination, comprising: An optical detection module for capturing optical signals generated during partial discharge and converting the optical signals into electrical signals; A signal processing module for transmitting the electrical signals to an analog signal processing unit and a digital signal processing unit for separate processing; A post-processing module for collecting and processing data generated by the analog signal processing unit and data generated by the digital signal processing unit.

[0012] As a preferred solution of the partial discharge optical detection system based on pulse width and amplitude cooperative discrimination, the optical detection module includes a coupled optical fiber probe and a photodiode, the optical fiber probe is used to capture optical signals generated during partial discharge, the optical fiber probe uses a quartz optical fiber probe, and the photodiode is used to convert the captured optical signals into electrical signals.

[0013] As a preferred solution of the partial discharge optical detection system based on pulse width and amplitude cooperative discrimination, the analog signal processing unit includes a wideband amplifier and a multi-stage filter, the wideband amplifier is used to amplify the electrical signals, the multi-stage filter includes a band-pass filter and a low-pass filter, the band-pass filter is used to filter out out-of-band interference signals, and the low-pass filter is used to suppress high-frequency noise, improve the signal-to-noise ratio and waveform fidelity of the electrical signals, and retain the amplitude information of the electrical signal pulses.

[0014] As a preferred scheme of the pulse width and amplitude collaborative discrimination partial discharge optical detection system, the wideband amplifier has a gain of not less than 80 times (≥40 dB), a bandwidth of more than 200 MHz, an input noise density of less than 5 nV / √Hz, and a rising edge of less than 1 ns.

[0015] As a preferred scheme of the pulse width and amplitude collaborative discrimination partial discharge optical detection system, the digital signal processing unit comprises a comparison amplifier, an analog-to-digital converter, and a digital processing unit. After the electric signal is amplified by the comparison amplifier, the electric signal is input to the analog-to-digital converter for digital sampling and then to the digital processing unit. After receiving the sampling data, the digital processing unit extracts the start time and end time of the electric pulse in real time, obtains the electric pulse width information, and generates a trigger signal based on the electric pulse characteristics, which is used to record the time node of the partial discharge and the phase interval in which the partial discharge occurs.

[0016] As a preferred scheme of the pulse width and amplitude collaborative discrimination partial discharge optical detection system, the comparison amplifier has a gain of between 10 and 20 times, a bandwidth of not less than 500 MHz, and a rising edge of less than 1 ns.

[0017] As a preferred scheme of the pulse width and amplitude collaborative discrimination partial discharge optical detection system, the post-processing module comprises a data acquisition module and a data processing module. The data acquisition module adopts a data acquisition card, which has a multi-channel input and is used to synchronously record the electric signal passing through the analog signal processing unit and the trigger signal generated by the digital signal processing unit. The data processing module performs fusion analysis on the electric signal passing through the analog signal processing unit and the trigger signal generated by the digital signal processing unit, comprehensively analyzes the amplitude information and width information of the electric signal and the trigger signal, and identifies the type of the partial discharge.

[0018] In another aspect, the application provides a pulse width and amplitude collaborative discrimination partial discharge optical detection method, which comprises the following steps: The light detection module is used to capture the optical signal generated in the partial discharge process and convert the optical signal into an electric signal; The signal processing module is used to transmit the electric signal to the analog signal processing unit and the digital signal processing unit for branch processing, respectively; The post-processing module is used to acquire the data generated by the analog signal processing unit and the data generated by the digital signal processing unit, and perform fusion analysis on the acquired data to identify the type of the partial discharge.

[0019] The present application has the beneficial effects that: the present application uses a double-path cooperative measurement strategy, that is, a wideband amplifier is used to ensure high-fidelity acquisition of the amplitude information of the electrical signal, the start and end time of the electrical pulse is accurately captured by comparing the amplifier and the analog-to-digital converter, and the two paths of information are fused and comprehensively judged, thereby effectively improving the sensitivity and anti-interference ability of the partial discharge detection, and being suitable for the field of high-precision partial discharge monitoring. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor. Among them: Figure 1 The flowchart of the present application. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be described in detail below with reference to the drawings of the specification. Embodiment 1

[0022] Reference Figure 1 The present embodiment is a partial discharge optical detection system for pulse width and amplitude cooperative discrimination, which comprises an optical detection module for capturing optical signals generated in the process of partial discharge and converting the optical signals into electrical signals; Since the partial discharge of the equipment will generate ultraviolet or visible light signals, and the optical signal measurement technology has the advantages of anti-electromagnetic interference and high sensitivity, it has become a means to detect the discharge of the equipment, so when the equipment is partially discharged, the optical detection module can capture the generated optical signals, and then convert the captured optical signals into electrical signals.

[0023] The signal processing module is used for transmitting the electrical signals to the analog signal processing unit and the digital signal processing unit for branch processing, respectively. After the captured optical signals are converted into electrical signals, a double-path cooperative measurement strategy is used to effectively improve the sensitivity and anti-interference ability of the partial discharge detection, and is suitable for the field of high-precision partial discharge monitoring.

[0024] The post-processing module is used for collecting and processing the data generated by the analog signal processing unit and the data generated by the digital signal processing unit.

[0025] The signals processed by the two paths are fused and analyzed to complete the recognition and classification of the partial discharge.

[0026] Preferably, the optical detection module comprises a fiber probe and a photodiode, the fiber probe is used to capture the optical signal generated in the process of partial discharge, the fiber probe is a quartz fiber probe, and the photodiode is used to convert the captured optical signal into an electrical signal.

[0027] The application adopts a quartz fiber probe with high sensitivity and low loss, the end of the fiber probe can be subjected to special grinding treatment to optimize the collection efficiency of a wide spectrum signal, the fiber probe is tightly coupled with a photodiode, the response time of the photodiode is better than 5 nanoseconds, the short pulse optical signal can be rapidly converted into an electrical signal output in the process of partial discharge, the interface structure of the fiber probe and the photodiode is reasonably designed, the optical signal has high transmission characteristics in the detection and conversion process, and the information of the original optical pulse is maximally reserved.

[0028] Preferably, the analog signal processing unit comprises a wideband amplifier and a multi-stage filter, the wideband amplifier is used to amplify the electrical signal, the multi-stage filter comprises a band-pass filter and a low-pass filter, the band-pass filter is used to filter out the out-of-band interference signal, and the low-pass filter is used to suppress high-frequency noise, improve the signal-to-noise ratio and waveform fidelity of the electrical signal, and reserve the amplitude information of the electrical signal pulse.

[0029] Preferably, the wideband amplifier has a gain of not less than 80 times (≥40 dB), a bandwidth of greater than 200 MHz, an input noise density of less than 5 nV / √Hz, and a rising edge of less than 1 ns.

[0030] The captured optical signal is converted into an electrical signal and enters the signal processing module to be processed in two ways. In the analog signal processing unit, the signal is first amplified by a wideband amplifier with low noise, high gain and wide bandwidth. The performance requirements of the wideband amplifier are as follows: the gain is not less than 80 times, the bandwidth is greater than 200 MHz, the input noise density is less than 5 nV / √Hz, the rising edge is less than 1 ns, and the wideband amplifier is connected in a direct current coupling mode to ensure the integrity of the low-frequency component. After wideband amplification, the signal is processed by a multi-stage filter in turn, including a band-pass filter with a center frequency and a bandwidth optimized according to the spectral characteristics of the partial discharge optical signal, and a low-pass filter with a cutoff frequency higher than 1.2 times the upper limit frequency of the band-pass filter. Thus, the out-of-band interference signal and high-frequency noise are effectively filtered out, the signal-to-noise ratio is improved, and the waveform fidelity is maintained.

[0031] Preferably, the digital signal processing unit comprises a comparison amplifier, an analog-to-digital converter and a digital processing unit, the electrical signal is amplified by the comparison amplifier and then input to the analog-to-digital converter for digital sampling and input to the digital processing unit, after receiving the sampling data, the digital processing unit extracts the start time and end time of the electrical pulse in real time, obtains the electrical pulse width information, and generates a trigger signal based on the electrical pulse characteristics, the trigger signal is used to record the time node of the partial discharge and the phase interval in which the partial discharge occurs.

[0032] Preferably, the gain of the comparison amplifier is between 10-20 times, the bandwidth is not less than 500 MHz, and the rising edge is less than 1 ns.

[0033] In the digital signal processing unit, the signal is first amplified by a high-bandwidth and fast-response comparison amplifier, the performance requirements of the comparison amplifier are that the gain is between 10-20 times, the bandwidth is not less than 500 MHz, the rising edge is less than 1 ns, and the group delay is flat, so as to ensure high-fidelity transmission of pulse shape and time structure, the output end can directly drive a 50-ohm load to match the input impedance of the analog-to-digital converter, the signal amplified by the comparison amplifier is then input to an analog-to-digital converter with a sampling rate not less than 1 GSa / s and a resolution not less than 12 bits for digital sampling, after receiving the sampling data, the digital processing unit extracts the start time and end time of the electrical pulse in real time, generates a synchronous trigger signal, and records relevant time parameters for subsequent analysis.

[0034] Preferably, the post-processing module comprises a data acquisition module and a data processing module, the acquisition module uses a data acquisition card, the data acquisition card has a multi-channel input for synchronously recording the electrical signal passing through the analog signal processing unit and the trigger signal generated by the digital signal processing unit, the data processing module performs fusion analysis on the electrical signal of the analog signal processing unit and the trigger signal generated by the digital signal processing unit, integrates the amplitude information and width information of the electrical signal and the trigger signal, and identifies the type of partial discharge.

[0035] The data acquisition card can synchronously acquire the electrical signal amplified and filtered by the analog signal processing unit and the trigger signal generated by the digital signal processing unit in real time, supports multi-channel synchronous input, has a sampling capacity of up to hundreds of megasamples per second and a resolution not less than 14 bits, the processor of the data processing module adopts a multi-core architecture and has high-efficiency parallel data processing capability, the system integrates the characteristics of partial discharge events by analyzing the electrical signal provided by the analog signal processing unit and the start and end time information of the electrical pulse provided by the digital signal processing unit, specifically, the processor obtains the pulse width by calculating the time difference between the rising edge and the falling edge of the electrical pulse, comprehensively judges in combination with the peak amplitude of the electrical signal, and classifies and evaluates the partial discharge events according to the set classification criteria (such as the pulse width being greater than 5 nanoseconds and the amplitude being greater than 1.5 volts). Embodiment 2

[0036] With reference to Figure 1 The embodiment is a partial discharge optical detection method based on pulse width and amplitude cooperation discrimination, comprising: capturing optical signals generated in the partial discharge process by an optical detection module, and converting the optical signals into electrical signals; transmitting the electrical signals to an analog signal processing unit and a digital signal processing unit for branch processing by a signal processing module; collecting data generated by the analog signal processing unit and data generated by the digital signal processing unit by a post-processing module, and identifying the type of partial discharge by fusion analysis on the collected data.

[0037] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not limited. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A partial discharge optical detection system with pulse width and amplitude collaborative discrimination, characterized in that, include: The optical detection module is used to capture the optical signals generated during partial discharge and convert the optical signals into electrical signals; The signal processing module is used to transmit electrical signals to the analog signal processing unit and the digital signal processing unit for split processing. The post-processing module is used to acquire and process data generated by the analog signal processing unit and the digital signal processing unit.

2. A partial discharge optical detection system for pulse width and amplitude co-discrimination as claimed in claim 1, characterized in that: The optical detection module includes a phase-coupled optical fiber probe and a photodiode. The optical fiber probe is used to capture the optical signal generated during partial discharge. The optical fiber probe is a quartz optical fiber probe. The photodiode is used to convert the captured optical signal into an electrical signal.

3. A partial discharge optical detection system for pulse width and amplitude correlation discrimination as claimed in claim 1, characterized in that: The analog signal processing unit includes a broadband amplifier and a multi-stage filter. The broadband amplifier is used to amplify the electrical signal. The multi-stage filter includes a band-pass filter and a low-pass filter. The band-pass filter is used to filter out interference signals outside the frequency band, and the low-pass filter is used to suppress high-frequency noise, improve the signal-to-noise ratio and waveform fidelity of the electrical signal, and preserve the amplitude information of the electrical signal pulse.

4. A partial discharge optical detection system for pulse width and amplitude co-discrimination as claimed in claim 3, characterized in that: The broadband amplifier has a gain of not less than 80 times (≥40 dB), a bandwidth greater than 200 MHz, an input noise density of less than 5 nV / √Hz, and a rise time of less than 1ns.

5. A partial discharge optical detection system for pulse width and amplitude co-discrimination as claimed in claim 4, characterised in that: The digital signal processing unit includes a comparator amplifier, an analog-to-digital converter, and a digital processing unit. After the electrical signal is amplified by the comparator amplifier, it is input to the analog-to-digital converter for digital sampling and then input to the digital processing unit. After receiving the sampled data, the digital processing unit extracts the start and end times of the electrical pulse in real time to obtain the electrical pulse width information, and generates a trigger signal based on the characteristics of the electrical pulse. The trigger signal is used to record the time node of partial discharge and its phase interval.

6. A partial discharge optical detection system for pulse width and amplitude co-discrimination as claimed in claim 5, characterized in that: The comparator amplifier gain is between 10 and 20 times, the bandwidth is not less than 500 MHz, and the rise time is less than 1 ns.

7. A partial discharge optical detection system for pulse width and amplitude co-discrimination as claimed in claim 6, characterised in that: The post-processing module includes a data acquisition module and a data processing module. The acquisition module uses a data acquisition card with multiple input channels to synchronously record the electrical signals from the analog signal processing unit and the trigger signals generated by the digital signal processing unit. The data processing module performs fusion analysis on the electrical signals from the analog signal processing unit and the trigger signals generated by the digital signal processing unit, and identifies the type of partial discharge by combining the amplitude and width information of the electrical signals and the trigger signals.

8. A partial discharge optical detection method based on the pulse width and amplitude collaborative discrimination according to any one of claims 1-7, characterized in that, Includes the following steps: The optical signal generated during partial discharge is captured by the optical detection module and converted into an electrical signal. The electrical signal is transmitted to the analog signal processing unit and the digital signal processing unit for split processing via the signal processing module. The post-processing module collects data generated by the analog signal processing unit and the digital signal processing unit, and then identifies the type of partial discharge by fusing and analyzing the collected data.

Images