Electric reactor vibration monitoring method based on contact sensor

Abstract

The invention discloses a reactor vibration monitoring method based on a contact sensor. The method mainly comprises the following steps: carrying out time domain analysis on an acquired vibration signal to extract a vibration amplitude and a root-mean-square value; spectral distribution is obtained through fast Fourier transform, and main vibration frequency components are identified; extracting a peak frequency fpeak, a peak amplitude Apeak, a spectrum energy integral Etotal and a peak width delta f in the spectrum; when the fpeakgt is determined to be fpeakgt; and determining that the signal is a partial discharge signal when the frequency is 100 kHz and the Apeak is more than three times higher than the background noise. According to the method, mechanical vibration and partial discharge signals can be effectively distinguished, and the detection sensitivity and the anti-interference capability are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power equipment monitoring and fault diagnosis, and particularly relates to an electric reactor vibration monitoring method based on a contact sensor. BACKGROUND

[0002] An electric reactor is an electrical device with inductive characteristics, which mainly produces impedance to current changes through its inductance, thereby playing a role in adjusting and protecting in the power system. According to different uses, electric reactors can be divided into shunt reactors, series reactors, filter reactors, current-limiting reactors, and smoothing reactors, etc. They are respectively used to absorb reactive power, limit short-circuit current, filter harmonics or smooth DC current, etc., and the core purpose is to control current or voltage changes by using inductive characteristics to ensure the stability and safety of system operation.

[0003] During the operation of the electric reactor, the alternating current produces an alternating magnetic field in the winding, which causes the winding and the core to be subjected to periodic mechanical stress and vibrate. The vibration frequency is usually related to the power frequency and its multiples, and belongs to low-frequency mechanical vibration signals. At the same time, partial discharge, as an electrical discharge phenomenon caused by insulation defects, occurs in local areas (such as air gaps, sharp tips, and bubbles inside), although it does not cause overall breakdown, it will produce high-frequency pulse electromagnetic waves, sound waves and light signals, and the characteristic vibration signal is usually in the range of tens of kHz to hundreds of MHz. In field monitoring, the high-frequency pulse of partial discharge signal is superimposed on the mechanical vibration signal, and accurate distinction between the two is crucial for equipment state evaluation.

[0004] In recent years, electric reactor vibration monitoring technology has attracted widespread attention. Chinese patent CN108195461A discloses an online monitoring method, device and system for electric reactor vibration, which comprises: through monitoring a plurality of sensors arranged at different positions of the electric reactor, extracting vibration signals under different states, analyzing the vibration signals, and determining the position of the vibration signal anomaly; according to the position of the vibration signal anomaly, combining the temperature of the plurality of sensors under the same state, and determining the best measurement position of the electric reactor. The online monitoring method, device and system for electric reactor vibration provided by the present application can realize online monitoring of electric reactor vibration, and can timely find out the hidden troubles of the electric reactor, avoid sudden accidents, and improve the safety and reliability of the electric reactor operation.

[0005] However, the prior art still has the following shortcomings: first, the frequency spectrum characteristics of partial discharge signals are not clearly specified in existing standards, and there is a lack of universal vibration monitoring devices or methods for different types and different service scenarios of electric reactors. Second, the existing technology focuses more on the collection and transmission of vibration signals, and lacks systematic signal conditioning and spectral analysis methods for accurately distinguishing low-frequency mechanical vibrations from high-frequency partial discharge pulse signals. Third, there is a lack of feasible methods for evaluating the working state of electric reactors through vibration monitoring, which cannot effectively predict device failures caused by long-term partial discharge, thereby causing corresponding safety hazards. Finally, although piezoelectric sensors show potential for application in partial discharge detection, their specific application scheme in electric reactor vibration monitoring, signal modulation module design, and partial discharge signal identification method have not yet formed a complete technical system. SUMMARY

[0006] To solve the above technical problems, the present application proposes the following technical solutions: An electric reactor vibration monitoring method based on a contact sensor, comprising the following steps: Step 1: arranging a piezoelectric ceramic vibration sensor on the core, winding or housing of the electric reactor, the sensitivity of the piezoelectric ceramic vibration sensor being 5-15 pC / g; Step 2: collecting the charge signal output by the piezoelectric ceramic vibration sensor and converting the charge signal into a voltage signal through a charge amplifier, the sensitivity of the charge amplifier being 5-20 g / V; Step 3: sequentially passing the voltage signal through a voltage follower, an active bandpass filter and an isolation amplifier for signal conditioning, wherein the active bandpass filter is used to remove high-frequency noise, low-frequency drift and power supply interference; Step 4: filtering out the direct current component in the voltage signal after signal conditioning through a coupling capacitor, the capacitance value of the coupling capacitor being 0.1-1 μF; Step 5: performing analog-to-digital conversion on the signal processed by the coupling capacitor, with a sampling frequency set to 100 Hz-1 MHz; Step 6: performing time domain analysis on the collected vibration signal to extract the vibration amplitude and root mean square value; Step 7: obtaining the frequency spectrum distribution through fast Fourier transform to identify the main vibration frequency components; Step 8: extracting the peak frequency fpeak, peak amplitude Apeak, spectral energy integral Etotal and peak width Δf in the frequency spectrum; Step 9: when fpeak>100 kHz and Apeak is more than 3 times the background noise, it is determined to be a partial discharge signal.

[0007] Further, the piezoelectric ceramic vibration sensor is installed on the surface of the reactor by screw fixing, magnetic attraction fixing or bonding.

[0008] Further, the piezoelectric ceramic element of the piezoelectric ceramic vibration sensor is BCTZ material.

[0009] Further, in step 3, the voltage follower is used to ensure that the input impedance is much higher than the output impedance of the piezoelectric element.

[0010] Further, in step 8, the frequency spectrum feature of the partial discharge signal is a sharp peak between 100-500 kHz.

[0011] Further, in step 5, data transmission is achieved by optical fiber communication or shielded twisted pair.

[0012] An electric reactor vibration monitoring system based on a contact sensor, comprising: A piezoelectric ceramic vibration sensor is arranged on the core, winding or shell of the reactor, and the sensitivity of the piezoelectric ceramic vibration sensor is 5-15 pC / g. A signal modulation module comprises a charge amplifier, a voltage follower, an active bandpass filter, an isolation amplifier and a coupling capacitor connected in sequence, the charge amplifier is used to convert the charge signal into a voltage signal and the sensitivity is 5-20 g / V, the active bandpass filter is used to remove high-frequency noise, low-frequency drift and power supply interference, and the capacitance value of the coupling capacitor is 0.1-1 μF. A data acquisition module is used to perform analog-to-digital conversion on the signals output by the signal modulation module, and the sampling frequency is 100 Hz-1 MHz. A data analysis module is used to perform time domain analysis and frequency spectrum analysis on the collected vibration signals, obtain the frequency spectrum distribution through fast Fourier transform and extract the peak frequency fpeak, peak amplitude Apeak, frequency spectrum energy integral Etotal and peak width Δf, and determine the partial discharge signal when fpeak>100 kHz and Apeak is more than 3 times the background noise. A monitoring terminal is used to receive the analysis results of the data analysis module and perform state evaluation and early warning.

[0013] Further, the piezoelectric ceramic vibration sensor comprises a joint, a shell, a mass block, a piezoelectric ceramic element and a device bottom fixing end.

[0014] Further, it further comprises a communication module, which realizes data transmission by optical fiber communication or shielded twisted pair.

[0015] Further, the piezoelectric ceramic vibration sensor is installed on the surface of the reactor by screw fixing, magnetic attraction fixing or bonding.

[0016] The present application has the following beneficial technical effects: The piezoelectric ceramic vibration sensor is arranged on the reactor winding to realize synchronous monitoring of the mechanical vibration signal of the device in the running process and the high-frequency pulse signal caused by partial discharge, the electrical signal output by the sensor is processed through amplification, filtering and impedance matching, high-precision sampling and spectrum analysis are performed, so that the low-frequency vibration and the high-frequency partial discharge pulse are distinguished. The present application can effectively distinguish the mechanical vibration and the partial discharge signal, improve the detection sensitivity and the anti-interference ability, and can evaluate the running state of different types of reactors and give early warning for the device failure caused by partial discharge. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structure schematic diagram of a reactor vibration monitoring system based on a contact sensor in an embodiment of the present application; Figure 2 is a schematic diagram of the sensor used in an embodiment of the present application; wherein 1 is a joint, 2 is a shell, 3 is a mass block, 4 is a piezoelectric ceramic element, and 5 is a device bottom fixed end; Figure 3 is a spectrum diagram of a typical discharge type; Figure 4 、 Figure 5 respectively show the sensitivity of different contact sensors in a wide frequency test range of 10Hz to 100Hz and 100kHz to 300kHz in different embodiments of the present application. DETAILED DESCRIPTION

[0018] In order for those skilled in the art to understand the technical solutions disclosed in the present application, the following will combine embodiments and related drawings to describe the technical solutions of the embodiments. Figures 1 to 5 The technical solutions of the embodiments are described, and the described embodiments are part of the embodiments of the present application, rather than all the embodiments. In this text, the phrase "embodiment" means that the specific features, structures or characteristics described in combination with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. Those skilled in the art can understand that the embodiments described herein can be combined with other embodiments.

[0019] In one embodiment, the present application discloses a reactor vibration monitoring method based on a contact sensor, comprising the following steps: Step 1: arranging a piezoelectric ceramic vibration sensor on the core, winding or shell of the reactor, the sensitivity of the piezoelectric ceramic vibration sensor being 5-15pC / g; Step 2: Collect the charge signal output by the piezoelectric ceramic vibration sensor and convert the charge signal into a voltage signal through a charge amplifier, the sensitivity of the charge amplifier being 5-20 g / V; Step 3: The voltage signal is sequentially subjected to signal conditioning through a voltage follower, an active band-pass filter and an isolation amplifier, wherein the active band-pass filter is used to remove high-frequency noise, low-frequency drift and power supply interference; Step 4: Remove the direct current component in the signal-conditioned voltage signal through a coupling capacitor, the capacitance of the coupling capacitor being 0.1-1 μF; Step 5: Perform analog-to-digital conversion on the signal processed by the coupling capacitor, the sampling frequency being set to 100 Hz-1 MHz; Step 6: Perform time-domain analysis on the collected vibration signal to extract the vibration amplitude and root mean square value; Step 7: Obtain the frequency spectrum distribution through fast Fourier transform to identify the main vibration frequency component; Step 8: Extract the peak frequency fpeak, peak amplitude Apeak, spectrum energy integral Etotal and peak width Δf in the frequency spectrum; Step 9: When fpeak>100 kHz and Apeak is higher than 3 times the background noise, it is determined to be a partial discharge signal.

[0020] In another embodiment, the piezoelectric ceramic vibration sensor is installed on the surface of the reactor by bolt fixation, magnetic attraction fixation or adhesion.

[0021] In another embodiment, the piezoelectric ceramic element of the piezoelectric ceramic vibration sensor is BCTZ material.

[0022] In another embodiment, in step 3, the voltage follower is used to ensure that the input impedance is much higher than the output impedance of the piezoelectric element.

[0023] In another embodiment, in step 8, the frequency spectrum characteristics of the partial discharge signal are a sharp peak between 100 kHz and 500 kHz.

[0024] In another embodiment, in step 5, data transmission is achieved through optical fiber communication or shielded twisted pair.

[0025] In another embodiment, the present application also discloses a reactor vibration monitoring system based on a contact sensor, comprising: A piezoelectric ceramic vibration sensor is arranged on the core, winding or shell of the reactor, the sensitivity of the piezoelectric ceramic vibration sensor being 5-15 pC / g; The signal modulation module comprises a charge amplifier, a voltage follower, an active band-pass filter, an isolation amplifier and a coupling capacitor connected in sequence, the charge amplifier is used for converting a charge signal into a voltage signal and has a sensitivity of 5-20 g / V, the active band-pass filter is used for removing high-frequency noise, low-frequency drift and power supply interference, and the coupling capacitor has a capacitance of 0.1-1 mu F; The data acquisition module is used for performing analog-digital conversion on the signal output by the signal modulation module, and has a sampling frequency of 100 Hz-1 MHz; The data analysis module is used for performing time-domain analysis and spectrum analysis on the collected vibration signal, obtaining a spectrum distribution through fast Fourier transform and extracting a peak frequency fpeak, a peak amplitude Apeak, a spectrum energy integral Etotal and a peak width Delta f, and determining that the signal is a partial discharge signal when fpeak>100 kHz and Apeak is higher than 3 times of background noise; The monitoring terminal is used for receiving the analysis result of the data analysis module and performing state evaluation and early warning.

[0026] For example, the data analysis module receives the data sent by the data acquisition module via the communication module. Figure 1 , Figure 1 The data analysis module is not shown.

[0027] In another embodiment, the piezoelectric ceramic vibration sensor comprises a joint, a shell, a mass block, a piezoelectric ceramic element and a device bottom fixed end.

[0028] In another embodiment, a communication module is further included, and the communication module realizes data transmission through optical fiber communication or shielded twisted pair.

[0029] In another embodiment, the piezoelectric ceramic vibration sensor is installed on the surface of the reactor through bolt fixing, magnetic attraction fixing or adhesion.

[0030] In another embodiment, the application discloses an on-line reactor vibration monitoring method based on a contact sensor, comprising the following steps: A piezoelectric ceramic vibration sensor with a sensitivity of 5-15 pC / g is arranged on the core, winding or shell of the reactor, and the sensor is installed through bolt fixing, magnetic attraction fixing or adhesion; A charge signal output by the sensor is collected and converted into a voltage signal through a charge amplifier with a sensitivity of 5-20 g / V; The voltage signal sequentially passes through a voltage follower, an active band-pass filter and an isolation amplifier for signal conditioning, wherein the voltage follower ensures that the input impedance is much higher than the output impedance of the piezoelectric element, and the active band-pass filter removes high-frequency noise, low-frequency drift and power supply interference; A direct current component is filtered through a coupling capacitor with a capacitance of 0.1-1 mu F; The processed signal is analog-to-digital converted, and the sampling frequency is set to 100 Hz-1 MHz; The collected vibration signal is analyzed in time domain to extract the vibration amplitude and root mean square value; The frequency spectrum distribution is obtained by fast Fourier transform to identify the main vibration frequency component; The peak frequency fpeak, peak amplitude Apeak, spectrum energy integral Etotal and peak width Δf in the frequency spectrum are extracted; when fpeak>100 kHz and Apeak is higher than 3 times the background noise, it is determined as a partial discharge signal.

[0031] For example, the background noise is measured under no discharge state; the piezoelectric ceramic element of the piezoelectric ceramic vibration sensor is BCTZ material, and data transmission is realized through optical fiber communication or shielded twisted pair. The spectrum characteristics of the partial discharge signal are sharp peaks between 100-500 kHz.

[0032] In another embodiment, the contact sensor-based reactor vibration monitoring method is as follows: 1) Piezoelectric ceramic vibration sensors are arranged at key positions such as the reactor core, winding or shell, which can be fixed by bolts or magnetic attraction; 2) The vibration signal during the test is collected, wherein the sensitivity of the piezoelectric sensor is 9 pC / g; 3) The charge signal output by the sensor is converted into a voltage signal by a charge amplifier, and then enters the signal modulation module, wherein the charge amplifier dynamically adjusts the sensitivity according to the piezoelectric sensor input signal size and test requirements, and the typical value is 10 g / V; a voltage follower is used between the sensor and the amplifier to ensure that the input impedance is much higher than the output impedance of the piezoelectric element; 4) An active band-pass filter is used to remove high-frequency noise, low-frequency drift and power supply interference, and an isolation amplifier is used to prevent high-voltage or surge signals from damaging the collection equipment; 5) The direct current component is filtered out through a coupling capacitor (usually 0.1-1 μF), and only the vibration signal is retained; 6) The conditioned analog signal enters the data acquisition module through the A / D sampling card, and the sampling frequency is generally set to 100 Hz-1 MHz to balance the low-frequency mechanical vibration and high-frequency partial discharge signal; 7) Data transmission is realized through optical fiber communication or shielded twisted pair to ensure signal integrity during long-distance transmission; 8) The collected vibration signal is analyzed in time domain to extract the vibration amplitude, root mean square value and other indicators to reflect the overall mechanical stability; 9) The frequency spectrum distribution is obtained by fast Fourier transform (FFT) to identify the main vibration frequency component.

[0033] An exemplary processing method of the monitoring result is as follows: 1) Transform the time-domain signal obtained by collection into a frequency spectrum to obtain the energy distribution of each frequency component, typically as shown in Figure 3 ; 2) If a sharp peak between 100-500 kHz appears in the frequency spectrum (such as at about 200 kHz in the figure), it is usually a partial discharge pulse signal; 3) Extract key feature parameters: peak frequency (f f peak ), peak amplitude (A A peak ), spectral energy integral (E E total ), and peak width (Δf f ); 4) If f f peak > 100 kHz and A A peak is much higher than the background noise (generally > 3 times), it can be determined as a partial discharge signal.

[0034] The following is a more specific example: Example 1: Typical Reactor Vibration Monitoring Implementation A piezoelectric ceramic vibration sensor with a sensitivity of 9 pC / g is arranged at a key position of the reactor core and is installed in a bolted manner; the charge signal output by the sensor is converted into a voltage signal by a charge amplifier with a sensitivity of 10 g / V; after the voltage signal passes through a voltage follower with an input impedance of 1 GΩ, it enters an active band-pass filter with a cutoff frequency of 1 Hz-500 kHz, and is then processed by an isolation amplifier; a 0.47 μF coupling capacitor is used to filter out the DC component; the signal is subjected to analog-to-digital conversion at a sampling frequency of 500 kHz; time-domain analysis shows that the vibration root mean square value is 0.12 m / s²; FFT spectrum analysis identifies the 50 Hz fundamental frequency and its harmonics, and detects a sharp peak with an amplitude of 5 times the background noise at 200 kHz, which is determined as a partial discharge signal. The piezoelectric ceramic element of the sensor uses BCTZ material, and shielded twisted pair is used for data transmission.

[0035] Verification: successfully distinguished 50 Hz mechanical vibration (0.12 m / s² RMS) from 200 kHz partial discharge signal (signal-to-noise ratio 5:1), verifying the effectiveness of the method Example 2: High-sensitivity sensor configuration A piezoelectric ceramic sensor (BCTZ material) with a sensitivity of 15 pC / g was used, and was fixed to the reactor winding by magnetic attraction; the sensitivity of the charge amplifier was set to 5 g / V to improve the small signal gain; the upper limit value of the coupling capacitor in the signal conditioning link was 1 μF; and the data was collected at a sampling frequency of 1 MHz. A 150 kHz partial discharge signal (signal-to-noise ratio 7:1) was detected, but the 50 Hz vibration signal was slightly attenuated (0.08 m / s² RMS) due to the filter setting.

[0036] Verification: The partial discharge detection sensitivity is improved by 40% (signal-to-noise ratio 7:1 vs 5:1), but the mechanical vibration measurement accuracy is reduced by 33% Example 3: Anti-interference implementation in the field In a strong electromagnetic interference environment, a 5 pC / g sensor was bonded to the reactor shell, and data was transmitted through an optical fiber; a two-stage filter was added to the signal modulation module, and the lower limit value of the coupling capacitor was 0.1 μF; and the sampling frequency was set to a lower limit of 600 kHz. A 300 kHz partial discharge signal (signal-to-noise ratio 4:1) was measured, effectively suppressing environmental noise interference below 2 kHz.

[0037] Verification: The partial discharge recognition ability is still maintained under 30 dB electromagnetic noise (signal-to-noise ratio 4:1), and the environmental noise suppression ratio is improved by 20 dB Comparative Example 1: Test conditions: same as Example 1: 9 pC / g sensor, 500 kHz sampling, same reactor sample Experimental results: partial discharge recognition accuracy 98%, mechanical vibration measurement error ± 5% Comparative Example 2: traditional accelerometer method Test conditions: same reactor was used, a 10 mV / g IEPE accelerometer was installed, and the sampling rate was 500 kHz Experimental results: only 50 Hz vibration (0.15 m / s² RMS) was detected, and a 200 kHz partial discharge signal (signal-to-noise ratio 1.2:1) was not recognized In another embodiment, in order to more intuitively reflect the sensitivity of the present application, the reference national grid test standard Q / GDW11021-2017 "Partial Discharge Ultrasonic Detector Test Specification" was tested, wherein a single test sensor and a calibration sensor (Type 4939, Brüel & Kjær, sensitivity of 3.85 mV•Pa-1) based on a contact sensor were placed on a variable vibration frequency excitation table, and a test platform was composed of a signal generator, a power amplifier, a charge amplifier, a digital acquisition card and an upper computer. The frequency spectrum response of the test sensor was obtained by comparing the outputs of the test sensor and the calibration sensor through the upper computer, and the frequency spectrum response result is as shown in Figure 4 、 Figure 5 . Figure 4 ,Figure 5 The sensitivity of different contact sensors in the wide frequency test range of 10Hz to 100Hz, 100kHz to 300kHz is shown respectively. For example, the single test sensor based on the contact sensor includes two different contact sensors of BZT-50BCT sensor (a typical one of BCTZ) and PZT-4 sensor, which are packaged with the same topology. The sensitivity in the figure is in dB, wherein the sensitivity of 0dB represents 1V·Pa -1 It can be seen that the sensor has high sensitivity to low-frequency mechanical vibration and high-frequency discharge signal, and can effectively distinguish mechanical vibration and discharge signal, and is suitable for monitoring the vibration of the electric reactor.

[0038] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents. The modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A contact sensor based method of monitoring vibration of a reactor, characterized by, The method comprises the following steps: Step 1: arranging a piezoelectric ceramic vibration sensor on the core, winding or shell of the reactor, the sensitivity of the piezoelectric ceramic vibration sensor being 5-15 pC / g; Step 2: collecting the charge signal output by the piezoelectric ceramic vibration sensor and converting the charge signal into a voltage signal through a charge amplifier, the sensitivity of the charge amplifier being 5-20 g / V; Step 3: sequentially subjecting the voltage signal to signal conditioning through a voltage follower, an active band-pass filter and an isolation amplifier, wherein the active band-pass filter is used to remove high-frequency noise, low-frequency drift and power supply interference; Step 4: filtering the direct current component in the signal-conditioned voltage signal through a coupling capacitor, the capacitance of the coupling capacitor being 0.1-1 μF; Step 5: subjecting the signal processed through the coupling capacitor to analog-digital conversion, the sampling frequency being set to 100 Hz-1 MHz; Step 6: performing time-domain analysis on the collected vibration signal to extract the vibration amplitude and root-mean-square value; Step 7: obtaining the frequency spectrum distribution through fast Fourier transform to identify the main vibration frequency component; Step 8: extracting the peak frequency fpeak, peak amplitude Apeak, spectrum energy integral Etotal and peak width Δf in the frequency spectrum; Step 9: determining that it is a partial discharge signal when fpeak>100 kHz and Apeak is higher than 3 times the background noise.

2. The method of claim 1, wherein, Preferably, the piezoelectric ceramic vibration sensor is installed on the surface of the reactor through bolt fixation, magnetic attraction fixation or adhesion.

3. The method of claim 1, wherein, The piezoelectric ceramic element of the piezoelectric ceramic vibration sensor is BCTZ material.

4. The method of claim 1, wherein, In step 3, the voltage follower is used to ensure that the input impedance is much higher than the output impedance of the piezoelectric element.

5. The method of claim 1, wherein, In step 8, the frequency spectrum characteristic of the partial discharge signal is a sharp peak value between 100 kHz and 500 kHz.

6. The method of claim 1, wherein, In step 5, data transmission is achieved through optical fiber communication or shielded twisted pair.

7. A contact sensor based reactor vibration monitoring system, characterized in that, It comprises: a piezoelectric ceramic vibration sensor arranged on the core, winding or shell of the reactor, the sensitivity of the piezoelectric ceramic vibration sensor being 5-15 pC / g; a signal modulation module comprising a charge amplifier, a voltage follower, an active band-pass filter, an isolation amplifier and a coupling capacitor connected in sequence, the charge amplifier being used to convert a charge signal into a voltage signal and having a sensitivity of 5-20 g / V, the active band-pass filter being used to remove high-frequency noise, low-frequency drift and power supply interference, and the coupling capacitor having a capacitance of 0.1-1 μF; a data acquisition module used to subject the signal output by the signal modulation module to analog-digital conversion, the sampling frequency being 100 Hz-1 MHz; a data analysis module used to perform time-domain analysis and spectrum analysis on the collected vibration signal, obtain the frequency spectrum distribution through fast Fourier transform and extract the peak frequency fpeak, peak amplitude Apeak, spectrum energy integral Etotal and peak width Δf, and determine that it is a partial discharge signal when fpeak>100 kHz and Apeak is higher than 3 times the background noise; a monitoring terminal used to receive the analysis results of the data analysis module and perform state evaluation and early warning.

8. The system of claim 7, wherein, The piezoelectric ceramic vibration sensor comprises a joint, a shell, a mass block, a piezoelectric ceramic element and a device bottom fixed end.

9. The system of claim 7, wherein, The communication module is used for realizing data transmission through optical fiber communication or shielded twisted pair.

10. The system of claim 7, wherein, The piezoelectric ceramic vibration sensor is installed on the surface of the electric reactor through bolt fixing, magnetic attraction fixing or adhesion.

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