Online detection system and detection method for characteristics of particles in transformer oil

Abstract

The invention provides an on-line detection system for characteristics of particles in transformer oil. The on-line detection system comprises an oil separator and a particle detection device, the oil separator is provided with an oil inlet interface and a thin-layer detection area, and the interior of the thin-layer detection area is a flat cavity communicated with the oil inlet interface; the particle detection device is arranged in the thin layer detection area. The detection method of the on-line detection system for the characteristics of the particles in the transformer oil comprises the following steps: S1, connecting an oil inlet interface of an oil separator with an outlet of an oil filter of the transformer oil, so that the transformer oil enters a flat cavity through the oil inlet interface, and a thin oil liquid layer is formed in the flat cavity; and S2, starting the particle detection device, and carrying out online monitoring and quantitative analysis on the oil layer by the particle detection device to calculate at least one characteristic parameter of particle size, concentration and morphology of particles contained in the oil layer. According to the method, the detection efficiency and economy can be effectively improved, and an accurate basis can be provided for state evaluation and maintenance decision of the transformer oil.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fluid particle detection, and in particular to a transformer oil particle property online detection system and method. BACKGROUND

[0002] As an important liquid insulation medium, the insulation performance of transformer oil directly affects the safe and stable operation of the transformer. Studies have shown that when impurity particles exist in the insulation medium, whether it is a single liquid insulation system or an oil-paper composite insulation structure, the comprehensive insulation performance will be significantly reduced. In particular, oil particles (including metal particles, fiber particles, etc.) have become one of the key factors leading to internal insulation failure of the transformer. Therefore, during the handling process before the transformer is put into operation, multiple links such as vacuum oil injection, cold / hot cycle filtration, and hot flushing under electric charge are usually required to strictly control the content of particle impurities in the oil.

[0003] However, with the long-term operation of the transformer, particle impurities in the oil will still gradually accumulate, especially cellulose particles, whose content often shows an upward trend. Due to the large amount of oil injection and complex flow channel structure inside the transformer, it is difficult to achieve multi-point and real-time particle impurity monitoring. At present, the main method is offline detection by periodic sampling and testing, which not only takes a long time, but also has obvious monitoring blind spots: oil particles may abnormally produce, rapidly develop and accumulate within the interval between two detections, thereby becoming a potential cause of sudden insulation accidents of the transformer.

[0004] Therefore, it is of great significance to develop a method that can realize rapid and online monitoring of the particle properties in the transformer oil. SUMMARY

[0005] In order to solve the technical problems in the background art, the present application provides a transformer oil particle property online detection system and method.

[0006] The transformer oil particle property online detection system provided by the present application comprises a oil distributor and a particle detection device, wherein: One end of the oil distributor is provided with an oil inlet interface, and the other end opposite to the oil inlet interface is arranged in a flat shape to form a thin layer detection area, and the inside of the thin layer detection area is a flat cavity in communication with the oil inlet interface; The particle detection device is arranged in the thin layer detection area and is used for online monitoring and quantitative analysis of at least one of the particle size, concentration and morphology of the particles contained in the fluid medium in the flat cavity.

[0007] Preferably, the oil distributor is internally provided with a liquid separation flow channel in communication with the oil inlet interface and the flat cavity, and the flow cross-sectional area of the liquid separation flow channel is greater than the cross-sectional area of the flat cavity.

[0008] Preferably, the liquid separation flow channel is in a spiral shape.

[0009] Preferably, the oil inlet interface is connected with an oil inlet pipeline, and a first electromagnetic valve is arranged at the oil inlet interface or in the oil inlet pipeline.

[0010] Preferably, a flow sensor is arranged at the oil inlet interface or in the oil inlet pipeline.

[0011] Preferably, the oil distributor is provided with an oil outlet communicating with the flat cavity at the other end opposite to the oil inlet interface.

[0012] Preferably, the oil outlet is connected with an oil outlet pipeline, and a second electromagnetic valve is arranged at the oil outlet or in the oil outlet pipeline.

[0013] Preferably, the particle detection device comprises a multi-frequency ultrasonic sensor array unit and a data processing unit; the multi-frequency ultrasonic sensor array unit is arranged in the thin layer detection area and used for emitting multi-frequency ultrasonic waves to the thin layer detection area and receiving penetrating signals and scattering signals after the action of particles in the thin layer detection area; the data processing unit is signal-connected with the multi-frequency ultrasonic sensor array unit and used for analyzing and processing the output signals of the multi-frequency ultrasonic sensor array unit and inversely calculating at least one characteristic parameter of the particles contained in the fluid medium in the flat cavity according to the processing result.

[0014] Preferably, the data processing unit is internally integrated with an ultrasonic signal feature and particle characteristic correlation mapping database, the data processing unit is configured to collect the output signals of the multi-frequency ultrasonic sensor array unit, extract signal features from the collected signals and perform matching analysis with the correlation mapping database to establish the correlation mapping between the ultrasonic signal features and the particle physical property parameters, and finally output the particle characteristic parameters corresponding to the signals.

[0015] Preferably, the multi-frequency ultrasonic sensor array unit comprises an ultrasonic emission module and an ultrasonic receiving module; the ultrasonic emission module is arranged on one side of the thin layer detection area and used for emitting ultrasonic wave signals to the thin layer detection area; the ultrasonic receiving module is oppositely arranged on the other side of the thin layer detection area and used for receiving the penetrating signals and scattering signals after the action of particles in the thin layer detection area; the data processing unit comprises a collection module, a storage module and a data processing module; the collection module is connected with the ultrasonic receiving module to collect the ultrasonic wave signals output by the ultrasonic receiving module; the correlation mapping database is stored in the storage module; the data processing module is connected with the collection module and the storage module respectively and used for extracting features from the collected ultrasonic wave signals and matching the extracted signal features with the correlation mapping database, and outputting the corresponding particle characteristic parameters according to the matching result.

[0016] Preferably, the data processing unit further comprises a display module connected with the data processing module and used for displaying the particle characteristic parameters output by the data processing module.

[0017] Preferably, the ultrasonic emission module is configured to emit ultrasonic waves containing at least two different frequencies.

[0018] Preferably, the ultrasonic emission end is configured to emit at least two ultrasonic waves with frequencies in the range of 0.5 MHz to 20 MHz alternately or simultaneously.

[0019] The present application provides a detection method of a transformer oil particle property online detection system, comprising the following steps: S1, connecting the oil inlet interface of the oil distributor with the outlet of the transformer oil filter to make the transformer oil enter the flat cavity through the oil inlet interface to form a thin oil layer in the flat cavity; S2, starting the particle detection device to online monitor and quantitatively analyze the oil layer by the particle detection device to calculate at least one characteristic parameter of the particle size, concentration and morphology of the particles in the oil layer.

[0020] Preferably, in step S2, the particle detection device comprises the following steps: S21, online detection and data analysis: the multi-frequency ultrasonic sensor array unit emits multi-frequency ultrasonic waves to the thin oil layer in step S1 and synchronously receives transmission and scattering signals; the data processing unit extracts signal features from the output signals of the multi-frequency ultrasonic sensor array unit and matches with the correlation mapping database, and outputs corresponding particle characteristic parameters according to the matching results; S22, result display: the results output by step S21 are displayed on the display module in real time.

[0021] Preferably, when the oil distributor is provided with an oil outlet, the oil outlet is connected with the inlet of the transformer oil filter.

[0022] The present application designs the end of the oil distributor as a flat thin layer detection area, so that the transformer oil flowing through the internal flat cavity forms a stable and uniform thin layer flow field, thereby reducing the interference of the oil layer thickness on the detection signal. At the same time, the particle detection device arranged in the thin layer detection area can online monitor and quantitatively analyze the particle size, concentration and morphology of the particles in the oil in the flat cavity in real time, so as to realize high sensitivity and high precision in-situ detection of the particle pollution in the transformer oil. The structural design effectively improves the detection efficiency and economy, and can provide accurate basis for the state evaluation and maintenance decision of the transformer oil. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The present application provides a structural diagram of a transformer oil particle property online detection system; Figure 2 The present application provides a structural diagram of a data processing unit in a transformer oil particle property online detection system. DETAILED DESCRIPTION

[0024] Referring to Figure 1 The present application provides an on-line detection system for particle characteristics in transformer oil, comprising an oil distributor 1 and a particle detection device.

[0025] One end of the oil distributor 1 is provided with an oil inlet interface 11, and the other end opposite to the oil inlet interface is flat, constituting a thin layer detection area 12. The inside of the thin layer detection area 12 is a flat cavity 13 in communication with the oil inlet interface 11, and the cross section is very thin and flat to form a stable thin layer of oil flow.

[0026] In order to optimize the flow field, the oil distributor 1 is further provided with a liquid separation flow channel 14 for connecting the oil inlet interface 11 and the flat cavity 13. The flow cross-sectional area of the liquid separation flow channel 14 is set to be larger than the cross-sectional area of the flat cavity 13. Preferably, the liquid separation flow channel 14 is spiral-shaped to achieve stable flow and preliminary uniform flow effect, and enable the particles in the oil to gather in the thin layer detection area 12.

[0027] An oil inlet pipeline is connected to the oil inlet interface 11, and a first electromagnetic valve 15 is installed at the oil inlet interface 11 or in the oil inlet pipeline, for controlling the on-off of the oil circuit, and a flow sensor 16 can be integrated to monitor the real-time flow. At the end of the thin layer detection area 12, an oil outlet 17 is provided for discharging the detected transformer oil, and the oil outlet 17 is connected to an oil outlet pipeline, and a second electromagnetic valve 18 is provided at the oil outlet 17 or in the oil outlet pipeline, for controlling the on-off of the oil outlet 17. Further, the oil outlet pipeline connected to the oil outlet 17 can be connected to the inlet of the transformer oil filter, realizing the circulation of the oil circuit.

[0028] The particle detection device is arranged in the thin layer detection area 12, for on-line monitoring and quantitative analysis of at least one of the particle size, concentration and morphology of the particles contained in the fluid medium in the flat cavity 13, which specifically comprises a multi-frequency ultrasonic sensor array unit 2 and a data processing unit 3.

[0029] The multi-frequency ultrasonic sensor array unit 2 includes an ultrasonic transmitting module 21 and an ultrasonic receiving module 22, which are accurately positioned and installed on both sides of the flat cavity 13, respectively. The ultrasonic transmitting module 21 adopts a multi-frequency ultrasonic transducer array, which is configured to simultaneously or alternately transmit at least two ultrasonic signals with frequencies ranging from 0.5 MHz to 20 MHz. The ultrasonic receiving module 22 adopts a corresponding receiving transducer array, which is used to receive the transmission signals penetrating the oil and particles in the flat cavity, and the scattering signals generated by the scattering of the particles.

[0030] Referring to Figure 2The data processing unit 3 is in signal connection with the ultrasonic receiving module 22 (if the flow sensor 16 is present, the data processing unit 3 can also be in connection with the flow sensor 16), and comprises a collection module, a storage module, a data processing module and a display module. The collection module is used for collecting the multi-channel and multi-frequency original ultrasonic signals output by the ultrasonic receiving module 22, and performing pretreatments such as filtering, amplification and analog-digital conversion. The storage module integrates an associated mapping database of ultrasonic signal features and particle characteristic parameters (the associated mapping database is obtained through a large number of experimental calibrations, and contains the quantitative corresponding relationship between the particles of different particle sizes, concentrations and materials (such as metal, fiber and carbide) and the attenuation spectrum, the sound velocity variation spectrum and the scattering spectrum of the multi-frequency ultrasonic signals). The data processing module is used for real-time extraction of signal features, matching of the extracted signal features with the associated mapping database, and output of the corresponding particle characteristic parameters according to the matching results. The display module is connected with the data processing module, and is used for real-time display of the above particle characteristic parameters, and can set a threshold value for early warning according to needs.

[0031] The detection method of the transformer oil particle characteristic on-line detection system provided by the application comprises the following steps: S1, system connection and oil flow preparation: close the first electromagnetic valve 15, connect the oil inlet interface 11 of the oil distributor 1 to the outlet of the transformer oil filter through an oil inlet pipeline. Connect the oil outlet 17 to the inlet of the filter through an oil outlet pipeline to form a closed detection loop. Open the first electromagnetic valve 15 and close the second electromagnetic valve 16, so that the transformer oil flows through the oil inlet interface 11, the oil flow channel 14 and enters the flat cavity 13. Since the cavity of the flat cavity 13 is flat and has a small cross-sectional area, the oil liquid forms a thin oil liquid layer with uniform thickness and stable flow rate in the cavity.

[0032] S2, start the particle detection device, and perform on-line monitoring and quantitative analysis on the oil liquid layer by the particle detection device to calculate at least one characteristic parameter of the particle size, concentration and morphology of the particles contained in the oil liquid layer. The specific steps are as follows: S21, on-line detection and data analysis: start the multi-frequency ultrasonic sensor array unit 2. The ultrasonic emission module 21 in the multi-frequency ultrasonic sensor array unit 2 emits multi-frequency ultrasonic waves to the thin oil liquid layer. The ultrasonic receiving module 22 in the multi-frequency ultrasonic sensor array unit 2 synchronously receives the transmission and scattering signals and transmits them to the data processing unit 3. The data processing module in the data processing unit 3 real-time extracts signal features, matches them with the associated mapping database, and outputs the corresponding particle characteristic parameters according to the matching results. The specific working flow is as follows: Firstly, the signal pretreated by the collecting module is analyzed in time-frequency domain, and the characteristic values such as sound attenuation, sound velocity change and scattering intensity under each frequency band are extracted to form a characteristic vector. Then, the characteristic vector is matched and analyzed with the associated mapping database in the storage module (such as based on machine learning algorithm). Finally, according to the optimal matching result, the real-time characteristic parameters (including particle size distribution, number concentration, total volume concentration and morphology characteristics, etc.) of the particles in the oil are calculated by inversion.

[0033] S22, result display and decision support: the detection result is displayed on the display module in real time, and the operator can evaluate the cleanliness state of the transformer oil according to the real-time data of the particle pollution, accurately judge the working efficiency of the oil filter, and scientifically formulate the filtering period and maintenance strategy.

[0034] As can be seen from the above, the oil layer thickness is effectively reduced by the flat cavity design, the ultrasonic wave attenuation is reduced, and the detection signal-to-noise ratio and sensitivity are enhanced. Combined with the multi-frequency ultrasonic sensing array and the pre-calibrated associated mapping database, the rapid, in-situ and high-precision quantitative analysis of the particle characteristics in the transformer oil is realized. The system can be integrated in the oil filtering circuit online to realize uninterrupted monitoring, and provides an efficient and reliable technical means for transformer condition maintenance and oil quality management.

[0035] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. An online detection system for particulate characteristics in transformer oil, characterized in that, include: Oil separator (1) and particulate detection device, wherein: One end of the oil separator (1) has an oil inlet (11), and the other end opposite to the oil inlet (11) is set in a flat shape to form a thin layer detection area (12), and the interior of the thin layer detection area (12) is a flat cavity (13) connected to the oil inlet (11). The particle detection device is set in the thin-layer detection area (12) and is used to monitor and quantify at least one characteristic parameter of the particle size, concentration and morphology of the particles contained in the fluid medium in the flat cavity (13) online.

2. The online detection system for particulate properties in transformer oil according to claim 1, characterized in that, The oil separator (1) has a liquid distribution channel (14) inside that connects the oil inlet (11) and the flat cavity (13), and the flow cross-sectional area of ​​the liquid distribution channel (14) is larger than the cross-sectional area of ​​the flat cavity (13); preferably, the liquid distribution channel (14) is spiral.

3. The online detection system for particulate properties in transformer oil according to claim 1, characterized in that, The oil inlet (11) is connected to an oil inlet pipe, and a first solenoid valve (15) is provided at the oil inlet (11) or in the oil inlet pipe; preferably, a flow sensor (16) is also provided at the oil inlet (11) or in the oil inlet pipe.

4. The online detection system for particulate characteristics in transformer oil according to claim 1, characterized in that, The oil separator (1) is provided with an oil outlet (17) connected to the flat cavity (13) at the other end opposite to the oil inlet (11); preferably, the oil outlet (17) is connected to an oil drain pipe, and a second solenoid valve (18) is provided at the oil outlet (17) or in the oil drain pipe.

5. The online detection system for particulate characteristics in transformer oil according to claim 1, characterized in that, The particle detection device includes a multi-frequency ultrasonic sensor array unit (2) and a data processing unit (3). The multi-frequency ultrasonic sensor array unit (2) is arranged in the thin-layer detection area (12) and is used to transmit multi-frequency ultrasonic waves to the thin-layer detection area (12) and receive the penetration signal and scattering signal after being acted upon by the particles in the thin-layer detection area (12). The data processing unit (3) is connected to the multi-frequency ultrasonic sensor array unit (2) and is used to analyze and process the output signal of the multi-frequency ultrasonic sensor array unit (2) and calculate at least one characteristic parameter of the particles contained in the fluid medium in the flat cavity (13) based on the processing result.

6. The online detection system for particulate characteristics in transformer oil according to claim 5, characterized in that, The data processing unit (3) has a built-in correlation mapping database of ultrasonic signal features and particle properties. The data processing unit (3) is configured to collect the output signal of the multi-frequency ultrasonic sensor array unit (2), extract signal features from the collected signal and perform matching analysis with the correlation mapping database to establish the correlation mapping between ultrasonic signal features and particle property parameters, and finally output the particle property parameters corresponding to the signal.

7. The online detection system for particulate characteristics in transformer oil according to claim 6, characterized in that, The multi-frequency ultrasonic sensing array unit (2) includes an ultrasonic transmitting module (21) and an ultrasonic receiving module (22); the ultrasonic transmitting module (21) is located on one side of the thin-layer detection area (12) and is used to transmit ultrasonic signals to the thin-layer detection area (12); the ultrasonic receiving module (22) is located on the other side of the thin-layer detection area (12) and is used to receive the penetration signal and the scattered signal after being acted upon by the particles in the thin-layer detection area (12); The data processing unit (3) includes an acquisition module, a storage module and a data processing module; the acquisition module is connected to the ultrasonic receiving module (22) to acquire the ultrasonic signal output by the ultrasonic receiving module (22); the association mapping database is stored in the storage module; the data processing module is connected to the acquisition module and the storage module respectively, and is used to extract features from the acquired ultrasonic signal, match the extracted signal features with the association mapping database, and output the corresponding particle characteristic parameters according to the matching result; Preferably, the data processing unit (3) further includes a display module, which is connected to the data processing module and is used to display the particle characteristic parameters output by the data processing module; Preferably, the ultrasonic transmitting module (21) is configured to transmit ultrasonic waves containing at least two different frequencies; preferably, the ultrasonic transmitting end is configured to transmit at least two ultrasonic waves with frequencies in the range of 0.5 MHz to 20 MHz alternately or simultaneously.

8. The detection method of the online detection system for particulate characteristics in transformer oil as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Connect the oil inlet (11) of the oil separator (1) to the outlet of the transformer oil filter so that the transformer oil enters the flat cavity (13) through the oil inlet (11) to form a thin oil layer in the flat cavity (13). S2. Activate the particle detection device to perform online monitoring and quantitative analysis of the oil layer, and calculate at least one characteristic parameter among the particle size, concentration and morphology of the particles contained in the oil layer.

9. The detection method of the online detection system for particulate characteristics in transformer oil according to claim 8, characterized in that, In step S2, the particle detection device includes the following steps: S21. Online detection and data analysis: The multi-frequency ultrasonic sensor array unit (2) emits multi-frequency ultrasonic waves to the thin layer of oil in step S1 and simultaneously receives transmitted and scattered signals; the data processing unit (3) extracts signal features from the output signal of the multi-frequency ultrasonic sensor array unit (2) and matches them with the associated mapping database, and outputs the corresponding particle characteristic parameters according to the matching results. S22. Result display: The result output in step S21 is displayed on the display module in real time.

10. The detection method of the online detection system for particulate characteristics in transformer oil according to claim 8, characterized in that, When the oil separator (1) is provided with an oil drain outlet (17), the oil drain outlet (17) is connected to the inlet of the transformer oil filter through the oil drain pipeline.

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