Fault diagnosis device and method based on transformer oil fluorescence multivariate correction analysis

Abstract

The application discloses a fault diagnosis device and method based on transformer oil fluorescence multivariate correction analysis, belongs to the technical field of transformer fault diagnosis, and solves the problems of large device volume and weight, high cost and inconvenience in use caused by directly collecting the fluorescence spectrum of transformer oil by using a fluorescence spectrometer in the prior art; the optimal excitation wavelength monochromatic excitation light generated by a fluorescence excitation source is used to excite the transformer oil in a fluorescence excitation detection device to generate fluorescence; the fluorescence excitation detection device generates fluorescence according to the input monochromatic excitation light and inputs the fluorescence into a fluorescence signal collection and analysis device; the fluorescence collection and analysis device adopts a multivariate correction filter group to collect and analyze the fluorescence signal emitted by the transformer oil, replaces the emission monochromator component of the fluorescence spectrometer, reduces the equipment cost and the equipment volume, the data processing is fast, the performance-price ratio of the transformer oil fault detection is improved, and the engineering application of the fluorescence monitoring technology in the transformer fault online diagnosis is realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of transformer fault diagnosis, and relates to a fault diagnosis device and method based on transformer oil fluorescence multivariate correction analysis. BACKGROUND

[0002] As the core of energy conversion in the process of power generation and distribution, transformers are huge in quantity, widely influential, and their running state directly affects the safe and reliable operation of the power system. Once an accident occurs in a transformer, not only the expensive electrical equipment (a single transformer costs up to 50 million yuan) is damaged, but also large-scale power outages occur, even causing casualties, environmental pollution, and huge economic and social losses. Therefore, monitoring the running state of the transformer is particularly important.

[0003] Transformer oil refers to a kind of insulating oil used in oil-filled electrical equipment such as transformers, reactors, transformers, bushings, and oil switches, which plays the role of insulation, cooling, and arc extinguishing. Transformer oil is a fractionation product of petroleum, and its main components are alkanes, cycloalkane saturated hydrocarbons, aromatic unsaturated hydrocarbons, and non-hydrocarbon compounds. Transformer oil can emit fluorescence under ultraviolet or X-ray irradiation. Fluorescence refers to a kind of cold luminescence phenomenon of photoluminescence. When a certain normal temperature substance is irradiated by a certain wavelength of incident light (usually ultraviolet or X-ray), it absorbs light energy and enters an excited state, and immediately de-excites and emits outgoing light (usually in the visible light band) with a longer wavelength than the incident light. Once the incident light is stopped, the luminescence phenomenon also disappears immediately. The outgoing light with this property is called fluorescence.

[0004] With the development of transformer operating state monitoring technology, mature monitoring methods such as partial discharge test method represented by field operation detection, insulation oil physicochemical test method represented by offline sampling, and dissolved gas analysis (DGA) technology represented by online automatic monitoring have appeared in succession. Among them, partial discharge test is often used for on-site inspection of insulation state before equipment is put into operation or after maintenance, and insulation oil physicochemical test needs to accurately measure the physicochemical properties of insulation oil in the laboratory. Both methods cannot realize online automatic monitoring and analysis of transformer operating state, while DGA is an online diagnosis technology for transformer state by analyzing the content of dissolved gas in oil, which has the advantages of not being affected by various electromagnetic interferences, high reliability of obtained data, and relatively mature technology, and has gradually become the mainstream of transformer operating state monitoring technology. However, with the increasing application of DGA, the following shortcomings are exposed: (1) the main transformer does not produce gas or releases little gas when discharging, and DGA cannot detect or detect low-concentration gas; (2) when the main transformer discharges, the discharge amount increases continuously in a short time, and a large amount of gas is released rapidly, while the single analysis time of the current DGA analysis method needs 2 hours. Whether it is missed detection or monitoring delay problem will cause certain safety accident hidden danger, therefore in recent years, a truly fast, real-time and safe transformer operating state monitoring technology based on fluorescence monitoring has been studied by more and more scholars.

[0005] The transformer operating state fluorescence detection technology (FMS) has the advantages of fast detection speed, real-time response, non-destructive detection and high precision, and has great potential in the field of transformer operating state monitoring technology. For example, the Chinese invention patent literature "A transformer insulation oil fluorescence online detection device" with application publication date of July 13, 2021 and application publication number of CN113109682A discloses a transformer insulation oil fluorescence online detection device with high sensitivity, short analysis time, no interference from surrounding environmental magnetic field and electric field, good stability and repeatability, which can realize online fault detection demand of transformer operating state. However, the existing transformer fluorescence monitoring is completed by laboratory condition using fluorescence spectrometer as a representative of scientific research level equipment to collect insulation oil fluorescence spectrum, and uses pattern recognition method to establish transformer operating fault diagnosis, which has the problems of large equipment volume, high cost, long data acquisition and processing time, etc. restricting online real-time monitoring capability. SUMMARY

[0006] The technical problem to be solved by the present application is how to design a transformer fault diagnosis device based on transformer oil fluorescence analysis, which is small in size and weight, low in cost and convenient to use, so as to solve the problems of large size and weight, high cost and inconvenience of use of the existing transformer oil fluorescence analysis fault diagnosis device which directly uses a fluorescence spectrometer to collect the fluorescence spectrum of transformer oil.

[0007] The present application solves the above technical problems by the following technical scheme:

[0008] The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis comprises a device shell (10), an oil pumping device (11), a fluorescence excitation source (12), a fluorescence excitation detection device (13), a fluorescence signal collection and analysis device (14) and a display screen (15). The oil pumping device (11), the fluorescence excitation source (12), the fluorescence excitation detection device (13) and the fluorescence signal collection and analysis device (14) are arranged in the interior of the device shell (10), and the display screen (15) is arranged on the front panel thereof. The oil pumping device (11) is in sealed connection with the transformer oil tank and the fluorescence excitation detection device (13) through pipelines. The fluorescence excitation source (12) is connected with the fluorescence excitation detection device (13) through an optical fiber, and the fluorescence excitation detection device (13) is connected with the fluorescence signal collection and analysis device (14) through an optical fiber. The oil pumping device (11) is used for inputting the insulating oil in the transformer oil tank into the fluorescence excitation detection device (13) by means of the pressure difference between the transformer oil tank and the fluorescence excitation detection device (13) after vacuumization. The fluorescence excitation source (12) generates monochromatic excitation light of an optimal excitation wavelength for exciting the transformer oil in the fluorescence excitation detection device (13) to generate fluorescence. The fluorescence excitation detection device (13) generates fluorescence according to the input monochromatic excitation light and inputs the fluorescence into the fluorescence signal collection and analysis device (14). The fluorescence signal collection and analysis device (14) collects and analyzes the fluorescence signal emitted by the transformer oil by using a multivariate correction filter set to determine the type of transformer fault. The display screen (15) is used for displaying the results collected and analyzed by the fluorescence signal collection and analysis device (14).

[0009] Further, the oil pumping device (11) comprises an oil inlet valve (111), an oil outlet valve (112), an oil pumping pump (113), an air pump (114), an oil inlet two-way (115), an oil discharge and air discharge three-way (116), a device bottom plate (117), and a mounting bracket (118); the oil inlet valve (111), the oil outlet valve (112), the oil pumping pump (113), and the air pump (114) are fixedly installed on the device bottom plate (117); the oil inlet two-way (115) and the oil discharge and air discharge three-way (116) are fixedly installed on the mounting bracket (118), and the mounting bracket (118) is fixedly installed on the device bottom plate (117); the oil pumping pump (113) is used for pumping out the transformer oil after detection from the fluorescence excitation detection device (13); the air pump (114) is used for pumping out impurity gas in the internal pipeline of the oil pumping device and in the fluorescence excitation detection device (13); one end of the oil inlet valve (111) is connected with an oil outlet of a transformer oil tank, the other end of the oil inlet valve (111) is connected with one end of the oil inlet two-way (115), and the other end of the oil inlet two-way (115) is connected with an oil inlet of the fluorescence excitation detection device (13); one end of the oil pumping pump (113) is connected with a first port of the oil discharge and air discharge three-way (116), the other end of the oil pumping pump (113) is connected with an oil outlet of the fluorescence excitation detection device (13), one end of the oil discharge and air discharge three-way (116) is connected with the other end of the oil outlet valve (112), and the other end of the oil outlet valve (112) is connected with an oil inlet of the transformer oil tank; and the third port of the oil discharge and air discharge three-way (116) is connected with one end of the air pump (114).

[0010] Further, the working process of the oil pumping device (11) comprises the following steps.

[0011] S1, the internal pipeline of the oil pumping device and the detection tank are pumped to be vacuum, specifically as follows: the oil inlet valve (111) and the oil outlet valve (112) are closed, the oil pumping pump (113) is set to be in a normal mode, the air pump (114) is started to pump the internal pipeline of the oil pumping device and the detection tank to be vacuum, after the vacuum is completed, the oil pumping pump (113) is set to be in a blocking mode and the air pump (114) is closed.

[0012] S2, the insulating oil is pumped into the detection tank, specifically as follows: the oil inlet valve (111) is opened, the insulating oil in the transformer oil tank is pumped into the detection tank by means of the pressure difference between the oil outlet of the transformer oil tank and the detection tank after being pumped to be vacuum, and the oil inlet valve (111) is closed after the oil is pumped in.

[0013] S3, the insulating oil is pumped back into the transformer oil tank, specifically as follows: after the detection is completed, the oil outlet valve (112) is opened, the air pump (114) is set to be in a blocking mode, and the oil pumping pump (113) is started to pump out the insulating oil in the detection tank and press it back into the transformer oil tank.

[0014] Further, the fluorescence excitation source (12) comprises: a fluorescence excitation darkroom (120), a monochromatic optimal wavelength LED excitation light source (121), a converging lens (123), and a fiber head (125); the monochromatic optimal wavelength LED excitation light source (121), the converging lens (123), and the fiber head (125) are fixedly arranged inside the fluorescence excitation darkroom (120), the converging lens (123) is arranged between the monochromatic optimal wavelength LED excitation light source (121) and the fiber head (125), and the center lines of the monochromatic optimal wavelength LED excitation light source (121), the converging lens (123), and the first fiber interface (126) are on a straight line; the optimal excitation wavelength of the monochromatic optimal wavelength LED excitation light source (121) is selected as follows: three-dimensional fluorescence spectrum data of different types of transformer oils is collected, the optimal excitation wavelength range is determined according to the fluorescence characteristic value distribution range of the transformer oil fluorescence spectrum, the main peak intensity of the sample characteristics under different excitation wavelengths is compared with the excitation wavelength as the abscissa and the main peak intensity as the ordinate, the discrete degree of the sample characteristics under different excitation wavelengths is compared with the excitation wavelength as the abscissa and the adopted coefficient of variation as the ordinate, the excitation wavelength with the maximum main peak intensity and coefficient of variation is selected as the excitation wavelength of the monochromatic optimal wavelength LED excitation light source (121); and the calculation formula of the coefficient of variation is as follows: ; wherein, The coefficient of variation is greater, and the discrete degree is greater.

[0015] Further, the fluorescence excitation source (12) further comprises: an excitation light source mounting bracket (122), a lens mounting bracket (124), and a first fiber interface (126); the excitation light source mounting bracket (122) is fixedly arranged on the bottom plate inside the fluorescence excitation darkroom (120), and the monochromatic optimal wavelength LED excitation light source (121) is mounted on the excitation light source mounting bracket (122); the lens mounting bracket (124) is fixedly arranged on the bottom plate inside the fluorescence excitation darkroom (120), and the converging lens (123) is embeddedly mounted in the lens mounting bracket (124); the first fiber interface (126) is fixedly arranged on the side wall outside the fluorescence excitation darkroom (120), and the fiber head (125) is connected with the first fiber interface (126) in a matching mode.

[0016] Further, the fluorescence excitation detection device (13) comprises: a detection cell darkroom (1311), a detection cell (1312), a reference cell (1313), an excitation light emission fiber probe (1316), a fluorescence receiving fiber probe (1317), a fiber head mover (1318), an excitation light transmission fiber head (1320), a fluorescence receiving fiber head (1321), an excitation light transmission fiber interface (1322), and a fluorescence receiving fiber interface (1323). The detection cell (1312) and the reference cell (1313) are arranged side by side at the bottom of the detection cell darkroom (1311). The detection cell (1312) is used to contain the transformer oil to be detected, and the reference cell (1313) is used to contain the standard solution. The excitation light transmission fiber interface (1322) and the fluorescence receiving fiber interface (1323) are arranged at the top of the detection cell darkroom (1311). One end of the excitation light transmission fiber interface (1322) and the fluorescence receiving fiber interface (1323) is connected to the fluorescence excitation source (12) and the fluorescence signal acquisition and analysis device (14) respectively. The other end of the excitation light transmission fiber interface (1322) and the fluorescence receiving fiber interface (1323) is connected to the excitation light transmission fiber head (1320) and the fluorescence receiving fiber head (1321) arranged in the detection cell darkroom (1311) respectively. The other end of the excitation light transmission fiber head (1320) and the fluorescence receiving fiber head (1321) is connected to the excitation light emission fiber probe (1316) and the fluorescence receiving fiber probe (1317) respectively. The fiber head mover (1318) is arranged above the detection cell (1312) and the reference cell (1313) in the detection cell darkroom (1311). The excitation light emission fiber probe (1316) and the fluorescence receiving fiber probe (1317) are arranged on the two sides of the fiber head mover (1318) respectively. The fiber head mover (1318) drives the excitation light emission fiber probe (1316) and the fluorescence receiving fiber probe (1317) to switch between the detection cell (1312) and the reference cell (1313).

[0017] Further, the working process of the fluorescence excitation detection device (13) for detecting the fluorescence spectrum intensity value of the transformer oil is as follows: the fiber head mover (1318) is moved above the detection cell (1312). The excitation light sequentially passes through the excitation light transmission fiber interface (1322), the excitation light transmission fiber head (1320), and the excitation light emission fiber probe (1316) to be incident into the detection cell (1312), so as to excite the transformer oil in the detection cell (1312) to generate fluorescence. The excited fluorescence sequentially passes through the fluorescence receiving fiber probe (1317), the fluorescence receiving fiber head (1321), and the fluorescence receiving fiber interface (1323) to be transmitted out. The fluorescence detector measures the fluorescence spectrum intensity value of the transformer oil under the current external condition.

[0018] Further, the calibration method of the fluorescence excitation detection device (13) is as follows: the fluorescence spectrum intensity values of the standard solution are measured under standard conditions and current external conditions respectively, the optical fiber head mover (1318) is moved above the reference cell (1313), excitation light successively passes through the excitation light transmission optical fiber interface (1322), the excitation light transmission optical fiber head (1320), the excitation light emission optical fiber probe (1316) and is incident into the reference cell (1313), and the standard solution in the reference cell (1313) is excited to generate fluorescence; the excited fluorescence successively passes through the fluorescence receiving optical fiber probe (1317), the fluorescence receiving optical fiber head (1321) and the fluorescence receiving optical fiber interface (1323) and is transmitted out, and the fluorescence spectrum intensity values of the standard solution are measured by the fluorescence detector;

[0019] The fluorescence spectrum intensity values of the standard solution measured under standard conditions are as follows: ;

[0020] The fluorescence spectrum intensity values of the standard solution measured under current external conditions are as follows: ;

[0021] The calibration coefficient of the device is as follows: ; wherein, represents the fluorescence spectrum of the standard solution measured under standard conditions, represents the fluorescence spectrum of the standard solution measured under current external conditions, represents the light filter transmittance of the fluorescence detector.

[0022] Further, the angle between the light path of the excitation light emission optical fiber probe (1316) and the light path of the fluorescence receiving optical fiber probe (1317) is 90 degrees.

[0023] Further, the fluorescence excitation detection device (13) further comprises an oil inlet pipeline (1314) and an oil outlet pipeline (1315); one side of the detection cell (1312) is provided with an oil inlet and an oil outlet, one end of the oil inlet pipeline (1314) is in sealed connection with the oil inlet, the other end of the oil inlet pipeline (1314) extends out of the detection cell darkroom (1311), and one end of the oil outlet pipeline (1315) is in sealed connection with the oil outlet, and the other end of the oil outlet pipeline (1315) extends out of the detection cell darkroom (1311).

[0024] Further, the fluorescence excitation detection device (13) further comprises: a stepper motor (1319), the optical fiber head mover (1318) adopts a walking structure of a sliding block (13181) and a slide rod (13182), the excitation light emitting optical fiber probe (1316) and the fluorescence receiving optical fiber probe (1317) are respectively arranged on the left and right sides of the sliding block (13181) of the optical fiber head mover (1318); the stepper motor (1319) is arranged on the back plate of the detection cell darkroom (1311), and the stepper motor (1319) is used to drive the sliding block (13181) of the optical fiber head mover (1318) to walk back and forth on the slide rod (13182), so as to simultaneously drive the excitation light emitting optical fiber probe (1316) and the fluorescence receiving optical fiber probe (1317) to switch between the detection cell (1312) and the reference cell (1313).

[0025] Further, the fluorescence signal collection and analysis device (14) comprises: a fluorescence signal collection and analysis darkroom (140), a fluorescence detector (141), a filter wheel (142), a multi-element correction filter set (143), an optical fiber head (145), and a second optical fiber interface (146); the fluorescence detector (141) and the filter wheel (142) are arranged inside the fluorescence signal collection and analysis darkroom (140); the multi-element correction filter set (143) is composed of a pair of matched positive and negative multi-element correction filters, and the multi-element correction filter set (143) is installed on the filter wheel (142); the filter wheel (142) is rotatably arranged between the fluorescence detector (141) and the optical fiber head (145); the optical fiber head (145) is arranged on the inner side wall of the fluorescence signal collection and analysis darkroom (140), the second optical fiber interface (146) is arranged on the outer side wall of the fluorescence signal collection and analysis darkroom (140), and the optical fiber head (145) is connected with the second optical fiber interface (146); the fluorescence receiving optical fiber interface (1323) is connected with the second optical fiber interface (146) through an optical fiber; the fluorescence detector (141) is used to receive the fluorescence signal emitted by the transformer oil and record the total fluorescence intensity value, and the multi-element correction filter set (143) is used to collect and analyze the fluorescence signal emitted by the transformer oil; in use, the positive or negative multi-element correction filter is rotated into position, so that the center lines of the optical fiber head (145), the positive or negative multi-element correction filter, and the receiving lens of the fluorescence detector (141) are on a straight line, and the fluorescence emitted by the transformer oil passes through the second optical fiber interface (146), the optical fiber head (145), the positive or negative multi-element correction filter, and the receiving lens of the fluorescence detector (141) in sequence.

[0026] The design method of the multi-element correction filter set (143) comprises the following steps:

[0027] S1, adopt the multiple regression correction method to calculate the mapping relationship between the transformer oil fluorescence spectrum and the aromatic hydrocarbon compound concentration, and obtain the multiple regression correction coefficient;

[0028] S2, hardware the multiple regression correction coefficient in step S1, and the specific process is as follows:

[0029] S21, the positive and negative coefficients of the multiple regression correction coefficient vector after standardization are used as the transmittance of the filter;

[0030] S22, according to the transmittance, the film system structure of the positive multiple correction filter and the negative multiple correction filter is designed.

[0031] Further, the mapping relationship in step S1 is as follows:

[0032] The transformer oil fluorescence spectrum and the aromatic hydrocarbon compound concentration are directly related, and the calculation formula of the aromatic hydrocarbon compound concentration is calculated by using multiple linear regression:

[0033]

[0034] Wherein, c is the aromatic hydrocarbon concentration, is the multiple regression correction coefficient of the fluorescence spectrum obtained from the 1st to nth wave band, is the fluorescence spectrum of the 1st to nth wave band, and b is the bias coefficient;

[0035] The vector form of the multiple linear regression correction calculation formula of the aromatic hydrocarbon compound concentration is:

[0036]

[0037] Wherein, is the regression correction coefficient vector; = , T , is the fluorescence spectrum vector.

[0038] Further, the calculation process of the transmittance in step S21 is as follows:

[0039] Define the half coefficient and , and are the positive and negative parts of , that is:

[0040] ;

[0041] Find the maximum value of the half coefficient:

[0042]

[0043] Thus, the transmittance of the positive and negative filters is respectively:

[0044]

[0045] Wherein, i=1, 2…n, n is a natural number, is a regression correction coefficient vector The i-th element of.

[0046] Further, the process of the film system structure design in step S22 is as follows: the transmittance vector t is divided into two parts according to the positive and negative values, forming a positive value vector A and a negative value vector B, the negative value vector B is taken as an absolute value to obtain a vector B2, and the positive filter and the negative filter are designed by taking the vector A and the vector B2 as the target; first, the initial film system structure of the filter is selected, then the thickness of each film layer is changed, and whether the similarity of the filter transmittance and the vector A and the vector B2 reaches a threshold value is judged, if yes, the positive filter and the negative filter design is completed; if no, whether the iteration reaches a predetermined number of times is judged, if the iteration does not reach the predetermined number of times, the thickness of each film layer is continued to be changed; if the iteration has reached the predetermined number of times, the film system layer number is increased, and the initial film system structure of the filter is reselected.

[0047] Further, the fluorescence signal acquisition and analysis device (14) further comprises: a filter wheel driving motor (144), a fluorescence detector mounting bracket (147), and a filter wheel driving motor mounting bracket (148), the fluorescence detector mounting bracket (147) is arranged on the inner bottom plate of the fluorescence signal acquisition and analysis darkroom (140), and the fluorescence detector (141) is fixedly installed on the fluorescence detector mounting bracket (147); the fluorescence detector mounting bracket (147) is provided with a through hole matched with the receiving lens of the fluorescence detector (141), and the receiving lens of the fluorescence detector (141) is aligned with the through hole; the filter wheel driving motor (144) is fixedly installed on the filter wheel driving motor mounting bracket (148), the filter wheel driving motor mounting bracket (148) is arranged on the inner bottom plate of the fluorescence signal acquisition and analysis darkroom (140), the filter wheel (142) is sleeved on the rotating shaft of the filter wheel driving motor (144), and the filter wheel driving motor (144) drives the filter wheel (142) to rotate.

[0048] The advantages of the present application are:

[0049] ​(1) The present application uses the monochromatic excitation light of the optimal excitation wavelength generated by the fluorescence excitation source (12) to excite the transformer oil in the fluorescence excitation detection device (13) to generate fluorescence, and the fluorescence excitation detection device (13) generates fluorescence according to the input monochromatic excitation light and inputs the fluorescence into the fluorescence signal acquisition and analysis device (14). The fluorescence acquisition and analysis device (14) uses a multi-element correction filter set to collect and analyze the fluorescence signal emitted by the transformer oil to determine the type of transformer fault. The multi-element correction filter set is used to collect and analyze the fluorescence signal emitted by the transformer oil, replacing the emission monochromator component of the fluorescence spectrometer. This not only reduces the cost and size of the equipment, but also improves the data processing speed and the performance-price ratio of the transformer oil fault detection. The present application forms a transformer fault diagnosis device with a simple structure, a small size, reliable function and portability, and realizes the engineering application of fluorescence monitoring technology in transformer fault online diagnosis.

[0050] (2) The oil extraction device (11) of the present application first extracts the internal pipeline and the detection tank of the oil extraction device through the air pump (114) to avoid the phenomenon that the impurity gas in the oil extraction device and the fluorescence detection device fills the transformer oil tank, thereby affecting the insulation performance of the transformer. Then, the pressure difference between the oil outlet of the transformer oil tank and the detection tank after being extracted is used to extract the insulating oil in the transformer oil tank into the detection tank. At this time, the oil extraction pump (113) does not work, thereby saving the detection cost. After the detection is completed, the insulating oil in the detection tank is extracted and pressed back into the transformer oil tank through the oil extraction pump (113), thereby realizing lossless detection and avoiding resource waste.

[0051] (3) The fluorescence excitation source (12) of the present application selects the excitation wavelength of the monochromatic optimal wavelength LED excitation light source (121) with the maximum peak intensity and variation coefficient as the optimal excitation wavelength by comparing the peak intensity and dispersion degree of the sample characteristics under different excitation wavelengths. The monochromatic optimal wavelength LED excitation light source (121) emits monochromatic excitation light, which is converged to the optical fiber head (125) through the converging lens (123). The optical fiber head (125) collects the excitation light and transmits it out through the first optical fiber interface (126) to excite the transformer oil to generate fluorescence. The device of the present application has a simple structure and greatly reduces the size and weight of the device compared with the prior art which directly uses a fluorescence spectrometer for excitation. The device is easy to use, has a long service life and low cost.

[0052] (4) The fluorescence excitation detection device (13) of the present application is provided with a detection tank (1312) and a reference tank (1313). The device is calibrated through the reference tank (1313) to calculate the calibration coefficient of the device. Then, the calibration coefficient is used to correct the transformer oil fluorescence spectrum intensity value measured by the detection tank (1312), so as to obtain the true transformer oil fluorescence spectrum intensity value, eliminate external factor interference and improve the detection accuracy of the device. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 is a front view of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0054] Figure 2 is a front view of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0055] Figure 3 is a rear view of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0056] Figure 4 is a left view of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0057] Figure 5 is a right view of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0058] Figure 6 is a top view of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0059] Figure 7 is a front view of an oil pumping device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0060] Figure 8 is a top view of an oil pumping device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0061] Figure 9 is a front view of an oil pumping device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0062] Figure 10 is a rear view of an oil pumping device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0063] Figure 11 is a left view of an oil pumping device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0064] Figure 12 is a right view of an oil pumping device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0065] Figure 13 is a flow chart of an oil pumping device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0066] Figure 14 is a first three-dimensional view of a fluorescence excitation source of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0067] Figure 15 is a second three-dimensional view of a fluorescence excitation source of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0068] Figure 16 is a top view of a fluorescence excitation source of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0069] Figure 17 is a flow chart of an optimal excitation wavelength selection method of a fluorescence excitation source of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0070] Figure 18 is an excitation wavelength scanning fluorescence spectrum of a new oil sample;

[0071] Figure 19 is a curve relationship diagram of the main peak intensity and different excitation wavelengths when determining the optimal excitation wavelength of Karamay oil;

[0072] Figure 20 is a curve relationship diagram of the coefficient of variation and different excitation wavelengths when determining the optimal excitation wavelength of Karamay oil;

[0073] Figure 21 is a front view of a fluorescence excitation detection device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0074] Figure 22 is a front view of a fluorescence excitation detection device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0075] Figure 23 is a rear view of a fluorescence excitation detection device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0076] Figure 24 is a left view of a fluorescence excitation detection device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0077] Figure 25 is a right view of a fluorescence excitation detection device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0078] Figure 26 is a top view of a fluorescence excitation detection device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0079] Figure 27 is a front view of a fluorescence signal acquisition and analysis device of a fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0080] Figure 28It is the front view of the fluorescence signal collection and analysis device of the fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0081] Figure 29 It is the rear view of the fluorescence signal collection and analysis device of the fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0082] Figure 30 It is the left view of the fluorescence signal collection and analysis device of the fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0083] Figure 31 It is the right view of the fluorescence signal collection and analysis device of the fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0084] Figure 32 It is the top view of the fluorescence signal collection and analysis device of the fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0085] Figure 33 It is the structural schematic diagram of the filter wheel of the fluorescence signal collection and analysis device of the fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0086] Figure 34 It is the transmittance calculation principle schematic diagram of the multivariate correction filter of the fluorescence signal collection and analysis device of the fault diagnosis device based on transformer oil fluorescence multivariate correction analysis;

[0087] Figure 35 It is the design flow chart of the membrane system structure of the multivariate correction filter of the fluorescence signal collection and analysis device of the fault diagnosis device based on transformer oil fluorescence multivariate correction analysis. DETAILED DESCRIPTION

[0088] To make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in a clear and complete manner with reference to the drawings in the specification and specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0089] The technical solutions of the present application will be further described below with reference to the drawings in the specification and specific embodiments:

[0090] Embodiment one

[0091] As Figures 1 to 6The transformer oil fluorescence multivariate correction analysis fault diagnosis device shown includes: device shell (10), oil pumping device (11), fluorescence excitation source (12), fluorescence excitation detection device (13), fluorescence signal acquisition and analysis device (14), display screen (15); The device shell (10) is divided into two layers, and the upper and lower layers are separated by a partition; The oil pumping device (11) and the fluorescence excitation detection device (13) are arranged on the bottom plate of the lower layer; The fluorescence excitation source (12) and the fluorescence signal acquisition and analysis device (14) are arranged on the partition between the upper and lower layers; The display screen (15) is arranged on the front panel of the upper layer.

[0092] The oil inlet of the oil pumping device (11) is sealingly connected to the oil outlet of the transformer oil tank through a pipeline; the oil outlet of the oil pumping device (11) is sealingly connected to the oil inlet of the transformer oil tank through a pipeline; one end of the oil inlet two-way pipe (115) of the oil pumping device (11) is sealingly connected to the oil inlet of the fluorescence excitation detection device (13); the first optical fiber interface (126) of the fluorescence excitation source (12) is connected to the excitation light transmission optical fiber interface (1322) of the fluorescence excitation detection device (13) through an optical fiber; the fluorescence receiving optical fiber interface (1323) of the fluorescence excitation detection device (13) is connected to the second optical fiber interface (146) of the fluorescence signal acquisition and analysis device (14) through an optical fiber.

[0093] The oil pumping device (11) is used to input the insulating oil in the transformer oil tank into the fluorescence excitation detection device (13) by the pressure difference between the transformer oil tank and the fluorescence excitation detection device (13) after vacuumizing; the monochromatic excitation light generated by the fluorescence excitation source (12) is used to excite the transformer oil in the fluorescence excitation detection device (13) to generate fluorescence; the fluorescence generated by the fluorescence excitation detection device (13) according to the input monochromatic excitation light is input into the fluorescence signal acquisition and analysis device (14); the fluorescence signal acquisition and analysis device (14) uses a multivariate correction filter set to collect the fluorescence signal emitted by the transformer oil and analyze the type of transformer fault; the display screen (15) is used to display the results collected and analyzed by the fluorescence signal acquisition and analysis device (14).

[0094] As Figures 7 to 12As shown, the oil pumping device (11) comprises an oil inlet valve (111), an oil outlet valve (112), an oil pumping pump (113), an air pump (114), an oil inlet two-way (115), an oil discharge and air discharge three-way (116), a mounting bracket (118), and a device bottom plate (117). The oil inlet valve (111), the oil outlet valve (112), the oil pumping pump (113), and the air pump (114) are fixedly installed on the device bottom plate (117). The oil inlet two-way (115) and the oil discharge and air discharge three-way (116) are fixedly installed on the mounting bracket (118), and the mounting bracket (118) is fixedly installed on the device bottom plate (117).

[0095] One end of the oil inlet valve (111) is sealingly connected to the oil outlet of the transformer oil tank through a pipeline. The other end of the oil inlet valve (111) is sealingly connected to one end of the oil inlet two-way (115) through a pipeline. The other end of the oil inlet two-way (115) is sealingly connected to the oil inlet of the detection cell of the fluorescence excitation detection device (13) through a pipeline. One end of the oil pumping pump (113) is sealingly connected to the first port of the oil discharge and air discharge three-way (116) through a pipeline. The other end of the oil pumping pump (113) is sealingly connected to the oil outlet of the detection cell of the fluorescence detection device through a pipeline. The second port of the oil discharge and air discharge three-way (116) is sealingly connected to one end of the oil outlet valve (112) through a pipeline. The other end of the oil outlet valve (112) is sealingly connected to the oil inlet of the transformer oil tank through a pipeline. The third port of the oil discharge and air discharge three-way (116) is sealingly connected to one end of the air pump (114) through a pipeline. The oil pumping pump (113) is used to pump out the transformer insulating oil from the detection cell of the fluorescence detection device after detection. The air pump (114) is used to pump out the impurity gas in the internal pipeline of the oil pumping device and the detection cell of the fluorescence detection device.

[0096] As shown in Figure 13 The working process of the oil pumping device is as follows:

[0097] 1) The internal pipeline of the oil pumping device and the detection cell are pumped to vacuum

[0098] The oil inlet valve (111) and the oil outlet valve (112) are closed, the oil pumping pump (113) is set to a constant-through mode, and the air pump (114) is started to pump the internal pipeline of the oil pumping device and the fluorescence excitation detection device (13) to vacuum. After the vacuuming is completed, the oil pumping pump (113) is set to a blocking mode and the air pump (114) is closed.

[0099] 2) The insulating oil is pumped into the fluorescence excitation detection device

[0100] The oil inlet valve (111) is opened. The insulating oil in the transformer oil tank is pumped into the detection cell of the fluorescence excitation detection device (13) by the pressure difference between the oil outlet of the transformer oil tank and the fluorescence excitation detection device (13) after being pumped to vacuum. After the oil inlet is completed, the oil inlet valve (111) is closed.

[0101] 3) Insulating oil is recharged into the transformer oil tank

[0102] After the detection is completed, the oil outlet valve (112) is opened, the air pump (114) is set to the blocking mode, and the oil pump (113) is started to pump out the insulating oil in the fluorescence excitation detection device (13) and press it back into the transformer oil tank.

[0103] As shown in Figures 14 to 16 The fluorescence excitation source (12) comprises a fluorescence excitation darkroom (120), a monochromatic optimal wavelength LED excitation light source (121), an excitation light source mounting bracket (122), a converging lens (123), a lens mounting bracket (124), a fiber head (125), and a first fiber interface (126). The excitation light source mounting bracket (122) is fixedly arranged at the left end of the inner bottom plate of the fluorescence excitation darkroom (120), and the monochromatic optimal wavelength LED excitation light source (121) is mounted on the excitation light source mounting bracket (122). The lens mounting bracket (124) is fixedly arranged at the middle position of the inner wall of the fluorescence excitation darkroom (120), and the converging lens (123) is embeddedly mounted in the lens mounting bracket (124). The fiber head (125) is fixedly arranged on the side wall at the right end of the inner wall of the fluorescence excitation darkroom (120), and the first fiber interface (126) is fixedly arranged on the side wall at the right end of the outer wall of the fluorescence excitation darkroom (120). The fiber head (125) is connected with the first fiber interface (126) in cooperation. The center lines of the monochromatic optimal wavelength LED excitation light source (121), the converging lens (123), and the first fiber interface (126) are on a straight line.

[0104] The inner wall of the fluorescence excitation darkroom (120) is coated with light-absorbing paint to avoid external interference light from entering and eliminate the influence of internal multiple reflection light. The monochromatic optimal wavelength LED excitation light source (121) emits monochromatic ultraviolet light for exciting transformer oil. The converging lens (123) is a convex lens used for converging the monochromatic ultraviolet light emitted by the monochromatic optimal wavelength LED excitation light source (121) onto the fiber head (125). The fiber head (125) is used for collecting the monochromatic ultraviolet light emitted by the monochromatic optimal wavelength LED excitation light source (121). The first fiber interface (126) is an ST-SC standard fiber interface used for guiding the monochromatic ultraviolet light emitted by the monochromatic optimal wavelength LED excitation light source (121) out.

[0105] The working process of the fluorescence excitation source is as follows:

[0106] The monochromatic optimal wavelength LED excitation light source (121) emits monochromatic excitation light, which is converged by the converging lens (123) onto the optical fiber head (125), which collects the excitation light and conducts it out through the first optical fiber interface (126) for exciting the transformer oil to generate fluorescence.

[0107] As shown in Figure 17 , the optimal excitation wavelength of the monochromatic optimal wavelength LED excitation light source (121) is selected as follows:

[0108] First, collect three-dimensional fluorescence spectrum data of different types of transformer oil, as shown in Figure 18 , the excitation wavelength scanning fluorescence spectrum of the new oil sample can be found that the fluorescence characteristic value of the transformer oil fluorescence spectrum is distributed between 350nm and 500nm, and in this range, the fluorescence spectrum can most significantly show the characteristics of the sample, i.e. the characteristic peak is clear and has regularity, and the excitation wavelength range is 270nm to 310nm.

[0109] Second, compare the main peak intensity of the sample characteristics under different excitation wavelengths with the excitation wavelength (Excitation Wavelength) as the horizontal coordinate and the main peak intensity (Peak Intensity) as the vertical coordinate; and compare the dispersion degree of the sample characteristics under different excitation wavelengths with the excitation wavelength (Excitation Wavelength) as the horizontal coordinate and the coefficient of variation (Coefficient of Variation) as the vertical coordinate; the calculation formula of the coefficient of variation (Coefficient of Variation) is as follows: ; wherein, is the coefficient of variation, δ is the standard deviation, μ is the average value, and the larger the coefficient of variation, the greater the dispersion; the optimal excitation wavelength should satisfy that the main peak intensity (Peak Intensity) and the coefficient of variation (Coefficient of Variation) are maximized.

[0110] As shown in Figure 19 and Figure 20 , the three-dimensional fluorescence spectrum analysis test is carried out on Karamay oil, the excitation wavelength is selected from 270nm to 310nm, the main peak intensity (Peak Intensity) and the coefficient of variation (Coefficient of Variation) are compared, and it is found that both are maximum when the excitation wavelength is 270nm, so the optimal excitation wavelength is 270nm.

[0111] As shown in Figures 21 to 26As shown, the fluorescence excitation detection device (13) comprises: a detection cell darkroom (1311), a detection cell (1312), a reference cell (1313), an oil inlet pipeline (1314), an oil outlet pipeline (1315), an excitation light emitting fiber probe (1316), a fluorescence receiving fiber probe (1317), a fiber head mover (1318), a stepping motor (1319), an excitation light transmission fiber head (1320), a fluorescence receiving fiber head (1321), an excitation light transmission fiber interface (1322), and a fluorescence receiving fiber interface (1323).

[0112] The detection cell (1312) and the reference cell (1313) are arranged side by side at the bottom of the detection cell darkroom (1311), and the detection cell (1312) is provided with an oil inlet and an oil outlet on one side. One end of the oil inlet pipeline (1314) is in sealed connection with the oil inlet, and the other end of the oil inlet pipeline (1314) extends out of the detection cell darkroom (1311). One end of the oil outlet pipeline (1315) is in sealed connection with the oil outlet, and the other end of the oil outlet pipeline (1315) extends out of the detection cell darkroom (1311). The detection cell (1312) and the reference cell (1313) are both closed containers, the main body of which is made of stainless steel, and the top of the container is sealed with a visible light-near infrared light quartz glass window sheet. The detection cell (1312) is used for containing the transformer oil to be detected, and the reference cell (1313) is used for containing the standard solution for calibration, which can be quinine sulfate or rhodamine solution.

[0113] The excitation light transmission fiber interface (1322) and the fluorescence receiving fiber interface (1323) are arranged at the top of the detection cell darkroom (1311). One end of the excitation light transmission fiber interface (1322) and the fluorescence receiving fiber interface (1323) is connected with the fluorescence excitation source and the fluorescence detector device, respectively. The other end of the excitation light transmission fiber interface (1322) and the fluorescence receiving fiber interface (1323) is correspondingly connected with one end of the excitation light transmission fiber head (1320) and the fluorescence receiving fiber head (1321) arranged at the top of the detection cell darkroom (1311), respectively. The other end of the excitation light transmission fiber head (1320) and the fluorescence receiving fiber head (1321) is correspondingly connected with the excitation light emitting fiber probe (1316) and the fluorescence receiving fiber probe (1317), respectively.

[0114] The excitation light transmission fiber interface (1322) adopts an ST-SC optical fiber connector for leading in the excitation light source, the fluorescence receiving fiber interface (1323) adopts an ST-SC optical fiber connector for leading out the fluorescence of the transformer oil excited, the excitation light transmission fiber head (1320) is used for making the excitation light source incident into the detection cell (1312) or the reference cell (1313), and the fluorescence receiving fiber head (1321) is used for receiving the fluorescence excited in the detection cell (1312) or the reference cell (1313).

[0115] The fiber head mover (1318) is arranged directly above the detection cell (1312) and the reference cell (1313) in the detection cell darkroom (1311), and the fiber head mover (1318) adopts a walking structure of a sliding block (13181) and a sliding rod (13182).

[0116] The excitation light emission fiber probe (1316) and the fluorescence receiving fiber probe (1317) are respectively arranged on the left and right sides of the sliding block (13181) of the fiber head mover (1318), the included angle between the light path of the excitation light emission fiber probe (1316) and the light path of the fluorescence receiving fiber probe (1317) is 90 degrees, the interference of scattered fluorescence is avoided to the maximum extent, and the signal-to-noise ratio is improved.

[0117] The stepping motor (1319) is arranged on the back plate of the detection cell darkroom (1311), the stepping motor (1319) is used for driving the sliding block (13181) of the fiber head mover (1318) to walk back and forth on the sliding rod (13182), so as to simultaneously drive the excitation light emission fiber probe (1316) and the fluorescence receiving fiber probe (1317) to switch between the detection cell (1312) and the reference cell (1313).

[0118] The inner wall of the detection cell darkroom (1311) is coated with light-absorbing paint to avoid external interference light from entering and eliminate the influence of internal multiple reflection light.

[0119] The working process of the transformer oil fluorescence excitation detection device of the embodiment is as follows:

[0120] (1) Device calibration

[0121] In the case that the characteristics of the transformer oil are unchanged, the main factors affecting the fluorescence intensity of the transformer oil are external factors, such as light source intensity attenuation, temperature, device response, etc., and for accurate quantitative detection, the influence of external factors needs to be eliminated, so the device needs to be calibrated to obtain the calibration coefficient of the device; the fluorescence spectrum intensity value of the transformer oil under the current condition is corrected by the calibration coefficient to obtain the real fluorescence spectrum intensity value of the transformer oil.

[0122] The process of device calibration is as follows:

[0123] The fluorescence spectrum intensity value of the standard solution is measured under standard conditions and current external conditions respectively, and the specific process is as follows: the stepping motor (1319) drives the optical fiber head mover (1318) to move above the reference cell (1313), the excitation light is incident into the reference cell (1313) through the excitation light transmission optical fiber interface (1322), the excitation light transmission optical fiber head (1320), and the excitation light emission optical fiber probe (1316) in turn, and the standard solution in the reference cell (1313) is excited to generate fluorescence; the excited fluorescence is transmitted out through the fluorescence receiving optical fiber probe (1317), the fluorescence receiving optical fiber head (1321), and the fluorescence receiving optical fiber interface (1323) in turn, and the fluorescence spectrum intensity value of the standard solution is measured by the fluorescence detector.

[0124] The fluorescence spectrum intensity value of the standard solution measured under standard conditions is: ;

[0125] The fluorescence spectrum intensity value of the standard solution measured under current external conditions is: ;

[0126] The calibration coefficient of the device is obtained as follows: ;

[0127] wherein, represents the fluorescence spectrum of the standard solution measured under standard conditions, represents the fluorescence spectrum of the standard solution measured under current external conditions, represents the transmittance of the filter of the fluorescence detector.

[0128] (2) Detection of fluorescence spectrum intensity value of transformer oil

[0129] The fluorescence spectrum intensity value of the transformer oil is measured under current external conditions, and the specific process is as follows: the stepping motor (1319) drives the optical fiber head mover (1318) to move above the detection cell (1312), the excitation light is incident into the detection cell (1312) through the excitation light transmission optical fiber interface (1322), the excitation light transmission optical fiber head (1320), and the excitation light emission optical fiber probe (1316) in turn, and the transformer oil in the detection cell (1312) is excited to generate fluorescence; the excited fluorescence is transmitted out through the fluorescence receiving optical fiber probe (1317), the fluorescence receiving optical fiber head (1321), and the fluorescence receiving optical fiber interface (1323) in turn, and the fluorescence spectrum intensity value of the transformer oil under current external conditions is measured by the fluorescence detector; the true fluorescence spectrum intensity value of the transformer oil is obtained by multiplying the fluorescence spectrum intensity value of the transformer oil under current external conditions by the calibration coefficient.

[0130] As Figures 27 to 32As shown, the fluorescence signal acquisition and analysis device (14) comprises: a fluorescence signal acquisition and analysis darkroom (140), a fluorescence detector (141), a filter wheel (142), a multi-element correction filter set (143), a filter wheel drive motor (144), a fiber head (145), a second fiber interface (146), a fluorescence detector mounting bracket (147), and a filter wheel drive motor mounting bracket (148).

[0131] The fluorescence detector (141) is fixedly installed on the fluorescence detector mounting bracket (147), which is arranged on the bottom plate inside the fluorescence signal acquisition and analysis darkroom (140). A through hole is formed in the fluorescence detector mounting bracket (147) and aligned with the receiving lens of the fluorescence detector (141). The inner wall of the fluorescence signal acquisition and analysis darkroom (140) is coated with light-absorbing paint to prevent external interference light from entering and eliminate the influence of internal multiple reflection light.

[0132] The filter wheel drive motor (144) is fixedly installed on the filter wheel drive motor mounting bracket (148), which is arranged on the bottom plate inside the fluorescence signal acquisition and analysis darkroom (140). The filter wheel (142) is arranged between the fluorescence detector (141) and the filter wheel drive motor (144), and is sleeved on the rotating shaft of the filter wheel drive motor (144). The filter wheel drive motor (144) drives the filter wheel (142) to rotate.

[0133] The fiber head (145) is fixedly arranged on the side wall at the right end inside the fluorescence signal acquisition and analysis darkroom (140). The second fiber interface (146) is fixedly arranged on the side wall at the right end outside the fluorescence signal acquisition and analysis darkroom (140). The fiber head (145) is connected with the second fiber interface (146).

[0134] As shown in Figure 33 The filter wheel (142) is disc-shaped, and a plurality of multi-element correction filter sets (143) of different wavelengths are installed on the edge of the filter wheel (142). The center lines of the fiber head (145), the multi-element correction filter set (143), the through hole in the fluorescence detector mounting bracket (147), and the receiving lens of the fluorescence detector (141) are on a straight line.

[0135] The working process of the device is as follows:

[0136] The filter wheel driving motor (144) drives the filter wheel (142) to rotate, and the multi-element correction filter group (143) of corresponding wavelength is aligned with the receiving lens of the fluorescent detector (141), and the fluorescent light emitted by the transformer oil passes through the second optical fiber interface (146), the optical fiber head (145), the multi-element correction filter group (143), the through hole on the fluorescent detector mounting bracket (147) and the receiving lens of the fluorescent detector (141) in turn; the multi-element correction filter group (143) is used for collecting, analyzing and processing the fluorescent light emitted by the transformer oil; the fluorescent detector (141) adopts a photomultiplier tube, which is used for receiving the fluorescent light emitted by the transformer oil and recording the total intensity value of the fluorescent light.

[0137] The design method of the multi-element correction filter group (143) is as follows:

[0138] The design principle of the multi-element correction filter is to hardwareize the multi-element linear regression correction coefficient vector for calculating the concentration of aromatic hydrocarbon compounds, and to realize the hardwareization of the multi-element correction coefficient by designing positive and negative correction filters.

[0139] The transformer oil fluorescence spectrum is directly related to the concentration of aromatic hydrocarbon compounds, and the calculation formula for calculating the concentration of aromatic hydrocarbon compounds by using multi-element linear regression is as follows:

[0140]

[0141] Wherein, c is the concentration of aromatic hydrocarbon, is the regression correction coefficient of the fluorescence spectrum obtained by the 1st to nth wave band, is the fluorescence spectrum of the 1st to nth wave band, and b is the bias coefficient;

[0142] The vector form of the multi-element linear regression correction calculation formula of the concentration of aromatic hydrocarbon compounds is as follows:

[0143]

[0144] Wherein, is the regression correction coefficient vector; = , T , is the fluorescence spectrum vector.

[0145] As Figure 34 shown, the positive and negative parts of the regression correction coefficient vector are made into two correction filters, that is, the positive and negative coefficients of the regression correction coefficient vector after standardization are taken as the transmittance of the filter.

[0146] The half coefficients and are defined, and are the positive and negative parts of , i.e.

[0147] ;

[0148] Find the maximum value of the half-coefficient:

[0149]

[0150] Thus, the transmittance of the positive and negative filters is respectively:

[0151] ;

[0152] Assuming the current detection target fluorescence spectrum is , the energy received by the detector is represented as:

[0153] ;

[0154] Measure and respectively, and finally the aromatic hydrocarbon concentration is calculated as follows:

[0155]

[0156] where, ; ; i=1, 2…n, n is a natural number, is the i-th element of the regression correction coefficient vector , is the i-th element of the vector , is the i-th element of the vector .

[0157] As shown in Figure 35 , the process of designing the film system structure is as follows: divide the transmittance vector t into two parts according to the positive and negative values, form the positive value vector A and the negative value vector B, take the absolute value of the negative value vector B to obtain the vector B2, and use the vector A and the vector B2 as the target to optimize the design of the positive filter and the negative filter; first, select the initial film system structure of the filter, then change the thickness of each film layer, and determine whether the similarity of the filter transmittance and the vector A and the vector B2 reaches the threshold value, if yes, the design of the positive filter and the negative filter is completed; if not, determine whether the iteration reaches the predetermined number of times, if the iteration does not reach the predetermined number of times, continue to change the thickness of each film layer; if the iteration has reached the predetermined number of times, increase the number of film system layers and then select the initial film system structure of the filter.

Claims

1. A fault diagnosis device based on multivariate fluorescence correction analysis of transformer oil, characterized in that, include: The device includes a housing (10), an oil pumping unit (11), a fluorescence excitation source (12), a fluorescence excitation detection device (13), a fluorescence signal acquisition and analysis device (14), and a display screen (15). The oil pumping unit (11), fluorescence excitation source (12), fluorescence excitation detection device (13), and fluorescence signal acquisition and analysis device (14) are all located inside the housing (10) and on the front panel of the display screen (15). The oil pumping unit (11) is sealed to the transformer oil tank and the fluorescence excitation detection device (13) via pipes. The fluorescence excitation source (12) is connected to the fluorescence excitation detection device (13) via optical fiber, and the fluorescence excitation detection device (13) is connected to the fluorescence signal acquisition and analysis device (14) via optical fiber. 11) The insulating oil in the transformer oil tank is input into the fluorescence excitation detection device (13) by relying on the pressure difference between the transformer oil tank and the fluorescence excitation detection device (13) after vacuuming; the monochromatic excitation light with the optimal excitation wavelength generated by the fluorescence excitation source (12) is used to excite the transformer oil in the fluorescence excitation detection device (13) to produce fluorescence; the fluorescence excitation detection device (13) generates fluorescence according to the input monochromatic excitation light and inputs it to the fluorescence signal acquisition and analysis device (14); the fluorescence signal acquisition and analysis device (14) uses a multi-element correction filter group to acquire and analyze the fluorescence signal emitted by the transformer oil to determine the type of transformer fault; the display screen (15) is used to display the results of the acquisition and analysis by the fluorescence signal acquisition and analysis device (14); A multi-element correction filter group consists of a pair of positive multi-element correction filters and a negative multi-element correction filter used in conjunction. Its design method is as follows: S1 uses a multivariate regression correction method to calculate the mapping relationship between the fluorescence spectrum of transformer oil and the concentration of aromatic hydrocarbon compounds, and obtains the multivariate regression correction coefficient; S2 embodies the multivariate regression correction coefficients from step S1 in hardware, as follows: S21 uses the positive and negative coefficients of the standardized multivariate regression correction coefficient vector as the transmittance of the filter; S22 designs the film structure of positive multi-element correction filters and negative multi-element correction filters based on transmittance.

2. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 1, characterized in that, The oil extraction device (11) includes: an oil inlet valve (111), an oil outlet valve (112), an oil pump (113), an air pump (114), an oil inlet two-way valve (115), an oil outlet three-way valve (116), a device base plate (117), and a mounting bracket (118); the oil inlet valve (111), the oil outlet valve (112), the oil pump (113), and the air pump (114) are all fixedly installed on the device base plate (117); the oil inlet two-way valve (115) and the oil outlet three-way valve (116) are all fixedly installed on the mounting bracket (118), and the mounting bracket (118) is fixedly installed on the device base plate (117); the oil pump (113) is used to extract the transformer oil after testing from the fluorescent excitation detection device (13); the air pump (114) is used to pump the oil in the oil extraction device... Impurity gases in the pipeline and in the fluorescence excitation detection device (13) of the fluorescence detection device are extracted; one end of the oil inlet valve (111) is connected to the oil outlet of the transformer oil tank, the other end of the oil inlet valve (111) is connected to one end of the oil inlet two-way valve (115), and the other end of the oil inlet two-way valve (115) is connected to the oil inlet of the fluorescence excitation detection device (13); one end of the oil pump (113) is connected to the first port of the oil drain and exhaust tee (116), the other end of the oil pump (113) is connected to the oil outlet of the fluorescence excitation detection device (13), the second port of the oil drain and exhaust tee (116) is connected to one end of the oil outlet valve (112), and the other end of the oil outlet valve (112) is connected to the oil inlet of the transformer oil tank; the third port of the oil drain and exhaust tee (116) is connected to one end of the air pump (114).

3. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 2, characterized in that, The working process of the oil pumping device (11) includes the following steps: S1. Vacuuming the internal pipelines and detection tank of the oil pumping unit, specifically as follows: close the oil inlet valve (111) and the oil outlet valve (112), set the oil pump (113) to the normal open mode, start the air pump (114) to evacuate the internal pipelines and detection tank of the oil pumping unit, and after the evacuation is completed, set the oil pump (113) to the blocking mode and turn off the air pump (114). S2. Insulating oil enters the test tank, specifically as follows: Open the oil inlet valve (111). The insulating oil in the transformer tank is drawn into the test tank by the pressure difference between the oil outlet of the transformer tank and the test tank after vacuuming. After the oil is inlet is completed, close the oil inlet valve (111). S3. The insulating oil is returned to the transformer tank as follows: After the test is completed, open the oil outlet valve (112), set the air pump (114) to the blocking mode, start the oil pump (113) to extract the insulating oil in the test pool and press it back into the transformer tank.

4. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 2, characterized in that, The fluorescence excitation source (12) includes: a fluorescence excitation dark chamber (120), a monochromatic optimal wavelength LED excitation source (121), a converging lens (123), and an optical fiber head (125); the monochromatic optimal wavelength LED excitation source (121), the converging lens (123), and the optical fiber head (125) are all fixedly disposed inside the fluorescence excitation dark chamber (120), and the converging lens (123) is disposed between the monochromatic optimal wavelength LED excitation source (121) and the optical fiber head (125); the center lines of the monochromatic optimal wavelength LED excitation source (121), the converging lens (123), and the first optical fiber interface (126) are on a straight line; The method for selecting the optimal excitation wavelength of the monochromatic optimal wavelength LED excitation source (121) is as follows: Three-dimensional fluorescence spectral data of different types of transformer oil are collected. Based on the distribution range of fluorescence characteristic values ​​of the transformer oil fluorescence spectrum, the optimal excitation wavelength range is determined. The peak intensity of the sample characteristics under different excitation wavelengths is compared using the excitation wavelength as the abscissa and the peak intensity as the ordinate. The dispersion of the sample characteristics under different excitation wavelengths is compared using the excitation wavelength as the abscissa and the coefficient of variation as the ordinate. The excitation wavelength that maximizes both the peak intensity and the coefficient of variation is selected as the excitation wavelength of the monochromatic optimal wavelength LED excitation source (121). The formula for calculating the coefficient of variation is as follows: ;in, δ is the coefficient of variation, μ is the standard deviation, and μ is the mean. The larger the coefficient of variation, the greater the dispersion.

5. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 4, characterized in that, The fluorescence excitation source (12) further includes: an excitation source mounting bracket (122), a lens mounting bracket (124), and a first optical fiber interface (126); the excitation source mounting bracket (122) is fixedly mounted on the bottom plate inside the fluorescence excitation dark chamber (120), and the monochromatic optimal wavelength LED excitation source (121) is mounted on the excitation source mounting bracket (122); the lens mounting bracket (124) is fixedly mounted on the bottom plate inside the fluorescence excitation dark chamber (120), and the converging lens (123) is embedded in the lens mounting bracket (124); the first optical fiber interface (126) is fixedly mounted on the side wall outside the fluorescence excitation dark chamber (120), and the optical fiber head (125) is connected to the first optical fiber interface (126).

6. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 1, characterized in that, The fluorescence excitation detection device (13) includes: a detection cell dark chamber (1311), a detection cell (1312), a reference cell (1313), an excitation light emission fiber probe (1316), a fluorescence receiving fiber probe (1317), a fiber head mover (1318), an excitation light transmission fiber head (1320), a fluorescence receiving fiber head (1321), an excitation light transmission fiber interface (1322), and a fluorescence receiving fiber interface (1323); the detection cell (1312), the reference cell (1313), and the reference cell (1314) are all part of the detection cell dark chamber (1311). 3) The test cells (1312) are arranged side by side at the bottom of the dark chamber (1311). The test cell (1312) is used to hold the transformer oil to be tested, and the reference cell (1313) is used to hold the standard solution for calibration. The excitation light transmission fiber optic interface (1322) and the fluorescence receiving fiber optic interface (1323) are located at the top outside the dark chamber (1311). One end of the excitation light transmission fiber optic interface (1322) and the fluorescence receiving fiber optic interface (1323) are respectively connected to the fluorescence excitation source (12) and the fluorescence signal acquisition and analysis device. The other ends of the excitation light transmission fiber optic interface (1322) and the fluorescence receiving fiber optic interface (1323) are respectively connected to one end of the excitation light transmission fiber optic head (1320) and the fluorescence receiving fiber optic head (1321) set inside the dark chamber (1311) of the detection cell. The other ends of the excitation light transmission fiber optic head (1320) and the fluorescence receiving fiber optic head (1321) are respectively connected to the excitation light emission fiber optic probe (1316) and the fluorescence receiving fiber optic probe (1317). The mover (1318) is located above the detection cell (1312) and the reference cell (1313) inside the dark chamber (1311) of the detection cell. The excitation light emitting fiber optic probe (1316) and the fluorescence receiving fiber optic probe (1317) are respectively located on both sides of the fiber optic head mover (1318). The fiber optic head mover (1318) simultaneously drives the excitation light emitting fiber optic probe (1316) and the fluorescence receiving fiber optic probe (1317) to switch between the detection cell (1312) and the reference cell (1313).

7. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 6, characterized in that, The working process of the fluorescence excitation detection device (13) for detecting the fluorescence spectral intensity value of transformer oil is as follows: the fiber optic head mover (1318) is moved above the detection pool (1312), and the excitation light is incident into the detection pool (1312) through the excitation light transmission fiber optic interface (1322), the excitation light transmission fiber optic head (1320), and the excitation light emission fiber optic probe (1316) in sequence, which excites the transformer oil in the detection pool (1312) to generate fluorescence; the excited fluorescence is transmitted out through the fluorescence receiving fiber optic probe (1317), the fluorescence receiving fiber optic head (1321), and the fluorescence receiving fiber optic interface (1323) in sequence, and the fluorescence detector measures the fluorescence spectral intensity value of the transformer oil under the current external conditions.

8. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 7, characterized in that, The calibration method of the fluorescence excitation detection device (13) is as follows: the fluorescence spectral intensity value of the standard solution is measured under standard conditions and current external conditions respectively. The fiber optic head mover (1318) is moved above the reference cell (1313). The excitation light is sequentially incident into the reference cell (1313) through the excitation light transmission fiber optic interface (1322), the excitation light transmission fiber optic head (1320), and the excitation light emission fiber optic probe (1316), which excites the standard solution in the reference cell (1313) to generate fluorescence. The excited fluorescence is sequentially transmitted through the fluorescence receiving fiber optic probe (1317), the fluorescence receiving fiber optic head (1321), and the fluorescence receiving fiber optic interface (1323). The fluorescence spectral intensity value of the standard solution is measured by the fluorescence detector. The fluorescence intensity values ​​of the standard solution measured under standard conditions are as follows: ; The fluorescence intensity values ​​of the standard solution measured under the current external conditions are: ; Therefore, the calibration coefficient of the device is obtained as follows: ;in, This represents the fluorescence spectrum of the standard solution measured under standard conditions. This represents the fluorescence spectrum of the standard solution measured under current external conditions. This indicates the transmittance of the filter in the fluorescence detector.

9. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 6, characterized in that, The angle between the optical path of the excitation light emitting fiber optic probe (1316) and the optical path of the fluorescence receiving fiber optic probe (1317) is 90 degrees.

10. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 6, characterized in that, The fluorescence excitation detection device (13) further includes an oil inlet pipe (1314) and an oil outlet pipe (1315); an oil inlet and an oil outlet are provided on one side of the detection cell (1312), one end of the oil inlet pipe (1314) is sealed to the oil inlet, and the other end of the oil inlet pipe (1314) extends outside the dark chamber (1311) of the detection cell, one end of the oil outlet pipe (1315) is sealed to the oil outlet, and the other end of the oil outlet pipe (1315) extends outside the dark chamber (1311) of the detection cell.

11. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 10, characterized in that, The fluorescence excitation detection device (13) further includes: a stepper motor (1319); the fiber optic head mover (1318) adopts a walking structure with a slider (13181) and a slide bar (13182); the excitation light emitting fiber optic probe (1316) and the fluorescence receiving fiber optic probe (1317) are respectively set on the left and right sides of the slider (13181) of the fiber optic head mover (1318); the stepper motor (1319) is set on the back plate of the dark chamber (1311) of the detection cell; the stepper motor (1319) is used to drive the slider (13181) of the fiber optic head mover (1318) to move back and forth on the slide bar (13182), thereby simultaneously driving the excitation light emitting fiber optic probe (1316) and the fluorescence receiving fiber optic probe (1317) to switch between the detection cell (1312) and the reference cell (1313).

12. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 6, characterized in that, The fluorescence signal acquisition and analysis device (14) includes: a fluorescence signal acquisition and analysis dark chamber (140), a fluorescence detector (141), a filter wheel (142), a multi-element correction filter group (143), an optical fiber head (145), and a second optical fiber interface (146); the fluorescence detector (141) and the filter wheel (142) are both located inside the fluorescence signal acquisition and analysis dark chamber (140); the multi-element correction filter group (143) is composed of a pair of positive multi-element correction filters and a negative multi-element correction filter, and the multi-element correction filter group (143) is mounted on the filter wheel (142), and the filter wheel (142) is rotatably located between the fluorescence detector (141) and the optical fiber head (145); the optical fiber head (145) is located on the inner side wall of the fluorescence signal acquisition and analysis dark chamber (140), and the second optical fiber interface (146) is located on the fluorescence signal acquisition and analysis dark chamber (140). On the side wall outside the analysis darkroom (140), the fiber optic head (145) is connected to the second fiber optic interface (146); the fluorescence receiving fiber optic interface (1323) is connected to the second fiber optic interface (146) through an optical fiber; the fluorescence detector (141) is used to receive the fluorescence signal emitted by the transformer oil and record the total fluorescence intensity value; the multi-element correction filter group (143) is used to collect and analyze the fluorescence signal emitted by the transformer oil; in use, the positive multi-element correction filter or the negative multi-element correction filter is rotated into place so that the center lines of the fiber optic head (145), the positive multi-element correction filter or the negative multi-element correction filter and the receiving lens of the fluorescence detector (141) are on a straight line, and the fluorescence emitted by the transformer oil passes through the second fiber optic interface (146), the fiber optic head (145), the positive multi-element correction filter or the negative multi-element correction filter and the receiving lens of the fluorescence detector (141) in sequence.

13. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 12, characterized in that, The mapping relationship described in step S1 is as follows: The fluorescence spectrum of transformer oil is directly related to the concentration of aromatic hydrocarbons. The formula for calculating the concentration of aromatic hydrocarbons is derived using multiple linear regression: Where c is the concentration of aromatic hydrocarbons. The multivariate regression correction coefficients for the fluorescence spectra obtained in bands 1 to n are used. Here, represents the fluorescence spectrum of the first to nth bands, and b is the bias coefficient. The vector form of the formula for calculating the concentration of aromatic hydrocarbon compounds using multiple linear regression correction is as follows: in, This is the vector of regression correction coefficients; = , T , is the fluorescence spectrum vector.

14. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 13, characterized in that, The calculation process for transmittance in step S21 is as follows: Define half coefficient and , and They are respectively The positive and negative parts, that is: ； Find the maximum value of the half coefficient: Therefore, the transmittances of the positive and negative filters are obtained as follows: ； Where i = 1, 2, ..., n, and n is a natural number. The regression correction coefficient vector The i-th element.

15. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 14, characterized in that, The process of designing the membrane structure in step S22 is as follows: the transmittance vector t is divided into two parts according to positive and negative values, forming a positive vector A and a negative vector B. The absolute value of the negative vector B is taken to obtain vector B2. The positive filter and the negative filter are designed with vector A and vector B2 as targets respectively. First, the initial membrane structure of the filter is selected. Then, the thickness of each membrane layer is changed, and it is judged whether the similarity between the transmittance of the filter and vector A and vector B2 reaches the threshold. If it does, the design of the positive filter and the negative filter is completed. If not, it is judged whether the iteration has reached the predetermined number of times. If the iteration has not reached the predetermined number of times, the thickness of each membrane layer is changed again. If the iteration has reached the predetermined number of times, the number of membrane layers is increased and the initial membrane structure of the filter is selected again.

16. The fault diagnosis device based on transformer oil fluorescence multivariate correction analysis according to claim 12, characterized in that, The fluorescence signal acquisition and analysis device (14) further includes: a filter wheel drive motor (144), a fluorescence detector mounting bracket (147), and a filter wheel drive motor mounting bracket (148). The fluorescence detector mounting bracket (147) is set on the inner bottom plate of the fluorescence signal acquisition and analysis dark chamber (140), and the fluorescence detector (141) is fixedly mounted on the fluorescence detector mounting bracket (147). The fluorescence detector mounting bracket (147) has a through hole that matches the receiving lens of the fluorescence detector (141), and the receiving lens of the fluorescence detector (141) is aligned with the through hole. The filter wheel drive motor (144) is fixedly mounted on the filter wheel drive motor mounting bracket (148), and the filter wheel drive motor mounting bracket (148) is set on the inner bottom plate of the fluorescence signal acquisition and analysis dark chamber (140). The filter wheel (142) is sleeved on the rotating shaft of the filter wheel drive motor (144), and the filter wheel drive motor (144) drives the filter wheel (142) to rotate.

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