Multi-sensor fusion transformer insulating oil aging degree evaluation method

Abstract

The invention discloses a multi-sensor fusion transformer insulating oil aging degree evaluation method. The method comprises the following steps: establishing an insulating oil aging degree comprehensive experiment platform; the method comprises the following steps: testing different aging degrees of transformer insulating oil through an insulating oil aging degree comprehensive experiment platform, and obtaining dielectric constants, pH values and light transmittance of the insulating oil under different aging degrees through multiple sensors; determining the weights of the dielectric constant, the pH value and the light transmittance by adopting an entropy method; and evaluating the aging degree of the transformer insulating oil based on the dielectric constant, the pH value, the light transmittance data and the weight thereof. According to the invention, a plurality of sensors are adopted to collect data and fuse the data, so that the aging degree of the transformer insulating oil can be accurately evaluated.

Description

Technical Field

[0001] The present invention relates to the field of transformers, and in particular to a multi-sensor fusion method for evaluating the aging degree of transformer insulating oil. Background Art

[0002] As a key component of transformer operation, transformer insulating oil plays a vital role in power systems. It is crucial for ensuring the proper functioning of transformers and the stable transmission of electrical energy. It is a crucial element in the power supply for social production and daily life. The degree of aging of transformer insulating oil has a direct and significant impact on the safe and stable operation of the entire power system.

[0003] Because transformer insulating oil operates in a complex and ever-changing environment, its aging rate is difficult to accurately assess under complex operating conditions. Long-term exposure to the combined effects of electricity, magnetism, heat, and force can exacerbate aging, potentially leading to transformer failure and disrupting the normal operation of the power system. Accurately monitoring the aging of transformer insulating oil has long been a pressing issue in existing technologies. Traditional monitoring methods often suffer from limitations such as low accuracy and incomplete monitoring. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a transformer insulating oil aging degree assessment method using multi-sensor fusion with simple algorithm and high accuracy.

[0005] The technical solution of the present invention to solve the above technical problems is: a method for evaluating the aging degree of transformer insulating oil by multi-sensor fusion, comprising the following steps:

[0006] Step 1: Build a comprehensive experimental platform for insulating oil aging;

[0007] Step 2: Test the different aging degrees of transformer insulating oil using the insulating oil aging comprehensive experimental platform, and use multiple sensors to obtain the dielectric constant, pH, and transmittance of the insulating oil at different aging degrees;

[0008] Step 3: Use the entropy method to determine the weights of dielectric constant, pH and transmittance;

[0009] Step 4: Evaluate the aging degree of transformer insulating oil based on the dielectric constant, pH, and transmittance data and their weights.

[0010] The above-mentioned multi-sensor fusion transformer insulating oil aging degree assessment method, in the step 1, the insulating oil aging degree comprehensive experimental platform includes a transformer insulating oil tank, insulating oil, a dielectric constant sensor, a pH electrode sensor, an optical sensor, an inlet pipe, an outlet pipe, an oil pump, a heater, a first temperature sensor, a second temperature sensor, a data acquisition system, a temperature control system and a computer, the insulating oil is installed in the transformer insulating oil tank, the transformer insulating oil tank is connected to the heater through the inlet pipe, the heater is connected to the transformer insulating oil tank through the outlet pipe, an oil pump is provided on the inlet pipe and the outlet pipe, the dielectric constant sensor, the pH electrode sensor, the optical sensor, the first temperature sensor and the second temperature sensor are installed inside the heater, the dielectric constant sensor, the pH electrode sensor and the optical sensor are respectively connected to the data acquisition system, the first temperature sensor and the second temperature sensor are respectively connected to the temperature control system, and the data acquisition system and the temperature control system are respectively connected to the computer.

[0011] In the above-mentioned multi-sensor fusion transformer insulating oil aging degree assessment method, in the insulating oil aging degree comprehensive experimental platform of step 1, after the insulating oil enters the heater, the insulating oil liquid level is higher than the top of the first temperature sensor, the second temperature sensor, the dielectric constant sensor, the pH electrode sensor and the optical sensor.

[0012] In the above-mentioned multi-sensor fusion transformer insulating oil aging degree assessment method, the specific process of step 2 is as follows:

[0013] The transformer insulating oil enters the heater through the oil pump. The computer sends instructions to the temperature control system. The temperature control system controls the first temperature sensor, the second temperature sensor and the heater. A control temperatures are set. An initial measurement is performed at each control temperature. Then, heating is performed at set intervals and then measured again after heating. A total of B heating times are performed, and a total of A×(B+1) insulating oils with different aging degrees are obtained. The dielectric constant sensor, pH electrode sensor and optical sensor are used to detect insulating oils with different aging degrees. The dielectric constant sensor measures the dielectric constant. The dielectric constant of the jth test at the i-th control temperature is recorded as K. i,j , the pH electrode sensor measures the pH, and the pH of the jth test at the i-th control temperature is recorded as pH i,j , the optical sensor measures the transmittance, and the transmittance of the jth test at the i-th control temperature is recorded as O i,j , collect data from each sensor through the data acquisition system, and transmit the data to the computer for storage.

[0014] In the above-mentioned multi-sensor fusion transformer insulating oil aging degree assessment method, in the step 2, three control temperatures are set. When the control temperatures are 80°C, 110°C, and 130°C, respectively, i is 1, 2, and 3, and the interval setting time is 48 hours. When j is 1, 2, 3, 4, 5, 6, 7, and 8, respectively, the time is 0 day, 2 days, 4 days, 6 days, 8 days, 10 days, 12 days, and 14 days.

[0015] In the above-mentioned multi-sensor fusion transformer insulating oil aging degree assessment method, the specific process of step three is as follows:

[0016] K i,j , pH i,j , O i,j Form a data set x i,j,m , m represents the detection index, m = 1 represents dielectric constant, m = 2 represents pH, and m = 3 represents transmittance;

[0017] The entropy method is used to weight the dielectric constant, pH and transmittance of each indicator under the same aging conditions. m The calculation method is as follows:

[0018] x i,j,m Perform data standardization to obtain the standardized data y i,j,m :

[0019]

[0020]

[0021] Calculate the proportion q of any sample in the indicator m i,j,m :

[0022]

[0023] Calculate the entropy value h of indicator m m :

[0024]

[0025] Calculate the coefficient of variation s of indicator m m :

[0026] s m =1-h m

[0027] Calculate the weight w of indicator m m :

[0028]

[0029] The specific process of step 4 of the above multi-sensor fusion transformer insulating oil aging assessment method is as follows:

[0030] First, preprocess the data of indicator m to obtain the preprocessed data y of indicator m p,m :

[0031]

[0032]

[0033] Where, y q,1 、y q,2 、y q,3 are the data when the test indicators are 1, 2, and 3, respectively. K0, pH0, and O0 are the initial reference dielectric constant, initial reference pH, and initial reference transmittance, respectively. K, pH, and O are the dielectric constant, pH, and transmittance of the tested insulating oil sample, respectively.

[0034] Then set the insulating oil aging degree assessment parameter Δ:

[0035] Δ=w1×y p,1 +w2×y p,2 +w3×y p,3

[0036] When the aging evaluation parameter of the insulating oil exceeds 8% of the aging evaluation parameter of new insulating oil, the computer will issue an early warning signal.

[0037] The beneficial effects of the present invention are as follows: the present invention first establishes a comprehensive experimental platform for the aging degree of insulating oil; then tests the different aging degrees of transformer insulating oil, and obtains the dielectric constant, pH and transmittance of the insulating oil at different aging degrees through multiple sensors; then adopts the entropy method to determine the weights of the dielectric constant, pH and transmittance; finally, the aging degree of the transformer insulating oil is evaluated based on the dielectric constant, pH and transmittance data and their weights; the present invention uses multiple sensors to collect data and fuses the data, which can provide an accurate evaluation of the aging degree of the transformer insulating oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is the overall flow chart of the present invention.

[0039] Figure 2 This is a schematic diagram of the structure of the comprehensive experimental platform for insulating oil aging degree built by the present invention. DETAILED DESCRIPTION

[0040] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0041] like Figure 1As shown, a multi-sensor fusion transformer insulation oil aging degree assessment method includes the following steps:

[0042] Step 1: Build a comprehensive experimental platform for insulating oil aging.

[0043] like Figure 2 As shown, the comprehensive experimental platform for insulating oil aging degree includes a transformer insulating oil tank 1, insulating oil 2, a dielectric constant sensor 3, a pH electrode sensor 4, an optical sensor 5, an inlet pipe 6, an outlet pipe 7, an oil pump 8, a heater 9, a first temperature sensor 10, a second temperature sensor 11, a data acquisition system 12, a temperature control system 13 and a computer 14. The insulating oil 2 is installed in the transformer insulating oil tank 1, the transformer insulating oil tank 1 is connected to the heater 9 through the inlet pipe 6, and the heater 9 is connected to the transformer insulating oil tank 1 through the outlet pipe 7. The inlet pipe 6 and the outlet pipe 7 are provided with an oil pump 8, the dielectric constant sensor 3, the pH electrode sensor 4, the optical sensor 5, the first temperature sensor 10 and the second temperature sensor 11 are installed inside the heater 9, the dielectric constant sensor 3, the pH electrode sensor 4 and the optical sensor 5 are respectively connected to the data acquisition system 12, the first temperature sensor 10 and the second temperature sensor 11 are respectively connected to the temperature control system 13, and the data acquisition system 12 and the temperature control system 13 are respectively connected to the computer 14. After the insulating oil 2 enters the heater 9 , the liquid level of the insulating oil 2 is higher than the tops of the first temperature sensor 10 , the second temperature sensor 11 , the dielectric constant sensor 3 , the pH electrode sensor 4 and the optical sensor 5 .

[0044] Step 2: Test the different aging degrees of transformer insulating oil through the comprehensive insulating oil aging degree experimental platform, and obtain the dielectric constant, pH and transmittance of the insulating oil at different aging degrees through multiple sensors.

[0045] The specific process of step 2 is:

[0046] The transformer insulating oil enters the heater through the oil pump. The computer sends instructions to the temperature control system, which controls the first temperature sensor, the second temperature sensor, and the heater. Three control temperatures are set. An initial measurement is performed at each control temperature, and then heating is performed at set intervals. After heating, another measurement is performed. A total of seven heatings are performed, resulting in a total of 24 insulating oils with different degrees of aging. The dielectric constant sensor, pH electrode sensor, and optical sensor are used to detect insulating oils with different degrees of aging. The dielectric constant sensor measures the dielectric constant. The dielectric constant of the jth test at the i-th control temperature is recorded as K. i,j , the pH electrode sensor measures the pH, and the pH of the jth test at the i-th control temperature is recorded as pH i,j , the optical sensor measures the transmittance, and the transmittance of the jth test at the i-th control temperature is recorded as Oi,j , the data from each sensor is collected through the data acquisition system and transmitted to the computer for storage; when the controlled temperatures are 80℃, 110℃, and 130℃ respectively, i is 1, 2, and 3 respectively, and the interval setting time is 48 hours. When j is 1, 2, 3, 4, 5, 6, 7, and 8 respectively, the time is 0 days, 2 days, 4 days, 6 days, 8 days, 10 days, 12 days, and 14 days respectively.

[0047] Step 3: Use the entropy method to determine the weights of dielectric constant, pH, and transmittance. The specific process is as follows:

[0048] K i,j , pH i,j , O i,j Form a data set x i,j,m , m represents the detection index, m = 1 represents dielectric constant, m = 2 represents pH, and m = 3 represents transmittance;

[0049] The entropy method is used to weight the dielectric constant, pH and transmittance of each indicator under the same aging conditions. m The calculation method is as follows:

[0050] x i,j,m Perform data standardization to obtain the standardized data y i,j,m :

[0051]

[0052]

[0053] Calculate the proportion q of any sample in the indicator m i,j,m :

[0054]

[0055] Calculate the entropy value h of indicator m m :

[0056]

[0057] Calculate the coefficient of variation s of indicator m m :

[0058] s m =1-h m

[0059] Calculate the weight w of indicator m m :

[0060]

[0061] Step 4: Evaluate the aging degree of transformer insulating oil based on the dielectric constant, pH, and transmittance data and their weights. The specific process is as follows:

[0062] First, preprocess the data of indicator m to obtain the preprocessed data y of indicator m p,m :

[0063]

[0064]

[0065] Where, y q,1 、y q,2 、y q,3 are the data when the test indicators are 1, 2, and 3, respectively. K0, pH0, and O0 are the initial reference dielectric constant, initial reference pH, and initial reference transmittance, respectively. K, pH, and O are the dielectric constant, pH, and transmittance of the tested insulating oil sample, respectively.

[0066] Then set the insulating oil aging degree assessment parameter Δ:

[0067] Δ=w1×y p,1 +w2×y p,2 +w3×y p,3

[0068] When the aging evaluation parameter of the insulating oil exceeds 8% of the aging evaluation parameter of new insulating oil, the computer will issue an early warning signal.

Claims

1. A method for evaluating the aging degree of transformer insulating oil based on multi-sensor fusion, characterized in that: The following steps are involved: Step 1: Build a comprehensive experimental platform for insulating oil aging; Step 2: Test the different aging degrees of transformer insulating oil using the insulating oil aging comprehensive experimental platform, and use multiple sensors to obtain the dielectric constant, pH, and transmittance of the insulating oil at different aging degrees; Step 3: Use the entropy method to determine the weights of dielectric constant, pH and transmittance; Step 4: Evaluate the aging degree of transformer insulating oil based on the dielectric constant, pH, and transmittance data and their weights.

2. The method for evaluating the aging degree of transformer insulating oil based on multi-sensor fusion according to claim 1, characterized in that: In the step 1, the comprehensive experimental platform for the degree of insulating oil aging includes a transformer insulating oil tank, insulating oil, a dielectric constant sensor, a pH electrode sensor, an optical sensor, an inlet pipe, an outlet pipe, an oil pump, a heater, a first temperature sensor, a second temperature sensor, a data acquisition system, a temperature control system and a computer. The insulating oil is installed in the transformer insulating oil tank, the transformer insulating oil tank is connected to the heater through the inlet pipe, the heater is connected to the transformer insulating oil tank through the outlet pipe, an oil pump is provided on the inlet pipe and the outlet pipe, the dielectric constant sensor, the pH electrode sensor, the optical sensor, the first temperature sensor and the second temperature sensor are installed inside the heater, the dielectric constant sensor, the pH electrode sensor and the optical sensor are respectively connected to the data acquisition system, the first temperature sensor and the second temperature sensor are respectively connected to the temperature control system, and the data acquisition system and the temperature control system are respectively connected to the computer.

3. The method for evaluating the aging degree of transformer insulating oil by multi-sensor fusion according to claim 2, characterized in that: In the insulating oil aging degree comprehensive experimental platform of step 1, after the insulating oil enters the heater, the insulating oil liquid level is higher than the top of the first temperature sensor, the second temperature sensor, the dielectric constant sensor, the pH electrode sensor and the optical sensor.

4. The method for evaluating the aging degree of transformer insulating oil based on multi-sensor fusion according to claim 2, characterized in that: The specific process of step 2 is: The transformer insulating oil enters the heater through the oil pump. The computer sends instructions to the temperature control system. The temperature control system controls the first temperature sensor, the second temperature sensor and the heater. A control temperatures are set. An initial measurement is performed at each control temperature. Then, heating is performed at set intervals and then measured again after heating. A total of B heating times are performed, and a total of A×(B+1) insulating oils with different aging degrees are obtained. The dielectric constant sensor, pH electrode sensor and optical sensor are used to detect insulating oils with different aging degrees. The dielectric constant sensor measures the dielectric constant. The dielectric constant of the jth test at the i-th control temperature is recorded as K. i,j , the pH electrode sensor measures the pH, and the pH of the jth test at the i-th control temperature is recorded as pH i,j , the optical sensor measures the transmittance, and the transmittance of the jth test at the i-th control temperature is recorded as O i,j , collect data from each sensor through the data acquisition system, and transmit the data to the computer for storage.

5. The method for evaluating the aging degree of transformer insulating oil based on multi-sensor fusion according to claim 4, characterized in that: In the step 2, three control temperatures are set. When the control temperatures are 80°C, 110°C, and 130°C respectively, i is 1, 2, and 3 respectively, and the interval setting time is 48 hours. When j is 1, 2, 3, 4, 5, 6, 7, and 8 respectively, the time is 0 day, 2 days, 4 days, 6 days, 8 days, 10 days, 12 days, and 14 days respectively.

6. The method for evaluating the aging degree of transformer insulating oil based on multi-sensor fusion according to claim 5, characterized in that: The specific process of step three is: K i,j , pH i,j , O i,j Form a data set x i,j,m , m represents the detection index, m = 1 represents dielectric constant, m = 2 represents pH, and m = 3 represents transmittance; The entropy method is used to weight the dielectric constant, pH and transmittance of each indicator under the same aging conditions. m The calculation method is as follows: x i,j,m Perform data standardization to obtain the standardized data y i,j,m : Calculate the proportion q of any sample in the indicator m i,j,m : Calculate the entropy value h of indicator m m : Calculate the coefficient of variation s of indicator m m : s m =1-h m Calculate the weight w of indicator m m :

7. The method for evaluating the aging degree of transformer insulating oil based on multi-sensor fusion according to claim 6, characterized in that: The specific process of step 4 is as follows: First, preprocess the data of indicator m to obtain the preprocessed data y of indicator m p,m : Where, y q,1 、y q,2 、y q,3 are the data when the test indicators are 1, 2, and 3, respectively. K0, pH0, and O0 are the initial reference dielectric constant, initial reference pH, and initial reference transmittance, respectively. K, pH, and O are the dielectric constant, pH, and transmittance of the tested insulating oil sample, respectively. Then set the insulating oil aging degree assessment parameter Δ: Δ=w1×y p,1 +w2×y p,2 +w3×y p,3 When the aging evaluation parameter of the insulating oil exceeds 8% of the aging evaluation parameter of new insulating oil, the computer will issue an early warning signal.

Images