Intelligent analysis method for oil temperature and oil level of transformer

Abstract

The invention provides an intelligent analysis method for the oil temperature and the oil level of a transformer. The method comprises the following steps: S1, acquiring oil temperature and oil level data of a transformer, generating displacement diagrams of two data in a coordinate system, drawing an actual oil temperature and oil level curve, and comparing the actual oil temperature and oil level curve with a standard oil temperature and oil level curve given by a manufacturer; s2, generating a relation function between the oil level and the oil temperature by using the transformer oil temperature and oil level monitoring, checking and analyzing device, and performing data comparison with a standard oil temperature and oil level curve given by a manufacturer; s3, analyzing whether the deviation between the oil temperature and oil level curve and a standard oil temperature and oil level curve given by a manufacturer exceeds an allowable value or not under the high-temperature and low-temperature operation conditions; according to the invention, quantitative data analysis can be carried out on the oil temperature and the oil quantity of the oil-immersed transformer.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid equipment, and in particular to an intelligent analysis method for transformer oil temperature and oil level. Background Art

[0002] In the existing technology, the oil-immersed transformer is filled with transformer oil. The transformer oil is communicated with the conservator through a connecting pipe. The oil temperature will change within a certain range according to the change of the ambient temperature and the change of the transformer load. The volume of the transformer oil also changes accordingly. Usually, the oil quantity of the transformer is confirmed by observing the indication of the oil level gauge installed on the conservator. The transformer oil temperature and oil level are important parameters reflecting the operation status of the transformer. Once the oil level gauge gets stuck, false oil level, or the oil level is too low or too high, it will affect the normal operation of the transformer.

[0003] The existing technology only manually observes the indication of the oil level gauge installed on the conservator to confirm whether the oil quantity of the transformer is normal, and does not perform quantitative data analysis on the oil temperature and oil quantity of the oil-immersed transformer.

[0004] The present invention proposes a solution to the above problems. Summary of the Invention

[0005] The present invention proposes an intelligent analysis method for transformer oil temperature and oil level, which can perform quantitative data analysis on the oil temperature and oil quantity of the oil-immersed transformer.

[0006] The present invention adopts the following technical solutions.

[0007] An intelligent analysis method for transformer oil temperature and oil level, the analysis performs abnormal phenomenon analysis by associating the oil level changes corresponding to different defects, including the following steps; Step S1, collect the transformer oil temperature and oil level data, use the transformer oil temperature and oil level monitoring and checking analysis device to monitor and store the data of the oil temperature and the transformer oil level for a long time, adopt the data displacement diagram, generate the displacement diagrams of the two data in the coordinate system, draw the actual oil temperature and oil level curve, compare it with the standard oil temperature and oil level curve given by the manufacturer, set the error range, and analyze whether the oil level is normal at different operating oil temperatures and whether there is a false oil level. Step S2, use the transformer oil temperature and oil level monitoring and checking analysis device to generate the relationship function between the oil level and the oil temperature, compare the data with the standard oil temperature and oil level curve given by the manufacturer, determine the upper limit and the lower limit of the error according to the data tracking, set the alarm threshold, and use the analysis logic unit in the data analysis controller to give an alarm. Step S3, analyzing whether the deviation of the oil temperature and oil level curve under high and low temperature operating conditions compared with the standard oil temperature and oil level curve given by the manufacturer exceeds the allowable value, analyzing the real oil temperature and oil level curve based on the long-term actual oil temperature and oil level curve data storage, and adjusting the alarm threshold using the linear regression principle to reduce the risk of false alarm refusal.

[0008] In step S1, the method for collecting oil level data is to collect data digitally through an oil level digital meter collection device; its working principle is: using the sliding resistor in the transformer oil level, when the oil level rises or falls, the sliding resistor resistance value changes, and at the same time, the oil level sensor generates a current change. A high-precision ammeter with a 485 interface is used to convert the current signal into a digital signal, and according to the corresponding current value, it is converted into the corresponding oil level by software.

[0009] In step S1, according to the current collected by the oil level sensor, the current is read and converted into a current signal using a digital 485 interface, and transmitted to a remote end for storage and analysis; the current signal is read by the intermediate equipment between the oil-immersed transformer and the remote data center, converted into a digital signal and sent to the central computer room using a digital 485 interface.

[0010] In step S1, the device for collecting oil level data also includes: Stainless steel electric box: used to install current and voltage meters; mA ammeter: used to collect transformer oil conservator current signals, convert current signals into digital signals and send them through the 485 interface. It also provides current digital display for easy remote monitoring and reading of digital signals; 0-24V specification voltmeter: used to monitor the voltage in the digital recording device. When the voltage is in an abnormal state, it will be transmitted to the 485 interface for remote alarm. Stop button with light: used to stop the device, lights up red when triggered; Illuminated start button: used to start the device, lights up green when triggered; Waterproof glass cover: used for waterproofing and visual observation of 0-24V voltmeter and mA ammeter; The data collected by the voltmeter and the data collected by the ammeter are sent simultaneously for comparison, and the authenticity of the data is analyzed and eliminated; For example, if 24V exceeds the set range, the software will no longer collect data. Conversely, if the current exceeds the range, the voltmeter will be used to determine whether the power supply is normal; The ammeter and voltmeter are made of non-reflective material to protect water resistance, and transparent for video reading via external devices; In step S1, the method for installing the equipment for collecting oil level data is as follows: Step A1: Install the fixed magnetic ring (7) in the stainless-steel electric box (1) outside the oil-immersed transformer. Flexible installation is achieved by using the fixed magnetic ring; Step A2: Connect the current line of the mA ammeter (2) to monitor the current, and connect a 3.0 - 24V voltmeter to monitor the voltage change; Step A3: Turn on the lighted start button (5) to start collecting current and convert it into a digital signal; Step A4: When not in use, turn on the lighted stop button (4) to turn off the oil level digital recording collection device.

[0011] The method uses an oil level digital recording data collection and analysis system to process the required data through a system architecture process of real-time data collection, analysis, transmission, storage, and finally display; specifically: After the system collects the original data through the front-end device, it is analyzed according to preset rules and then transmitted to the auxiliary control system processing module; that is, at the data transmission level, RabbitMQ is used to efficiently transmit the analyzed device data; After receiving the data, the auxiliary control system stores the data; that is, through the data persistence layer, real-time data is stored in the MySql database, and historical data is stored in the TDengine time series database; at the same time, it is convenient to quickly and efficiently obtain real-time data and basic account books. Redis is used for frequently used data to cache the basic information of the device. At the same time, to ensure that the data is quickly and real-time responded to the system interface, the WebSocket technology is adopted to push the data in real-time.

[0012] The data processing algorithm process adopted in Step S2 is to compare the collected data with the threshold set by the substation system. The data analysis status is divided into normal, warning, general, serious, and critical; In Step S2, using the transformer oil temperature and oil level monitoring and verification analysis device, long-term detection is carried out on the oil temperature, the running temperature, and the volume of transformer oil to generate the relationship function among the three. The upper limit and lower limit of the relationship function are determined by long-term monitoring and the detection of the transformer status; the analysis logic unit in the data analysis controller is used for alarm.

[0013] Step S2 includes the following oil level fault judgment methods: Method a1. Compare with the standard oil temperature and oil level curve. If the change in the actual oil temperature and oil level data does not exceed ±5%, and 115% of the standard oil level > actual oil level > 110% of the standard oil level, the fault conclusion is: general defect: slightly high oil level; Method a2. Compare with the standard oil temperature and oil level curve. If the change in the actual oil temperature and oil level data does not exceed ±5%, and 120% of the standard oil level > actual oil level ≥ 115% of the standard oil level, the fault conclusion is: General defect: The oil level is slightly high, and an alarm is required; Method a3. Compare with the standard oil temperature and oil level curve. If the change in the actual oil temperature and oil level data does not exceed ±5%), and the actual oil level ≥ 120% of the standard oil level, the fault conclusion is: General defect, and key reminder is required: The oil level is relatively high; Method a4. Compare with the standard oil temperature and oil level curve. If the change in the actual oil temperature and oil level data does not exceed ±5%, and 90% of the standard oil level ≤ actual oil level < 95% of the standard oil level, the fault conclusion is: General defect: The oil level is slightly low; Method a5. Compare with the standard oil temperature and oil level curve. If the change in the actual oil temperature and oil level data does not exceed ±5%, and 85% of the standard oil level ≤ actual oil level < 90% of the standard oil level, the fault conclusion is: General defect: The oil level is low; Method a6. Compare with the standard oil temperature and oil level curve. If the change in the actual oil temperature and oil level data does not exceed ±5%, and the actual oil level < 85% of the standard oil level, the fault conclusion is: General defect: The oil level is relatively low, and an alarm is required.

[0014] Step S2 includes the following methods for judging the slope fault of oil temperature and oil level: Method a7. Compare with the standard oil temperature and oil level curve X0. If the slope X1 of the actual oil temperature and oil level curve changes greatly, that is, 80%X0 < X1 < 85%X0, the fault conclusion is: General defect: The change of the oil level is slow; Method a8. Compare with the standard oil temperature and oil level curve X0. If the slope X1 of the actual oil temperature and oil level curve changes greatly, that is, X1 < 80%X0, the fault conclusion is: General defect, and an alarm is required: The change of the oil level is very slow; Suspected breathing blockage, meter jamming; Method a9. Compare with the standard oil temperature and oil level curve X0. If the slope X of the actual oil temperature and oil level curve changes greatly, that is, 130%X0 < X1, the fault conclusion is: General defect, and an alarm is required: Abnormal change of the oil level; Suspected air accumulation in the pipeline or corrugated leak point.

[0015] In step S3, based on the storage of the actual oil temperature and oil level curve data for half a year or one year, analyze the real oil temperature and oil level curve.

[0016] The present invention can perform quantitative data analysis on the oil temperature and oil quantity of an oil-immersed transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described in detail below with reference to the drawings and specific embodiments: Appendix Figure 1 is a schematic diagram of an oil level digital meter collecting device; Appendix Figure 2It is a side schematic diagram of the oil level digital indication collection device; Appendix Figure 3 It is a wiring schematic diagram when collecting current signals; Appendix Figure 4 It is a schematic diagram of the method flow of the present invention; Appendix Figure 5 It is a comparison schematic diagram of the standard curve and the abnormal curve of the transformer oil temperature and oil level; Appendix Figure 6 It is a comparison schematic diagram of the oil temperature and oil level slope and the actual measurement value during data collection. Specific implementation mode

[0018] As shown in the figure, an intelligent analysis method for transformer oil temperature and oil level, the analysis is carried out by associating the oil level changes corresponding to different defects to analyze abnormal phenomena, including the following steps; Step S1: Collect the transformer oil temperature and oil level data, use the transformer oil temperature and oil level monitoring and verification analysis device to monitor and store the data of the oil temperature and the transformer oil level for a long time, adopt a data displacement diagram, generate a displacement diagram of the two data in the coordinate system, draw the actual oil temperature and oil level curve, compare it with the standard oil temperature and oil level curve given by the manufacturer, set an error range, and analyze whether the oil level is normal at different operating oil temperatures and whether there is a false oil level. Step S2: Use the transformer oil temperature and oil level monitoring and verification analysis device to generate a relationship function between the oil level and the oil temperature, compare the data with the standard oil temperature and oil level curve given by the manufacturer, determine the upper limit and the lower limit of the error according to data tracking, set an alarm threshold, and use the analysis logic unit in the data analysis controller to give an alarm; Step S3: Analyze whether the deviation of the oil temperature and oil level curve from the standard oil temperature and oil level curve given by the manufacturer exceeds the allowable value under high-temperature and low-temperature operating conditions, analyze the real oil temperature and oil level curve according to the long-term storage of actual oil temperature and oil level curve data, and use the principle of linear regression to adjust the alarm threshold to reduce the risk of false alarms and missed alarms.

[0019] In step S1, the method for collecting oil level data is to digitally collect data through an oil level digital indication collection device; its working principle is: using the sliding rheostat in the transformer oil level, when the oil level rises or falls, it drives the change of the sliding rheostat resistance value, and at the same time makes the oil level sensor generate a current change. Use a high-precision ammeter with a 485 interface to convert the current signal into a digital signal, and convert it into the corresponding oil level with software according to the corresponding current value.

[0020] In step S1, according to the current collected by the oil level sensor, the current is read and converted into a current signal using a digital 485 interface, and transmitted to a remote end for storage and analysis; the current signal is read by the intermediate equipment between the oil-immersed transformer and the remote data center, converted into a digital signal and sent to the central computer room using a digital 485 interface.

[0021] In step S1, the device for collecting oil level data also includes: Stainless steel electric box: used to install current and voltage meters; mA ammeter: used to collect transformer oil conservator current signals, convert current signals into digital signals and send them through the 485 interface. It also provides current digital display for easy remote monitoring and reading of digital signals; 0-24V specification voltmeter: used to monitor the voltage in the digital recording device. When the voltage is in an abnormal state, it will be transmitted to the 485 interface for remote alarm. Stop button with light: used to stop the device, lights up red when triggered; Illuminated start button: used to start the device, lights up green when triggered; Waterproof glass cover: used for waterproofing and visual observation of 0-24V voltmeter and mA ammeter; The data collected by the voltmeter and the data collected by the ammeter are sent simultaneously for comparison, and the authenticity of the data is analyzed and eliminated; For example, if 24V exceeds the set range, the software will no longer collect data. Conversely, if the current exceeds the range, the voltmeter will be used to determine whether the power supply is normal; The ammeter and voltmeter are made of non-reflective material to protect water resistance, and transparent for video reading via external devices; In step S1, the method for installing the equipment for collecting oil level data is as follows: Step A1: Use the fixed magnetic ring (7) in the stainless steel electrical box (1) to install it on the outside of the oil-immersed transformer. Use the fixed magnetic ring to achieve flexible installation; Step A2, connect the mA ammeter (2) current line to monitor the current, and connect the 3.0-24V voltmeter to monitor the voltage change; Step A3, turn on the start button with light (5) to start collecting current and convert it into a digital signal; Step A4: When not in use, turn on the stop button (4) with light and close the oil level digital marking and collecting device.

[0022] The method adopts the oil level digital indication data collection and analysis system, and processes the required data through the system architecture flow of real-time data collection, data analysis, data transmission, data storage, and finally data display; specifically: After the system collects the original data through the front-end device, it is analyzed according to preset rules and then transmitted to the auxiliary control system processing module; that is, at the data transmission level, RabbitMQ is used to efficiently transmit the analyzed device data; After the auxiliary control system receives the data, it stores the data; that is, through the data persistence level, the real-time data is stored in the MySql database, and the historical data is stored in the TDengine time series database; at the same time, it is convenient to quickly and efficiently obtain the real-time data and basic account. For the commonly used data, Redis is used to cache the basic information of the device. At the same time, to ensure that the data is quickly and real-time responded to the system interface, the WebSocket technology is adopted to push the data in real-time.

[0023] The data processing algorithm process adopted in step S2 is to compare the collected data with the threshold set by the substation system. The data analysis status is divided into normal, warning, general, serious, and critical; In step S2, the transformer oil temperature and oil level monitoring and calibration analysis device is used to detect the oil temperature, the running temperature, and the volume of transformer oil for a long time, and generate the relationship function between the three. The upper limit and the lower limit of the relationship function are determined by long-term monitoring and the detection of the transformer status; the analysis logic unit in the data analysis controller is used to alarm.

[0024] Step S2 includes the following oil level fault judgment methods: Method a1. Compare the standard oil temperature and oil level curve. If the change of the actual oil temperature and oil level data does not exceed ±5%, and 115% of the standard oil level > actual oil level > 110% of the standard oil level, the fault conclusion is: general defect: slightly high oil level; Method a2. Compare the standard oil temperature and oil level curve. If the change of the actual oil temperature and oil level data does not exceed ±5%, and 120% of the standard oil level > actual oil level ≥ 115% of the standard oil level, the fault conclusion is: general defect: slightly high oil level, and an alarm is required; Method a3. Compare the standard oil temperature and oil level curve. If the change of the actual oil temperature and oil level data does not exceed ±5%, and the actual oil level ≥ 120% of the standard oil level, the fault conclusion is: general defect, and key reminder is required: high oil level; Method a4. Compare the standard oil temperature and oil level curve. If the change of the actual oil temperature and oil level data does not exceed ±5%, and 90% of the standard oil level ≤ actual oil level < 95% of the standard oil level, the fault conclusion is: general defect: slightly low oil level; Method a5. Compare the standard oil temperature and oil level curve. If the change of the actual oil temperature and oil level data does not exceed ±5%, and 85% of the standard oil level ≤ actual oil level < 90% of the standard oil level, the fault conclusion is: general defect: low oil level; Method a6. Compare with the standard oil temperature and oil level curve. If the change in the actual oil temperature and oil level data does not exceed ±5%, and the actual oil level < 85% of the standard oil level, then the fault conclusion is: General defect: The oil level is relatively low, and an alarm is required.

[0025] Step S2 includes the following method for judging the slope fault of oil temperature and oil level: Method a7. Compare with the standard oil temperature and oil level curve X0. If the slope X1 of the actual oil temperature and oil level curve changes significantly, that is, 80%X0 < X1 < 85%X0, then the fault conclusion is: General defect: The change of the oil level is slow; Method a8. Compare with the standard oil temperature and oil level curve X0. If the slope X1 of the actual oil temperature and oil level curve changes significantly, that is, X1 < 80%X0, then the fault conclusion is: General defect, alarm required: The change of the oil level is very slow; Suspected breathing blockage, meter jamming; Method a9. Compare with the standard oil temperature and oil level curve X0. If the slope X of the actual oil temperature and oil level curve changes significantly, that is, 130%X0 < X1, then the fault conclusion is: General defect, alarm required: Abnormal change of the oil level; Suspected gas accumulation in the pipeline or corrugated leakage point.

[0026] In step S3, according to the storage of the actual oil temperature and oil level curve data for half a year or one year, analyze the real oil temperature and oil level curve.

[0027] In this example, after checking and collecting the oil temperature and oil level data of the transformer, and automatically checking and analyzing them with the data curve of the transformer at the factory, comparing the oil levels at the same oil temperature, and comparing the oil temperature and oil level under the same load, curve analysis data is formed and alarm thresholds are set for decision-making and handling.

[0028] Embodiment: During the operation of the transformer, due to the thermal expansion and contraction effect of the transformer oil, the oil level in the oil conservator shows a positive correlation with the increase in temperature. For different structures of the oil conservator, the transformer manufacturer will provide the corresponding standard oil temperature and oil level curve, which generally shows a linear increase. However, in actual operation, defects such as oil level jamming, false oil level, and air leakage may occur in both the common capsule-type oil conservator and the bellows-type oil conservator.

[0029] In this example, according to the monitored actual oil temperature and oil level curve, analyze different phenomena in the oil temperature and oil level curve for different working conditions. Use the transformer oil temperature and oil level monitoring and calibration analysis device to detect the oil temperature, oil temperature, operating temperature, and transformer oil volume for a long time, generate the relationship function among the three, and use long-term monitoring and transformer status detection. Determine the upper limit and lower limit of the function. Use the analysis logic unit in the data analysis controller to give an alarm. 1. Alarm for high or low oil level According to the experience of substation maintenance, in daily operation and maintenance work, due to the sluggish effect of oil extraction test and oil level (the oil pressure change caused by oil temperature is generally a staged change due to pressure conduction and jamming. The oil level will change only after the oil temperature changes and accumulates a certain oil pressure, so there is a delay). Generally, the oil level deviation is within 10%, which is considered normal. Therefore, the oil level deviation defects are divided into the following categories: The oil level is slightly high: Compared with the standard oil temperature and oil level curve, the slope of the actual oil temperature and oil level curve does not change much (no more than ±5%), 115% standard oil level > actual oil level > 110% standard oil level High oil level: Compared with the standard oil temperature and oil level curve, the slope of the actual oil temperature and oil level curve does not change much (no more than ±5%), 120% standard oil level > actual oil level ≥ 115% standard oil level The oil level is high (important reminder): Compared with the standard oil temperature and oil level curve, the slope of the actual oil temperature and oil level curve does not change much (no more than ±5%), and the actual oil level is ≥120% of the standard oil level The oil level is slightly low: Compared with the standard oil temperature and oil level curve, the slope of the actual oil temperature and oil level curve does not change much (no more than ±5%), 90% standard oil level ≤ actual oil level < 95% standard oil level Low oil level: Compared with the standard oil temperature and oil level curve, the slope of the actual oil temperature and oil level curve does not change much (no more than ±5%), 85% standard oil level ≤ actual oil level < 90% standard oil level The oil level is low (important reminder): Compared with the standard oil temperature and oil level curve, the slope of the actual oil temperature and oil level curve does not change much (no more than ±5%), and the actual oil level is <85% of the standard oil level In addition, attention should also be paid to the phenomenon of the oil level being close to full and no oil level.

[0030] Oil level > 8.5 grids (important reminder): Prevent the transformer oil pillow from overfilling, which may result in a full oil level at a high temperature, causing the oil pressure to rise beyond the upper limit, leading to oil leakage from the sealing ring and even the risk of the pressure relief valve actuating; Oil level <1.5 grids (important reminder): Prevent the transformer from having too little oil to fill the entire transformer, resulting in reduced internal insulation and insulation breakdown, short circuit and tripping.

[0031] 2. Oil temperature and oil level slope change alarm The standard oil temperature and oil level curve is a linear straight line, that is, the slope is fixed, and the oil level changes linearly with the oil temperature. However, in actual operation, the oil level may change slowly with the oil temperature due to reasons such as meter stagnation, bellows jamming, and breathing pipe blockage, which is reflected in the phenomenon of a smaller slope on the oil temperature and oil level curve monitored during actual operation; it may also be due to air accumulation at the breathing pipe or bellows leak point, causing the oil level to change faster with the oil temperature, which is reflected in the phenomenon of a larger slope on the oil temperature and oil level curve monitored during actual operation. Based on on-site maintenance experience, the defects are divided into the following categories after considering the errors: Slow oil level change (suspected poor ventilation): Comparing with the standard oil temperature - oil level curve, the slope X of the actual oil temperature - oil level curve changes significantly (80%X0 < X < 85%X0). Very slow oil level change (suspected blockage of breather or meter jamming): Comparing with the standard oil temperature - oil level curve, the slope X of the actual oil temperature - oil level curve changes significantly (X < 80%X0). Abnormal oil level change (suspected air accumulation in pipeline or corrugated leakage point): Comparing with the standard oil temperature - oil level curve, the slope X of the actual oil temperature - oil level curve changes significantly (130%X0 < X). 3. Alarm for unchanged oil level During actual operation, due to reasons such as abnormal signal transmission, damaged oil level gauge, and false oil level caused by air accumulation, the oil level may not change for a long time. Therefore, these defects are classified into the following categories: The oil level data has not changed for 3 consecutive days The oil level data has not changed for 5 consecutive days The oil level data has not changed for 10 consecutive days.

[0032] The corresponding handling methods for the above - mentioned defects are as follows: 1. High oil level: Track and analyze the oil level change. Analyze whether there has been oil replenishment work recently. If there has been no oil replenishment work recently, suspect damage to the oil level gauge or internal air accumulation, and replace the oil level gauge or vent in time. If there has been oil replenishment work recently, it may be caused by excessive oil replenishment, and oil should be drained in time.

[0033] 2. Low oil level: Track and analyze the oil level change. Analyze whether there is a leakage defect in the main transformer. If there is a leakage defect in the main transformer, it should be disposed of in time, and the leakage point should be eliminated by replacing the sealing ring, tightening the bolts, etc.; if there is no oil leakage in the main transformer, suspect damage to the oil level gauge, air leakage, etc., and replace the oil level gauge or block the leakage point for treatment.

[0034] 3. Slow oil level change: Track and analyze the oil level change. Analyze whether there is poor ventilation in the breather of the main transformer. If it is determined that the breather has no ventilation, prepare for power outage, withdraw the heavy gas protection, and prevent the heavy gas from operating to trip the main transformer due to excessive oil flow caused by too high oil pressure after the breather blockage is disposed of. After power outage, clean the breathing pipeline to ensure smooth breathing.

[0035] 4. Long - term unchanged oil level: Track and analyze the oil level change. Analyze whether there is jamming of the oil level gauge. Gently tap the meter with an insulating rod. If it still cannot return to normal, observe the breathing condition of the main transformer. If it is determined that the breather has no ventilation, handle it as above; if there is breathing, measure the actual oil level by means of U - tube, infrared temperature measurement, etc., and compare with the oil level display. If there is a large error, suspect damage to the oil level gauge and replace it after power outage This example also includes the following analysis methods, 1. In the comparison of the standard oil temperature and oil level data curve, the oil level changes in a stepwise manner with the change of oil temperature. The change of oil level lags behind the change of oil temperature, but after the change of oil level, it conforms to the standard oil level, and the heating and cooling conform to the lag characteristics. For example, in the standard curve, when the oil temperature is 20°C, it corresponds to 4 grids of oil level; when it is 25°C, it corresponds to 4.3 grids of oil level; when the oil temperature is 30°C, it corresponds to 4.7 grids of oil level. During actual operation, for heating: when the oil temperature rises from 20°C to 25°C, the change of oil level is small; when it rises to 30°C, the oil level rises to 4.7 grids, which conforms to the standard oil level. During actual operation, for cooling: when the oil temperature drops from 30°C to 25°C, the change of oil level is small, about 4.6 grids; when it drops to 20°C, the oil level drops to 4 grids, which conforms to the standard oil level. Fault conclusion: General defect (alarm): The change of oil level lags behind (suspected bellows jamming, capsule blockage). The oil level changes in a stepwise manner with the change of oil temperature, and the change of oil level lags behind the change of oil temperature. A certain amount needs to be accumulated to cause the change of oil temperature. It is judged as bellows jamming or the change of the capsule is blocked.

[0036] 2. The oil temperature data remains unchanged after 5 consecutive days of monitoring. Fault conclusion: General defect (alarm): The oil temperature data has not changed for a long time (suspected signal transmission abnormality, oil temperature gauge damage).

[0037] 3. The oil level data remains unchanged after 15 consecutive days of monitoring. Fault conclusion: General defect (alarm): The oil level data has not changed for a long time (suspected transmission abnormality, oil level gauge damage, false oil level due to gas accumulation).

[0038] 4. The oil level data is 8.5 grids. Fault conclusion: (alarm): Pay attention to the oil temperature, load and high oil level situation.

[0039] 5. The oil level data is 1.5 grids. Fault conclusion: (alarm): Pay attention to the oil temperature, load and low oil level situation.

Claims

1. An intelligent analysis method for the oil temperature and oil level of a transformer, characterized in that: The above analysis conducts abnormal phenomenon analysis by correlating the oil level changes corresponding to different defects, including the following steps; Step S1: Collect the oil temperature and oil level data of the transformer. Use the transformer oil temperature and oil level monitoring and verification analysis device to monitor and store the data of the oil temperature and the transformer oil level for a long time. Adopt a data displacement diagram to generate a displacement diagram of the two data in the coordinate system, draw the actual oil temperature and oil level curve, compare it with the standard oil temperature and oil level curve given by the manufacturer, set the error range, and analyze whether the oil level is normal at different operating oil temperatures; Step S2: Use the transformer oil temperature and oil level monitoring and verification analysis device to generate a relationship function between the oil level and the oil temperature, compare the data with the standard oil temperature and oil level curve given by the manufacturer, determine the upper limit and the lower limit of the error according to data tracking, set the alarm threshold, and use the analysis logic unit in the data analysis controller to give an alarm; Step S3: Analyze whether the deviation of the oil temperature and oil level curve from the standard oil temperature and oil level curve given by the manufacturer exceeds the allowable value under high-temperature and low-temperature operating conditions. According to the long-term storage of actual oil temperature and oil level curve data, analyze the real oil temperature and oil level curve, and use the principle of linear regression to adjust the alarm threshold to reduce the risk of false alarms and missed alarms.

2. The intelligent analysis method for transformer oil temperature and oil level according to claim 1, characterized in that: In step S1, the method of collecting oil level data is to digitally collect data through an oil level digital meter collection device; Its working principle is: utilize the sliding rheostat in the transformer oil level. When the oil level rises or falls, it drives the change of the resistance value of the sliding rheostat, and at the same time causes a current change in the oil level sensor; Use a high-precision ammeter with a 485 interface to convert the current signal into a digital signal, and convert it into the corresponding oil level with software according to the corresponding current value.

3. The intelligent analysis method for transformer oil temperature and oil level according to claim 2, characterized in that: In step S1, according to the current collected by the oil level sensor, read the current and convert it into a current signal using a digital 485 interface, and transmit it to the remote end for storage and analysis; the intermediate device between the oil-immersed transformer and the remote data center reads the current signal, converts it into a digital signal and sends it to the central computer room using a digital 485 interface.

4. The intelligent analysis method for transformer oil temperature and oil level according to claim 2, characterized in that: In step S1, the equipment for collecting oil level data also includes: Stainless steel electrical box: used for installing current and voltage meters; mA-rated ammeter: used for collecting the current signal of the transformer oil conservator, and converting the current signal into a digital signal and sending it through a 485 interface; And provide the display of the current digital value for easy remote monitoring and reading of the digital value; 0-24V-rated voltmeter: used for monitoring the voltage inside the digital meter device. When the voltage is in an abnormal state, it will be transmitted to the 485 interface for remote alarm; Stop button with a light: used to stop the equipment, and the red light will light up when triggered; Start button with a light: used to start the equipment, and the green light will light up when triggered; Waterproof glass cover: used for the waterproof and visual observation of the 0-24V voltmeter and mA ammeter; The data collected by the voltmeter and the data collected by the ammeter are sent simultaneously for comparison to analyze and eliminate the authenticity of the data; For example, if the 24v exceeds the set range, the software will no longer collect data; Conversely, if the current exceeds the range, the voltmeter will also be used to judge whether the power supply is normal; The ammeter and voltmeter are protected from water with non-reflective materials and are made transparent for video reading via external devices.

5. The intelligent analysis method for transformer oil temperature and oil level according to claim 4, characterized in that: In step S1, the installation method of the device for collecting oil level data is as follows: Step A1: Install the fixed magnetic ring (7) in the stainless steel electrical box (1) outside the oil-immersed transformer; Flexible installation is achieved using the fixed magnetic ring; Step A2: Connect the current line of the mA ammeter (2) to monitor the current, and connect a 3.0 - 24V voltmeter to monitor the voltage change; Step A3: Turn on the lighted start button (5) to start collecting the current and convert it into a digital signal; Step A4: When not in use, turn on the lighted stop button (4) to turn off the oil level digital meter collection device.

6. The intelligent analysis method for transformer oil temperature and oil level according to claim 1, characterized in that: The method uses an oil level digital meter data collection and analysis system to process the required data through a system architecture process of real-time data collection, analysis, transmission, storage, and finally display; specifically: After the system collects the raw data through the front-end device, it is analyzed according to preset rules and then transmitted to the auxiliary control system processing module; that is, at the data transmission level, RabbitMQ is used to efficiently transmit the analyzed device data; After receiving the data, the auxiliary control system stores the data; that is, through the data persistence layer, the real-time data is stored in the MySql database, and the historical data is stored in the TDengine time series database; at the same time, it is convenient to quickly and efficiently obtain the real-time data and the basic ledger. For commonly used data, Redis is used to cache the basic information of the device; At the same time, to ensure that the data is quickly and real-time responded to the system interface, the WebSocket technology is used to push the data in real-time.

7. The intelligent analysis method for transformer oil temperature and oil level according to claim 1, characterized in that: The data processing algorithm process in step S2 is to compare the collected data with the threshold set by the station system. The data analysis status is divided into normal, warning, general, serious, and critical; In step S2, using the transformer oil temperature and oil level monitoring and verification analysis device, long-term detection is carried out on the oil temperature, the operating temperature, and the volume of the transformer oil to generate a relationship function between the three. The upper limit and the lower limit of the relationship function are determined using long-term monitoring and the detection of the transformer status; the analysis logic unit in the data analysis controller is used to give an alarm.

8. The intelligent analysis method for transformer oil temperature and oil level according to claim 7, characterized in that: Step S2 includes the following oil level fault judgment methods: Method a1. Compare with the standard oil temperature and oil level curve. If the change in the actual oil temperature and oil level data does not exceed ±5%, and 115% of the standard oil level > actual oil level > 110% of the standard oil level, then the fault conclusion is: General defect: The oil level is slightly high; Method a2. Compare with the standard oil temperature and oil level curve. If the change in the actual oil temperature and oil level data does not exceed ±5%, and 120% of the standard oil level > actual oil level ≥ 115% of the standard oil level, then the fault conclusion is: General defect: The oil level is slightly high, and an alarm is required; Method a3. Compare with the standard oil temperature and oil level curve. If the change in the actual oil temperature and oil level data does not exceed ±5%, and the actual oil level ≥ 120% of the standard oil level, then the fault conclusion is: General defect, and key reminder is required: The oil level is high; Method a4. Compare with the standard oil temperature and oil level curve. If the change in the actual oil temperature and oil level data does not exceed ±5%, and 90% of the standard oil level ≤ actual oil level < 95% of the standard oil level, then the fault conclusion is: General defect: The oil level is slightly low; Method a5. Compare with the standard oil temperature and oil level curve. If the change in the actual oil temperature and oil level data does not exceed ±5%, and 85% of the standard oil level ≤ actual oil level < 90% of the standard oil level, then the fault conclusion is: General defect: The oil level is low; Method a6. Compare with the standard oil temperature and oil level curve. If the change in the actual oil temperature and oil level data does not exceed ±5%, and actual oil level < 85% of the standard oil level, then the fault conclusion is: General defect: The oil level is relatively low, and an alarm is required.

9. The intelligent analysis method for transformer oil temperature and oil level according to claim 7, characterized in that: Step S2 includes the following fault judgment methods for the slope of oil temperature and oil level: Method a7. Compare with the standard oil temperature and oil level curve X0. If the slope X1 of the actual oil temperature and oil level curve changes significantly, that is, 80%X0 < X1 < 85%X0, then the fault conclusion is: General defect: The change of the oil level is slow; Method a8. Compare with the standard oil temperature and oil level curve X0. If the slope X1 of the actual oil temperature and oil level curve changes significantly, that is, X1 < 80%X0, then the fault conclusion is: General defect, alarm required: The change of the oil level is very slow; Suspected breathing blockage, meter jamming; Method a9. Compare with the standard oil temperature and oil level curve X0. If the slope X of the actual oil temperature and oil level curve changes significantly, that is, 130%X0 < X1, then the fault conclusion is: General defect, alarm required: Abnormal change of the oil level; Suspected air accumulation in the pipeline or corrugated leak point.

10. The intelligent analysis method for transformer oil temperature and oil level according to claim 1, characterized in that: In step S3, analyze the real oil temperature and oil level curve based on the storage of the actual oil temperature and oil level curve data for half a year or one year.

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