A system for evaluating the operation status of transformers based on data analysis

Abstract

The present invention belongs to the technical field of transformer operation status evaluation, and specifically discloses a transformer operation status evaluation system based on data analysis, the system comprising: a transformer mechanical property monitoring module, a transformer mechanical property analysis module, a transformer chemical property monitoring module, a transformer chemical property analysis module, a transformer operation status analysis module, a database and a transformer operation status feedback terminal; the present invention improves the effectiveness of transformer equipment performance evaluation by analyzing the mechanical property qualification index of the transformer according to the vibration information of each mechanical component in the transformer, thereby ensuring the accuracy of the transformer life and fault evaluation, and ensuring the pertinence of the subsequent maintenance of the transformer, and at the same time, by analyzing the chemical property qualification index of the transformer according to the chemical property information of the transformer, the accuracy of fault cause judgment is improved, thereby improving the reliability of transformer operation risk evaluation.

Description

Technical Field

[0001] The invention belongs to the technical field of transformer operating status evaluation, and relates to a transformer operating status evaluation system based on data analysis. Background Art

[0002] A transformer is a device that converts voltage or current in proportion, and mainly includes voltage transformers and current transformers. In order to ensure the safe and stable operation of the power system, it is necessary to evaluate the operating status of the transformer.

[0003] For example, the Chinese invention patent with publication number CN105303065B discloses a method for inspecting the operating condition of a current transformer. The present invention discloses a method for inspecting the operating condition of a current transformer with high efficiency and comprehensive and accurate inspection results. The inspection method collects basic information data and on-site operation data of the current transformer, classifies the collected data and calculates the operating state value RI of the current transformer. The actual operating state corresponding to the actual operating condition value of the current transformer is determined by the correspondence between the preset operating condition value of the current transformer and the operating state. The inspection method is efficient and will not cause failure of the originally normally operating equipment due to human factors. The inspection method takes into account the influence of the secondary load value, the primary current percentage, the ambient temperature, the ambient relative humidity, the residual magnetism, and the magnetic field of the adjacent primary conductor on the current transformer, and can realize a comprehensive inspection of the operating condition of the current transformer, ensuring that the final inspection result is accurate, comprehensive, and highly reliable. It is suitable for promotion and application in the field of state assessment technology of gateway metering equipment.

[0004] For example, the Chinese invention patent with publication number CN117216673A discloses a current transformer monitoring, evaluation and maintenance platform, including a multimodal sensor module, a monitoring module, a pre-training module, a state evaluation module, a maintenance decision correction module and a historical state database; the monitoring module is used to remotely receive data collected by the multimodal sensor module, and store and output the data; the historical state database stores the historical operating parameters of the current transformer and the corresponding state evaluation results; the pre-training module trains the support vector machine model according to the data in the historical state database to obtain a classifier; the state evaluation module evaluates the state of the current transformer based on the collected data; the maintenance decision correction module corrects the maintenance strategy based on the state evaluation results. The present invention can improve the state evaluation accuracy and maintenance efficiency of the current transformer.

[0005] The above existing technologies have the following deficiencies: 1. The current evaluation of the operating status of the transformer is mainly based on the collected data and historical operating parameters. That is, insufficient attention is paid to the mechanical characteristics of the transformer during operation, and the effectiveness of the performance evaluation of the transformer equipment cannot be guaranteed, resulting in insufficient accuracy in the evaluation of the life and failure of the transformer, and the inability to guarantee the targeted subsequent maintenance of the transformer.

[0006] 2. The current inspection of the operating conditions of the transformer is mainly to determine the actual operating state corresponding to the actual operating condition value of the transformer through the correspondence between the preset transformer operating condition value and the operating state. That is, the influence of the chemical property information on the actual operating condition of the transformer during the operation of the transformer is not considered, so the accuracy of fault diagnosis cannot be guaranteed, which leads to insufficient accuracy in judging the cause of the fault and insufficient reliability in the risk assessment of transformer operation. Summary of the invention

[0007] In view of this, in order to solve the problems raised in the above background technology, a transformer operation status evaluation system based on data analysis is now proposed.

[0008] The purpose of the present invention can be achieved through the following technical solutions: The present invention provides a transformer operating status evaluation system based on data analysis, including: a transformer mechanical characteristics monitoring module, which is used to monitor the vibration information of each mechanical component in the transformer, including the vibration frequency of the iron core at each monitoring time point, the loudness of the sound, the vibration amplitude of the winding at each monitoring time point, the load current, the temperature and the displacement of each installed and fixed component at each monitoring time point.

[0009] The transformer mechanical characteristic analysis module is used to analyze the transformer mechanical characteristic qualification index according to the vibration information of each mechanical component in the transformer.

[0010] The transformer chemical property monitoring module is used to monitor the chemical property information of the transformer, including the dielectric constant and breakdown voltage of the insulating oil at each monitoring time point, the acid value of the insulating oil at the current monitoring time point, the dielectric loss factor and the viscosity of the insulating oil at each temperature.

[0011] The mutual inductor chemical property analysis module is used to analyze the chemical property qualification index of the mutual inductor according to the chemical property information of the mutual inductor.

[0012] The transformer operation status analysis module is used to analyze the transformer operation status qualification level according to the transformer's mechanical property qualification index and chemical property qualification index.

[0013] The database is used to store the permissible range of the load current of the winding, store the temperature corresponding to each qualified viscosity range of the insulating oil in the transformer, and store the initial acid value of the insulating oil in the transformer.

[0014] The transformer operation status feedback terminal is used to provide corresponding feedback according to the qualified level of the transformer operation status.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention analyzes the mechanical characteristic qualification index of the transformer according to the vibration information of each mechanical component in the transformer, thereby avoiding the current lack of attention to the mechanical characteristics of the transformer during operation, improving the effectiveness of the performance evaluation of the transformer equipment, thereby ensuring the accuracy of the evaluation of the transformer life and faults, and ensuring the targeted subsequent maintenance of the transformer.

[0016] (2) The present invention analyzes the chemical property qualification index of the transformer based on the chemical property information of the transformer, thus breaking the current deficiency of not considering the influence of the chemical property information on the actual operating conditions of the transformer during operation, ensuring the accuracy of fault diagnosis, thereby improving the accuracy of fault cause judgment, and at the same time improving the reliability of transformer operation risk assessment.

[0017] (3) The present invention improves the comprehensiveness of the transformer mechanical characteristics analysis by conducting a comprehensive transformer mechanical characteristics qualification index analysis based on the core, winding and mounting components in the transformer, thereby improving the timeliness of the discovery of potential mechanical component problems and the accuracy of fault tracing, thereby improving the targeted maintenance of mechanical components.

[0018] (4) The present invention evaluates the operating status of the transformer from two dimensions, namely, the mechanical properties and chemical properties of the transformer, thereby avoiding the one-sidedness of single-dimensional evaluation. At the same time, by setting weights for the transformer mechanical property qualification index and the transformer chemical property qualification index, the accuracy of the transformer operating status qualification index is improved, thereby reducing the operating and maintenance costs of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0020] Figure 1 It is a schematic diagram of the connection of each module of the system of the present invention.

[0021] Figure 2 It is a schematic diagram of the connection steps of the mechanical property qualification index analysis step of the present invention.

[0022] Figure 3 It is a schematic diagram of the connection steps of the chemical property qualification index analysis of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] See also Figure 1 As shown, the present invention provides a transformer operating status evaluation system based on data analysis, the system comprising: a transformer mechanical property monitoring module, a transformer mechanical property analysis module, a transformer chemical property monitoring module, a transformer chemical property analysis module, a transformer operating status analysis module, a database and a transformer operating status feedback terminal.

[0025] In the above, the transformer mechanical characteristic analysis module is connected to the transformer mechanical characteristic monitoring module, the transformer operation status analysis module and the database respectively, the transformer chemical characteristic analysis module is connected to the transformer chemical characteristic monitoring module, the transformer operation status analysis module and the database respectively, and the transformer operation status analysis module is also connected to the transformer operation status feedback terminal.

[0026] The transformer mechanical characteristic monitoring module is used to monitor the vibration information of each mechanical component in the transformer, including the vibration frequency and sound loudness of the iron core at each monitoring time point, the vibration amplitude of the winding at each monitoring time point, the load current, the temperature and the displacement of each installed and fixed component at each monitoring time point.

[0027] It should be added that the vibration frequency of the core in the transformer at each monitoring time point is obtained by monitoring the acceleration sensor installed on the core in the transformer. Its working principle is: based on the piezoelectric effect, when the core of the transformer vibrates, the piezoelectric crystal inside the acceleration sensor is deformed by the inertial force, thereby generating a charge signal proportional to the acceleration, and converting the charge signal into a voltage signal. The voltage signal is then converted into a discrete digital signal through analog-to-digital conversion, and the discrete digital signal is input into the data acquisition device to obtain the signal spectrum through discrete Fourier transform. Then, by finding the peak position in the spectrum, the main frequency components of the vibration signal and their corresponding amplitudes can be determined. For example, if an obvious peak is found at 200Hz in the spectrum diagram, and the amplitude corresponding to the peak is much higher than the amplitudes of other frequency components, it can be determined that 200Hz is one of the main frequencies of the transformer core vibration, thereby obtaining the vibration frequency of the core in the sensor at each monitoring time point.

[0028] It should be added that the sound loudness of the iron core in the mutual inductor at each monitoring time point is obtained by monitoring with a microphone placed close to the iron core of the mutual inductor casing. The working principle is based on the fact that sound waves cause the diaphragm of the microphone to vibrate, thereby causing the coil connected to the diaphragm to move in the magnetic field, generating an electrical signal related to the sound intensity and frequency. By performing spectrum analysis methods such as fast Fourier transform (FFT) on the sound signal, a spectrum diagram of the sound signal is obtained, and the frequency components and amplitude distribution in the spectrum are analyzed. Through analysis of the spectrum, the generation mechanism and characteristics of the iron core sound are understood, and then the sound loudness of the iron core in the mutual inductor is obtained by calculating the sum of energy within a specific frequency range in the spectrum or the amplitude-weighted average.

[0029] In a specific embodiment, assuming that a microphone is used as a sensor, after calibration, its sensitivity is mV / Pa, that is, each Pascal of sound pressure produces a 50mV voltage output. At a certain monitoring time point, the microphone output voltage signal collected by the data acquisition device is mV. According to the formula ,in is the sound loudness (unit: dB), is the actual sound pressure, is the reference sound pressure (usually Pa), and the actual sound pressure is calculated as Pa, then the sound loudness at the monitoring time point is dB.

[0030] It should be added that the vibration amplitude is obtained by monitoring the displacement sensor placed on the transformer housing near the winding position. The displacement sensor directly measures the displacement change of the winding relative to a fixed reference point. The vibration amplitude can be approximately regarded as half of the difference between the peak value and the valley value in the displacement change data, that is, finding the maximum value in the displacement change. and minimum value , then the vibration amplitude The formula Calculated.

[0031] It should be added that the load current of the winding in the transformer at each monitoring time point is obtained by using the current conversion function of the current transformer to convert the large current on the primary side into the small current on the secondary side for measurement. A current transformer with a suitable transformation ratio is selected so that its primary side is connected in series with the winding circuit of the transformer, and the secondary side is connected to a measuring instrument such as an ammeter, a power meter, etc. For example, for a winding with a primary current of several hundred amperes, a transformation ratio of When the secondary ammeter reading is 2.5A, the load current of the primary winding is A, and use the load current of the primary winding as the load current of the transformer winding, and then obtain the load current of the transformer winding at each monitoring time point.

[0032] It should be added that the temperature of the winding in the transformer at each monitoring time point is monitored by a temperature sensor placed near the transformer winding.

[0033] It should be added that the various installation and fixing components in the transformer include but are not limited to a housing, a base, connecting bolts, core clamps, wiring terminals, connecting wires and connectors, etc.

[0034] It should be added that the displacement of each installation and fixing component in the mutual inductor at each monitoring time point is monitored by a displacement sensor installed on each installation and fixing component.

[0035] The transformer mechanical characteristic analysis module is used to analyze the transformer mechanical characteristic qualification index according to the vibration information of each mechanical component in the transformer.

[0036] See also Figure 2 As shown, exemplarily, the analysis of the qualified index of the mechanical characteristics of the transformer includes: P1, analyzing the qualified index of the vibration of the iron core in the transformer according to the vibration frequency and sound loudness of the iron core at each monitoring time point.

[0037] Further, the analysis of the vibration qualification index of the iron core in the mutual inductor includes: P1-1, confirming the vibration frequency qualification index of the iron core according to the vibration frequency of the iron core at each monitoring time point.

[0038] Furthermore, the confirmation of the vibration frequency qualification index of the iron core includes: P1-1-1, comparing the vibration frequency of the iron core at each monitoring time point with a set allowable iron core vibration frequency range.

[0039] P1-1-2. If the vibration frequency of the iron core at a certain monitoring time point is within the set allowable iron core vibration frequency range, the vibration frequency qualification index of the iron core at the monitoring time point is recorded as 1.

[0040] P1-1-3. If the vibration frequency of the iron core at a certain monitoring time point is greater than the set upper limit value of the allowable iron core vibration frequency interval, the ratio of the set upper limit value of the allowable iron core vibration frequency interval to the vibration frequency of the iron core at the monitoring time point shall be used as the vibration frequency qualification index of the iron core at the monitoring time point.

[0041] P1-1-4. If the vibration frequency of the iron core at a certain monitoring time point is less than the set lower limit of the allowable iron core vibration frequency range, the ratio of the vibration frequency of the iron core at the monitoring time point to the set lower limit of the allowable iron core vibration frequency range is used as the vibration frequency qualification index of the iron core at the monitoring time point, thereby obtaining the vibration frequency qualification index of the iron core at each monitoring time point.

[0042] P1-1-5. Calculate the average value of the vibration frequency qualification index of the iron core at each monitoring time point, and use the average calculation result as the vibration frequency qualification index of the iron core.

[0043] In a specific embodiment, if the set permissible core vibration frequency interval is [20 Hz, 50 Hz], at five monitoring time points, the vibration frequencies of the core are measured to be 30 Hz, 40 Hz, 60 Hz, 15 Hz, and 55 Hz, respectively.

[0044] Calculate the vibration frequency qualification index at each monitoring time point: Monitoring time point 1: The vibration frequency is 30Hz, which is within the permitted iron core vibration frequency range [20Hz, 50Hz], then the vibration frequency qualification index at monitoring time point 1 is 1.

[0045] Monitoring time point 2: The vibration frequency is 40Hz, and within the allowable core vibration frequency range [20Hz, 50Hz], the vibration frequency qualification index at monitoring time point 2 is 1.

[0046] Monitoring time point 3: The vibration frequency is 60Hz, which is greater than the upper limit of the permissible core vibration frequency range of 50Hz. The vibration frequency qualification index at monitoring time point 3 is .

[0047] Monitoring time point 4: The vibration frequency is 15Hz, which is less than the lower limit of the permissible core vibration frequency range of 20Hz. The vibration frequency qualification index at monitoring time point 4 is .

[0048] Monitoring time point 5: The vibration frequency is 55Hz, which is greater than the upper limit of the permissible core vibration frequency range of 50Hz. The vibration frequency qualification index at monitoring time point 3 is .

[0049] The vibration frequency qualification index of the iron core is .

[0050] P1-2. Compare the sound loudness of the iron core at each monitoring time point with the set allowable iron core sound loudness.

[0051] P1-3. If the sound loudness of the iron core at a certain monitoring time point is less than or equal to the set allowable iron core sound loudness, the monitoring time point of the iron core is recorded as a sound loudness qualified monitoring time point.

[0052] P1-4. Count the number of monitoring time points at which the sound loudness is qualified and the number of monitoring time points, and use the ratio of the number of monitoring time points at which the sound loudness is qualified to the number of monitoring time points as the sound loudness qualified index of the iron core.

[0053] P1-5. The average calculation result of the vibration frequency qualified index and the sound loudness qualified index of the core is used as the vibration qualified index of the core in the mutual inductor.

[0054] P2. Analyze the vibration qualification index of the winding in the transformer based on the vibration amplitude, load current and temperature of the winding at each monitoring time point.

[0055] Furthermore, the analysis of the vibration qualification index of the winding in the mutual inductor includes: P2-1, comparing the vibration amplitude of the winding at each monitoring time point with the set vibration amplitude. If the vibration amplitude of the winding at a certain monitoring time point is less than or equal to the set vibration amplitude, then the monitoring time point of the winding is recorded as a vibration amplitude qualified monitoring time point.

[0056] P2-2. Count the number of vibration amplitude qualified monitoring time points, and use the ratio of the number of monitoring time points as the vibration amplitude qualified index of the winding, recorded as .

[0057] P2-3, record the load current of the winding at each monitoring time point as , is the monitoring time point number, , and extract the allowable range of the load current of the winding from the database as .

[0058] P2-4. Statistical analysis of the load current deviation index of the winding at each monitoring time point , .

[0059] P2-5. Statistical calculation of winding load current qualification index , , is the number of monitoring time points.

[0060] P2-6. Calculate the mean value of the winding temperature at each monitoring time point to obtain the average temperature of the winding, which is recorded as .

[0061] P2-7. Filter out the maximum temperature from the winding temperature at each monitoring time point and record it as .

[0062] P2-8. Statistical winding temperature qualification index , , To set the reference winding temperature.

[0063] It should be added that It is extracted from the technical specification table of transformer operating status evaluation.

[0064] P2-9. Statistical analysis of vibration qualification index of windings in transformers , , , and are the weights of the set winding vibration amplitude qualified index, winding load current qualified index and winding temperature qualified index, respectively. , .

[0065] It should be added that a larger vibration amplitude not only indicates that there may be problems with the winding, but also further affects the performance of the transformer. For example, excessive vibration may cause increased insulation wear on the winding, reduce insulation performance, increase the risk of short circuit, and thus affect the measurement accuracy and reliability of the transformer. By focusing on the vibration amplitude qualification index, these potential risks can be discovered in time to ensure the normal operation of the transformer, so it should be given a greater weight. Temperature is one of the important factors affecting winding performance and life. Excessive winding temperature may be caused by overload, poor heat dissipation or insulation damage, and these problems are often related to winding failures. For example, insulation aging or damage may cause local overheating, which in turn affects the mechanical and electrical properties of the winding, making it The vibration characteristics change. Although temperature change is an indirect indicator of the winding state relative to the vibration amplitude, it is also important for timely detection of potential faults. Therefore, the weight of its qualified index should be second only to the weight of the vibration amplitude qualified index. There is a certain correlation between the load current and the winding vibration amplitude. During normal operation, the vibration amplitude increases steadily with the increase of load current, but the current is not the only factor that directly causes abnormal winding vibration. Compared with the vibration amplitude and temperature, the effect of load current on the winding vibration qualified index is relatively indirect. The change of load current needs to pass through intermediate links such as electromagnetic force to affect the vibration of the winding, and the current change within a certain range may not immediately cause obvious vibration problems in the winding. Therefore, setting , in order to facilitate analysis, The specific value can be 0.5. The specific value can be 0.3. The specific value can be 0.2.

[0066] P3. Analyze the vibration qualification index of the fixed components installed in the transformer according to the displacement of each fixed component at each monitoring time point.

[0067] Furthermore, the analysis of the vibration qualification index of the installation and fixing components in the mutual inductor includes: P3-1, selecting the maximum displacement of each installation and fixing component from the displacement of each installation and fixing component at each monitoring time point.

[0068] P3-2. Compare the maximum displacement of each installation component with the set allowable displacement of the installation component.

[0069] P3-3. If the maximum displacement of a certain installation component is less than or equal to the set allowable displacement of the installation component, the installation component is recorded as a displacement qualified installation component.

[0070] P3-4. Count the number of qualified displacement installation components and the number of installed components, and use the ratio of the number of qualified displacement installation components to the number of installed components as the vibration qualified index of the fixed components installed in the transformer.

[0071] The embodiment of the present invention analyzes the mechanical characteristic qualification index of the transformer according to the vibration information of each mechanical component in the transformer, thereby avoiding the current insufficient attention to the mechanical characteristics of the transformer during operation, improving the effectiveness of the performance evaluation of the transformer equipment, thereby ensuring the accuracy of the evaluation of the transformer life and faults, and ensuring the targeted subsequent maintenance of the transformer.

[0072] P4. Select the minimum value from the vibration qualified index of the core, winding and installation and fixing parts of the transformer as the qualified index of the mechanical characteristics of the transformer and record it as .

[0073] The embodiment of the present invention improves the comprehensiveness of the transformer mechanical characteristic analysis by performing a comprehensive transformer mechanical characteristic qualification index analysis based on the iron core, winding and installation and fixing components in the transformer, thereby improving the timeliness of the discovery of potential mechanical component problems and the accuracy of fault tracing, thereby improving the pertinence of mechanical component maintenance.

[0074] The mutual inductor chemical property monitoring module is used to monitor the chemical property information of the mutual inductor, including the dielectric constant and breakdown voltage of the insulating oil at each monitoring time point, the acid value and dielectric loss factor of the insulating oil at the current monitoring time point, and the viscosity of the insulating oil at each temperature.

[0075] It should be added that the dielectric constant of the insulating oil in the transformer at each monitoring time point is obtained by detecting it through an insulation detection device placed in the insulating oil. The measurement principle is to use a high-precision sensor and a specific test circuit to measure the capacitance and other parameters of the insulating oil, and then calculate the dielectric constant based on the relationship between these parameters and the dielectric constant. The relationship between capacitance and dielectric constant is: The calculation formula for capacitance (in is the capacitance, is the dielectric constant, is the plate area, is the plate spacing), when the plate area and plate spacing are fixed, the capacitance is proportional to the dielectric constant, that is, the larger the dielectric constant, the larger the capacitance value, and the smaller the dielectric constant, the smaller the capacitance value.

[0076] It should be added that the breakdown voltage of the insulating oil in the transformer at each monitoring time point is obtained by monitoring through an electromagnetic induction type partial discharge monitoring sensor placed in the insulating oil. Its working principle is: when there is partial discharge in the insulating oil, high-frequency pulse current and electromagnetic wave signals will be generated. The partial discharge monitoring sensor captures these signals through capacitive coupling or electromagnetic induction, and converts them into electrical signals and transmits them to the monitoring system. Then, by observing the amplitude, pulse width, pulse rise time and other parameters of the partial discharge signal on the time axis, the characteristic parameters of the partial discharge signal are obtained, and then the breakdown voltage of the insulating oil in the transformer at each monitoring time point is obtained through a quantitative correlation model between the characteristic parameters of the partial discharge signal and the breakdown voltage of the insulating oil.

[0077] It should be added that the quantitative correlation model between the characteristic parameters of the partial discharge signal and the breakdown voltage of the insulating oil refers to: finding the mathematical relationship between the parameters such as the discharge amplitude, the number of discharges, the discharge energy and the breakdown voltage by adopting methods such as regression analysis and artificial neural networks.

[0078] It should be added that the acid value of the insulating oil in the transformer at the current monitoring time point is obtained by placing a chemical sensor in the insulating oil to sense the concentration changes of chemical substances related to the acid value in the insulating oil in real time and convert them into electrical signals or optical signals. For example, a chemical sensor can react chemically with acidic substances to produce potential changes or current changes, thereby indirectly reflecting the acid value.

[0079] It should be added that the dielectric loss factor of the insulating oil in the transformer at the current monitoring time point is obtained by monitoring it through a capacitive sensor placed in the insulating oil. Using the capacitance principle, when the dielectric loss factor of the insulating oil changes, it will cause the sensor capacitance value to change. By measuring the change in capacitance value, the size of the dielectric loss factor is indirectly reflected.

[0080] It should be added that the viscosity of the insulating oil in the transformer at various temperatures is monitored by a vibration viscosity sensor placed in the insulating oil.

[0081] The mutual inductor chemical property analysis module is used to analyze the chemical property qualification index of the mutual inductor according to the chemical property information of the mutual inductor.

[0082] See also Figure 3As shown, exemplarily, the analysis of the chemical property qualification index of the transformer includes: Q1, according to the dielectric constant and breakdown voltage of the insulating oil at each monitoring time point, the insulation performance qualification index of the insulating oil is calculated. .

[0083] Further, the insulating oil insulation performance qualified index is calculated, including: Q1-1, comparing the dielectric constant of the insulating oil at each monitoring time point with the dielectric constant interval corresponding to the set dielectric constant qualified index of each insulating oil, to obtain the dielectric constant qualified index of the insulating oil at each monitoring time point .

[0084] Q1-2. According to the statistical method of the dielectric constant qualified index of the insulating oil at each monitoring time point, the breakdown voltage qualified index of the insulating oil at each monitoring time point is obtained by the same method and recorded as .

[0085] Q1-3. Statistics on insulation performance qualification index of insulating oil , .

[0086] In a specific embodiment, if the dielectric constant intervals corresponding to the dielectric constant qualification indexes of each insulating oil are: when the dielectric constant qualification index of the insulating oil is 0.9, the dielectric constant is in the range of 2.35-2.4, when the dielectric constant qualification index of the insulating oil is 0.7, the dielectric constant is in the range of 2.25-2.35, when the dielectric constant qualification index of the insulating oil is 0.5, the dielectric constant is in the range of 2.2-2.25, and when the dielectric constant qualification index of the insulating oil is 0, the dielectric constant is less than 2.2 or greater than 2.4.

[0087] If the breakdown voltage intervals corresponding to the breakdown voltage qualification indexes of the insulating oils are: When the breakdown voltage qualification index of the insulating oil is 0.9, the breakdown voltage is , when the insulation oil breakdown voltage qualification index is 0.7, the breakdown voltage is , when the insulation oil breakdown voltage qualification index is 0.5, the breakdown voltage is , when the insulation oil breakdown voltage qualification index is 0, the breakdown voltage is .

[0088] If the insulating oil is At the monitoring time point, the dielectric constant was measured to be 2.32 and the breakdown voltage was 48. At the monitoring time point, the dielectric constant was measured to be 2.23 and the breakdown voltage was 38, so the insulation performance qualification index of the insulating oil is .

[0089] Q2. According to the acid value and dielectric loss factor of the insulating oil at the current monitoring time point, calculate the qualified index of the insulating oil's antioxidant performance .

[0090] Furthermore, the statistical insulating oil's antioxidant performance qualified index includes: Q2-1, extracting the initial acid value of the insulating oil in the transformer from the database.

[0091] Q2-2. Subtract the acid value of the insulating oil at the current monitoring time point from the initial acid value to obtain the acid value difference of the insulating oil, recorded as .

[0092] Q2-3. The dielectric loss factor of the insulating oil at the current monitoring time point is recorded as .

[0093] Q2-4. Statistics on the qualified index of the anti-oxidation performance of insulating oil , , and They are the set allowable acid value difference of insulating oil and the allowable dielectric loss factor of insulating oil respectively.

[0094] It should be added that and All of them are extracted from the technical specification table of transformer operating status evaluation.

[0095] Q3. Extract the temperature corresponding to each qualified viscosity range of the insulating oil in the transformer from the database.

[0096] Q4. Match and compare the viscosity of the insulating oil at each temperature with the temperature corresponding to each qualified viscosity range of the insulating oil in the transformer.

[0097] Q5. If the viscosity of the insulating oil at a certain temperature is within the qualified viscosity range of the insulating oil at that temperature, the qualified viscosity index of the insulating oil at that temperature shall be recorded as 1.

[0098] Q6. If the viscosity of the insulating oil at a certain temperature is less than the lower limit of the qualified viscosity range of the insulating oil at that temperature, the ratio of the viscosity of the insulating oil at that temperature to the lower limit of its qualified viscosity range shall be taken as the viscosity qualification index of the insulating oil at that temperature.

[0099] Q7. If the viscosity of the insulating oil at a certain temperature is greater than the upper limit of the qualified viscosity range of the insulating oil at that temperature, the ratio of the upper limit of the qualified viscosity range of the insulating oil at that temperature to its viscosity is taken as the qualified viscosity index of the insulating oil at that temperature, and then the qualified viscosity index of the insulating oil at each temperature is obtained.

[0100] Q8. Calculate the average value of the viscosity qualification index of the insulating oil at each temperature, and use the calculation result as the viscosity qualification index of the insulating oil, recorded as .

[0101] Q9. Select the minimum value from the insulation performance qualified index, antioxidant performance qualified index and viscosity qualified index of the insulating oil as the chemical property qualified index of the transformer, recorded as .

[0102] The embodiment of the present invention analyzes the chemical property qualification index of the transformer according to the chemical property information of the transformer, thereby breaking the current deficiency of not considering the influence of the chemical property information on the actual operating conditions of the transformer during the operation of the transformer, ensuring the accuracy of fault diagnosis, thereby improving the accuracy of fault cause judgment, and at the same time improving the reliability of transformer operation risk assessment.

[0103] The transformer operation status analysis module is used to analyze the transformer operation status qualification level according to the transformer mechanical property qualification index and chemical property qualification index.

[0104] Exemplarily, the analyzing the qualified level of the operating status of the transformer includes: extracting the qualified index of the mechanical characteristics of the transformer Chemical properties qualification index of the transformer .

[0105] Statistical operation status qualification index of transformer , , and are the weights of the set transformer mechanical characteristic qualification index and transformer chemical characteristic qualification index, , .

[0106] It should be added that the problems of the mechanical characteristics of the transformer are often sudden. For example, when subjected to external force impact, long-term vibration fatigue, etc., the installation and fixing parts of the transformer may suddenly loosen or break, causing the transformer to instantly lose normal mechanical support, and then cause serious failures. Such sudden failures may have a greater impact on the normal operation of the power system and may even cause accidents such as local power outages. Changes in chemical properties are usually gradually accumulated during long-term operation and generally will not suddenly cause serious failures of the transformer. Therefore, setting , in order to facilitate analysis, The specific value can be 0.6. The specific value can be 0.4.

[0107] The operating state qualified index of the transformer is matched and compared with the operating state qualified indexes corresponding to each operating state qualified grade to obtain the operating state qualified grade of the transformer.

[0108] The embodiment of the present invention evaluates the operating status of the transformer from two dimensions, namely, the mechanical properties and chemical properties of the transformer, thereby avoiding the one-sidedness of single-dimensional evaluation. At the same time, by setting the weights of the transformer mechanical property qualification index and the transformer chemical property qualification index, the accuracy of confirming the transformer operating status qualification index is improved, thereby reducing the operating and maintenance costs of the transformer.

[0109] The database is used to store the permissible range of the load current of the winding, store the temperature corresponding to each qualified viscosity range of the insulating oil in the mutual inductor, and store the initial acid value of the insulating oil in the mutual inductor.

[0110] The transformer operation status feedback terminal is used to provide corresponding feedback according to the qualified level of the transformer operation status.

[0111] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, they shall all fall within the protection scope of the present invention.

Claims

1. A system for evaluating the operation status of a transformer based on data analysis, characterized in that: The system includes: The transformer mechanical characteristic monitoring module is used to monitor the vibration information of each mechanical component in the transformer, including the vibration frequency and sound loudness of the iron core at each monitoring time point, the vibration amplitude of the winding at each monitoring time point, the load current, the temperature, and the displacement of each installed and fixed component at each monitoring time point; The transformer mechanical characteristic analysis module is used to analyze the transformer mechanical characteristic qualification index according to the vibration information of each mechanical component in the transformer; The transformer chemical property monitoring module is used to monitor the chemical property information of the transformer, including the dielectric constant and breakdown voltage of the insulating oil at each monitoring time point, the acid value and dielectric loss factor of the insulating oil at the current monitoring time point, and the viscosity of the insulating oil at each temperature; A transformer chemical property analysis module is used to analyze the transformer chemical property qualification index according to the transformer chemical property information; A transformer operation status analysis module is used to analyze the transformer operation status qualification level according to the transformer mechanical property qualification index and chemical property qualification index; A database for storing the permissible range of load current of the winding, storing the temperature corresponding to each qualified viscosity range of the insulating oil in the transformer, and storing the initial acid value of the insulating oil in the transformer; The transformer operation status feedback terminal is used to provide corresponding feedback according to the qualified level of the transformer operation status.

2. The system for evaluating the operation status of a transformer based on data analysis according to claim 1, characterized in that: The analysis of the mechanical characteristic qualification index of the transformer includes: P1. Analyze the vibration qualification index of the core in the transformer according to the vibration frequency and sound loudness of the core at each monitoring time point; P2. Analyze the vibration qualification index of the winding in the transformer according to the vibration amplitude, load current and temperature of the winding at each monitoring time point; P3. Analyze the vibration qualification index of the fixed components installed in the transformer according to the displacement of each fixed component at each monitoring time point; P4. Select the minimum value from the vibration qualified index of the core, winding and installation and fixing parts of the transformer as the qualified index of the mechanical characteristics of the transformer and record it as .

3. The system for evaluating the operation status of a transformer based on data analysis according to claim 2, characterized in that: The analysis of the vibration qualification index of the core in the transformer includes: According to the vibration frequency of the iron core at each monitoring time point, confirm the vibration frequency qualification index of the iron core; Compare the sound loudness of the iron core at each monitoring time point with the set allowable iron core sound loudness; If the sound loudness of the iron core at a certain monitoring time point is less than or equal to the set permissible iron core sound loudness, the monitoring time point of the iron core is recorded as the sound loudness qualified monitoring time point; The number of sound loudness qualified monitoring time points and the number of monitoring time points are counted, and the ratio of the number of sound loudness qualified monitoring time points to the number of monitoring time points is used as the sound loudness qualified index of the iron core; The average calculation result of the vibration frequency qualified index and the sound loudness qualified index of the core is taken as the vibration qualified index of the core in the mutual inductor.

4. The system for evaluating the operation status of a transformer based on data analysis according to claim 3 is characterized in that: The confirmation of the vibration frequency qualification index of the iron core includes: Compare the vibration frequency of the iron core at each monitoring time point with the set allowable iron core vibration frequency range; If the vibration frequency of the iron core at a certain monitoring time point is within the set permissible iron core vibration frequency range, the vibration frequency qualification index of the iron core at the monitoring time point is recorded as 1; If the vibration frequency of the iron core at a certain monitoring time point is greater than the set upper limit value of the permissible iron core vibration frequency interval, the ratio of the set upper limit value of the permissible iron core vibration frequency interval to the vibration frequency of the iron core at the monitoring time point is used as the vibration frequency qualification index of the iron core at the monitoring time point; If the vibration frequency of the iron core at a certain monitoring time point is less than the set lower limit of the permissible iron core vibration frequency interval, the ratio of the vibration frequency of the iron core at the monitoring time point to the set lower limit of the permissible iron core vibration frequency interval is used as the vibration frequency qualification index of the iron core at the monitoring time point, thereby obtaining the vibration frequency qualification index of the iron core at each monitoring time point; The vibration frequency qualified index of the iron core at each monitoring time point is averaged and the average calculation result is used as the vibration frequency qualified index of the iron core.

5. The system for evaluating the operation status of a transformer based on data analysis according to claim 2, characterized in that: The analysis of the vibration qualification index of the winding in the transformer includes: The vibration amplitude of the winding at each monitoring time point is compared with the set vibration amplitude. If the vibration amplitude of the winding at a certain monitoring time point is less than or equal to the set vibration amplitude, the monitoring time point of the winding is recorded as the vibration amplitude qualified monitoring time point; The number of qualified monitoring time points of vibration amplitude is counted, and the ratio of it to the number of monitoring time points is used as the qualified index of vibration amplitude of the winding, which is recorded as ; The load current of the winding at each monitoring time point is recorded as , is the monitoring time point number, , and extract the allowable range of the load current of the winding from the database as ; Statistical winding load current deviation index at each monitoring time point , ; Statistical winding load current qualification index , , is the number of monitoring time points; The mean temperature of the winding at each monitoring time point is calculated to obtain the average temperature of the winding, which is recorded as ; The maximum temperature is selected from the temperatures of the winding at each monitoring time point and recorded as ; Statistical winding temperature qualification index , , To set the reference winding temperature; Statistical analysis of vibration qualification index of windings in transformers , , , and are the weights of the set winding vibration amplitude qualification index, winding load current qualification index and winding temperature qualification index, respectively. , .

6. The system for evaluating the operation status of a transformer based on data analysis according to claim 2, characterized in that: The analysis of the vibration qualification index of the fixed components installed in the transformer includes: Filter out the maximum displacement of each installation and fixing component from the displacements of each installation and fixing component at each monitoring time point; Compare the maximum displacement of each installation component with the set allowable displacement of the installation component; If the maximum displacement of a certain installation component is less than or equal to the set allowable displacement of the installation component, the installation component is recorded as a displacement qualified installation component; The number of qualified installation components with displacement and the number of installation components are counted, and the ratio of the number of qualified installation components with displacement to the number of installation components is used as the vibration qualified index of the fixed components installed in the transformer.

7. The system for evaluating the operation status of a transformer based on data analysis according to claim 1, characterized in that: The chemical property qualification index of the analysis transformer includes: Q1. According to the dielectric constant and breakdown voltage of the insulating oil at each monitoring time point, the insulation performance qualification index of the insulating oil is calculated. ; Q2. According to the acid value and dielectric loss factor of the insulating oil at the current monitoring time point, calculate the qualified index of the insulating oil's antioxidant performance ; Q3. Extract the temperature corresponding to each qualified viscosity range of the insulating oil in the transformer from the database; Q4. Match and compare the viscosity of the insulating oil at each temperature with the temperature corresponding to each qualified viscosity range of the insulating oil in the transformer; Q5. If the viscosity of the insulating oil at a certain temperature is within the qualified viscosity range of the insulating oil at that temperature, the qualified viscosity index of the insulating oil at that temperature is recorded as 1; Q6. If the viscosity of the insulating oil at a certain temperature is less than the lower limit of the qualified viscosity range of the insulating oil at that temperature, the ratio of the viscosity of the insulating oil at that temperature to the lower limit of its qualified viscosity range shall be taken as the qualified viscosity index of the insulating oil at that temperature; Q7. If the viscosity of the insulating oil at a certain temperature is greater than the upper limit of the qualified viscosity range of the insulating oil at the temperature, the ratio of the upper limit of the qualified viscosity range of the insulating oil at the temperature to its viscosity is taken as the qualified viscosity index of the insulating oil at the temperature, and then the qualified viscosity index of the insulating oil at each temperature is obtained; Q8. Calculate the average value of the viscosity qualification index of the insulating oil at each temperature, and use the calculation result as the viscosity qualification index of the insulating oil, recorded as ; Q9. Select the minimum value from the insulation performance qualified index, antioxidant performance qualified index and viscosity qualified index of the insulating oil as the chemical property qualified index of the transformer, recorded as .

8. The system for evaluating the operation status of a transformer based on data analysis according to claim 7, characterized in that: The statistical insulation performance qualification index of the insulating oil includes: The dielectric constant of the insulating oil at each monitoring time point is compared with the dielectric constant interval corresponding to the set dielectric constant qualified index of each insulating oil, and the dielectric constant qualified index of the insulating oil at each monitoring time point is obtained. ; According to the statistical method of the dielectric constant qualified index of the insulating oil at each monitoring time point, the breakdown voltage qualified index of the insulating oil at each monitoring time point is obtained and recorded as ; Statistics on insulation performance qualification index of insulating oil , .

9. The system for evaluating the operation status of a transformer based on data analysis according to claim 7, characterized in that: The statistical anti-oxidation performance qualification index of insulating oil includes: Extract the initial acid value of the insulating oil in the transformer from the database; The acid value of the insulating oil at the current monitoring time point is subtracted from the initial acid value to obtain the acid value difference of the insulating oil, which is recorded as ; The dielectric loss factor of the insulating oil at the current monitoring time point is recorded as ; Statistics on the qualified index of the anti-oxidation performance of insulating oil , , and They are the set allowable acid value difference of insulating oil and the allowable dielectric loss factor of insulating oil respectively.

10. The system for evaluating the operation status of a transformer based on data analysis according to claim 2, characterized in that: The analysis of the operating status qualification level of the transformer includes: Extracting the mechanical characteristics qualification index of the transformer Chemical properties qualification index of the transformer ; Statistical operation status qualification index of transformer , , and are the weights of the set transformer mechanical characteristic qualification index and transformer chemical characteristic qualification index, , ; The operating state qualified index of the transformer is matched and compared with the operating state qualified indexes corresponding to each operating state qualified grade to obtain the operating state qualified grade of the transformer.

Images