Electronic transformer insulation ageing monitoring method and system

Abstract

The application discloses an electronic transformer insulation aging monitoring method and system, relates to the technical field of power equipment monitoring, and is used for effectively identifying and warning insulation aging caused by atypical chemical products generated by an electronic transformer under high-frequency stress, so as to improve the operation stability of the electronic transformer. The method comprises the following steps: receiving real-time light intensity data sent by a photoelectric sensor, the real-time light intensity data being an electric signal obtained by photoelectric conversion of a light signal penetrating through insulation oil by the photoelectric sensor, the light signal being a signal emitted by an optical detection device to a channel through which the insulation oil flows, and the light signal having characteristic absorption to atypical chemical products in the insulation oil; calculating a real-time light absorption rate of the insulation oil based on the real-time light intensity data; and generating an insulation aging warning signal when the real-time light absorption rate meets a preset condition.

Description

Technical Field

[0001] This application relates to the field of power equipment monitoring technology, and in particular to a method and system for monitoring the insulation aging of electronic transformers. Background Technology

[0002] In new energy power systems, electronic transformers, as key equipment, exhibit significantly different aging mechanisms compared to traditional power frequency transformers due to the superimposed stress of high-frequency voltage ripple from the front-end power electronic converter. This unique operating environment leads to non-uniform and localized degradation of the insulation materials, potentially generating atypical chemical products that are difficult to identify using traditional monitoring methods.

[0003] For example, in large-scale photovoltaic power plants, electronic transformers experience voltage ripple introduced by high-frequency switching noise from inverter clusters. These high-frequency ripple components are applied to the transformer's high-voltage windings, causing the insulating medium to convert electric field energy into heat energy under the influence of a high-frequency electric field, forming numerous dispersed, transient micro-hot spots. These micro-hot spots continuously act on the insulating material, altering the chemical bond breaking paths and potentially generating larger molecular weight alcohols or ketones that are not considered in traditional dissolved gas analysis (DGA), i.e., atypical chemical products.

[0004] However, existing insulation condition monitoring methods typically employ periodic sampling and dissolved gas analysis to determine the insulation aging status of electronic transformers. Traditional dissolved gas analysis (DGA) primarily focuses on characteristic gases such as hydrogen, methane, ethane, ethylene, and acetylene, and cannot effectively detect these atypical chemical products. This makes it difficult to effectively identify and provide early warning of this specific aging mode caused by high-frequency dielectric losses during the operation of electronic transformers, thereby affecting their operational stability. Summary of the Invention

[0005] This application provides a method and system for monitoring the insulation aging of electronic transformers, which can effectively identify and warn of insulation aging caused by atypical chemical products generated under high-frequency stress in electronic transformers, thereby improving the operational stability of electronic transformers.

[0006] The first aspect of this application provides a method for monitoring the insulation aging of electronic transformers, including:

[0007] The device receives real-time light intensity data sent by a photoelectric sensor. The real-time light intensity data is an electrical signal obtained by the photoelectric sensor through photoelectric conversion of the light signal after penetrating the insulating oil. The light signal is a signal emitted by the optical detection device into the channel through which the insulating oil flows. The light signal has characteristic absorption for atypical chemical products in the insulating oil.

[0008] The real-time light absorption rate of the insulating oil is calculated based on the real-time light intensity data;

[0009] When the real-time light absorption rate meets the preset conditions, an insulation aging warning signal is generated.

[0010] Optionally, before calculating the real-time light absorption rate of the insulating oil based on the real-time light intensity data, the method further includes:

[0011] Obtain the real-time temperature data of the insulating oil;

[0012] The real-time light intensity data is corrected based on the real-time temperature data;

[0013] The calculation of the real-time light absorption rate of the insulating oil based on the real-time light intensity data includes:

[0014] The real-time light absorption rate of the insulating oil is calculated based on the corrected real-time light intensity data.

[0015] Optionally, the step of correcting the real-time light intensity data based on the real-time temperature data includes:

[0016] Obtain the historical light intensity dataset transmitted by the photoelectric sensor;

[0017] The light intensity data of the insulating oil in the same state at different temperatures are extracted from the historical light intensity dataset to determine the correspondence between the temperature and light intensity data of the insulating oil.

[0018] Based on the aforementioned correspondence, determine the set of light intensity deviation values ​​corresponding to different temperatures;

[0019] A correction model is established based on the set of light intensity deviation values;

[0020] Based on the correction model, a target light intensity deviation value matching the real-time temperature data is determined;

[0021] The real-time light intensity data is corrected based on the target light intensity deviation value.

[0022] Optionally, before generating the insulation aging warning signal, the method further includes:

[0023] Obtain the real-time output power of the power electronic converter at the front end of the electronic transformer;

[0024] The light absorption rate change curve and the output power change curve are determined based on all the real-time light absorption rates and the real-time output power within a preset time period, respectively.

[0025] Calculate the first correlation strength between the light absorptivity change curve and the output power change curve;

[0026] When the first correlation strength is greater than the preset correlation strength threshold, the step of generating an insulation aging warning signal is executed.

[0027] Optionally, before generating the insulation aging warning signal, the method further includes:

[0028] Obtain the real-time switching frequency of the power electronic converter at the front end of the electronic transformer;

[0029] The switching frequency variation curve is determined based on all the real-time switching frequencies within a preset time period;

[0030] Calculate the second correlation strength between the light absorptivity change curve and the switching frequency change curve;

[0031] When the second correlation strength is greater than the preset correlation strength threshold and all the real-time switching frequencies within the preset time period are within the varnish deterioration danger range, a varnish deterioration log is generated.

[0032] When both the first correlation strength and the second correlation strength are less than or equal to the preset correlation strength threshold, an auxiliary material leaching interference log is generated.

[0033] The step of generating an insulation aging warning signal when the first correlation strength is greater than a preset correlation strength threshold includes:

[0034] When the first correlation strength is greater than the preset correlation strength threshold and all the real-time switching frequencies within the preset time period are not within the varnish deterioration danger range, the step of generating an insulation aging warning signal is executed.

[0035] Optionally, the insulation aging warning signal includes a first-level warning signal, a second-level warning signal, and a third-level warning signal. Generating the insulation aging warning signal when the real-time light absorption rate meets a preset condition includes:

[0036] Obtain the cumulative change and rate of change of the real-time light absorption rate within a preset time period;

[0037] When the cumulative change is greater than a preset change threshold and the change rate is less than or equal to a preset change rate threshold, a first-level warning signal is generated.

[0038] When the cumulative change is less than or equal to a preset change threshold and the change rate is greater than a preset change rate threshold, a second-level warning signal is generated.

[0039] When the cumulative change exceeds a preset change threshold and the change rate exceeds a preset change rate threshold, a third-level warning signal is generated.

[0040] Optionally, the insulation aging warning signal further includes a fourth-level warning signal, and after generating the third-level warning signal, the method further includes:

[0041] When the real-time light absorption rate is greater than the preset light absorption rate threshold, a fourth-level warning signal is generated.

[0042] Optionally, calculating the real-time light absorption rate of the insulating oil based on the real-time light intensity data includes:

[0043] Acquire the initial light intensity data of the light signal emitted by the optical detection device;

[0044] Calculate the difference between the initial light intensity data and the real-time light intensity data;

[0045] The real-time light absorption rate of the insulating oil is determined by calculating the ratio between the difference and the initial light intensity data.

[0046] Optionally, the optical signal includes multiple wavelengths of light, each wavelength having characteristic absorption for different types of atypical chemical products in the insulating oil.

[0047] The second aspect of this application provides an electronic transformer insulation aging monitoring system, comprising:

[0048] The receiving unit is used to receive real-time light intensity data sent by the photoelectric sensor. The real-time light intensity data is an electrical signal obtained by the photoelectric sensor through photoelectric conversion of the light signal after penetrating the insulating oil. The light signal is a signal emitted by the optical detection device to the channel through which the insulating oil flows. The light signal has characteristic absorption of atypical chemical products in the insulating oil.

[0049] A calculation unit is used to calculate the real-time light absorption rate of the insulating oil based on the real-time light intensity data;

[0050] The generation unit is used to generate an insulation aging warning signal when the real-time light absorption rate meets the preset conditions.

[0051] As can be seen from the above technical solutions, this application has the following effects:

[0052] First, real-time light intensity data from a photoelectric sensor is received. This data is an electrical signal obtained by the photoelectric sensor converting the light signal after it penetrates the insulating oil into a photoelectric signal. This light signal is emitted by the optical detection device into the channel through which the insulating oil flows. This light signal exhibits characteristic absorption of atypical chemical products in the insulating oil. Then, the real-time light absorptivity of the insulating oil is calculated based on the real-time light intensity data. When the real-time light absorptivity meets a preset condition, an insulation aging warning signal is generated. Because the light signal emitted by the optical detection device exhibits characteristic absorption of atypical chemical products in the insulating oil, the light intensity of the light signal received by the photoelectric sensor will weaken if the insulating oil contains atypical chemical products after the light signal penetrates it. Therefore, by calculating the real-time light absorptivity of the insulating oil to this light signal and using this real-time light absorptivity to determine the timing of generating an insulation aging warning signal, it is possible to effectively identify and warn of insulation aging caused by atypical chemical products generated in electronic transformers under high-frequency stress, thereby improving the operational stability of electronic transformers. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of an embodiment of a method for monitoring the insulation aging of an electronic transformer according to this application;

[0054] Figure 2 This is a schematic diagram of another embodiment of the electronic transformer insulation aging monitoring method in this application;

[0055] Figure 3 This is a schematic diagram of another embodiment of the electronic transformer insulation aging monitoring method in this application;

[0056] Figure 4 This is a schematic diagram of another embodiment of the electronic transformer insulation aging monitoring method in this application;

[0057] Figure 5 This is a schematic diagram of another embodiment of the electronic transformer insulation aging monitoring method in this application;

[0058] Figure 6 This is a schematic diagram of another embodiment of the electronic transformer insulation aging monitoring method in this application;

[0059] Figure 7 This is a schematic diagram of an embodiment of an electronic transformer insulation aging monitoring system according to this application. Detailed Implementation

[0060] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0061] It should be understood that, when used in this application specification, the term "comprising" indicates the presence of the described feature, integral, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof.

[0062] It should also be understood that the term “and / or” as used in this application specification means any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations.

[0063] As used in this application specification, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [the described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [the described condition or event] is detected," or "in response to detection of [the described condition or event]."

[0064] Furthermore, in the description of this application, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0065] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0066] In existing technologies, insulation condition monitoring methods typically employ periodic sampling and dissolved gas analysis to determine the insulation aging state of electronic transformers. However, traditional dissolved gas analysis (DGA) primarily focuses on characteristic gases such as hydrogen, methane, ethane, ethylene, and acetylene, and cannot effectively detect these atypical chemical products. Consequently, it becomes difficult to effectively identify and provide early warnings of this specific aging mode caused by high-frequency dielectric losses during the operation of electronic transformers, thus affecting the operational stability of the transformers.

[0067] Based on this, this application discloses a method and system for monitoring the insulation aging of electronic transformers, which can effectively identify and warn of insulation aging caused by atypical chemical products generated under high-frequency stress in electronic transformers, thereby improving the operational stability of electronic transformers.

[0068] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0069] The electronic transformer insulation aging monitoring method described in this application is implemented in systems, terminals, or other devices with logic analysis and processing capabilities. This embodiment uses its application to a microcontroller as an example. It should be noted that a microcontroller, also known as a single-chip microcomputer, is a single-chip microcomputer that integrates a central processing unit, memory, various input / output interfaces, timers / counters, interrupt systems, and other key functions.

[0070] Please see Figure 1 As shown, one embodiment of the electronic transformer insulation aging monitoring method in this application includes:

[0071] 101. Receive real-time light intensity data sent by the photoelectric sensor. The real-time light intensity data is the electrical signal obtained by the photoelectric sensor through photoelectric conversion of the light signal after penetrating the insulating oil. The light signal is the signal emitted by the optical detection device to the channel through which the insulating oil flows. The light signal has characteristic absorption of atypical chemical products in the insulating oil.

[0072] In this embodiment, the optical detection device is positioned on one side of the channel through which the insulating oil flows, while the photoelectric sensor is positioned on the other side. The photoelectric sensor and the optical detection device are on the same horizontal line and are positioned opposite each other. The optical detection device emits a light signal of a certain wavelength into the channel through which the insulating oil flows. This light signal penetrates the insulating oil in the channel and is received by the photoelectric sensor on the other side of the channel. The photoelectric sensor is electrically connected to a microcontroller. After receiving the light signal, the photoelectric sensor converts the light signal into an electrical signal that the microcontroller can recognize. The electrical signal received by the microcontroller is the real-time light intensity data.

[0073] It should be noted that the characteristic absorption of light signals by atypical chemical products in insulating oil means that when light signals of a specific wavelength penetrate the insulating oil, they are selectively absorbed by specific chemical substances produced by insulation aging, resulting in a decrease in light intensity. This can be achieved using light sources in specific wavelengths, such as ultraviolet, visible, or infrared light. Its main purpose is to identify and quantify degradation products related to high-frequency dielectric loss in insulating oil that are difficult to detect using traditional monitoring methods. Atypical chemical products refer to specific molecules that dissolve or disperse in the insulating oil, different from traditional thermal or discharge aging products, after the breaking of chemical bonds or structural rearrangement of the insulating material under the influence of high-frequency dielectric loss in electronic transformers. These atypical chemical products can specifically be alcohols, ketones, esters, or specific polymer fragments; no specific limitation is made here.

[0074] Understandably, the optical detection device can employ one or more light-emitting diodes (LEDs) or laser diodes, whose emitted light signals are selected to be absorbed by atypical chemical products commonly found in insulating oil due to high-frequency dielectric losses. For example, a light source with specific absorption peaks in the ultraviolet or near-infrared bands can be selected. The channel through which the insulating oil flows can be a transparent flow cell integrated into the oil circulation pipeline of the electronic transformer, ensuring that the light signal can stably penetrate the insulating oil. The photoelectric sensor, which can be a photodiode or phototransistor, is placed on the other side of the flow cell to receive the light signal after it has penetrated the insulating oil and convert it into an electrical signal. This electrical signal is amplified and converted from analog to digital to form real-time light intensity data, which is then transmitted to the microcontroller.

[0075] 102. Calculate the real-time light absorption rate of insulating oil based on real-time light intensity data;

[0076] In this embodiment, the real-time light absorption rate refers to the degree of attenuation of the intensity of a light signal after it penetrates the insulating oil, relative to its initial intensity. This attenuation is related to the concentration of atypical chemical products in the insulating oil. For example, when there are no atypical chemical products in the insulating oil, the intensity of the light signal penetrating the insulating oil remains unchanged, and the real-time light absorption rate of the insulating oil may be 0. When there are a small amount of atypical chemical products in the insulating oil, the intensity of the light signal penetrating the insulating oil will be slightly attenuated, and the real-time light absorption rate of the insulating oil may be a small value. When there are a large amount of atypical chemical products in the insulating oil, the intensity of the light signal penetrating the insulating oil will be severely attenuated, and the real-time light absorption rate of the insulating oil may be a large value. The real-time light absorption rate of the insulating oil can be calculated using the Beer-Lambert law or a simple light intensity ratio. This real-time light absorption rate is used to quantify the content of atypical chemical products in the insulating oil, thereby reflecting the degree of insulation aging in the electronic transformer.

[0077] 103. When the real-time light absorption rate meets the preset conditions, an insulation aging warning signal is generated.

[0078] Preset conditions refer to specific thresholds or rules used to determine whether the insulation aging state has reached the warning level. These preset conditions can be set using a single light absorption rate threshold, a light absorption rate change rate threshold, or a cumulative light absorption rate change threshold, to trigger corresponding warning mechanisms based on different stages or severity of insulation aging. When the real-time light absorption rate meets the preset conditions, the microcontroller generates an insulation aging warning signal. This warning signal can manifest as a digital signal sent to the control center, the illumination of a warning light, or by sending an SMS or email notification to maintenance personnel via the communication module; the specific method is not limited here.

[0079] In this embodiment, because the light signal emitted by the optical detection device has a characteristic absorption effect on atypical chemical products in the insulating oil, when the light signal penetrates the insulating oil, if the insulating oil contains atypical chemical products, the light intensity of the light signal received by the photoelectric sensor will weaken. Therefore, by calculating the real-time light absorption rate of the insulating oil to this light signal and using this real-time light absorption rate to determine the timing of generating an insulation aging warning signal, it is possible to effectively identify and warn of insulation aging caused by atypical chemical products generated in the electronic transformer under high-frequency stress, thereby improving the operational stability of the electronic transformer.

[0080] Please see Figure 2 As shown, another embodiment of the electronic transformer insulation aging monitoring method in this application includes:

[0081] 201. Receive real-time light intensity data sent by the photoelectric sensor. The real-time light intensity data is the electrical signal obtained by the photoelectric sensor through photoelectric conversion of the light signal after penetrating the insulating oil. The light signal is the signal emitted by the optical detection device to the channel through which the insulating oil flows. The light signal includes multiple different wavelengths of light. Each different wavelength of light has characteristic absorption for different types of atypical chemical products in the insulating oil.

[0082] Optionally, in this embodiment, multiple different wavelengths of light refer to the light emitted into the insulating oil during the optical detection process not being of a single frequency or color, but rather composed of at least two or more light sources with different wavelengths. This can be achieved by using multiple independent light sources that emit light sequentially or simultaneously, or by using a broadband light source combined with a spectrometer to selectively acquire light of different wavelengths for targeted detection of different types of chemical substances in the insulating oil.

[0083] It is understandable that, due to the unique characteristic absorption of different wavelengths of light by different types of atypical chemical products in insulating oil, each atypical aging product will cause attenuation of the optical signal within its specific wavelength range. By emitting optical signals of different wavelengths into the insulating oil, multiple aging products present in the insulating oil can be distinguished and identified, rather than simply detecting overall absorption changes. For example, if there are two atypical chemical products, A and B, in the insulating oil, with product A having strong absorption at wavelength λ1 and product B having strong absorption at wavelength λ2, then by simultaneously monitoring the light absorption rates at wavelengths λ1 and λ2, it can be determined whether the concentration of product A, product B, or both has increased. This ability to identify different aging products allows for the generation of insulation aging warning signals based on real-time light absorption rates, enabling not only the determination of whether the insulating oil is aging, but also further analysis of the type and main causes of aging. Therefore, in this way, this embodiment can provide richer and more accurate aging information, overcoming the limitation that a single wavelength optical signal cannot comprehensively reflect the concentration changes of multiple products, and significantly improving the accuracy and effectiveness of insulation aging monitoring.

[0084] 202. Obtain the initial light intensity data of the light signal emitted by the optical detection device;

[0085] 203. Calculate the difference between the initial light intensity data and the real-time light intensity data;

[0086] 204. Determine the real-time light absorption rate of the insulating oil by calculating the ratio between the difference and the initial light intensity data;

[0087] Optionally, in this embodiment, the initial light intensity data refers to the original intensity of the light signal emitted by the optical detection device under conditions of no insulating oil absorption or a known standard state. The initial light intensity data can be measured when the channel through which the insulating oil flows is empty or filled with a known standard medium, or obtained by periodically calibrating the light source output intensity of the optical detection device to provide a stable reference light intensity unaffected by insulating oil absorption, facilitating subsequent accurate evaluation of the insulating oil's absorption characteristics. When calculating the real-time light absorption rate of the insulating oil, the initial light intensity data is first subtracted from the real-time light intensity data received after the light signal penetrates the insulating oil. The calculated difference directly reflects the intensity loss of the light signal due to absorption when passing through the insulating oil. Then, this difference is divided by the initial light intensity data, and the quotient is the real-time light absorption rate of the insulating oil. This calculation method normalizes the light absorption rate, effectively eliminating the influence of external factors such as fluctuations in the light source of the optical detection device and interference from ambient light on the measurement results. This allows the obtained real-time light absorption rate to more accurately reflect the concentration changes of atypical chemical products in the insulating oil, thus providing more reliable and stable input data for subsequent insulation aging early warning, and thereby improving the reliability of the entire monitoring process.

[0088] 205. Obtain the cumulative change and rate of change of real-time light absorption rate within a preset time period;

[0089] 206. When the cumulative change is greater than the preset change threshold and the change rate is less than or equal to the preset change rate threshold, a first-level warning signal is generated.

[0090] 207. When the cumulative change is less than or equal to the preset change threshold and the rate of change is greater than the preset rate of change threshold, a second-level warning signal is generated.

[0091] 208. When the cumulative change exceeds the preset change threshold and the rate of change exceeds the preset rate of change threshold, a third-level warning signal is generated.

[0092] Optionally, in this embodiment, the cumulative change in real-time light absorption rate within a preset time period refers to the total cumulative change in real-time light absorption rate from the starting point to the current point within a specific monitoring period. The cumulative change can be calculated by taking the difference between the maximum and minimum values ​​of real-time light absorption rate within the preset time period, or by taking the difference between the average and initial values ​​of real-time light absorption rate within the preset time period, to reflect the long-term aging cumulative effect of insulating oil. The rate of change of real-time light absorption rate refers to how quickly the real-time light absorption rate changes per unit time. This can be calculated by taking the linear regression slope of the real-time light absorption rate within the preset time period, or by taking the ratio of the difference in light absorption rate between two adjacent sampling points to the time interval, to reflect the short-term severity of the aging process of insulating oil. The preset threshold for the change in real-time light absorption rate is a reference value used to determine whether the cumulative aging degree of insulating oil has reached a certain critical level. It can be set based on factors such as historical operating data, equipment type, type of insulating oil, and industry standards, to distinguish different degrees of long-term aging cumulative effects. The preset rate of change threshold is a reference value used to determine whether the aging rate of insulating oil has reached a certain critical level. It can be set based on equipment operating experience, fault mode analysis, and safety margins to differentiate between different degrees of short-term aging severity. The first-level warning signal indicates that the insulating oil has a certain degree of aging risk, but the aging process is relatively stable. This can be represented by a low-level warning icon on the system interface, log records, or non-emergency notifications, aiming to prompt maintenance personnel to pay attention to the equipment status and conduct regular inspections. The second-level warning signal indicates that the aging process of the insulating oil is accelerating, and there may be sudden deterioration problems. This can be represented by a medium-level warning icon on the system interface, SMS notifications, or email reminders, aiming to prompt maintenance personnel to immediately inspect the equipment. The third-level warning signal indicates that the aging of the insulating oil is severe and the aging process is rapid, requiring immediate emergency measures. This can be represented by a high-level warning icon on the system interface, audible and visual alarms, or remote shutdown commands, aiming to prompt maintenance personnel to take immediate emergency measures to prevent faults. In this way, by comprehensively considering the cumulative change and rate of change of the real-time light absorbance of the insulating oil, the insulation aging early warning signals can be graded, thus achieving a more precise reflection of the actual degree of insulation aging and effectively avoiding the judgment bias that may be caused by a single threshold warning. Furthermore, the warning information can more accurately reflect the actual progress and urgency of insulation aging. Maintenance personnel can take targeted maintenance and intervention measures based on different levels of warning signals, thereby further improving the accuracy of insulation aging monitoring and reducing the risk of equipment downtime due to insulation faults in electronic transformers.

[0093] 209. When the real-time light absorption rate is greater than the preset light absorption rate threshold, a fourth-level warning signal is generated.

[0094] Optionally, in this embodiment, the fourth-level warning signal refers to a high-risk insulation aging warning, the purpose of which is to indicate that the insulating oil has reached an extremely high level of deterioration, requiring immediate emergency measures. The preset light absorption rate threshold is a critical light absorption rate value used to determine whether the insulating oil has reached an extremely high level of deterioration. This threshold can be set according to the type of insulating oil, equipment operating environment, safety standards, and historical operating data. Its purpose is to provide an objective judgment basis based on the absolute value of real-time light absorption rate, to compensate for the shortcomings of relying solely on changing trends for warnings. When the real-time light absorption rate reaches a preset critical level, i.e., greater than the preset light absorption rate threshold, a fourth-level warning signal will be immediately generated even if the cumulative change and rate of change have not yet triggered a third-level warning. It is understood that this fourth-level warning signal can trigger an emergency shutdown procedure or send a highest-priority alarm to maintenance personnel to prompt them to immediately inspect or replace the insulating oil in the electronic transformer, thereby avoiding potential equipment failures. In this way, the shortcomings of relying solely on cumulative changes and rates of change for insulation aging early warning can be compensated, improving the sensitivity and reliability of insulation aging monitoring, thereby reflecting the true state of the insulating oil more comprehensively and in a timely manner, and effectively ensuring the safe operation of electronic transformers.

[0095] In other embodiments, please refer to Figure 3 As shown, prior to step 102, the electronic transformer insulation aging monitoring method of this application may further include:

[0096] 301. Obtain real-time temperature data of the insulating oil;

[0097] 302. Correct the real-time light intensity data based on the real-time temperature data;

[0098] 303. Calculate the real-time light absorption rate of insulating oil based on the corrected real-time light intensity data.

[0099] Optionally, in this embodiment, since the temperature of the insulating oil directly affects its optical properties, such as density, refractive index, and the molecular motion state of dissolved substances, these changes can cause varying degrees of attenuation or scattering of the light signal when penetrating the insulating oil. This results in the real-time light intensity data received by the photoelectric sensor deviating from its true value at standard temperature. Therefore, real-time temperature data can be used to correct the real-time light intensity data to eliminate or reduce the impact of insulating oil temperature changes on the real-time light intensity data received by the photoelectric sensor, thereby obtaining real-time light intensity data closer to reality. Specifically, a high-precision platinum resistance temperature sensor or thermistor can be used, directly installed in the insulating oil circulation pipeline or inside the oil tank to continuously monitor the temperature changes of the insulating oil. When the photoelectric sensor sends real-time light intensity data, the corresponding real-time temperature data is recorded simultaneously.

[0100] Please refer to Figure 4 As shown, step 302 may specifically include:

[0101] 401. Obtain the historical light intensity dataset transmitted by the photoelectric sensor;

[0102] 402. Extract the light intensity data of insulating oil in the same state at different temperatures from the historical light intensity dataset to determine the correspondence between the temperature of the insulating oil and the light intensity data;

[0103] 403. Determine the set of light intensity deviation values ​​corresponding to different temperatures based on the correspondence.

[0104] 404. Establish a correction model based on the set of light intensity deviation values;

[0105] 405. Determine the target light intensity deviation value that matches the real-time temperature data based on the calibration model;

[0106] 406. Correct the real-time light intensity data based on the target light intensity deviation value.

[0107] Optionally, the historical light intensity dataset refers to the collection of data recorded by photoelectric sensors at different times and under different environmental conditions, measuring and recording the light intensity of insulating oil. Its purpose is to provide a sufficient data foundation for subsequently establishing a calibration relationship between temperature and light intensity. Insulating oil in the same state means that the chemical composition, aging degree, and other physical properties that may affect light intensity measurement of the insulating oil remain consistent during light intensity data extraction. Specifically, this can be achieved by ensuring, under controlled experimental conditions or by screening historical data, that the insulating oil corresponding to the selected data points is in an initial state without significant aging, or in a specific aging stage. The purpose is to eliminate the influence of changes in the insulating oil's own state on the light intensity data, thereby more accurately reflecting the single effect of temperature on light intensity. The light intensity deviation value set refers to the deviation of the measured light intensity value from a certain reference light intensity value at different temperatures, such as the light intensity value at a standard temperature. Specifically, this can be achieved by comparing the light intensity values ​​at different temperatures with a preset reference light intensity value and calculating the difference or ratio. Specifically, the historical light intensity dataset sent by the photoelectric sensor is first acquired. This historical data contains light intensity information of the insulating oil at different temperatures. Then, from these historical light intensity datasets, light intensity data of insulating oil in the same state at different temperatures are extracted to eliminate interference from the aging or state changes of the insulating oil itself on light intensity measurement, thereby revealing a more accurate intrinsic correspondence between temperature and light intensity. Based on this, according to the determined correspondence, a set of light intensity deviation values ​​corresponding to different temperatures is calculated and formed. These light intensity deviation values ​​quantify the specific impact of temperature changes on light intensity measurement. Subsequently, a calibration model is established using this set of light intensity deviation values. This model can transform discrete deviation data into a continuous calibration function, allowing the corresponding light intensity deviation to be predicted based on any real-time temperature data. When real-time temperature data is received, a target light intensity deviation value matching the current real-time temperature data can be determined based on this calibration model. Finally, this target light intensity deviation value is used to correct the real-time light intensity data, thereby effectively eliminating the influence of temperature on light intensity measurement. This method of establishing a dynamic calibration model based on historical data can adapt to the light intensity response characteristics of insulating oil at different temperatures, providing more accurate calibration even if the state of the insulating oil changes slightly over time. Therefore, the corrected real-time light intensity data can more accurately reflect the concentration changes of atypical chemical products in insulating oil, thereby making the subsequent calculation of the real-time light absorption rate of insulating oil more accurate, thus significantly improving the accuracy and reliability of insulation aging monitoring of electronic transformers.

[0108] In other embodiments, please refer to Figure 5 As shown, prior to step 103, the electronic transformer insulation aging monitoring method of this application may further include:

[0109] 501. Obtain the real-time output power of the power electronic converter at the front end of the electronic transformer;

[0110] 502. Determine the light absorption rate change curve and the output power change curve based on all real-time light absorption rates and real-time output power within the preset time period;

[0111] 503. Calculate the first correlation strength between the light absorptivity change curve and the output power change curve;

[0112] 504. When the first correlation strength is greater than the preset correlation strength threshold, execute the step of generating an insulation aging warning signal.

[0113] Optionally, in the operating environment of electronic transformers connected to the grid of new energy sources, changes in the light absorption of insulating oil may originate from two different physicochemical processes. One is caused by high-frequency voltage components generated by the power electronic converter at the transformer's front end, which act on the insulating material over a long period, causing the chemical bonds to break and producing specific alcohols or ketones. These substances dissolve in the oil and absorb ultraviolet light of specific wavelengths. The other is that in the auxiliary sealing components of the electronic transformer, due to differences in material properties or manufacturing processes, certain additives slowly decompose and dissolve into the oil under long-term immersion in oil and temperature effects. These additives also happen to exhibit similar light absorption characteristics at the same ultraviolet wavelength. Therefore, by correlating the trend of light absorption rate changes with the operating conditions of the power electronic converter at the front end of the electronic transformer, the cause of the changes in light absorption rate can be determined, thus avoiding misdiagnosis of the insulation status of the electronic transformer and unnecessary shutdowns due to signal source confusion.

[0114] Specifically, real-time output power refers to the actual electrical power output by the power electronic converter to the electronic transformer at a given moment. It can be obtained from a power sensor installed at the output of the power electronic converter or from the product of real-time voltage and current acquired through the converter's internal control system. The light absorptivity variation curve and the output power variation curve refer to trend graphs or data sequences formed by connecting continuously collected real-time light absorptivity data points and real-time output power data points in chronological order over a preset time period. These can be determined using methods such as time series analysis, moving average, or curve fitting, and are used to visually demonstrate the dynamic changes of these two parameters over time. The first correlation strength refers to the statistical correlation or coupling relationship between the light absorptivity variation curve and the output power variation curve. It can be calculated using statistical methods such as Pearson correlation coefficient, Spearman's rank correlation coefficient, or mutual information, and is used to quantitatively assess whether there is a synchronous or causal relationship between changes in light absorptivity and changes in output power. When the calculated first correlation strength is greater than the preset correlation strength threshold, it indicates a significant correlation between changes in light absorptivity and output power. In this case, the increase in light absorptivity is more likely due to changes in operating load rather than actual aging of the insulation material. Therefore, the microcontroller will suppress or not immediately execute the step of generating an insulation aging warning signal. Conversely, if the first correlation strength is not greater than the preset correlation strength threshold, it indicates a weak correlation between changes in light absorptivity and output power. In this case, the increase in light absorptivity is more likely to reflect the actual deterioration of the insulation material, and the microcontroller will then execute the step of generating an insulation aging warning signal. This mechanism makes the generation of insulation aging warning signals more reliable, effectively avoiding false alarms caused by fluctuations in operating conditions, thereby achieving a more accurate judgment of the insulation aging status of electronic transformers.

[0115] For further details, please refer to Figure 6 As shown, prior to step 103, the electronic transformer insulation aging monitoring method of this application may further include:

[0116] 601. Obtain the real-time switching frequency of the power electronic converter at the front end of the electronic transformer;

[0117] 602. Determine the switching frequency variation curve based on all real-time switching frequencies within a preset time period;

[0118] 603. Calculate the second correlation strength between the light absorptivity change curve and the switching frequency change curve;

[0119] 604. When the second correlation strength is greater than the preset correlation strength threshold and all real-time switching frequencies within the preset time period are within the varnish deterioration danger range, a varnish deterioration log is generated.

[0120] 605. When both the first correlation strength and the second correlation strength are less than or equal to the preset correlation strength threshold, an auxiliary material leaching interference log is generated.

[0121] 606. When the first correlation strength is greater than the preset correlation strength threshold and all real-time switching frequencies within the preset time period are not within the varnish deterioration danger range, execute the step of generating an insulation aging warning signal.

[0122] Optionally, the varnish on the internal windings of the electronic transformer, when continuously excited by an electric field at a specific switching frequency, will cause a sharp increase in its dielectric loss and begin localized pyrolysis. Furthermore, certain chemical groups contained in the varnish decomposition products can absorb the light signal emitted by the photodetector. Therefore, in addition to the synchronous acquisition of the insulating oil light absorption rate and the total output power of the inverter at the front end of the electronic transformer, synchronous acquisition and analysis of the inverter's real-time switching frequency data can be further introduced. This will further distinguish whether the light absorption signal originates from the slow dissolution of benign auxiliary materials or from the degradation of critical components that threaten the structural safety of the equipment, triggered by specific, non-high-power operating conditions. This will prevent the judgment logic from misjudging a serious degradation symptom as a non-emergency disturbance due to relying solely on a single operating condition parameter.

[0123] The second correlation strength is a quantitative indicator of the correlation between the light absorptivity change curve and the switching frequency change curve. It can be calculated using statistical methods such as Pearson correlation coefficient, Spearman rank correlation coefficient, or mutual information, and is used to assess the correlation between changes in the concentration of atypical chemical products in insulating oil and changes in the switching frequency of the power electronic converter. The varnish degradation hazard range refers to a defined range of the power electronic converter's switching frequency. Within this range, the degradation process of auxiliary insulating materials such as varnish may be accelerated or significantly affected. This range can be determined through experimental testing, historical data analysis, or simulation, with the aim of identifying the risk of varnish degradation caused by the defined switching frequency. When the second correlation strength exceeds a preset correlation strength threshold, and all real-time switching frequencies within a preset time period are within the varnish degradation hazard range, the system determines that insulation aging is likely mainly caused by varnish degradation and generates a varnish degradation log. This allows maintenance personnel to specifically identify and address varnish degradation issues, avoiding misclassification of such degradation as other types of insulation aging. Meanwhile, to avoid misjudgments, the system generates an auxiliary material leaching interference log when both the first correlation strength between the light absorptivity change curve and the output power change curve, and the second correlation strength between the light absorptivity change curve and the switching frequency change curve, are less than or equal to a preset correlation strength threshold. This indicates that the change in light absorptivity may not be caused by insulation aging, but rather by interference from the leaching of auxiliary materials, thus avoiding interference from non-aging factors and improving the accuracy of the early warning. Furthermore, in the process of generating the insulation aging early warning signal, the step of generating the insulation aging early warning signal is only executed when the first correlation strength is greater than the preset correlation strength threshold, and all real-time switching frequencies within the preset time period are not within the varnish deterioration danger range. This means that only after excluding limiting interference factors such as varnish deterioration and auxiliary material leaching is the correlation between light absorptivity and output power used as the basis for insulation aging early warning. Through this multi-dimensional, hierarchical judgment logic, this embodiment can more meticulously identify true insulation aging, avoiding false alarms or missed alarms caused by a single indicator or interference factor, thereby improving the reliability and directionality of insulation aging early warning.

[0124] Please see Figure 7 As shown, one embodiment of the electronic transformer insulation aging monitoring system in this application includes:

[0125] The receiving unit 701 is used to receive real-time light intensity data sent by the photoelectric sensor. The real-time light intensity data is an electrical signal obtained by the photoelectric sensor through photoelectric conversion of the light signal after penetrating the insulating oil. The light signal is a signal emitted by the optical detection device to the channel through which the insulating oil flows. The light signal has characteristic absorption of atypical chemical products in the insulating oil.

[0126] The calculation unit 702 is used to calculate the real-time light absorption rate of the insulating oil based on real-time light intensity data;

[0127] The generation unit 703 is used to generate an insulation aging warning signal when the real-time light absorption rate meets the preset conditions.

[0128] In this embodiment, the receiving unit 701 receives real-time light intensity data sent by the photoelectric sensor. This real-time light intensity data is an electrical signal obtained by the photoelectric sensor through which the light signal penetrating the insulating oil is converted into a photoelectric signal. This light signal is emitted by the optical detection device into the channel through which the insulating oil flows. This light signal has characteristic absorption of atypical chemical products in the insulating oil. The calculation unit 702 calculates the real-time light absorption rate of the insulating oil based on the real-time light intensity data. When the real-time light absorption rate meets a preset condition, the generation unit 703 generates an insulation aging warning signal. Because the light signal emitted by the optical detection device has characteristic absorption of atypical chemical products in the insulating oil, when the light signal penetrates the insulating oil, if the insulating oil contains atypical chemical products, the light intensity of the light signal received by the photoelectric sensor will weaken. Therefore, by calculating the real-time light absorption rate of the insulating oil to this light signal and using this real-time light absorption rate to determine the timing of generating an insulation aging warning signal, it is possible to effectively identify and warn of insulation aging caused by atypical chemical products generated in the electronic transformer under high-frequency stress, thereby improving the operational stability of the electronic transformer.

[0129] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0130] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0131] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0132] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0133] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for monitoring the insulation aging of electronic transformers, characterized in that, include: The device receives real-time light intensity data sent by a photoelectric sensor. The real-time light intensity data is an electrical signal obtained by the photoelectric sensor through photoelectric conversion of the light signal after penetrating the insulating oil. The light signal is a signal emitted by the optical detection device into the channel through which the insulating oil flows. The light signal has characteristic absorption for atypical chemical products in the insulating oil. The real-time light absorption rate of the insulating oil is calculated based on the real-time light intensity data; When the real-time light absorption rate meets the preset conditions, the real-time output power of the power electronic converter at the front end of the electronic transformer is obtained; The light absorption rate change curve and the output power change curve are determined based on all the real-time light absorption rates and the real-time output power within a preset time period, respectively. Calculate the first correlation strength between the light absorptivity change curve and the output power change curve, where the first correlation strength is the statistical correlation or coupling relationship between the light absorptivity change curve and the output power change curve; Obtain the real-time switching frequency of the power electronic converter at the front end of the electronic transformer; The switching frequency variation curve is determined based on all the real-time switching frequencies within a preset time period; Calculate the second correlation strength between the light absorption rate change curve and the switching frequency change curve, whereby the second correlation strength is a quantitative index of the degree of correlation between the light absorption rate change curve and the switching frequency change curve; When the second correlation strength is greater than the preset correlation strength threshold and all the real-time switching frequencies within the preset time period are within the varnish deterioration danger range, a varnish deterioration log is generated. When both the first correlation strength and the second correlation strength are less than or equal to the preset correlation strength threshold, an auxiliary material leaching interference log is generated. When the first correlation strength is greater than the preset correlation strength threshold and all the real-time switching frequencies within the preset time period are not within the varnish deterioration danger range, an insulation aging warning signal is generated.

2. The method for monitoring the insulation aging of electronic transformers according to claim 1, characterized in that, Before calculating the real-time light absorption rate of the insulating oil based on the real-time light intensity data, the method further includes: Obtain the real-time temperature data of the insulating oil; The real-time light intensity data is corrected based on the real-time temperature data; The calculation of the real-time light absorption rate of the insulating oil based on the real-time light intensity data includes: The real-time light absorption rate of the insulating oil is calculated based on the corrected real-time light intensity data.

3. The method for monitoring the insulation aging of electronic transformers according to claim 2, characterized in that, The step of correcting the real-time light intensity data based on the real-time temperature data includes: Obtain the historical light intensity dataset transmitted by the photoelectric sensor; The light intensity data of the insulating oil in the same state at different temperatures are extracted from the historical light intensity dataset to determine the correspondence between the temperature and light intensity data of the insulating oil. Based on the aforementioned correspondence, determine the set of light intensity deviation values ​​corresponding to different temperatures; A correction model is established based on the set of light intensity deviation values; Based on the correction model, a target light intensity deviation value matching the real-time temperature data is determined; The real-time light intensity data is corrected based on the target light intensity deviation value.

4. The method for monitoring the insulation aging of electronic transformers according to claim 1, characterized in that, The insulation aging early warning signal includes a first-level early warning signal, a second-level early warning signal, and a third-level early warning signal. The generation of the insulation aging early warning signal when the real-time light absorption rate meets a preset condition includes: Obtain the cumulative change and rate of change of the real-time light absorption rate within a preset time period; When the cumulative change is greater than a preset change threshold and the change rate is less than or equal to a preset change rate threshold, a first-level warning signal is generated. When the cumulative change is less than or equal to a preset change threshold and the change rate is greater than a preset change rate threshold, a second-level warning signal is generated. When the cumulative change exceeds a preset change threshold and the change rate exceeds a preset change rate threshold, a third-level warning signal is generated.

5. The method for monitoring the insulation aging of electronic transformers according to claim 4, characterized in that, The insulation aging warning signal also includes a fourth-level warning signal. After generating the third-level warning signal, the method further includes: When the real-time light absorption rate is greater than the preset light absorption rate threshold, a fourth-level warning signal is generated.

6. The method for monitoring the insulation aging of electronic transformers according to claim 1, characterized in that, The calculation of the real-time light absorption rate of the insulating oil based on the real-time light intensity data includes: Acquire the initial light intensity data of the light signal emitted by the optical detection device; Calculate the difference between the initial light intensity data and the real-time light intensity data; The real-time light absorption rate of the insulating oil is determined by calculating the ratio between the difference and the initial light intensity data.

7. The method for monitoring the insulation aging of electronic transformers according to any one of claims 1 to 6, characterized in that, The optical signal comprises multiple wavelengths of light, each wavelength exhibiting characteristic absorption for different types of atypical chemical products in the insulating oil.

8. An electronic transformer insulation aging monitoring system, characterized in that, include: The receiving unit is used to receive real-time light intensity data sent by the photoelectric sensor. The real-time light intensity data is an electrical signal obtained by the photoelectric sensor through photoelectric conversion of the light signal after penetrating the insulating oil. The light signal is a signal emitted by the optical detection device to the channel through which the insulating oil flows. The light signal has characteristic absorption of atypical chemical products in the insulating oil. A calculation unit is used to calculate the real-time light absorption rate of the insulating oil based on the real-time light intensity data; The generation unit is configured to: acquire the real-time output power of the power electronic converter at the front end of the electronic transformer when the real-time light absorption rate meets a preset condition; determine the light absorption rate change curve and the output power change curve based on all the real-time light absorption rates and the real-time output power within a preset time period; calculate the first correlation strength between the light absorption rate change curve and the output power change curve, wherein the first correlation strength is the statistical correlation or coupling relationship between the light absorption rate change curve and the output power change curve; acquire the real-time switching frequency of the power electronic converter at the front end of the electronic transformer; determine the switching frequency change curve based on all the real-time switching frequencies within a preset time period; and calculate the light absorption rate change... The second correlation strength between the curve and the switching frequency change curve is a quantitative indicator of the correlation between the light absorption rate change curve and the switching frequency change curve. When the second correlation strength is greater than a preset correlation strength threshold and all real-time switching frequencies within the preset time period are within the varnish degradation danger range, a varnish degradation log is generated. When both the first correlation strength and the second correlation strength are less than or equal to the preset correlation strength threshold, an auxiliary material leaching interference log is generated. When the first correlation strength is greater than the preset correlation strength threshold and all real-time switching frequencies within the preset time period are not within the varnish degradation danger range, an insulation aging warning signal is generated.

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