Transformer cooling control method, system and equipment and storage medium

Abstract

The invention relates to the technical field of transformers, in particular to a transformer cooling control method, system and device and a storage medium, and the method comprises the following steps: obtaining an electrical characteristic quantity signal and a thermotechnical state quantity signal of a transformer; based on the electrical characteristic quantity signal and the thermal state quantity signal, a top oil temperature prediction value at the next moment is calculated, a dynamically adjusted safety margin is coupled to determine an oil temperature threshold value, and the safety margin is dynamically adjusted according to the real-time electrical characteristic quantity signal; performing nonlinear fusion on the electrical characteristic quantity signal and the thermotechnical state quantity signal to generate a compound control quantity; and taking the oil temperature threshold value as a safety reference, and executing a staged cooling strategy according to the compound control quantity. According to the method, the electrical and thermal quantities are fused, the oil temperature threshold is determined by predicting the oil temperature and dynamically adjusting the safety margin, and the composite control quantity is nonlinearly generated to realize graded cooling, so that the problems of lag, isolation and rigidity of a traditional transformer cooling control scheme are solved, and the timeliness, accuracy and adaptability of cooling control are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of transformers, and in particular to a transformer cooling control method, system, device and storage medium. Background Art

[0002] Power transformers are core equipment for voltage conversion, power transmission, and distribution in power systems. Their operational reliability is directly related to the safety and stability of the power grid. Among all types of transformers, oil-immersed transformers are widely used in power transmission and distribution networks due to their excellent insulation performance, high heat dissipation efficiency, and moderate maintenance costs. They hold a particularly dominant position in medium- and high-voltage power systems.

[0003] As a core device in the power system, the operating temperature of the oil-immersed transformer directly affects the insulation performance and service life. Traditional cooling control methods generally rely on a single temperature threshold (such as a fixed 55°C to trigger cooling), which is difficult to adapt to dynamic load changes in complex power grid environments and has the following significant defects: (1) Response lag problem. There is thermal inertia in the change of transformer oil temperature. When cooling is triggered only by the real-time top oil temperature signal, it is impossible to predict the rapid temperature rise caused by sudden load changes (such as short circuit faults, start-up and shutdown of large equipment); for example, when the high-voltage side current suddenly increases, the winding loss increases sharply, but there is a delay in the increase of oil temperature. Traditional control is prone to local overheating due to the lag in cooling start, which accelerates insulation aging; (2) Signal isolation limitation. Traditional strategies only rely on thermal state quantities and ignore the strong correlation between electrical characteristic quantity signals and the heating process; for example, under the same oil temperature, the hot spot temperature of the winding under high load operation is much higher than that under low load state. Only relying on the oil temperature signal can effectively control the temperature rise. This will cause the cooling strategy to be out of line with the actual heating risk; (3) The threshold is rigid. The fixed threshold cannot adapt to the ambient temperature fluctuations and load characteristics. In low temperature environments, the fixed threshold may lead to over-cooling and increase energy consumption. In high temperature and high load scenarios, the high threshold may lead to insufficient cooling, posing a safety hazard. In addition, there are differences in the thermal capacity and heat dissipation efficiency of different types of transformers. It is difficult to achieve both universality and accuracy with a unified threshold. (4) The control strategy is single. Traditional cooling systems mostly use a "full open / full closed" binary control mode, which cannot dynamically adjust the cooling intensity according to real-time working conditions. For example, in the stage of slow load increase, there is no need to start all cooling devices, but the traditional strategy may be fully invested due to reaching the threshold, resulting in energy waste. When the load increases suddenly, the temperature may be out of control due to insufficient cooling capacity.

[0004] In summary, traditional transformer cooling control methods have obvious shortcomings in terms of safety, economy and adaptability. There is an urgent need for an intelligent control solution that integrates multi-dimensional signals, has predictive capabilities and dynamic adjustment characteristics. Summary of the Invention

[0005] The object of the present invention is to provide a transformer cooling control method, system, device and storage medium to solve the problems of response lag, signal isolation, threshold rigidity, etc. existing in traditional oil-immersed transformer cooling control.

[0006] The present invention is implemented through the following technical solution: A transformer cooling control method includes the following steps: Obtain electrical characteristic quantity signals and thermal state quantity signals of the oil-immersed transformer; Based on the electrical characteristic signal and the thermal state signal, the predicted value of the top oil temperature at the next moment is calculated and coupled with the dynamically adjusted safety margin to determine the oil temperature threshold. The safety margin is dynamically adjusted according to the real-time electrical characteristic signal. Perform nonlinear fusion of electrical characteristic quantity signals and thermal state quantity signals to generate composite control quantity; Taking the oil temperature threshold as the safety benchmark, a hierarchical cooling strategy is implemented according to the composite control quantity.

[0007] According to a preferred embodiment, the electrical characteristic quantity signal includes at least the high-voltage side CT current signal and the current change rate, and the thermal state quantity signal includes at least the top oil temperature signal and the ambient temperature signal of the oil-immersed transformer.

[0008] According to a preferred embodiment, the top oil temperature prediction value is obtained by using a pre-built LSTM prediction model based on the electrical characteristic quantity signal and the thermal state quantity signal.

[0009] According to a preferred embodiment, the method further includes preprocessing the acquired electrical characteristic quantity signals and thermal state quantity signals, wherein the preprocessing includes normalization processing and sliding average filtering processing.

[0010] According to a preferred embodiment, the dynamic adjustment rule of the safety margin is: When the pre-processed current change rate is greater than the preset load change threshold, the safety margin is reduced; When the pre-processed high-voltage side CT current signal is less than a preset current threshold, the safety margin is increased.

[0011] According to a preferred embodiment, the calculation expression of the composite control amount is: ,in, is the composite control quantity, and is the dynamic weight coefficient, With the high-voltage side CT current signal Increase nonlinearly, is the temperature difference between the top oil temperature signal and the ambient temperature signal, is the rate of change of current.

[0012] According to a preferred embodiment, the hierarchical cooling strategy is specifically as follows: when When the temperature is greater than or equal to the first preset value, the cooling actuator operates in a strong cooling mode; when When the value is less than the first preset value and greater than the second preset value, the cooling actuator operates in a balanced mode; when When the temperature is less than or equal to the second preset value, the cooling actuator operates in the energy-saving mode.

[0013] The present invention also provides a transformer cooling control system, which is applied to the above-mentioned transformer cooling control method, and the system includes: A data acquisition module is used to obtain electrical characteristic quantity signals and thermal state quantity signals of the oil-immersed transformer; A first processing module is configured to calculate a predicted top layer oil temperature at the next moment based on the electrical characteristic signal and the thermal state signal, and determine an oil temperature threshold by coupling it with a dynamically adjusted safety margin, where the safety margin is dynamically adjusted based on the real-time electrical characteristic signal; The second processing module is used to perform nonlinear fusion of the electrical characteristic quantity signal and the thermal state quantity signal to generate a composite control quantity; The execution module is used to execute the hierarchical cooling strategy according to the composite control quantity with the oil temperature threshold as the safety benchmark.

[0014] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the transformer cooling control method described above is implemented.

[0015] The present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the transformer cooling control method as described above is implemented.

[0016] The technical solution of a transformer cooling control method, system, device and storage medium provided by the present invention has at least the following advantages and beneficial effects: (1) The present invention obtains electrical characteristic quantity signals such as high-voltage side CT current signal and current change rate, combines them with thermal state quantities such as top oil temperature and ambient temperature, and uses LSTM prediction model to calculate the top oil temperature prediction value at the next moment in advance, breaking the hysteresis limitation of traditional reliance on real-time temperature signals; at the same time, by sensing the load mutation trend through the current change rate, the cooling strategy can be adjusted in advance before the temperature rises significantly, effectively avoiding cooling lag caused by thermal inertia, improving the timeliness and predictability of cooling control, and reducing the risk of insulation overheating; (2) The safety margin is dynamically adjusted according to the real-time electrical characteristic quantity signal. When the current change rate is greater than the preset load change threshold (such as a sudden increase in load), the safety margin is reduced to tighten the oil temperature threshold and start strong cooling in advance; when the high-voltage side current is less than the preset current threshold (such as light load operation), The safety margin is increased to avoid overcooling. This dynamic adjustment mechanism not only ensures safety redundancy in high-load and high-risk scenarios, but also reduces unnecessary cooling energy consumption at low loads, balances safety and economy, and realizes dynamic adaptation and precise protection of the safety margin; (3) The present invention generates a composite control quantity by nonlinear fusion of electrical characteristic signals and thermal state quantities, overcoming the limitations of traditional single temperature signals; in the composite control quantity, the squared current term can reflect the load loss heating intensity, the temperature difference term reflects the actual heat dissipation pressure, and the current change rate term captures the dynamic trend of the load. The synergistic effect of the three makes the control strategy more in line with the actual operating conditions of the transformer; at the same time, the hierarchical cooling strategy can be flexibly switched according to the composite control quantity to adapt to different load intensities and environmental conditions, avoiding the energy waste or insufficient cooling problems of the traditional "full on / full off" mode, and enhancing the comprehensiveness and adaptability of the control strategy; (4) Signal noise interference is reduced through preprocessing to ensure the accuracy of input data. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic flow chart of a transformer cooling control method provided in Example 1 of the present invention; Figure 2 Schematic diagram of dual-signal coupling and hierarchical control provided in Example 1 of the present invention; DETAILED DESCRIPTION To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of 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. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0018] Example 1 This embodiment provides a transformer cooling control method. Figure 1 This is a flow chart of the transformer cooling control method, see Figure 1 As shown, the transformer cooling control method includes the following steps: Signal acquisition: Acquire the electrical characteristic quantity signals and thermal status quantity signals of the oil-immersed transformer. In some preferred embodiments, the electrical characteristic quantity signals include at least the high-voltage side CT current signal and the current change rate, and the thermal status quantity signals include at least the top oil temperature signal and the ambient temperature signal of the oil-immersed transformer. In addition, other signals can be used to replace the high-voltage side CT current signal and the top oil temperature signal, such as vibration signals, noise analysis, or infrared temperature monitoring. However, it is necessary to consider whether these signals can accurately reflect the thermal state of the transformer and whether they are sufficiently real-time. We will not elaborate on this here.

[0019] Signal Preprocessing: In this embodiment, the acquired electrical characteristic and thermal state signals are preprocessed. This preprocessing includes normalization and sliding average filtering. Specifically, this embodiment reduces signal noise interference through preprocessing, ensuring the accuracy of the input data.

[0020] Oil temperature prediction: In this embodiment, based on the electrical characteristic signal and the thermal state signal, the top oil temperature prediction value at the next moment is calculated, for example, the top oil temperature 10 minutes later is predicted; in some preferred embodiments, the top oil temperature prediction value is obtained by using a pre-built LSTM prediction model based on the electrical characteristic signal and the thermal state signal; in addition, other time series prediction models can be used as an alternative, such as GRU, ARIMA, or a simpler regression model; it is worth mentioning that model-free control strategies such as fuzzy control or PID control can also be used, but the parameters need to be adjusted dynamically, which will not be elaborated here.

[0021] Specifically, this embodiment obtains electrical characteristic signals such as the high-voltage side CT current signal and current change rate, combines them with thermal state quantities such as the top oil temperature and ambient temperature, and uses the LSTM prediction model to calculate the predicted value of the top oil temperature at the next moment in advance, breaking the hysteresis limitation of the traditional reliance on real-time temperature signals; at the same time, by sensing the load mutation trend through the current change rate, the cooling strategy can be adjusted in advance when the temperature has not risen significantly, effectively avoiding cooling lag caused by thermal inertia, improving the timeliness and predictability of cooling control, and reducing the risk of insulation overheating.

[0022] Dynamic generation of oil temperature threshold: In this embodiment, the oil temperature threshold is determined by coupling the top oil temperature prediction value with a dynamically adjusted safety margin. The safety margin is dynamically adjusted based on the real-time electrical characteristic signal. In addition, the oil temperature threshold can also be generated by other methods, such as a thermal balance equation based on a physical model, or using an expert system rule base rather than a machine learning model. These methods are not elaborated here.

[0023] In some preferred embodiments, the dynamic adjustment rule of the safety margin is: when the preprocessed current change rate is greater than the preset load change threshold, the safety margin is reduced; when the preprocessed high-voltage side CT current signal is less than the preset current threshold, the safety margin is increased.

[0024] Specifically, the safety margin is dynamically adjusted according to the real-time electrical characteristic signal. When the current change rate is greater than the preset load change threshold (such as a sudden increase in load), the safety margin is reduced to tighten the oil temperature threshold and start strong cooling in advance; when the high-voltage side current is less than the preset current threshold (such as light load operation), the safety margin is increased to avoid excessive cooling. This dynamic adjustment mechanism not only ensures safety redundancy in high-load and high-risk scenarios, but also reduces unnecessary cooling energy consumption at low load, balances safety and economy, and realizes dynamic adaptation and precise protection of the safety margin.

[0025] Compound control quantity generation: see Figure 2 As shown, in this embodiment, the electrical characteristic quantity signal and the thermal state quantity signal are nonlinearly fused to generate a composite control quantity.

[0026] In some preferred embodiments, the calculation expression of the composite control amount is: ,in, is the composite control quantity, and is the dynamic weight coefficient, With the high-voltage side CT current signal Increase nonlinearly, is the temperature difference between the top oil temperature signal and the ambient temperature signal, is the rate of change of current.

[0027] Specifically, this embodiment generates a composite control quantity through nonlinear fusion of the electrical characteristic signal and the thermal state quantity, overcoming the limitations of the traditional single temperature signal; in the composite control quantity, the squared current term can reflect the heat intensity of the load loss, the temperature difference term reflects the actual heat dissipation pressure, and the current change rate term captures the dynamic trend of the load. The synergistic effect of the three makes the control strategy more in line with the actual operating conditions of the transformer; at the same time, the hierarchical cooling strategy can be flexibly switched according to the composite control quantity to adapt to different load intensities and environmental conditions, avoiding the energy waste or insufficient cooling problems in the traditional "full on / full off" mode, and enhancing the comprehensiveness and adaptability of the control strategy.

[0028] Execution cooling: In this embodiment, the oil temperature threshold is used as a safety benchmark, and a graded cooling strategy is implemented according to the composite control quantity to control the variable frequency oil pump, multi-stage fan and electric water valve; in addition, other types of drivers or actuators can also be used as substitutes, such as solenoid valves, dampers controlled by stepper motors, etc.

[0029] In some preferred embodiments, the staged cooling strategy is specifically as follows: When the value is greater than or equal to the first preset value, the cooling actuator operates in the strong cooling mode; when When the value is less than the first preset value and greater than the second preset value, the cooling actuator operates in a balanced mode; when When the temperature is less than or equal to the second preset value, the cooling actuator operates in the energy-saving mode.

[0030] Furthermore, the transformer cooling control method provided in this embodiment also includes switching to a backup control strategy and triggering a multi-level alarm when a sensor failure is detected or the prediction error of the LSTM prediction model is greater than a preset error threshold; wherein the backup control strategy specifically calculates the top oil temperature prediction value based on the preset temperature value and the high-voltage side CT current signal, wherein the preset temperature value is set to 65°C; the multi-level alarm specifically includes local sound and light alarm, remote platform notification, and emergency shutdown; specifically, this embodiment combines multi-level alarm with backup strategy to effectively ensure robustness.

[0031] Example 2 This embodiment provides a transformer cooling control system, which is applied to the transformer cooling control method of embodiment 1. The system includes: a data acquisition module, a first processing module, a second processing module and an execution module; Among them, the data acquisition module is used to obtain the electrical characteristic quantity signal and thermal state quantity signal of the oil-immersed transformer; the first processing module is used to calculate the top oil temperature prediction value at the next moment based on the electrical characteristic quantity signal and the thermal state quantity signal, and determine the oil temperature threshold by coupling the dynamically adjusted safety margin. The safety margin is dynamically adjusted according to the real-time electrical characteristic quantity signal; the second processing module is used to nonlinearly fuse the electrical characteristic quantity signal and the thermal state quantity signal to generate a composite control quantity; the execution module is used to use the oil temperature threshold as a safety benchmark and execute a hierarchical cooling strategy according to the composite control quantity.

[0032] Example 3 This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the transformer cooling control method of embodiment 1 is implemented.

[0033] Example 4 This embodiment provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the transformer cooling control method of embodiment 1 is implemented.

[0034] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A transformer cooling control method, characterized in that: The steps include: Obtain electrical characteristic quantity signals and thermal state quantity signals of the oil-immersed transformer; Based on the electrical characteristic signal and the thermal state signal, the predicted value of the top oil temperature at the next moment is calculated and coupled with the dynamically adjusted safety margin to determine the oil temperature threshold. The safety margin is dynamically adjusted according to the real-time electrical characteristic signal. Perform nonlinear fusion of electrical characteristic quantity signals and thermal state quantity signals to generate composite control quantity; Taking the oil temperature threshold as the safety benchmark, a hierarchical cooling strategy is implemented according to the composite control quantity.

2. The transformer cooling control method according to claim 1, characterized in that: The electrical characteristic quantity signal includes at least the high-voltage side CT current signal and the current change rate, and the thermal state quantity signal includes at least the top oil temperature signal and the ambient temperature signal of the oil-immersed transformer.

3. The transformer cooling control method according to claim 1, characterized in that: The top oil temperature prediction value is obtained by using a pre-built LSTM prediction model based on the electrical characteristic signal and the thermal state signal.

4. The transformer cooling control method according to claim 2, wherein: The method also includes preprocessing the acquired electrical characteristic quantity signals and thermal state quantity signals, wherein the preprocessing includes normalization processing and sliding average filtering processing.

5. The transformer cooling control method according to claim 4, characterized in that: The dynamic adjustment rule of safety margin is: When the pre-processed current change rate is greater than the preset load change threshold, the safety margin is reduced; When the pre-processed high-voltage side CT current signal is less than a preset current threshold, the safety margin is increased.

6. The transformer cooling control method according to claim 4, characterized in that: The calculation expression of the composite control quantity is: ,in, is the composite control quantity, and is the dynamic weight coefficient, With the high-voltage side CT current signal Increase nonlinearly, is the temperature difference between the top oil temperature signal and the ambient temperature signal, is the rate of change of current.

7. The transformer cooling control method according to claim 6, characterized in that: The hierarchical cooling strategy is as follows: when When the temperature is greater than or equal to the first preset value, the cooling actuator operates in a strong cooling mode; when When the value is less than the first preset value and greater than the second preset value, the cooling actuator operates in a balanced mode; when When the temperature is less than or equal to the second preset value, the cooling actuator operates in the energy-saving mode.

8. A transformer cooling control system, applied to the transformer cooling control method according to any one of claims 1 to 7, characterized in that the system include: A data acquisition module is used to obtain electrical characteristic quantity signals and thermal state quantity signals of the oil-immersed transformer; A first processing module is configured to calculate a predicted top layer oil temperature at the next moment based on the electrical characteristic signal and the thermal state signal, and determine an oil temperature threshold by coupling it with a dynamically adjusted safety margin, where the safety margin is dynamically adjusted based on the real-time electrical characteristic signal; The second processing module is used to perform nonlinear fusion of the electrical characteristic quantity signal and the thermal state quantity signal to generate a composite control quantity; The execution module is used to execute the hierarchical cooling strategy according to the composite control quantity with the oil temperature threshold as the safety benchmark.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the transformer cooling control method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that A computer program is stored on a computer-readable storage medium, and when the computer program is executed by a processor, the transformer cooling control method according to any one of claims 1 to 7 is implemented.

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