Methods, devices, and media for measuring the internal winding temperature of oil-immersed power transformers

Abstract

This invention discloses a method, device, and medium for measuring the internal winding temperature of an oil-immersed power transformer. The method includes: estimating an initial value of the winding temperature distribution based on the collected bus voltage and load current of the oil-immersed power transformer using the principle of heating due to winding resistance loss; receiving collected data on the oil flow velocity, number of fan groups in operation, heating value of winding resistance loss, heating value of core hysteresis loss, and heating value of tank eddy current loss, and inputting these data, along with the initial value of the winding temperature distribution, into a heat dissipation model of the oil-immersed power transformer for calculation, outputting calculated values ​​of oil surface temperature and ambient temperature; and determining the optimal winding temperature distribution of the oil-immersed power transformer if the calculated values ​​of oil surface temperature and ambient temperature satisfy a pre-set objective function.

Description

Technical Field

[0001] This invention relates to the field of transformer winding temperature measurement technology, and more specifically, to a method, apparatus, and medium for measuring the internal winding temperature of an oil-immersed power transformer. Background Technology

[0002] Currently, the winding temperature of oil-immersed power transformers is generally measured indirectly using the oil surface thermometer method. This method uses the copper oil temperature rise simulated by the current matching device to represent the equivalent winding temperature. However, since the current matching device can only simulate the copper oil temperature rise under the rated operating conditions of the transformer after the parameters are set, and the transformer load is constantly changing during actual operation, the cooler operation mode is also constantly adjusted according to the load, the current matching device set according to the rated operating conditions cannot adjust the parameters according to the actual load changes of the transformer, resulting in inaccurate winding temperature measurement. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method, device, and medium for measuring the internal winding temperature of an oil-immersed power transformer.

[0004] According to one aspect of the present invention, a method for measuring the internal winding temperature of an oil-immersed power transformer is provided, comprising:

[0005] Based on the collected bus voltage and load current of the oil-immersed power transformer, the initial value of the winding temperature distribution is estimated using the principle of heating due to winding resistance loss.

[0006] The system receives and collects data on the oil flow velocity, number of fan groups on, winding resistance loss heat generation, core hysteresis loss heat generation, and tank eddy current loss heat generation of the power transformer. These data, along with the initial value of the winding temperature distribution, are input into the heat dissipation model of the oil-immersed power transformer for calculation. The system outputs the calculated oil surface temperature and ambient temperature.

[0007] Under the condition that the calculated oil surface temperature and the calculated ambient temperature satisfy the collected measured oil surface temperature and ambient temperature, the optimal winding temperature distribution of the oil-immersed power transformer is determined.

[0008] Alternatively, the objective function is as follows:

[0009]

[0010] Among them, T m The estimated temperatures at the transformer oil surface thermometer and the ambient thermometer are calculated based on the heat dissipation model. This represents the actual measured temperature at that point, and k is the total number of oil surface thermometers and ambient thermometers.

[0011] Optionally, it also includes:

[0012] If the calculated values ​​of oil surface temperature and ambient temperature do not meet the pre-set objective function compared with the collected measured values ​​of oil surface temperature and ambient temperature, the initial value of winding temperature distribution is adjusted using the particle swarm optimization algorithm, and the calculated values ​​of oil surface temperature and ambient temperature are iteratively calculated.

[0013] Under the condition that the calculated oil surface temperature and the calculated ambient temperature satisfy the collected measured oil surface temperature and ambient temperature, the optimal winding temperature distribution of the oil-immersed power transformer is determined.

[0014] Optionally, it also includes:

[0015] Bus voltage and load current are collected using voltage transformers and current transformers on the high-voltage winding of oil-immersed power transformers.

[0016] The oil surface temperature is measured by installing a first number of oil surface thermometers on the top of the oil tank of the oil-immersed power transformer.

[0017] A second number of ambient temperature meters are installed outside the oil tank of the oil-immersed power transformer to collect ambient temperature measurements.

[0018] The oil flow velocity and the number of fan groups activated are collected through the cooler of the oil-immersed power transformer.

[0019] Optionally, it also includes:

[0020] The DL-IoT local module receives bus voltage, load current, oil surface temperature measurement, ambient temperature measurement, oil flow rate, and the number of fan groups in operation.

[0021] Optionally, the DL-IoT local module includes: an analog signal conversion circuit, a digital signal conversion circuit, a microprocessor, a DL-IoT wireless module, a power supply module, and an antenna, wherein...

[0022] The analog signal conversion circuit is used to convert the bus voltage, load current, oil surface temperature measurement value, ambient temperature measurement value and oil flow velocity into digital signals and transmit them to the microprocessor.

[0023] The switch signal conversion circuit is used to convert the number of fan groups turned on into digital signals and send them to the microprocessor;

[0024] The microprocessor receives digital signals and communicates with the DL-IoT wireless module via a 485 serial port, and transmits digital signals via an antenna.

[0025] Optionally, the DL-IoT local module also includes a power module for powering the microprocessor and the DL-IoT wireless module.

[0026] According to another aspect of the present invention, a device for measuring the internal winding temperature of an oil-immersed power transformer is provided, comprising:

[0027] The estimation module is used to estimate the initial value of the winding temperature distribution based on the bus voltage and load current of the oil-immersed power transformer and the principle of heating due to winding resistance loss.

[0028] The output module is used to receive the collected oil flow velocity, number of fan groups on, winding resistance loss heat value, core hysteresis loss heat value and oil tank eddy current loss heat value of the power transformer, and input them along with the initial value of the winding temperature distribution into the heat dissipation model of the oil-immersed power transformer for calculation, and output the calculated value of oil surface temperature and ambient temperature.

[0029] The first determining module is used to determine the optimal winding temperature distribution of an oil-immersed power transformer when the calculated oil surface temperature and the calculated ambient temperature, along with the collected measured oil surface temperature and ambient temperature, satisfy a pre-set objective function.

[0030] According to another aspect of the present invention, a computer-readable storage medium is provided, the storage medium storing a computer program for performing the methods described in any of the above aspects of the present invention.

[0031] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising: a processor; a memory for storing executable instructions of the processor; the processor being configured to read the executable instructions from the memory and execute the instructions to implement the method described in any of the preceding aspects of the present invention.

[0032] Therefore, this invention uses an indirect method to measure the temperature distribution of oil-immersed power transformer windings. It wirelessly collects the load current, cooler oil flow velocity, number of fan groups in operation, and oil surface temperature of the oil-immersed power transformer. Combining the structure of the transformer windings, core, and cooler, it inversely optimizes the temperature distribution of the transformer windings. Compared with current winding thermometers, it integrates more information and the measurement results are more accurate. Attached Figure Description

[0033] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0034] Figure 1 This is a flowchart illustrating a method for measuring the internal winding temperature of an oil-immersed power transformer according to an exemplary embodiment of the present invention.

[0035] Figure 2 This is a structural framework diagram of an exemplary embodiment of the present invention for a method for measuring the internal winding temperature of an oil-immersed power transformer.

[0036] Figure 3 This is a structural diagram of a DL-IoT local module provided in an exemplary embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of the flow structure of a method for measuring the internal winding temperature of an oil-immersed power transformer provided in an exemplary embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of the structure of an oil-immersed power transformer internal winding temperature measuring device provided in an exemplary embodiment of the present invention;

[0039] Figure 6 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. Detailed Implementation

[0040] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0041] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0042] Those skilled in the art will understand that the terms "first," "second," etc., in the embodiments of the present invention are only used to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them.

[0043] It should also be understood that in the embodiments of the present invention, "multiple" can refer to two or more, and "at least one" can refer to one, two or more.

[0044] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more unless explicitly defined or given contrary instructions in the context.

[0045] Furthermore, the term "and / or" in this invention is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this invention generally indicates that the preceding and following related objects have an "or" relationship.

[0046] It should also be understood that the description of the various embodiments in this invention emphasizes the differences between the various embodiments, and the similarities or similarities can be referred to each other. For the sake of brevity, they will not be described in detail.

[0047] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0048] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0049] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0050] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0051] The embodiments of this invention can be applied to electronic devices such as terminal devices, computer systems, and servers, and can operate together with a wide range of other general-purpose or special-purpose computing system environments or configurations. Well-known examples of terminal devices, computing systems, environments, and / or configurations suitable for use with electronic devices such as terminal devices, computer systems, and servers include, but are not limited to: personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments including any of the above systems, etc.

[0052] Electronic devices such as terminal devices, computer systems, and servers can be described in the general context of computer system executable instructions (such as program modules) executed by a computer system. Typically, program modules can include routines, programs, object programs, components, logic, data structures, etc., which perform specific tasks or implement specific abstract data types. Computer systems / servers can be implemented in distributed cloud computing environments, where tasks are executed by remote processing devices linked through communication networks. In distributed cloud computing environments, program modules can reside on local or remote computing system storage media, including storage devices.

[0053] Exemplary methods

[0054] Figure 1 This is a schematic flowchart illustrating a method for measuring the internal winding temperature of an oil-immersed power transformer according to an exemplary embodiment of the present invention. This embodiment can be applied to electronic devices, such as... Figure 1 As shown, the method 100 for measuring the internal winding temperature of an oil-immersed power transformer includes the following steps:

[0055] Step 101: Based on the collected bus voltage and load current of the oil-immersed power transformer, estimate the initial value of the winding temperature distribution using the principle of heating due to winding resistance loss.

[0056] Step 102: Receive the collected oil flow velocity, number of fan groups on, winding resistance loss heat value, core hysteresis loss heat value, and oil tank eddy current loss heat value of the power transformer, and input them along with the initial value of the winding temperature distribution into the heat dissipation model of the oil-immersed power transformer for calculation, and output the calculated oil surface temperature value and the calculated ambient temperature value.

[0057] Step 103: Determine the optimal winding temperature distribution of the oil-immersed power transformer if the calculated oil surface temperature and the calculated ambient temperature satisfy the pre-set objective function.

[0058] Alternatively, the objective function is as follows:

[0059]

[0060] Among them, T m The estimated temperatures at the transformer oil surface thermometer and the ambient thermometer are calculated based on the heat dissipation model. This represents the actual measured temperature at that point, and k is the total number of oil surface thermometers and ambient thermometers.

[0061] Optionally, it also includes:

[0062] If the calculated values ​​of oil surface temperature and ambient temperature do not meet the pre-set objective function compared with the collected measured values ​​of oil surface temperature and ambient temperature, the initial value of winding temperature distribution is adjusted using the particle swarm optimization algorithm, and the calculated values ​​of oil surface temperature and ambient temperature are iteratively calculated.

[0063] Under the condition that the calculated oil surface temperature and the calculated ambient temperature satisfy the collected measured oil surface temperature and ambient temperature, the optimal winding temperature distribution of the oil-immersed power transformer is determined.

[0064] Optionally, it also includes:

[0065] Bus voltage and load current are collected using voltage transformers and current transformers on the high-voltage winding of oil-immersed power transformers.

[0066] The oil surface temperature is measured by installing a first number of oil surface thermometers on the top of the oil tank of the oil-immersed power transformer.

[0067] A second number of ambient temperature meters are installed outside the oil tank of the oil-immersed power transformer to collect ambient temperature measurements.

[0068] The oil flow velocity and the number of fan groups activated are collected through the cooler of the oil-immersed power transformer.

[0069] Optionally, it also includes:

[0070] The DL-IoT local module receives bus voltage, load current, oil surface temperature measurement, ambient temperature measurement, oil flow rate, and the number of fan groups in operation.

[0071] Optionally, the DL-IoT local module includes: an analog signal conversion circuit, a digital signal conversion circuit, a microprocessor, a DL-IoT wireless module, a power supply module, and an antenna, wherein...

[0072] The analog signal conversion circuit is used to convert the bus voltage, load current, oil surface temperature measurement value, ambient temperature measurement value and oil flow velocity into digital signals and transmit them to the microprocessor.

[0073] The switch signal conversion circuit is used to convert the number of fan groups turned on into digital signals and send them to the microprocessor;

[0074] The microprocessor receives digital signals and communicates with the DL-IoT wireless module via a 485 serial port, and transmits digital signals via an antenna.

[0075] Optionally, the DL-IoT local module also includes a power module for powering the microprocessor and the DL-IoT wireless module.

[0076] Specifically, refer to Figure 2 As shown, the method for measuring the internal winding temperature of an oil-immersed power transformer according to the present invention is based on this device, which includes an oil-immersed power transformer, a voltage transformer, a current transformer, a cooler, an oil surface thermometer, an ambient thermometer, a DL-IoT local module, a DL-IoT gateway, and a station-side IoT platform. The present invention is implemented on the station-side IoT platform.

[0077] A current transformer is connected to the high-voltage winding of the oil-immersed power transformer to collect the load current of the transformer. A voltage transformer collects the bus voltage. The oil flow velocity and the number of fan groups on the transformer's cooler can be collected. An oil surface thermometer is installed on the top of the transformer's oil tank to collect the top oil surface temperature. An ambient thermometer is installed outside the oil tank to collect the ambient temperature. The load current collected by the current transformer, the bus voltage collected by the current transformer, the oil flow velocity of the cooler, and the top oil temperature collected by the oil surface thermometer and the ambient thermometer are all DC4-20mA signals. The number of fan groups on the cooler is a switching signal. The DC4-20mA signal and the switching signal are converted into digital signals by the DL-IoT local module and then converged to the DL-IoT gateway via wireless communication. They are then transmitted to the station-end IoT platform. The station-end IoT platform integrates the transformer winding structure and the signals collected by the DL-IoT gateway to calculate the temperature distribution of the transformer winding.

[0078] like Figure 3 The diagram shows the structure of the DL-IoT local module, which includes a signal conversion circuit, a microprocessor, a DL-IoT wireless module, a power supply module, and an antenna. The power supply module supplies power to the microprocessor and the DL-IoT wireless module. The DC 4-20mA analog signal is converted into a digital signal by the analog signal conversion circuit and then transmitted to the microprocessor. The switch signal is converted into a digital signal by the switch signal conversion circuit and then transmitted to the microprocessor. The microprocessor communicates with the DL-IoT wireless module through a 485 serial port and finally transmits the signal through the antenna.

[0079] Figure 4 The diagram shows the flowchart of the method for inverting the internal winding temperature distribution of a transformer. The heat sources inside the transformer are three parts: winding resistance loss heat generation, core hysteresis loss heat generation, and tank eddy current loss heat generation. Using the transformer bus voltage and load current as inputs, combined with the transformer's rated parameters, the heat generated by the three heat sources under the current load can be calculated, and the estimated value of the winding temperature distribution can be obtained. This value is then used as the initial value input to the heat dissipation model for iterative calculation.

[0080] The transformer's heat dissipation model characterizes the heat dissipation process from the heat source to the environment. Heat from the windings and core is transferred to the transformer oil via thermal conduction. The transformer oil exchanges heat with the cooler through thermal convection. Simultaneously, heat from the transformer oil is transferred to the oil tank via thermal conduction, and the oil tank transfers heat to the external environment through thermal conduction and radiation. The heat dissipation model uses the cooler oil flow velocity and the number of fan groups as inputs, and calculates the oil surface temperature and ambient temperature using a model composed of thermal conduction, thermal convection, and thermal radiation. The calculated oil surface temperature and ambient temperature are compared with data collected by an oil surface thermometer and an ambient thermometer. If the error is large, the winding temperature distribution is corrected, and the calculation is iterated until the error meets the requirements.

[0081] Figure 4The diagram shows the flowchart of the optimization algorithm for inverting the internal winding temperature distribution of a transformer. Two oil level thermometers are installed inside the transformer (the number is not limited here and can be determined according to requirements), and four ambient temperature thermometers are installed outside the transformer (the number is not limited here and can be determined according to requirements). To ensure that the inversion optimization result is as close as possible to the actual value, a combined genetic algorithm and particle swarm optimization algorithm is used. The objective function is set as follows:

[0082]

[0083] Among them, T m The estimated temperatures at the transformer oil surface thermometer and the ambient thermometer are calculated based on the heat dissipation model. This represents the actual measured temperature at that point, and k is the total number of oil surface thermometers and ambient thermometers.

[0084] The optimization algorithm includes the following steps:

[0085] The first step is to initialize the population particle count, velocity limit, maximum number of iterations / objective function threshold, and set constraints.

[0086] The second step, by Figure 3 The winding temperature distribution estimated by the intermediate bus voltage and load current is used as the temperature of the initial population, and the initial speed is set.

[0087] The third step is to solve for the objective function value and the selection operator. In this patent, the championship selection operator is used.

[0088] The fourth step is to sort the particle swarm according to the selection operator value and update the historical optimal solution and global optimal solution for each particle.

[0089] The fifth step is to select the top half of the population with the best performance as the parent particles, and calculate the offspring particles according to the following formulas (1) to (4). The specific steps are as follows:

[0090] The objective function value of each particle is compared with that of the others in turn, and the result is integrated using the champion selection operator. Once all particles in the iteration have completed their integration, the magnitude of the champion selection operator represents the performance level of the individual particles. In the improved algorithm, a physical quantity representing the genetic concept—the hybridization probability p—is assigned. t The value ranges from 0 to 1 and can be customized by the user to address specific problems. In the process of genetic reproduction, the parent particles are selected as the top half of the high-performing individuals in the t-th generation particle swarm, while the latter half are eliminated. The temperature value T of the offspring particles in the t-th generation particle swarm is then determined. t With the velocity v of the offspring particles t The reproductive renewal process is

[0091] child1(T t =ptparent1(T t )+(1.0-p t parent2(T t (1)

[0092] child2(T t =ptparent2(T t )+(1.0-p t parent1(T t (2)

[0093]

[0094]

[0095] The sixth step is to form a new population by combining the parent and child particles, and update the temperature and velocity of the particles according to the following formulas (5) to (6). The specific steps are as follows:

[0096] The offspring produced by parent generation will replace the poorly performing latter half of the particles that were eliminated, forming the 1st generation particle swarm together with the original parent particles. The velocity and temperature values ​​of the newly generated 1st generation particle swarm can be obtained as follows:

[0097] v t+1 =ω t v t +c1r1(T Hbest -T t )+c2r2(T Gbest -T t (5)

[0098] T t+1 =T t +v t+1 (6)

[0099] In the formula: ω t Let T be the inertia weight at iteration t, c1 and c2 be the learning factors, and r1 and r2 be random numbers following a (0,1) distribution. Hbest The optimal temperature value in particle history, T Gbest This is the globally optimal temperature value for the particle.

[0100] The selection and adjustment strategy for inertia weights and learning factors in the particle swarm optimization algorithm is set as follows:

[0101]

[0102] To reduce the number of unknown variables, the learning factor is considered as a function of the inertia weight. The nonlinear relationship expression is then:

[0103]

[0104] An inertia weight adjustment strategy with an exponentially decreasing inertia function is adopted:

[0105] ω t =ω end +(ω start -ω end )*exp[-20(t / T) 6 (9)

[0106] Step 7: Determine whether the maximum number of iterations or the objective function threshold has been reached. If the requirements are met, stop the calculation and output the temperature value of the current population as the optimal winding temperature distribution.

[0107] Therefore, this invention uses an indirect method to measure the winding temperature of an oil-immersed power transformer. It wirelessly collects the load current, cooler oil flow velocity, number of fan groups in operation, and oil surface temperature of the oil-immersed power transformer. Combining the structure of the transformer winding, core, and cooler, it inversely optimizes the temperature distribution of the transformer winding. Compared with current winding thermometers, it integrates more information and the measurement results are more accurate.

[0108] Exemplary device

[0109] Figure 5 This is a schematic diagram of the structure of an oil-immersed power transformer internal winding temperature measuring device provided in an exemplary embodiment of the present invention. Figure 5 As shown, the device 500 includes:

[0110] The estimation module 510 is used to estimate the initial value of the winding temperature distribution based on the bus voltage and load current of the oil-immersed power transformer and the principle of heating due to winding resistance loss.

[0111] The output module 520 is used to receive the collected oil flow velocity, number of fan groups on, winding resistance loss heat value, core hysteresis loss heat value and oil tank eddy current loss heat value of the power transformer, and input them along with the initial value of the winding temperature distribution into the heat dissipation model of the oil-immersed power transformer for calculation, and output the calculated value of oil surface temperature and the calculated value of ambient temperature.

[0112] The first determining module 530 is used to determine the optimal winding temperature distribution of an oil-immersed power transformer when the calculated oil surface temperature and the calculated ambient temperature satisfy a pre-set objective function with the collected measured oil surface temperature and the measured ambient temperature.

[0113] Alternatively, the objective function is as follows:

[0114]

[0115] Among them, T m The estimated temperatures at the transformer oil surface thermometer and the ambient thermometer are calculated based on the heat dissipation model. This represents the actual measured temperature at that point, and k is the total number of oil surface thermometers and ambient thermometers.

[0116] Optionally, the device 500 also includes:

[0117] The calculation module is used to adjust the initial value of the winding temperature distribution using a particle swarm optimization algorithm and iteratively calculate the calculated values ​​of the oil surface temperature and ambient temperature when the calculated values ​​of the oil surface temperature and ambient temperature do not meet the pre-set objective function.

[0118] The second determining module is used to determine the optimal winding temperature distribution of an oil-immersed power transformer when the calculated oil surface temperature and the calculated ambient temperature satisfy a pre-set objective function.

[0119] Optionally, the device 500 also includes:

[0120] The first acquisition module is used to acquire bus voltage and load current through voltage transformers and current transformers on the high-voltage winding of the oil-immersed power transformer.

[0121] The second acquisition module is used to acquire oil surface temperature measurements by setting a first number of oil surface thermometers on the top of the oil tank of the oil-immersed power transformer.

[0122] The third acquisition module is used to acquire ambient temperature measurements by installing a second number of ambient thermometers outside the oil tank of the oil-immersed power transformer.

[0123] The fourth data acquisition module is used to collect oil flow velocity and the number of fan groups turned on through the cooler of the oil-immersed power transformer.

[0124] Optionally, the device 500 also includes:

[0125] The receiving module is used to receive bus voltage, load current, oil surface temperature measurement, ambient temperature measurement, oil flow rate, and number of fan groups in operation via the DL-IoT local module.

[0126] Optionally, the DL-IoT local module includes: an analog signal conversion circuit, a digital signal conversion circuit, a microprocessor, a DL-IoT wireless module, a power supply module, and an antenna, wherein...

[0127] The analog signal conversion circuit is used to convert the bus voltage, load current, oil surface temperature measurement value, ambient temperature measurement value and oil flow velocity into digital signals and transmit them to the microprocessor.

[0128] The switch signal conversion circuit is used to convert the number of fan groups turned on into digital signals and send them to the microprocessor;

[0129] The microprocessor receives digital signals and communicates with the DL-IoT wireless module via a 485 serial port, and transmits digital signals via an antenna.

[0130] Optionally, the DL-IoT local module also includes a power module for powering the microprocessor and the DL-IoT wireless module.

[0131] Exemplary electronic devices

[0132] Figure 6 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. For example... Figure 6 As shown, the electronic device 60 includes one or more processors 61 and a memory 62.

[0133] The processor 61 may be a central processing unit (CPU) or other form of processing unit with data processing and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0134] The memory 62 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 61 may execute the program instructions to implement the methods of the software programs of the various embodiments of the present invention described above, and / or other desired functions. In one example, the electronic device may also include an input device 63 and an output device 64, these components being interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0135] In addition, the input device 63 may also include, for example, a keyboard, a mouse, etc.

[0136] The output device 64 can output various information to the outside. The output device 64 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0137] Of course, for the sake of simplicity, Figure 6Only some of the components of this electronic device relevant to the present invention are shown, omitting components such as buses, input / output interfaces, etc. In addition, the electronic device may include any other suitable components depending on the specific application.

[0138] Exemplary computer program products and computer-readable storage media

[0139] In addition to the methods and apparatus described above, embodiments of the present invention may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps in the methods according to various embodiments of the present invention described in the "Exemplary Methods" section above.

[0140] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of the present invention. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0141] Furthermore, embodiments of the present invention may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps of the methods according to various embodiments of the present invention described in the "Exemplary Methods" section above.

[0142] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0143] The basic principles of the present invention have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in the present invention are merely examples and not limitations, and should not be considered as essential features of each embodiment of the present invention. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the present invention to the necessity of employing the aforementioned specific details.

[0144] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For system embodiments, since they largely correspond to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0145] The block diagrams of devices, systems, devices, and systems involved in this invention are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, systems, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0146] The methods and systems of the present invention may be implemented in many ways. For example, they may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order of steps for the methods is for illustrative purposes only, and the steps of the methods of the present invention are not limited to the order specifically described above unless otherwise specifically stated. Furthermore, in some embodiments, the present invention may also be implemented as a program recorded on a recording medium, the program comprising machine-readable instructions for implementing the methods according to the present invention. Thus, the present invention also covers recording media storing programs for performing the methods according to the present invention.

[0147] It should also be noted that in the systems, apparatus, and methods of the present invention, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered equivalents of the present invention. The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the invention. Therefore, the invention is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0148] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A method for measuring the internal winding temperature of an oil-immersed power transformer, characterized in that, include: Based on the collected bus voltage and load current of the oil-immersed power transformer, the initial value of the winding temperature distribution is estimated using the principle of heating due to winding resistance loss. The system receives and collects the oil flow velocity, number of fan groups on, winding resistance loss heat value, core hysteresis loss heat value, and tank eddy current loss heat value of the oil-immersed power transformer, and inputs them along with the initial value of the winding temperature distribution into the heat dissipation model of the oil-immersed power transformer for calculation, and outputs the calculated oil surface temperature value and the calculated ambient temperature value. If the calculated oil surface temperature and the calculated ambient temperature, together with the collected measured oil surface temperature and ambient temperature, satisfy a pre-set objective function threshold, the optimal winding temperature distribution of the oil-immersed power transformer is determined. The objective function is as follows: in, , These are the estimated and actual measured temperatures at the transformer oil surface thermometer and the ambient thermometer, respectively, calculated according to the heat dissipation model, where k is the total number of oil surface thermometers and ambient thermometers. The method further includes: If the calculated oil surface temperature and the calculated ambient temperature do not meet the preset objective function thresholds compared with the collected measured oil surface temperature and the measured ambient temperature, the initial value of the winding temperature distribution is adjusted using a particle swarm optimization algorithm, and the calculated oil surface temperature and the calculated ambient temperature are iteratively calculated. If the calculated oil surface temperature and the calculated ambient temperature, together with the collected measured oil surface temperature and ambient temperature, satisfy a pre-set objective function threshold, the optimal winding temperature distribution of the oil-immersed power transformer is determined.

2. The method according to claim 1, characterized in that, Also includes: The bus voltage and the load current are collected by voltage transformers and current transformers on the high-voltage winding of the oil-immersed power transformer; The oil surface temperature is measured by installing a first number of oil surface thermometers on the top of the oil tank of the oil-immersed power transformer. The ambient temperature measurement value is collected by installing a second number of ambient thermometers outside the oil tank of the oil-immersed power transformer; The oil flow velocity and the number of fan groups turned on are collected through the cooler of the oil-immersed power transformer.

3. The method according to claim 1, characterized in that, Also includes: The DL-IoT local module receives the bus voltage, the load current, the oil surface temperature measurement, the ambient temperature measurement, the oil flow rate, and the number of fan groups in operation.

4. The method according to claim 3, characterized in that, The DL-IoT local module includes: an analog signal conversion circuit, a digital signal conversion circuit, a microprocessor, a DL-IoT wireless module, a power supply module, and an antenna. The analog signal conversion circuit is used to convert the bus voltage, the load current, the oil surface temperature measurement value, the ambient temperature measurement value, and the oil flow velocity into digital signals and transmit them to the microprocessor; The switching signal conversion circuit is used to convert the number of fan groups turned on into digital signals and send them to the microprocessor; The microprocessor receives digital signals and communicates with the DL-IoT wireless module via a 485 serial port, and transmits the digital signals through the antenna.

5. The method according to claim 4, characterized in that, The DL-IoT local module also includes a power module for supplying power to the microprocessor and the DL-IoT wireless module.

6. A device for measuring the temperature of the internal windings of an oil-immersed power transformer, used to implement the method described in any one of claims 1-5, characterized in that, include: The estimation module is used to estimate the initial value of the winding temperature distribution based on the bus voltage and load current of the oil-immersed power transformer and the principle of heating due to winding resistance loss. The output module is used to receive the collected oil flow velocity, number of fan groups on, winding resistance loss heat value, core hysteresis loss heat value and oil tank eddy current loss heat value of the oil-immersed power transformer, and input them along with the initial value of the winding temperature distribution into the heat dissipation model of the oil-immersed power transformer for calculation, and output the calculated value of oil surface temperature and ambient temperature. The first determining module is used to determine the optimal winding temperature distribution of the oil-immersed power transformer when the calculated oil surface temperature and the calculated ambient temperature satisfy a pre-set objective function with the collected measured oil surface temperature and ambient temperature.

7. A computer-readable storage medium, characterized in that, The storage medium stores a computer program for performing the method described in any one of claims 1-5.

8. An electronic device, characterized in that, The electronic device includes: processor; Memory used to store the processor's executable instructions; The processor is configured to read the executable instructions from the memory and execute the instructions to implement the method described in any one of claims 1-5.

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