Time-harmonic field excitation equivalent method based on transformer load loss and related device

Abstract

The invention discloses a time-harmonic field excitation equivalence method based on transformer load loss and a related device, and relates to the field of transformers, and the method comprises the steps: obtaining a to-be-equivalently-excited current of a target transformer under a direct current magnetic bias condition, calculating an equivalent current inductance component of the to-be-equivalently-excited current equivalent to a power frequency according to a magnetic field energy conservation equivalence principle, and calculating the equivalent current inductance component of the to-be-equivalently-excited current; according to the ohmic loss and eddy current loss conservation equivalence principle, the equivalent current resistance component of the to-be-equivalent excitation current equivalent to the power frequency is calculated, and according to the equivalent current inductance component and the equivalent current resistance component, the load loss of the target transformer and the temperature rise value of the structural part are calculated in the time-harmonic field finite element simulation software. Therefore, the method takes the load loss as an equivalent basis, enables the to-be-equivalent excitation current to be equivalent to the equivalent current inductance component and the equivalent current resistance component under the power frequency, achieves the calculation of the temperature rise value of the structural member in the time-harmonic field finite element simulation software, saves time and labor, is easy to converge, and reduces the resource consumption.

Description

Technical Field

[0001] The present application relates to the field of transformers, and in particular to a time-harmonic field excitation equivalent method based on transformer load loss and a related device. Background Art

[0002] Geomagnetic storms and unipolar asymmetric operation of DC transmission projects are the main reasons for the DC bias of transformers. DC bias will cause a sharp increase in the degree of excitation saturation, leading to asymmetry of the core flux, which in turn makes the transformer magnetic circuit unbalanced and significantly increases the leakage flux, affecting the transformer's loss, temperature rise and noise. In severe cases, it may even cause transformer insulation damage, causing serious faults and directly threatening the safe operation of the power system. Therefore, it is of great significance to study the impact of DC bias on transformer load loss and temperature rise.

[0003] Under the condition of DC bias, the excitation current of the transformer contains the fundamental wave and a large number of harmonic components of different orders. Its waveform is a non-sinusoidal asymmetric peak wave, which means that the excitation current can only be calculated in the transient field finite element simulation software to obtain the temperature rise value of the transformer structure. However, the calculation method in the transient field finite element simulation software is time-consuming and labor-intensive, and the transient field solution process is difficult to converge, so it may not be possible to obtain the required load loss and temperature rise value of the structure. Summary of the invention

[0004] In view of the above problems, this application provides a time-harmonic field excitation equivalent method based on transformer load loss and related devices to achieve the purpose of obtaining the load loss and structural temperature rise value of the target transformer based on the excitation current in the time-harmonic field finite element simulation software. The specific scheme is as follows: The first aspect of the present application provides a time-harmonic field excitation equivalent method based on transformer load loss, comprising: Obtaining the equivalent excitation current of the target transformer under the DC bias condition; According to the equivalent principle of conservation of magnetic field energy, the inductance component of the excitation current to be equivalent to the excitation current at the power frequency is calculated as the equivalent current inductance component; According to the ohmic loss and eddy current loss conservation equivalent principle, the excitation current resistance component equivalent to the excitation current at the power frequency is calculated as the equivalent current resistance component; According to the equivalent current inductance component and the equivalent current resistance component, the load loss and the temperature rise value of the structural parts of the target transformer are calculated in the time-harmonic field finite element simulation software.

[0005] In a possible implementation, the step of obtaining the equivalent excitation current of the target transformer under the DC bias condition includes: Obtaining the basic parameter value of the target transformer, calling a pre-generated excitation current calculation program to determine the equivalent excitation current according to the basic parameter value; And / or, obtaining current field recording data of the target transformer, and obtaining the equivalent excitation current based on the current field recording data.

[0006] In a possible implementation, the step of calculating the excitation current inductance component of the excitation current to be equivalent to the excitation current at the power frequency based on the equivalent principle of magnetic field energy conservation includes: According to the equivalent principle of conservation of magnetic field energy, determine the first function of the fundamental wave and harmonics of each order of the transformer excitation current and the inductance component of the equivalent power frequency excitation current; Rewriting the first function by using the fundamental wave correction coefficient and each order harmonic correction coefficient to obtain a corrected function; Determining the fundamental component and harmonic components of each order of the equivalent excitation current; Obtaining correction coefficient values ​​of all components of the current to be equivalently excited, wherein all components include the fundamental wave component and harmonic components of each order; Substitute the fundamental component and harmonic components of each order of the excitation current to be equivalent, and the correction coefficient values ​​of all components of the excitation current to be equivalent into the corrected function to obtain the excitation current inductance component equivalent to the excitation current to be equivalent at the power frequency.

[0007] In a possible implementation, the calculation of the excitation current resistance component equivalent to the excitation current to be equivalent to the excitation current at the power frequency based on the ohmic loss and eddy current loss conservation equivalent principle includes: According to the ohmic loss and eddy current loss conservation equivalent principle, determine the second function of the fundamental wave and each order harmonic of the transformer excitation current and the equivalent power frequency excitation current resistance component; Determining the fundamental component and harmonic components of each order of the equivalent excitation current; Substitute the fundamental wave component and harmonic components of each order of the excitation current to be equivalent into the second function to obtain the excitation current resistance component equivalent to the excitation current to be equivalent at the power frequency.

[0008] In a possible implementation, determining the fundamental component and harmonic components of each order of the current to be equivalently excited includes: Performing Fourier transformation on the current to be equivalently excited, to obtain the fundamental component and harmonic components of each order of the current to be equivalently excited.

[0009] In a possible implementation, the calculating of the load loss and the temperature rise of the structural parts of the target transformer in time-harmonic field finite element simulation software according to the equivalent current inductance component and the equivalent current resistance component includes: Determining a target equivalent power frequency excitation current according to the equivalent current inductance component and the equivalent current resistance component; The target equivalent power frequency excitation current is determined as the excitation source of the solver in the time-harmonic field finite element simulation software, and the load loss and structural component temperature rise value of the target transformer are calculated based on the solver.

[0010] The second aspect of the present application provides a time-harmonic field excitation equivalent device based on transformer load loss, comprising: A current acquisition module, used to obtain the equivalent excitation current of the target transformer under the DC bias condition; An inductance equivalent module is used to calculate the excitation current inductance component of the excitation current to be equivalent to the power frequency according to the equivalent principle of magnetic field energy conservation as the equivalent current inductance component; A resistance equivalent module, used for calculating the excitation current resistance component equivalent to the excitation current under the power frequency according to the ohmic loss and eddy current loss conservation equivalent principle as the equivalent current resistance component; The temperature rise calculation module is used to calculate the load loss and structural temperature rise value of the target transformer in the time-harmonic field finite element simulation software according to the equivalent current inductance component and the equivalent current resistance component.

[0011] The third aspect of the present application provides a computer program product, including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements the time-harmonic field excitation equivalent method based on transformer load loss of the above-mentioned first aspect or any implementation method of the first aspect.

[0012] A fourth aspect of the present application provides an electronic device, comprising at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs; The processor is used to execute the computer program so that the electronic device can implement the time-harmonic field excitation equivalent method based on transformer load loss of the above-mentioned first aspect or any implementation manner of the first aspect.

[0013] In a fifth aspect, the present application provides a computer storage medium, which carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement the time-harmonic field excitation equivalent method based on transformer load loss of the above-mentioned first aspect or any implementation method of the first aspect.

[0014] By means of the above technical scheme, the time-harmonic field excitation equivalent method based on transformer load loss provided by the present application obtains the target transformer's equivalent excitation current under DC bias conditions. Considering that under DC bias conditions, changes in the inductance component of the excitation current will cause changes in the magnetic field, thereby affecting the distribution and energy of the leakage magnetic field, for this reason, the present application can calculate the inductance component of the excitation current equivalent to the power frequency based on the equivalent principle of magnetic field energy conservation, as the equivalent current inductance component. At the same time, due to the change in the core saturation and flux distribution under DC bias conditions, the current in the winding and the flux in the core will be distorted, causing the resistance loss (including ohmic loss and eddy current loss) in the winding to change. Therefore, the present application can also calculate the excitation current resistance component of the excitation current equivalent to the power frequency based on the equivalent principle of ohmic loss and eddy current loss conservation, as the equivalent current resistance component. Finally, the present application can calculate the load loss and structural temperature rise of the target transformer in the time-harmonic field finite element simulation software based on the equivalent current inductance component and the equivalent current resistance component. It can be seen from this that the present application can equate the equivalent excitation current containing the fundamental wave and a large number of harmonic components of different orders to an equivalent current inductance component and an equivalent current resistance component under the industrial frequency, so that the present application can be simulated and calculated in the time-harmonic field finite element simulation software of the magnetic field and coupled thermal field, which is more time-saving, labor-saving and easy to converge. In addition, it reduces resource consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the accompanying drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and the originals and elements are not necessarily drawn to scale.

[0016] Figure 1 A schematic diagram of a system architecture provided for this application; Figure 2 A schematic diagram of an optional hardware structure of the terminal 100 provided in this application; Figure 3 A schematic diagram of the structure of a server 200 provided in this application; Figure 4 A flow chart of a time-harmonic field excitation equivalent method based on transformer load loss provided in this application; Figure 5 Schematic diagram of the waveform of the transformer excitation current under 1A DC bias; Figure 6 is the T-type equivalent circuit diagram of the target transformer; Figure 7 It is a schematic diagram of the proportion of each order harmonic of the transformer excitation current under 1A DC bias; Figure 8A schematic diagram of the structure of a time-harmonic field excitation equivalent device based on transformer load loss provided in this application; Fig. 9 A schematic diagram of the structure of an electronic device provided in this application. DETAILED DESCRIPTION

[0017] The following describes the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. The terms used in the implementation method section of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application.

[0018] The embodiments of the present application are described below in conjunction with the accompanying drawings. Those skilled in the art will appreciate that, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0019] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and need not be used to describe a specific order or sequential order. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, which is only to describe the distinction mode adopted by the objects of the same attributes when describing in the embodiments of the present application. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, so that the process, method, system, product or equipment comprising a series of units need not be limited to those units, but may include other units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0020] See also Figure 1 , Figure 1 A schematic diagram of a system architecture is shown. The system may include a terminal 100 and a server 200. The server 200 may include one or more servers ( Figure 1 In the example, a server is included, and the server 200 can provide the method provided in the embodiment of the present application for one or more terminals.

[0021] Among them, an application can be installed on the terminal 100, and the above application and web page can provide an interface. The terminal 100 can receive relevant parameters entered by the user on the interface and send the above parameters to the server 200. The server 200 can obtain processing results based on the received parameters and return the processing results to the terminal 100.

[0022] It should be understood that in some optional implementations, the terminal 100 can also complete the action of obtaining the processing result based on the received parameters by itself without the cooperation of the server, and the embodiments of the present application are not limited to this.

[0023] Next describe Figure 1The product form of the mid-terminal 100; The terminal 100 in the embodiment of the present application can be a mobile phone, a tablet computer, a wearable device, a vehicle-mounted device, an augmented reality (AR) / virtual reality (VR) device, a laptop computer, an ultra-mobile personal computer (UMPC), a netbook, a personal digital assistant (PDA), etc., and the embodiment of the present application does not impose any restrictions on this.

[0024] Figure 2 An optional hardware structure diagram of the terminal 100 is shown.

[0025] refer to Figure 2 As shown, the terminal 100 may include a radio frequency unit 110, a memory 120, an input unit 130, a display unit 140, a camera 150 (optional), an audio circuit 160 (optional), a speaker 161 (optional), a microphone 162 (optional), an earphone jack 163 (optional), a processor 170, an external interface 180, a power supply 190 and other components. Those skilled in the art will appreciate that Figure 2 These are merely examples of terminals or multi-function devices and do not constitute limitations on the terminals or multi-function devices, which may include more or fewer components than those shown in the figures, or combinations of certain components, or different components.

[0026] The input unit 130 can be used to receive input digital or character information, and generate key signal input related to the user settings and function control of the portable multifunctional device. Specifically, the input unit 130 may include a touch screen 131 (optional) and / or other input devices 132. The touch screen 131 can collect the user's touch operations on or near it (such as the user's operation on or near the touch screen using any suitable object such as fingers, joints, stylus, etc.), and drive the corresponding connection device according to a pre-set program. The touch screen can detect the user's touch action on the touch screen, convert the touch action into a touch signal and send it to the processor 170, and can receive and execute the command sent by the processor 170; the touch signal at least includes the touch point coordinate information. The touch screen 131 can provide an input interface and an output interface between the terminal 100 and the user. In addition, the touch screen can be implemented using multiple types such as resistive, capacitive, infrared and surface acoustic wave. In addition to the touch screen 131, the input unit 130 can also include other input devices. Specifically, other input devices 132 may include, but are not limited to, one or more of a physical keyboard, function keys (such as a volume control key, a switch key, etc.), a trackball, a mouse, a joystick, and the like.

[0027] Among them, the input device 132 can receive input data and the like.

[0028] The display unit 140 may be used to display information input by a user or provided to a user, various menus of the terminal 100, an interactive interface, file display, and / or playback of any multimedia file.

[0029] The memory 120 can be used to store instructions and data. The memory 120 can mainly include an instruction storage area and a data storage area. The data storage area can store various data, such as multimedia files, texts, etc.; the instruction storage area can store software units such as operating systems, applications, instructions required for at least one function, or their subsets and extensions. It can also include a non-volatile random access memory; provide the processor 170 with hardware, software and data resources including management of computing and processing equipment, and support control software and applications. It is also used for the storage of multimedia files, and the storage of running programs and applications.

[0030] The processor 170 is the control center of the terminal 100. It uses various interfaces and lines to connect various parts of the entire terminal 100. By running or executing instructions stored in the memory 120 and calling data stored in the memory 120, it executes various functions of the terminal 100 and processes data, thereby controlling the terminal device as a whole. Optionally, the processor 170 may include one or more processing units; preferably, the processor 170 may integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, user interface and application program, and the modem processor mainly processes wireless communication. It is understandable that the above-mentioned modem processor may not be integrated into the processor 170. In some embodiments, the processor and the memory may be implemented on a single chip, and in some embodiments, they may also be implemented separately on separate chips. The processor 170 may also be used to generate corresponding operation control signals, send them to corresponding components of the computing and processing device, read and process data in the software, especially read and process data and programs in the memory 120, so that each functional module therein performs corresponding functions, thereby controlling the corresponding components to act according to the requirements of the instructions.

[0031] Among them, the memory 120 can be used to store software codes related to the time-harmonic field excitation equivalent method based on transformer load loss, the processor 170 can execute the steps of the time-harmonic field excitation equivalent method based on transformer load loss, and can also schedule other units (such as the above-mentioned input unit 130 and the display unit 140) to implement corresponding functions.

[0032] The radio frequency unit 110 (optional) can be used for receiving and sending information or receiving and sending signals during a call, for example, after receiving the downlink information of the base station, it is sent to the processor 170 for processing; in addition, the designed uplink data is sent to the base station. Generally, the RF circuit includes but is not limited to an antenna, at least one amplifier, a transceiver, a coupler, a low noise amplifier (Low Noise Amplifier, LNA), a duplexer, etc. In addition, the radio frequency unit 110 can also communicate with network devices and other devices through wireless communication. The wireless communication can use any communication standard or protocol, including but not limited to Global System of Mobile Communication (Global System of Mobile Communication, GSM), General Packet Radio Service (General Packet Radio Service, GPRS), Code Division Multiple Access (Code Division Multiple Access, CDMA), Wideband Code Division Multiple Access (Wideband Code Division Multiple Access, WCDMA), Long Term Evolution (Long Term Evolution, LTE), email, Short Messaging Service (SMS), etc.

[0033] In this embodiment of the present application, the RF unit 110 can send data to the server 200 and receive processing results sent by the server 200.

[0034] It should be understood that the radio frequency unit 110 is optional and can be replaced by other communication interfaces, such as a network port.

[0035] The terminal 100 also includes a power supply 190 (such as a battery) for supplying power to various components. Preferably, the power supply can be logically connected to the processor 170 through a power management system, so that the power management system can manage functions such as charging, discharging, and power consumption.

[0036] The terminal 100 further includes an external interface 180 , which may be a standard Micro USB interface or a multi-pin connector, and may be used to connect the terminal 100 to communicate with other devices, or to connect a charger to charge the terminal 100 .

[0037] Although not shown, the terminal 100 may also include a flashlight, a wireless fidelity (WiFi) module, a Bluetooth module, sensors with different functions, etc., which are not described in detail here. Some or all of the methods described below may be applied in the following embodiments. Figure 2 In the terminal 100 shown.

[0038] Next describe Figure 1 The product form of the server 200; Figure 3 A schematic diagram of the structure of a server 200 is provided, such as Figure 3 As shown, the server 200 includes a bus 201, a processor 202, a communication interface 203, and a memory 204. The processor 202, the memory 204, and the communication interface 203 communicate with each other via the bus 201.

[0039] The bus 201 may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 3 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0040] The processor 202 may be any one or more of a central processing unit (CPU), a graphics processing unit (GPU), a microprocessor (MP), or a digital signal processor (DSP).

[0041] The memory 204 may include a volatile memory, such as a random access memory (RAM). The memory 204 may also include a non-volatile memory, such as a read-only memory (ROM), a flash memory, a hard disk drive (HDD), or a solid state drive (SSD).

[0042] Among them, the memory 204 can be used to store software codes related to the time-harmonic field excitation equivalent method based on transformer load loss, the processor 202 can execute the steps of the time-harmonic field excitation equivalent method based on transformer load loss of the chip, and can also schedule other units to implement corresponding functions.

[0043] It should be understood that the above-mentioned terminal 100 and server 200 can be centralized or distributed devices, and the processors in the above-mentioned terminal 100 and server 200 (such as processor 170 and processor 202) can be hardware circuits (such as application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), general-purpose processors, DSPs, microprocessors or microcontrollers, etc.), or a combination of these hardware circuits. For example, the processor can be a hardware system with an instruction execution function, such as a CPU, DSP, etc., or a hardware system without an instruction execution function, such as an ASIC, FPGA, etc., or a combination of the above-mentioned hardware systems without an instruction execution function and hardware systems with an instruction execution function.

[0044] The present application provides a time-harmonic field excitation equivalent method based on transformer load loss. The time-harmonic field excitation equivalent method based on transformer load loss of the embodiment of the present application is described in detail below in conjunction with the accompanying drawings.

[0045] Reference Figure 4 , Figure 4 A flow chart of a time-harmonic field excitation equivalent method based on transformer load loss provided in an embodiment of the present application, the method may include: Step S401: Obtain the equivalent excitation current of the target transformer under the DC bias condition.

[0046] DC bias refers to the presence of a certain DC component in the transformer excitation current. When the target transformer is under DC bias conditions, its excitation current waveform will be distorted, harmonics will be aggravated, and the waveform will appear as a non-sinusoidal and asymmetrical peak wave, such as Figure 5 The waveform diagram of the transformer excitation current under 1A DC bias is shown in the figure. At the moment of 0.005, the excitation current value increases sharply, presenting a non-sinusoidal and asymmetric peak wave. It can be seen that the excitation current of the target transformer under DC bias condition is the key to studying the DC bias characteristics of the target transformer.

[0047] The target transformer mentioned above refers to the transformer object studied in this application. For example, the basic parameter values ​​of the target transformer studied in this application are as follows: power supply voltage U=317543V, number of turns of excitation coil N is 706, core cross-sectional area S is 11594.99㎝², core window height is 2410mm, core diameter is 1265mm, frequency is 50Hz, transformer load loss (rated) is: 1248675W, transformer impedance (rated) is 14%. Take the calculation of transformer structural component loss under 1A DC bias as an example, where the harmonic order is 31.

[0048] It should be noted that the above basic parameter values ​​are only examples and are not intended to limit the present application.

[0049] For the convenience of subsequent introduction, this application defines the excitation current of the target transformer under the DC bias condition as the equivalent excitation current.

[0050] As introduced in the background technology, the above-mentioned equivalent excitation current is a non-sinusoidal waveform containing a fundamental component and multiple harmonic components of different orders. This waveform cannot be realized in the solution of the time-harmonic field and can only be solved through the transient field. Since the transient field solution is time-consuming and labor-intensive and difficult to fit, in order to solve these problems, the inventor of this case thought that the equivalent excitation current can be converted to the power frequency in an equivalent way, so that the converted equivalent current can solve the load loss and the temperature rise of the structural parts in the time-harmonic field.

[0051] See also Figure 6 As shown in the figure, it is the T-type equivalent circuit diagram of the target transformer. When a short circuit occurs on one winding terminal of the target transformer (for example Figure 6 The two circles on the left are connected and short-circuited, or Figure 6 When the two circles on the right are connected and short-circuited, Figure 6 The excitation branch components in the dashed box (i.e. and The proportion of the excitation branch voltage is very small and can be basically ignored. It can be approximately considered that the excitation branch voltage is equal to the power supply voltage. Figure 6 The equivalent series impedance of the T-type equivalent circuit diagram shown is , that is, the following formula (1) is obtained.

[0052] Formula (1); in, Indicates the short-circuit impedance value of the target transformer, in ohms (Ω). In actual applications, the short-circuit impedance value can be obtained by testing the target transformer or calculating based on the basic parameter values ​​mentioned above; Represents the resistance component of the target transformer short-circuit impedance, in Ω; Represents the reactance component of the target transformer short-circuit impedance in Ω.

[0053] It can be seen from formula (1) that the load loss of the target transformer can be divided into two categories: resistive loss and inductive loss.

[0054] The magnitude of the above-mentioned resistive loss is related to the magnitude of the current flowing through the conductor. Therefore, the resistive loss is divided into coil loss, lead loss, eddy current loss in metal structural parts, eddy current loss in the core sheet and eddy current loss in the leakage magnetic shield.

[0055] The magnitude of the above-mentioned inductive loss is related to the magnitude of the leakage magnetic field energy stored in the magnetic material components in the target transformer. Therefore, the inductive loss is divided into hysteresis loss in the iron core, hysteresis loss in the magnetic metal structure and hysteresis loss in the leakage magnetic shield.

[0056] Based on the above introduction, in order to be able to equate the equivalent excitation current containing the fundamental component and multiple harmonic components of different orders to the equivalent current under the industrial frequency (for the sake of distinction, the equivalent current is defined as the target equivalent industrial frequency excitation current below), so as to save time and resources and perform harmonic field finite element simulation calculations on the magnetic field and coupled thermal field, the inventor of this case thought of that when performing equivalent excitation under DC bias conditions on the target transformer, it can be divided into two parts: resistance loss characteristic equivalence and leakage magnetic field energy equivalence.

[0057] Step S402: According to the equivalent principle of conservation of magnetic field energy, the excitation current inductance component of the excitation current to be equivalent to the power frequency is calculated as the equivalent current inductance component.

[0058] Following the above introduction, this embodiment can perform leakage magnetic field energy equivalence. To this end, this embodiment can convert the equivalent excitation current to be converted into an equivalent current inductance component at the power frequency (ie, fundamental frequency) based on the equivalent principle of magnetic field energy conservation.

[0059] Here, the equivalent principle of conservation of magnetic field energy means that the leakage magnetic field energy under the equivalent excitation current is equal to the leakage magnetic field energy under the equivalent current inductance component. More specifically, the first leakage magnetic field energy obtained based on the equivalent excitation current and the equivalent inductance is equal to the second leakage magnetic field energy obtained based on the equivalent current inductance component and the equivalent inductance.

[0060] It should be understood that the equivalent inductance is the same as the previous Therefore, in this embodiment, the equivalent inductance can be obtained based on the above formula (1) and the following formulas (2), (3) and (4).

[0061] Quantitatively obtained in Joules The calculation formula is: Formula (2); in, Indicates the load loss of the target transformer in watts (W). In actual applications, the load loss can be obtained by testing the target transformer or by calculating based on the basic parameter values ​​mentioned above; Indicates that the load loss of the target transformer reaches The corresponding coil load excitation current.

[0062] The reactance component of the target transformer short-circuit impedance The calculation formula is: Formula (3).

[0063] Then, the calculation formula of the equivalent inductance of the target transformer is as follows: Formula (4); in, represents the equivalent inductance of the target transformer, in Henry (H); Represents the reactance component of the target transformer short-circuit impedance The power frequency during the test is measured in Hertz (Hz), usually 50Hz or 60Hz.

[0064] Step S403: According to the ohmic loss and eddy current loss conservation equivalent principle, the excitation current resistance component of the excitation current to be equivalent to the power frequency is calculated as the equivalent current resistance component.

[0065] Following the above introduction, this embodiment can also perform resistance loss characteristic equivalence. To this end, this embodiment can convert the current to be equivalent to the current resistance component at the power frequency according to the ohmic loss and eddy current loss conservation equivalence principle.

[0066] Here, the ohmic loss and eddy current loss conservation equivalent principle means that the resistance and eddy current loss under the equivalent excitation current are equal to the resistance and eddy current loss under the inductive component of the equivalent current.

[0067] Step S404: Calculate the load loss and temperature rise of the structural parts of the target transformer in a time-harmonic field finite element simulation software according to the equivalent current inductance component and the equivalent current resistance component.

[0068] As mentioned above, the equivalent current inductance component and the equivalent current resistance component are both equivalent data under the power frequency, which do not contain harmonic components of various orders. Therefore, they can be simulated and calculated in the time-harmonic field finite element simulation software to obtain the load loss and structural temperature rise of the target transformer.

[0069] The time-harmonic field excitation equivalent method based on transformer load loss provided in the present application obtains the target transformer's equivalent excitation current under DC bias conditions. Considering that under DC bias conditions, changes in the inductance component of the excitation current will cause changes in the magnetic field, thereby affecting the distribution and energy of the leakage magnetic field, for this reason, the present application can calculate the inductance component of the excitation current equivalent to the power frequency based on the equivalent principle of magnetic field energy conservation, as the equivalent current inductance component. At the same time, due to the change in core saturation and flux distribution under DC bias conditions, the current in the winding and the flux in the core will be distorted, causing the resistance loss (including ohmic loss and eddy current loss) in the winding to change. Therefore, the present application can also calculate the excitation current resistance component of the excitation current equivalent to the power frequency based on the equivalent principle of ohmic loss and eddy current loss conservation, as the equivalent current resistance component. Finally, the present application can calculate the load loss and structural temperature rise of the target transformer in the time-harmonic field finite element simulation software based on the equivalent current inductance component and the equivalent current resistance component. It can be seen from this that the present application can equate the equivalent excitation current containing the fundamental wave and a large number of harmonic components of different orders to an equivalent current inductance component and an equivalent current resistance component under the industrial frequency, so that the present application can be simulated and calculated in the time-harmonic field finite element simulation software of the magnetic field and coupled thermal field, which is more time-saving, labor-saving and easy to converge. In addition, it reduces resource consumption.

[0070] In some embodiments of the present application, the process of "obtaining the equivalent excitation current of the target transformer under the DC bias condition" in step S401 is introduced.

[0071] In a possible implementation, the present embodiment may pre-write an excitation current calculation program. When it is necessary to determine the excitation current to be equivalent, the basic parameter value of the target transformer described above may be obtained, and then the pre-generated excitation current calculation program may be called to determine the excitation current to be equivalent based on the basic parameter value. More specifically, the basic parameter value is substituted into the excitation current calculation program to obtain the excitation current to be equivalent.

[0072] In another possible implementation, the present embodiment may also record the current field recording data of the target transformer by means of a recording device, and then the present embodiment may obtain the current to be equivalently excited based on the current field recording data.

[0073] Of course, the process of "obtaining the equivalent excitation current of the target transformer under DC bias conditions" can also be implemented in other ways, for example, through experiments, etc., and this application does not make specific limitations.

[0074] When the equivalent excitation current is obtained, the equivalent current inductance component can be obtained according to the above step S402 in this embodiment.

[0075] Optionally, the process of step S402 "calculating the inductance component of the excitation current to be equivalent to the power frequency based on the equivalent principle of conservation of magnetic field energy" may include: determining the first function of the fundamental wave and each order harmonic of the transformer excitation current and the equivalent power frequency excitation current inductance component based on the equivalent principle of conservation of magnetic field energy; rewriting the first function by the fundamental wave correction coefficient and each order harmonic correction coefficient to obtain a corrected function; determining the fundamental wave component and each order harmonic component of the excitation current to be equivalent; obtaining the correction coefficient values ​​of all components of the excitation current to be equivalent, all components including the fundamental wave component and each order harmonic component; substituting the fundamental wave component and each order harmonic component of the excitation current to be equivalent, as well as the correction coefficient values ​​of all components of the excitation current to be equivalent into the corrected function to obtain the inductance component of the excitation current to be equivalent to the power frequency.

[0076] Specifically, those skilled in the art should understand that the leakage magnetic field energy of the transformer is stored in the form of equivalent leakage inductance. There is the following relationship between the leakage magnetic field energy and the leakage magnetic field energy: Formula (5); in, Indicates the effective value of the AC current flowing through the target transformer, in amperes (A); Represents the leakage magnetic field energy of the target transformer inductance.

[0077] As mentioned above, the equivalent excitation current under DC bias conditions contains the fundamental wave and a large number of harmonic components of different orders. Therefore, for different order harmonic power supply excitation, the above formula (5) can be transformed into the following formula (6): Formula (6); in, represents the j-order harmonic excitation ( , j=1 represents fundamental excitation, n represents the total order of the harmonic components to be equivalent, taking the basic parameter values ​​in the previous text as an example, when n=31), the leakage magnetic field energy stored in the equivalent inductance of the target transformer is in joule (J); It represents the effective value of the j-order harmonic excitation current flowing through the target transformer, in A.

[0078] Therefore, the total leakage magnetic field energy of all orders is The calculation formula is: Formula (7).

[0079] The equivalent power frequency excitation current inductance component (i.e., the equivalent power frequency excitation current inductance component at the fundamental frequency, also known as the equivalent power frequency excitation current inductance component at the power frequency) is recorded as , then the above formula (5) can also be transformed into the following formula (8): Formula (8).

[0080] Then, according to the equivalence principle of magnetic field energy conservation, the above formula (7) and formula (8) are equal, and the first function determined is as follows: Formula (9).

[0081] This achieves the determination of the fundamental wave of the transformer excitation current based on the equivalent principle of magnetic field energy conservation. And each order harmonic ~ The inductive component of the equivalent power frequency excitation current The first function of .

[0082] Considering that the loss characteristic curves of magnetic materials stored in the material library in the magnetic field finite element simulation software are usually obtained by testing under power frequency excitation conditions, but as the frequency increases, the increase in the hysteresis loss of the magnetic material changes in direct proportion to the increase in frequency. Therefore, it is also necessary to introduce corresponding loss correction coefficients in the equivalent transformation of each order of harmonic currents. That is, this embodiment also needs to rewrite the first function shown in formula (9) by the fundamental correction coefficient and each order of harmonic correction coefficients to obtain a corrected function, as shown in formula (10): Formula (10); in, It represents the j-order harmonic correction coefficient (j=1 represents the fundamental correction coefficient), and its calculation formula is as follows: Formula (11); in, Indicates the harmonic influence coefficient, which is optional and has a value between 0.9 and 1; Indicates the harmonic order coefficient, optional, and its value is between 0.07 and 0.09.

[0083] Based on the above corrected function, this embodiment needs to determine the parameter values ​​of each parameter included in the corrected function, and substitute the parameter values ​​into formula (10) to obtain .

[0084] Based on this, the present embodiment can first determine the fundamental component and harmonic components of the equivalent excitation current, that is, Optionally, the above process of "determining the fundamental component and harmonic components of each order of the equivalent excitation current" may include: performing Fourier transform on the equivalent excitation current to obtain the fundamental component and harmonic components of each order of the equivalent excitation current.

[0085] In order to improve efficiency, optionally, the above Fourier transform may be a fast Fourier transform, and the fundamental component and harmonic components of each order of the equivalent excitation current obtained are: ,here, represents the equivalent excitation current to be excited, represents the fundamental component of the equivalent excitation current, ~ Represents the harmonic components of each order of the equivalent excitation current.

[0086] See also Figure 7 , is a schematic diagram of the proportion of each order harmonic of the transformer excitation current under 1A DC bias. It can be seen that as the order gradually increases, the percentage of harmonic proportion gradually decreases.

[0087] This embodiment can also obtain the correction coefficient values ​​of all components of the equivalent excitation current, wherein the correction coefficient value of any component can be obtained by obtaining the above and Calculated.

[0088] Finally, in this embodiment, the fundamental wave component and harmonic components of each order of the above-mentioned equivalent excitation current, as well as the correction coefficient values ​​of all components of the equivalent excitation current can be substituted into the corrected function, that is, Substituting into formula (10) ,Will Substituting into formula (10) , and so on, and substitute the correction coefficient values ​​of each component into the formula (10) , that is, the inductance component of the excitation current equivalent to the power frequency can be obtained, that is, the equivalent current inductance component .

[0089] like Figure 4 As shown in the process, in this embodiment, the equivalent current resistance component can also be obtained according to the above step S403.

[0090] Optionally, the process of step S403 "calculating the excitation current resistance component of the excitation current to be equivalent to the power frequency based on the equivalent principle of conservation of ohmic loss and eddy current loss" may include: determining the second function of the fundamental wave and each order harmonic of the transformer excitation current and the equivalent power frequency excitation current resistance component based on the equivalent principle of conservation of ohmic loss and eddy current loss; determining the fundamental wave component and each order harmonic component of the excitation current to be equivalent; substituting the fundamental wave component and each order harmonic component of the excitation current to be equivalent into the second function to obtain the excitation current resistance component of the excitation current to be equivalent to the power frequency.

[0091] Specifically, those skilled in the art should understand that when a load current flows, the resistance loss can be divided into direct resistance loss caused by pure current flow (including coil loss and lead loss) and indirect eddy current loss caused by the change of magnetic field caused by the load current in metal structures or iron core sheets and magnetic shielding (including eddy current loss in metal structures, eddy current loss in iron core sheets and eddy current loss in leakage magnetic shielding).

[0092] For direct resistance loss, coil loss and lead loss are characterized by the loss caused by current flowing through the resistor, and the equivalent power of the linear circuit can be characterized as the heat generated by the resistor. Therefore, the following formula (12) is obtained: Formula (12); in, represents direct resistance loss; Represents the total equivalent resistance in Ω. , Represents the coil equivalent resistance, Indicates the linear equivalent resistance; It indicates the effective value of the AC current flowing through the target transformer, in A.

[0093] For indirect resistance loss, when there is current When current flows through, the leakage magnetic field strength generated by indirect resistance loss It can be expressed as: Formula (13); in, Indicates the number of coil turns, in turns; represents the Rockwell coefficient; Indicates the coil reactance height; It indicates the effective value of the AC current flowing through the target transformer, in A.

[0094] Then, the eddy current loss generated by the leakage magnetic field in its structural parts can be expressed as: Formula (14); in, Indicates indirect resistance loss; Represents the eddy current loss coefficient, the value depends on the properties of the magnetic material; Indicates the reversal frequency of the magnetic field; Indicates the thickness of the conductor; It represents the magnetic permeability of the conductor; Indicates the volume of magnetic material; Indicates magnetic density, .

[0095] make , then formula (14) can be further simplified as: Formula (15).

[0096] As mentioned above, the magnetic field energy equivalence that determines resistive loss is based on the energy equivalence method. It is believed that the energy representation form of coil loss, lead loss, eddy current loss in metal structural parts, eddy current loss in core sheets, and eddy current loss in leakage magnetic shielding is the heating power of the resistor. Therefore, according to the previous statement: Formula (16); in, Indicates the resistance and eddy current loss generated by the equivalent resistance of the target transformer; represents the equivalent coefficient; It indicates the effective value of the AC current flowing through the target transformer, in A.

[0097] As mentioned above, the equivalent excitation current under DC bias conditions contains the fundamental wave and a large number of harmonic components of different orders. Therefore, for different order harmonic power supply excitation, the above formula (16) can be transformed into the following formula (17): Formula (17); in, represents the j-order harmonic excitation ( , j=1 represents fundamental excitation, n represents the total order of the harmonic components to be equivalent, taking the basic parameter values ​​in the previous text as an example, the resistance and eddy current loss generated by the equivalent resistance of the target transformer when n=31), the unit is J; It represents the effective value of the j-order harmonic excitation current flowing through the target transformer, in A.

[0098] Therefore, the calculation formula for the total resistance and eddy current loss under all orders is: Formula (18).

[0099] The equivalent power frequency excitation current resistance component (i.e., the equivalent power frequency excitation current resistance component at the fundamental frequency, also called the equivalent power frequency excitation current resistance component at the power frequency) is recorded as , then the above formula (16) can also be transformed into the following formula (19): Formula (19).

[0100] Then, according to the equivalence principle of Ohmic loss and eddy current loss conservation, the above formula (18) and formula (19) are equal, and the second function determined is as follows: Formula (20).

[0101] This achieves the determination of the fundamental wave of the transformer excitation current based on the equivalent principle of ohmic loss and eddy current loss conservation. And each order harmonic ~ The equivalent power frequency excitation current resistance component The second function of .

[0102] Since the resistive loss does not change with the increase of frequency, there is no need to rewrite it. The second function is the function that will eventually be substituted into the data for calculation. Then, based on the above second function, this embodiment needs to determine the parameter values ​​of each parameter included in the second function, and substitute the parameter values ​​into formula (20) to obtain .

[0103] Based on this, the present embodiment can first determine the fundamental component and harmonic components of the equivalent excitation current, that is, The value of , this process corresponds to the previous step S402, and the details can be referred to the previous introduction, which will not be repeated here.

[0104] Finally, in this embodiment, the fundamental component and harmonic components of the above-mentioned equivalent excitation current can be substituted into the second function, that is, Substituting into formula (20) ,Will Substituting into formula (20) , and so on, we can get the equivalent excitation current equivalent to the excitation current inductance component under the power frequency, that is, the equivalent current resistance component .

[0105] Further, after the equivalent current inductance component and the equivalent current resistance component are obtained, step S404 may be performed.

[0106] Optionally, the process of step S404 "calculating the load loss and structural temperature rise of the target transformer in the time-harmonic field finite element simulation software according to the equivalent current inductance component and the equivalent current resistance component" may include: determining the target equivalent power frequency excitation current according to the equivalent current inductance component and the equivalent current resistance component, determining the target equivalent power frequency excitation current as the excitation source of the solver in the time-harmonic field finite element simulation software, and obtaining the load loss and structural temperature rise of the target transformer according to the solver calculation.

[0107] Optionally, the target equivalent power frequency excitation current can be determined using the following formula (21): .

[0108] Formula (21).

[0109] The time-harmonic field equivalent excitation source method provided in the present application is compared with the transient field finite element method provided in the background technology, and the results are shown in the following table.

[0110] method time consuming CPU usage Convergence characteristics Transient Field Finite Element Method 7 days 97% Difficult to converge Time-harmonic field equivalent excitation source method 6-7 hours 30% Easy to converge It can be seen that the time-harmonic field equivalent excitation source method provided by the present application is more time-saving, has a low resource occupancy rate, and has a good convergence effect compared to transient field calculation. This is mainly because under the condition of DC bias magnetization, the excitation current of the target transformer is manifested as the superposition of multiple frequency harmonic currents, and the waveform also shows a certain non-sinusoidality, which means that when using transient field calculation, magnetic field calculations at different frequencies and additional calculations of non-effective fields must be performed, resulting in a sharp increase in time cost; secondly, when the transient field is calculated, the impedance boundary method cannot be applied, which greatly increases the mesh segmentation component during finite element calculation, causing the resource occupancy rate to rise; finally, the convergence problems sometimes brought about by transient field calculations will also greatly consume time and resource costs. The use of a time-harmonic field equivalent excitation source method provided by the present application can significantly avoid the above problems, and transform the transient field finite element simulation solution problem, which was originally time-consuming and required a large amount of hardware resources, into a time-saving and low-resource-consuming time-harmonic field finite element simulation solution problem, which greatly improves the calculation efficiency.

[0111] The above introduces a time-harmonic field excitation equivalent method based on transformer load loss provided by an embodiment of the present application. The following will introduce a device for executing the above-mentioned time-harmonic field excitation equivalent method based on transformer load loss.

[0112] See also Figure 8 , Figure 8 The schematic diagram of the structure of a time-harmonic field excitation equivalent device based on transformer load loss provided in the embodiment of the present application. Figure 8 As shown, the device may include: A current acquisition module 501 is used to acquire the equivalent excitation current of the target transformer under the DC bias condition; The inductance equivalent module 502 is used to calculate the inductance component of the excitation current to be equivalent to the power frequency according to the equivalent principle of magnetic field energy conservation, as the equivalent current inductance component; The resistance equivalent module 503 is used to calculate the excitation current resistance component equivalent to the excitation current at the power frequency according to the ohmic loss and eddy current loss conservation equivalent principle as the equivalent current resistance component; The temperature rise calculation module 504 is used to calculate the load loss and temperature rise value of the structural parts of the target transformer in the time-harmonic field finite element simulation software according to the equivalent current inductance component and the equivalent current resistance component.

[0113] In one possible implementation, the above-mentioned current acquisition module can be specifically used to: obtain the basic parameter value of the target transformer, call a pre-generated excitation current calculation program to determine the equivalent excitation current based on the basic parameter value; and / or obtain the current field recording data of the target transformer, and obtain the equivalent excitation current based on the current field recording data.

[0114] In a possible implementation, the inductance equivalent module may include: a first function determination module, a function rewriting module, a first component determination module, a correction coefficient value acquisition module and a first value substitution module; A first function determination module is used to determine the first function of the fundamental wave and harmonics of the transformer excitation current and the inductance component of the equivalent power frequency excitation current according to the equivalent principle of magnetic field energy conservation; A function rewriting module, used for rewriting the first function by using a fundamental wave correction coefficient and each order harmonic correction coefficient to obtain a corrected function; A first component determination module, used to determine the fundamental component and harmonic components of each order of the equivalent excitation current; A correction coefficient value acquisition module is used to obtain the correction coefficient values ​​of all components of the equivalent excitation current, where all components include fundamental wave components and harmonic components of various orders; The first numerical substitution module is used to substitute the fundamental component and harmonic components of each order of the excitation current to be equivalent, and the correction coefficient values ​​of all components of the excitation current to be equivalent into the corrected function to obtain the excitation current inductance component equivalent to the excitation current under the power frequency.

[0115] In a possible implementation, the resistance equivalent module may include: a second function determination module, a second component determination module, and a second value substitution module; A second function determination module is used to determine the second function of the fundamental wave and each order harmonic of the transformer excitation current and the equivalent power frequency excitation current resistance component according to the equivalent principle of ohmic loss and eddy current loss conservation; A second component determination module, used to determine the fundamental component and harmonic components of each order of the equivalent excitation current; The second numerical substitution module is used to substitute the fundamental component and harmonic components of each order of the excitation current to be equivalent into the second function to obtain the excitation current resistance component equivalent to the excitation current to be equivalent at the power frequency.

[0116] In a possible implementation, the process in which the first component determination module and the second component determination module respectively determine the fundamental component and harmonic components of each order of the equivalent excitation current may include: performing Fourier transform on the equivalent excitation current to obtain the fundamental component and harmonic components of each order of the equivalent excitation current.

[0117] In a possible implementation, the temperature rise calculation module may include: a current equivalent module and a time-harmonic field calculation module.

[0118] A current equivalent module is used to determine a target equivalent power frequency excitation current according to an equivalent current inductance component and an equivalent current resistance component; The time-harmonic field calculation module is used to determine the target equivalent power frequency excitation current as the excitation source of the solver in the time-harmonic field finite element simulation software, and obtain the load loss and structural temperature rise of the target transformer based on the solver calculation.

[0119] The time-harmonic field excitation equivalent device based on transformer load loss provided in the present application corresponds to the time-harmonic field excitation equivalent method based on transformer load loss provided in the previous text. For details, please refer to the previous introduction and will not be repeated here.

[0120] The present application also provides an electronic device in an embodiment. Fig. 9 As shown, it shows a schematic diagram of the structure of an electronic device suitable for implementing the embodiment of the present application. The electronic device in the embodiment of the present application may include but is not limited to fixed terminals such as mobile phones, laptops, PDAs (personal digital assistants), PADs (tablet computers), desktop computers, etc. Fig. 9 The electronic device shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0121] like Fig. 9 As shown, the electronic device may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 601, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 602 or a program loaded from a storage device 608 to a random access memory (RAM) 603. When the electronic device is powered on, various programs and data required for the operation of the electronic device are also stored in the RAM 603. The processing device 601, the ROM 602, and the RAM 603 are connected to each other via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0122] Typically, the following devices may be connected to the I / O interface 605: an input device 606 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 607 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 608 including, for example, a memory card, a hard disk, etc.; and a communication device 609. The communication device 609 may allow the electronic device to communicate with other devices wirelessly or by wire to exchange data. Although Fig. 9An electronic device having various devices is shown, but it should be understood that it is not required to implement or possess all the devices shown. More or fewer devices may be implemented or possessed instead.

[0123] An embodiment of the present application also provides a computer program product including computer-readable instructions. When the computer-readable instructions are executed on an electronic device, the electronic device implements any time-harmonic field excitation equivalent method based on transformer load loss provided in the embodiment of the present application.

[0124] A computer-readable storage medium is also provided in an embodiment of the present application. The storage medium carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement any time-harmonic field excitation equivalent method based on transformer load loss provided in an embodiment of the present application.

[0125] It should also be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed over multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the drawings of the device embodiments provided by the present application, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines.

[0126] Through the description of the above implementation mode, the technicians in the field can clearly understand that the present application can be implemented by means of software plus necessary general hardware, and of course, it can also be implemented by special hardware including special integrated circuits, special CPUs, special memories, special components, etc. In general, all functions completed by computer programs can be easily implemented by corresponding hardware, and the specific hardware structure used to implement the same function can also be various, such as analog circuits, digital circuits or special circuits. However, for the present application, software program implementation is a better implementation mode in more cases. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a readable storage medium, such as a computer floppy disk, a U disk, a mobile hard disk, a ROM, a RAM, a disk or an optical disk, etc., including a number of instructions to enable a computer device (which can be a personal computer, a training device, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0127] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.

[0128] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website site, a computer, a training device, or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, training device, or data center. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a training device, a data center, etc. that includes one or more available media integrations. The available medium may be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)), etc.

Claims

1. A time-harmonic field excitation equivalent method based on transformer load loss, characterized in that: include: Obtaining the equivalent excitation current of the target transformer under the DC bias condition; According to the equivalent principle of conservation of magnetic field energy, the inductance component of the excitation current to be equivalent to the excitation current at the power frequency is calculated as the equivalent current inductance component; According to the ohmic loss and eddy current loss conservation equivalent principle, the excitation current resistance component equivalent to the excitation current at the power frequency is calculated as the equivalent current resistance component; According to the equivalent current inductance component and the equivalent current resistance component, the load loss and the temperature rise value of the structural parts of the target transformer are calculated in the time-harmonic field finite element simulation software.

2. The time-harmonic field excitation equivalent method based on transformer load loss according to claim 1 is characterized in that: The step of obtaining the equivalent excitation current of the target transformer under the DC bias condition includes: Obtaining the basic parameter value of the target transformer, calling a pre-generated excitation current calculation program to determine the equivalent excitation current according to the basic parameter value; And / or, obtaining current field recording data of the target transformer, and obtaining the equivalent excitation current based on the current field recording data.

3. The time-harmonic field excitation equivalent method based on transformer load loss according to claim 1 is characterized in that: The method of calculating the excitation current inductance component of the excitation current to be equivalent to the excitation current at the power frequency based on the equivalent principle of magnetic field energy conservation includes: According to the equivalent principle of conservation of magnetic field energy, determine the first function of the fundamental wave and harmonics of each order of the transformer excitation current and the inductance component of the equivalent power frequency excitation current; Rewriting the first function by using the fundamental wave correction coefficient and each order harmonic correction coefficient to obtain a corrected function; Determining the fundamental component and harmonic components of each order of the equivalent excitation current; Obtaining correction coefficient values ​​of all components of the current to be equivalently excited, wherein all components include the fundamental wave component and harmonic components of each order; Substitute the fundamental component and harmonic components of each order of the excitation current to be equivalent, and the correction coefficient values ​​of all components of the excitation current to be equivalent into the corrected function to obtain the excitation current inductance component equivalent to the excitation current to be equivalent at the power frequency.

4. The time-harmonic field excitation equivalent method based on transformer load loss according to claim 1 is characterized in that: The calculation of the excitation current resistance component equivalent to the excitation current to be equivalent to the excitation current at the power frequency based on the ohmic loss and eddy current loss conservation equivalent principle includes: According to the ohmic loss and eddy current loss conservation equivalent principle, determine the second function of the fundamental wave and each order harmonic of the transformer excitation current and the equivalent power frequency excitation current resistance component; Determining the fundamental wave component and harmonic components of each order of the equivalent excitation current; Substitute the fundamental wave component and harmonic components of each order of the excitation current to be equivalent into the second function to obtain the excitation current resistance component equivalent to the excitation current to be equivalent at the power frequency.

5. The time-harmonic field excitation equivalent method based on transformer load loss according to claim 3 or 4 is characterized in that: The determining of the fundamental wave component and harmonic components of each order of the current to be equivalently excited comprises: Performing Fourier transformation on the current to be equivalently excited, to obtain the fundamental component and harmonic components of each order of the current to be equivalently excited.

6. The time-harmonic field excitation equivalent method based on transformer load loss according to claim 1 is characterized in that: The step of calculating the load loss and temperature rise of the structural parts of the target transformer in time-harmonic field finite element simulation software according to the equivalent current inductance component and the equivalent current resistance component includes: Determining a target equivalent power frequency excitation current according to the equivalent current inductance component and the equivalent current resistance component; The target equivalent power frequency excitation current is determined as the excitation source of the solver in the time-harmonic field finite element simulation software, and the load loss and structural component temperature rise value of the target transformer are calculated based on the solver.

7. A time-harmonic field excitation equivalent device based on transformer load loss, characterized in that: include: A current acquisition module, used to obtain the equivalent excitation current of the target transformer under the DC bias condition; An inductance equivalent module is used to calculate the excitation current inductance component of the excitation current to be equivalent to the power frequency according to the equivalent principle of magnetic field energy conservation as the equivalent current inductance component; A resistance equivalent module, used for calculating the excitation current resistance component equivalent to the excitation current under the power frequency according to the ohmic loss and eddy current loss conservation equivalent principle as the equivalent current resistance component; The temperature rise calculation module is used to calculate the load loss and structural temperature rise value of the target transformer in the time-harmonic field finite element simulation software according to the equivalent current inductance component and the equivalent current resistance component.

8. A computer program product, characterized in that The method comprises computer-readable instructions, and when the computer-readable instructions are executed on an electronic device, the electronic device implements the time-harmonic field excitation equivalent method based on transformer load loss as claimed in any one of claims 1 to 6.

9. An electronic device, characterized in that: The method comprises at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs; The processor is used to execute the computer program so that the electronic device can implement the time-harmonic field excitation equivalent method based on transformer load loss as described in any one of claims 1 to 6.

10. A computer storage medium, characterized in that: The storage medium carries one or more computer programs, which, when executed by an electronic device, enable the electronic device to implement the time-harmonic field excitation equivalent method based on transformer load loss as described in any one of claims 1 to 6.

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