Superconductive power equipment electromagnetic-heat flow coupling simulation method and equipment based on iterative algorithm, medium and program product

Abstract

The invention relates to a superconducting power equipment electromagnetic-heat flow coupling simulation method based on an iterative algorithm, superconducting power equipment electromagnetic-heat flow coupling simulation equipment, a medium and a program product. The simulation method comprises the following steps: constructing a simplified basic model of superconducting power equipment; calculating steady-state alternating-current loss distribution of the coil; simulating and calculating the temperature distribution of the superconducting coil and the cooling liquid; the obtained superconducting coil and cooling liquid temperature distribution is fed back to an electromagnetic simulation process as an input temperature boundary condition to calculate alternating current loss, the alternating current loss is fed back to a heat flow simulation process to calculate temperature distribution, and an iterative loop is formed; and determining the total AC loss of the superconducting equipment according to AC loss distribution in iteration, and calculating the change rate based on the total AC loss before and after. Compared with the prior art, the method can comprehensively consider the mutual influence of the electromagnetic field and the thermal field on the premise that the simulation complexity is not remarkably increased, and the alternating current loss and the temperature of the superconducting power equipment are accurately obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of superconducting power equipment, and in particular, to an electromagnetic-thermal fluid coupling simulation method, device, medium, and program product for superconducting power equipment based on an iterative algorithm. Background Art

[0002] With the continuous development of the power system, the demand for large-capacity and high-efficiency power equipment is increasing day by day. Superconducting power equipment emerges as the times require and is developed based on the superconducting characteristics exhibited by superconducting materials in a specific low-temperature environment. Superconducting materials show extremely small losses when current passes through them, and have significant advantages such as high energy efficiency, high current-carrying capacity, and compact design. This makes the application of superconducting power equipment in the power system have great potential, covering various types such as superconducting reactors, superconducting cables, superconducting transformers, superconducting fault current limiters, superconducting fans, etc., and can effectively improve the overall efficiency of the power system and optimize the system structure.

[0003] However, the operating characteristics of superconducting power equipment are extremely complex. The losses and current-carrying capacity of superconducting materials are strongly correlated with temperature, magnetic field, and electric field, and are extremely sensitive to small changes in electromagnetic and temperature. When performing loss and temperature simulation analysis on superconducting power equipment, the mutual influence between the electromagnetic field and the thermal field must be fully considered to ensure that the simulation results can accurately reflect the actual operating state of the equipment.

[0004] However, due to the significant nonlinear characteristics and large aspect ratio of the superconducting tape itself, and the fact that the thermal simulation process involves fluid simulation of the coolant, when separately simulating the electromagnetic field and the thermal field of superconducting power equipment, a relatively high simulation complexity has been faced. If directly adopting the method of joint simulation of the electromagnetic field and the thermal field, its complexity will be greatly increased, which not only places extremely high requirements on computing resources but also makes it difficult to complete the simulation process efficiently and accurately.

[0005] In summary, the existing superconducting power equipment simulation technologies have many difficulties and challenges in the face of electromagnetic-thermal fluid coupling simulation. There is an urgent need for a simulation method that can comprehensively consider the mutual influence between the electromagnetic field and the thermal field without significantly increasing the simulation complexity and can relatively accurately obtain the AC losses and temperature of superconducting power equipment to meet the requirements of various aspects such as the research, design, and operation optimization of superconducting power equipment, and promote the further development and application of superconducting power equipment in the power field. Summary of the Invention

[0006] The object of the present invention is to overcome the defects existing in the above-mentioned prior art and provide an electromagnetic-thermal fluid coupling simulation method, device, medium, and program product for superconducting power equipment based on an iterative algorithm, wherein the electromagnetic simulation and the thermal simulation are relatively independent, and the results of the electromagnetic simulation and the thermal simulation are used as inputs for each other, so that the mutual influence of the electromagnetic field and the thermal field can be comprehensively considered without significantly increasing the simulation complexity, and the AC loss and temperature of the superconducting power equipment can be obtained more accurately.

[0007] The object of the present invention can be achieved by the following technical solutions:

[0008] The first aspect of the present invention provides an electromagnetic-thermal fluid coupling simulation method for superconducting power equipment based on an iterative algorithm, including the following steps:

[0009] S1: Construct a simplified basic model of the superconducting power equipment;

[0010] S2: Set the initial temperature, and calculate the steady-state AC loss distribution of the coil according to the simplified basic model in S1;

[0011] S3: Based on the simplified basic model in S1 and the superconducting coil AC loss distribution data obtained in S2, simulate and calculate the temperature distribution of the superconducting coil and the coolant;

[0012] S4: Feed back the temperature distribution of the superconducting coil and the coolant obtained in S3 to the electromagnetic simulation process in S2 as the input temperature boundary condition to calculate the AC loss, and then feed back the AC loss to the heat flow simulation process in S3 to calculate the temperature distribution, forming an iterative cycle;

[0013] S5: Determine the total AC loss of the superconducting equipment according to the AC loss distribution in the iteration in S4, and calculate the change rate based on the total AC loss before and after.

[0014] Further, in S1, it specifically includes the following steps:

[0015] Considering the structural characteristics of the superconducting power equipment and the accuracy requirements of the electromagnetic-thermal fluid coupling simulation, construct a simulation basic model of the superconducting power equipment. By simplifying the original model of the superconducting power equipment, remove the non-critical components that affect the simulation complexity, extract the core components carrying current and simplify the geometric structures of their coils and coolant inlets and outlets, and at the same time select the coolant area.

[0016] Further, in S2, it specifically includes the following steps:

[0017] Based on the basic model constructed in S2, extract the superconducting coil part of the basic model. According to the characteristics of the superconducting material and the operating conditions of the equipment, set the initial temperature of the superconducting coil, perform simulation calculations on the transient electric field and current distribution of the superconducting coil, and deduce the steady-state AC loss distribution of the coil based on the calculation results.

[0018] Further, in S3, it specifically includes the following steps:

[0019] Based on the basic model determined in S1 and the AC loss data of the superconducting coil obtained in S2, the heat leakage of the dewar and casing in the superconducting power equipment is applied to the wall surface in the form of a heat flux boundary, the AC loss of the superconducting coil is accurately loaded onto the superconducting coil as a heat excitation, a material with similar thermal physical properties to the superconducting tape is used to replace the superconducting tape to simplify the thermal physical property model, the boundary types of the coolant inlet and outlet are set according to the principles of fluid mechanics and heat transfer and combined with the actual operating environment of the equipment, and the steady-state simulation calculation is carried out while fully considering the influence of gravity, so as to obtain the temperature distributions of the superconducting coil and the coolant.

[0020] Further, in S4, it specifically includes the following steps:

[0021] The superconducting coil temperature distribution data obtained in S3 is used as feedback information and input into the electromagnetic characteristic simulation process with the superconducting coil in the S1 basic model as the object, as the temperature condition for re-performing the transient electric field and current distribution simulation calculations of the superconducting coil, and the steps of calculating the AC loss distribution of the superconducting coil and the temperature distributions of the superconducting coil and the coolant are repeated, thereby forming an iterative cycle mechanism of electromagnetic-thermal flow coupling simulation;

[0022] During the iteration process, the electromagnetic simulation parameters are adaptively adjusted according to the temperature distribution results obtained in the previous cycle, and the heat flow distribution is recalculated based on the adjusted electromagnetic simulation results, and this is repeated in turn until the convergence condition is met.

[0023] Further, in S5, it specifically includes the following steps:

[0024] According to the AC loss distribution data of the superconducting coil obtained in each cycle during the S4 iteration process, a calculation method adapted to the structural characteristics and operating mode of the superconducting power equipment is used to determine the total AC loss of the superconducting power equipment;

[0025] At the same time, based on the total AC loss data determined by the previous and subsequent two iterative calculations, the change rate is determined according to the calculation rules determined in advance based on the electromagnetic-thermal flow coupling relationship and engineering application requirements. When the change rate is less than the preset threshold, the iteration is determined to converge, and then the total AC loss value of the superconducting power equipment determined at this time and the corresponding temperature distribution data of the superconducting coil and the coolant are output.

[0026] Further, in S5, the convergence threshold in the iterative calculation process is set based on the type of superconducting power equipment, operating conditions, and required simulation accuracy.

[0027] In a second aspect of the present invention, an electronic device is provided, including a memory and a processor, and the processor is configured to execute a program in the memory to implement the electromagnetic-thermal fluid coupling simulation method for superconducting power equipment based on the iterative algorithm as described above.

[0028] In a third aspect of the present invention, a storage medium containing computer-executable instructions is provided, and when the computer-executable instructions in the storage medium are executed by a computer processor, they are used to execute the electromagnetic-thermal fluid coupling simulation method for superconducting power equipment based on the iterative algorithm as described above.

[0029] In a fourth aspect of the present invention, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, it implements the electromagnetic-thermal fluid coupling simulation method for superconducting power equipment based on the iterative algorithm as described above.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1) Through the innovative method of relatively independent and mutually iterative input of electromagnetic simulation and thermal simulation, the present invention successfully solves the problem of overly high complexity in the joint simulation of the electromagnetic field and thermal field of superconducting power equipment without significantly increasing the simulation complexity. This iterative algorithm can accurately comprehensively consider the mutual influence of the electromagnetic field and thermal field, so that the simulation results are more in line with the actual operating conditions of superconducting power equipment, providing a more reliable basis for the optimal design of the equipment, helping to improve the performance and stability of superconducting power equipment, and reducing the trial-and-error cost and time cost in the R & D process.

[0032] 2) The simulation method proposed by the present invention can obtain the AC loss and temperature of superconducting power equipment more accurately. Accurate calculation of AC loss can help improve the energy utilization efficiency of superconducting power equipment and avoid problems such as energy waste or equipment overload caused by inaccurate loss estimation; while accurate temperature acquisition is crucial for the stable operation of superconducting materials, ensuring that superconducting power equipment operates within a safe temperature range, extending the service life of superconducting materials, improving the reliability and safety of equipment operation, further promoting the large-scale application and popularization of superconducting power equipment in the power system, and promoting the development of the power industry towards a more efficient and intelligent direction. Description of the Drawings

[0033] Figure 1 It is a schematic diagram of a simplified model of a superconducting reactor;

[0034] Figure 2 It is a schematic diagram of a superconducting coil model (single-phase) of a superconducting reactor;

[0035] Figure 3 It is a spatial AC loss distribution diagram (unit: W) of a three-phase superconducting reactor;

[0036] Figure 4 is the temperature distribution diagram of the three-phase superconducting reactor (unit: K);

[0037] Figure 5 is the total loss change diagram during the iteration process of the three-phase superconducting reactor;

[0038] Figure 6 is the overall flowchart of Embodiment 1. Specific Embodiments

[0039] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. In the technical solution, features such as component models, material names, connection structures, control methods, algorithms, etc. that are not clearly described are regarded as common technical features disclosed in the prior art.

[0040] Embodiment 1

[0041] The first aspect of the present invention provides a method for electromagnetic-thermal fluid coupling simulation of superconducting power equipment based on an iterative algorithm, including the following steps:

[0042] S1: Construct a simplified basic model of the superconducting power equipment;

[0043] In S1, the following steps are specifically included:

[0044] Considering the structural characteristics of the superconducting power equipment and the accuracy requirements of electromagnetic-thermal fluid coupling simulation, construct a simulation basic model of the superconducting power equipment. By simplifying the original model of the superconducting power equipment, remove non-critical components that affect the simulation complexity, extract the core components carrying current and simplify the geometric structures of their coils and coolant inlets and outlets, and at the same time select the coolant area.

[0045] In step S1, the present invention constructs a simplified basic model of the superconducting power equipment following the principle of "simplifying to focus on the core and being precise to meet the requirements". First, the structural characteristics of the superconducting power equipment are fully considered because the structure of the equipment determines the basic mode of its electromagnetic and heat flow behaviors. At the same time, according to the accuracy requirements of the electromagnetic-thermal flow coupling simulation, it is ensured that the simplified model can effectively reduce the simulation complexity on the premise of meeting the engineering accuracy requirements. On this basis, targeted simplification is carried out on the original model of the superconducting power equipment, removing non-critical components that will increase the simulation complexity. These non-critical components often have little influence on the coupling relationship between the electromagnetic field and the thermal field, and removing them can reduce unnecessary computational workload and data processing difficulty. Then, the core components carrying current are extracted because current is the key factor generating the electromagnetic field and causing heat loss, and the electromagnetic and thermal behaviors of the core components play a decisive role in the performance of the whole equipment. Further simplify the geometric structures of the coils and the coolant inlet and outlet of the core components to reduce the geometric complexity of the model while retaining the key features, facilitating subsequent simulation calculations and analyses. At the same time, the coolant region is selected. The coolant plays a crucial role in heat exchange in the superconducting power equipment. Selecting the coolant region helps to accurately simulate the heat flow transfer process and provides clear boundaries and scopes of action for subsequent thermal simulation calculations.

[0046] S2: Set the initial temperature and calculate the steady-state AC loss distribution of the coils according to the simplified basic model in S1;

[0047] In S2, the following specific steps are included:

[0048] Based on the basic model constructed in S2, extract the superconducting coil part of the basic model. According to the characteristics of the superconducting material and the operating conditions of the equipment, set the initial temperature of the superconducting coil, conduct simulation calculations on the transient electric field and current distribution of the superconducting coil, and deduce the steady-state AC loss distribution of the coil based on the calculation results.

[0049] In step S2, the present invention calculates the steady-state AC loss distribution of the coil following the principle of "deriving the steady-state loss through transient simulation based on the initial conditions". First, based on the simplified basic model constructed in S1, the superconducting coil part is extracted, because the superconducting coil is the key area where AC losses are generated. Then, according to the characteristics of the superconducting material (such as the characteristics of the critical current density, resistivity, etc. varying with temperature) and the actual operating conditions of the device (such as the magnitude of the current, frequency, etc.), the initial temperature of the superconducting coil is reasonably set. The setting of the initial temperature provides the necessary starting conditions for the subsequent electromagnetic simulation calculation. Next, the transient electric field and current distribution of the superconducting coil are simulated and calculated. Transient simulation can capture the dynamic change process of the electric field and current in the time dimension, so as to more accurately reflect the state of the electromagnetic field at different time points. Based on the results of the transient simulation calculation, the steady-state AC loss distribution of the coil is derived, because the steady-state loss is a key parameter when the device operates stably for a long time. By obtaining the steady-state loss distribution from the analysis of the transient process, accurate electromagnetic loss data can be provided for the subsequent thermal simulation and the performance evaluation of the device, and then the accurate simulation analysis of the electromagnetic-thermal fluid coupling characteristics of the superconducting power device can be realized.

[0050] S3: According to the simplified basic model in S1 and the superconducting coil AC loss distribution data obtained in S2, simulate and calculate the temperature distribution of the superconducting coil and the coolant.

[0051] In S3, it specifically includes the following steps:

[0052] According to the basic model determined in S1 and the superconducting coil AC loss data obtained in S2, apply the heat leakage of the dewar and the casing in the superconducting power device to the wall surface in the form of a heat flux boundary, accurately load the AC loss of the superconducting coil as a heat source on the superconducting coil, use a material with similar thermal properties to the superconducting tape to replace the superconducting tape to simplify the thermal property model, set the boundary types of the coolant inlet and outlet according to the principles of fluid mechanics and heat transfer in combination with the actual operating environment of the device, and at the same time fully consider the influence of gravity to carry out steady-state simulation calculation, so as to obtain the temperature distribution of the superconducting coil and the coolant.

[0053] In step S3, based on the basic model determined in S1 and the AC loss data of the superconducting coil obtained in S2, the present invention uses the principle of "comprehensive multi-factor simulation" to simulate and calculate the temperature distributions of the superconducting coil and the coolant. First, the heat leakage of the dewar and the casing is applied to the wall surface in the form of a heat flux boundary to simulate the heat exchange between the equipment and the outside world during actual operation. Then, the AC loss of the superconducting coil is accurately loaded onto the superconducting coil as a heat excitation, because the AC loss is the main heat source that causes the temperature of the coil to rise. To simplify the thermal property model, a material similar to the thermal property of the superconducting tape is used to replace the superconducting tape, which can not only ensure the accuracy of the simulation but also reduce the complexity of the model. According to the principles of fluid mechanics and heat transfer, and combined with the actual operating environment of the equipment, the boundary types of the coolant inlet and outlet are set, such as boundary conditions of velocity, temperature, pressure, etc., to truly reflect the flow and heat transfer process of the coolant. At the same time, the influence of gravity on the coolant flow and temperature distribution is fully considered, and a steady-state simulation calculation is carried out. By comprehensively considering multiple factors such as heat leakage, AC loss, material thermal properties, coolant flow, and gravity, the temperature distributions of the superconducting coil and the coolant are finally obtained.

[0054] S4: Feed back the temperature distributions of the superconducting coil and the coolant obtained in S3 to the electromagnetic simulation process in S2 as the input temperature boundary conditions to calculate the AC loss, and then feed back the AC loss to the heat flux simulation process in S3 to calculate the temperature distribution, forming an iterative cycle.

[0055] In S4, it specifically includes the following steps:

[0056] Take the superconducting coil temperature distribution data obtained in S3 as feedback information and input it into the electromagnetic characteristic simulation process with the superconducting coil in the S1 basic model as the object, as the temperature condition for re-simulating the transient electric field and current distribution of the superconducting coil, and repeat the steps of calculating the AC loss distribution of the superconducting coil and the temperature distributions of the superconducting coil and the coolant, thereby forming an iterative cycle mechanism for electromagnetic-thermal flux coupling simulation;

[0057] During the iteration process, adaptively adjust the electromagnetic simulation parameters according to the temperature distribution results obtained in the previous cycle, and recalculate the heat flux distribution based on the adjusted electromagnetic simulation results, and repeat this process until the convergence condition is met.

[0058] In step S4, the present invention adopts the principle of "bidirectional feedback iterative optimization" to achieve accurate calculation of electromagnetic-thermal fluid coupling simulation. Specifically, the temperature distributions of the superconducting coil and the coolant obtained in S3 are fed back to the electromagnetic simulation process in S2 as new input temperature boundary conditions to recalculate the AC loss, because the change in temperature will affect the electromagnetic characteristics of the superconducting material, thereby changing the distribution of the AC loss. Subsequently, the recalculated AC loss is fed back to the thermal fluid simulation process in S3 to update the calculation of the temperature distribution, because the heat generated by the AC loss will change the temperature fields of the superconducting coil and the coolant. Through this bidirectional feedback mechanism of feeding the electromagnetic simulation results back to the thermal fluid simulation and then feeding the thermal fluid simulation results back to the electromagnetic simulation, an iterative cycle is formed. In each iteration process, the electromagnetic simulation parameters are adaptively adjusted according to the temperature distribution results obtained in the previous iteration to more accurately reflect the changes in electromagnetic characteristics under actual working conditions; at the same time, based on the adjusted electromagnetic simulation results, the thermal fluid distribution is recalculated to further accurately simulate the temperature field. This iterative cycle will be repeated in turn until the calculation results meet the preset convergence condition, that is, the change rate of the total AC loss obtained from the two consecutive iterative calculations is less than the set threshold, so as to ensure that the AC loss distribution and temperature distribution data of the superconducting coil finally obtained can accurately reflect the electromagnetic-thermal fluid coupling characteristics of the superconducting power equipment during actual operation

[0059] S5: Determine the total AC loss of the superconducting device based on the AC loss distribution in the iteration in S4, and calculate the change rate based on the total AC losses before and after.

[0060] In S5, the following steps are specifically included:

[0061] According to the AC loss distribution data of the superconducting coil obtained in each cycle of the iteration process in S4, adopt a calculation method adapted to the structural characteristics and operation mode of the superconducting power equipment to determine the total AC loss of the superconducting power equipment;

[0062] At the same time, based on the total AC loss data determined by the two consecutive iterative calculations, determine its change rate according to the calculation rules determined in advance based on the electromagnetic-thermal fluid coupling relationship and engineering application requirements. When the change rate is less than the preset threshold, it is determined that the iteration converges, and then output the total AC loss value of the superconducting power equipment determined at this time and the corresponding temperature distribution data of the superconducting coil and the coolant.

[0063] The convergence threshold in the iterative calculation process is set based on the type of superconducting power equipment, operating conditions, and required simulation accuracy.

[0064] In step S5, the present invention follows the principle of "iterative result evaluation and convergence determination" to determine the total AC loss of the superconducting power equipment and the corresponding temperature distribution data. First, collect the AC loss distribution data of the superconducting coil obtained in each cycle during the S4 iteration process, and these data cover the loss conditions under different temperature conditions. Then, adopt a calculation method adapted to the structural characteristics of the superconducting power equipment (such as coil layout, cooling system configuration, etc.) and operating modes (such as current magnitude, operating frequency, etc.) to integrate and analyze these distribution data, so as to accurately determine the total AC loss of the entire superconducting power equipment. At the same time, based on the total AC loss data determined by the previous two iterative calculations, according to a predetermined calculation rule, which comprehensively considers the electromagnetic-thermal fluid coupling relationship and the requirements of engineering applications for accuracy and efficiency, calculate the change rate of the total AC loss. When this change rate is less than a preset threshold, it indicates that the iterative calculation has tended to be stable and the error is within an acceptable range, and at this time, the iteration is determined to converge. Finally, output the total AC loss value of the superconducting power equipment determined at this time and the corresponding temperature distribution data of the superconducting coil and the coolant. These data provide key quantitative bases for the design optimization, performance evaluation, and operation control of the superconducting power equipment, ensuring the accuracy and reliability of the simulation results.

[0065] Embodiment 2

[0066] This embodiment provides an electronic device, including a memory and a processor. The processor is used to execute the program in the memory to implement the electromagnetic-thermal fluid coupling simulation method of the superconducting power equipment based on the iterative algorithm as described above. This electronic device stores key information such as program codes, model data, parameter settings, and intermediate calculation results required for the simulation in the built-in memory, providing data support for the simulation process. And the powerful processor is responsible for efficiently executing the program in the memory and accurately performing complex electromagnetic field and thermal field calculations, including but not limited to key steps such as transient electric field current distribution calculation, steady-state AC loss derivation, temperature distribution simulation, and parameter adjustment in the iterative loop. Such a configuration of the electronic device enables the simulation method to quickly and accurately complete the comprehensive simulation analysis of the electromagnetic-thermal fluid coupling characteristics of the superconducting power equipment with the help of the high-speed processing ability of modern computing technology, thereby providing real-time and efficient technical support for the R & D design, performance optimization, and fault prediction of the superconducting power equipment, and promoting the rapid development and wide application of superconducting power technology in practical engineering applications.

[0067] Embodiment 3

[0068] This embodiment provides a storage medium containing computer-executable instructions. When the storage medium of the computer-executable instructions is executed by a computer processor, it is used to execute the electromagnetic-thermal fluid coupling simulation method of superconducting power equipment based on the iterative algorithm as described above. Such a storage medium can be in various forms such as optical discs, hard disks, USB flash drives, solid-state memories, etc. It stores computer program codes specifically written to implement this simulation method. When these storage media storing computer-executable instructions are loaded into a computer device and the instructions therein are executed by the computer processor, key simulation steps such as the construction of a simplified model of the superconducting power equipment, the setting of the initial temperature and the calculation of AC losses, the simulation calculation of the temperature distribution, and the iterative loop can be completed in sequence according to the preset steps and logic. This enables the simulation method to break through the limitations of hardware devices and flexibly run on different computer platforms in the form of software, greatly improving the portability and generality of the simulation method.

[0069] Example 4

[0070] This embodiment provides a computer program product, including a computer program that, when executed by a processor, implements the electromagnetic-thermal fluid coupling simulation method of superconducting power equipment based on the iterative algorithm as described above. This computer program product encapsulates the complete simulation program code, which can implement a series of complex simulation steps from the simplification of the superconducting power equipment model, the setting of initial conditions, to the iterative coupling calculation of the electromagnetic field and the thermal field. When the computer program is executed by the processor, it can automatically call relevant calculation modules and algorithms, efficiently process a large amount of simulation data, and generate the electromagnetic-thermal fluid coupling characteristic results of the superconducting power equipment under different operating conditions. This form of computer program product is not only convenient for installation and deployment in different computer systems and network environments, but also can continuously optimize the simulation algorithm and add new functional modules through software updates to meet the needs of the continuous development of superconducting power equipment technology and the increasing diversification of application scenarios.

[0071] Application Example 1

[0072] The general flowchart of this application example is as Figure 6 shown.

[0073] 1. Simplify the model of the superconducting power equipment, remove the relatively complex insulating skeleton and bushing structures, extract the main components carrying current, simplify the geometric structures such as coils and coolant inlets, and select the coolant area. Taking a 10 kV / 1 Mvar compact superconducting shunt reactor as an example, remove the skeleton and connectors of the superconducting reactor, simplify the superconducting coil into the corresponding geometric shape, select the liquid nitrogen area and simplify the liquid nitrogen inlet and outlet structures to construct a basic model, as Figure 1 shown.

[0074] 2. Extract the superconducting coil part, asFigure 2 As shown. Set the initial temperature of the superconducting coil, simulate and calculate the transient electric field and current distribution of the superconducting coil, calculate the steady-state AC loss distribution P of the coil. The spatial AC loss distribution diagram of the three-phase superconducting reactor is shown in Figure 3 . Due to the existence of zero initial conditions, the calculation results are not stable in the first half cycle. Take the average value of the AC loss power in the second half cycle to calculate the AC loss distribution of the superconducting coil, as shown in Equation (1).

[0075]

[0076] For example, set the initial temperature of the superconducting coil to 77K, and apply the set AC current I = I peak sin(2πft).

[0077] 3. Consider all the heat leakage of the dewar and the casing as heat flux boundaries added to the wall, and take the AC loss of the superconducting coil as a heat excitation and load it on the superconducting coil. Since the Hastelloy of the substrate accounts for most of the thickness of the high-temperature superconducting tape and its thermal properties are similar to those of stainless steel, stainless steel is used to replace the superconducting tape. According to the principles of fluid mechanics and heat transfer, set the boundary types related to velocity and temperature for the coolant inlet and the corresponding boundary types for the outlet. The simulation takes into account the influence of gravity and only focuses on the steady-state situation. Through simulation calculation, the temperature distributions of the superconducting coil and liquid nitrogen in the superconducting electrical equipment are obtained. The temperature distribution diagram of the three-phase superconducting reactor is shown in Figure 3 , the liquid nitrogen enters the inlet with a set velocity of 0.8m / s and a temperature of 70K, and the outflow boundary is set for the liquid nitrogen outlet.

[0078] 4. Use the calculated temperature distribution of the superconducting coil as the temperature condition in Step 2, repeat Steps 2 and 3, and perform iterative calculations on the temperature and AC loss distribution of the superconducting coil.

[0079] 5. Calculate the total AC loss P of the superconducting electrical equipment from the AC loss distribution P v of the superconducting coil, as shown in Equation (2). For the total AC losses P n and P n-1 of the two consecutive iterative calculation results, define the change rate δ, as shown in Equation (3). Figure 4 is the total loss change during the iteration of the three-phase superconducting reactor. If the change rate is less than 1%, it is considered that the result converges, and output the total AC loss P and temperature of the superconducting electrical equipment.

[0080] P = ∫ V P v dV (2)

[0081]

[0082] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those who are familiar with the technology in this field can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A superconducting power equipment electromagnetic-thermal coupling simulation method based on iterative algorithm, characterized in that: The following steps are involved: S1: Construct a simplified basic model of superconducting power equipment; S2: Set the initial temperature and calculate the coil steady-state AC loss distribution according to the simplified basic model in S1; S3: Based on the simplified basic model in S1 and the superconducting coil AC loss distribution data obtained in S2, the temperature distribution of the superconducting coil and the coolant is simulated and calculated; S4: Feedback the temperature distribution of the superconducting coil and the coolant obtained in S3 to the electromagnetic simulation process in S2 as the input temperature boundary condition to calculate the AC loss, and then feed back the AC loss to the heat flow simulation process in S3 to calculate the temperature distribution, forming an iterative cycle; S5: Determine the total AC loss of the superconducting device according to the AC loss distribution in the iteration in S4, and calculate the change rate based on the total AC loss before and after.

2. According to the iterative algorithm-based electromagnetic-thermal coupling simulation method for superconducting power equipment according to claim 1, it is characterized in that: S1 specifically includes the following steps: Considering the structural characteristics of superconducting power equipment and the accuracy requirements of electromagnetic-thermal-fluid coupling simulation, a basic simulation model of superconducting power equipment is constructed. By simplifying the original model of the superconducting power equipment, non-critical components that affect the complexity of the simulation are removed, the core components that carry current are extracted, and the geometric structures of the coils and coolant inlets and outlets are simplified. At the same time, the coolant area is selected.

3. The electromagnetic-thermal coupling simulation method of superconducting power equipment based on an iterative algorithm according to claim 1 is characterized in that: S2 specifically includes the following steps: Based on the basic model constructed by S2, the superconducting coil part in the basic model is extracted. According to the characteristics of superconducting materials and the operating conditions of the equipment, the initial temperature of the superconducting coil is set, and the transient electric field and current distribution of the superconducting coil are simulated and calculated. Based on the calculation results, the steady-state AC loss distribution of the coil is derived.

4. The electromagnetic-thermal coupling simulation method of superconducting power equipment based on an iterative algorithm according to claim 1, characterized in that: S3 specifically includes the following steps: According to the basic model determined by S1 and the AC loss data of the superconducting coil obtained by S2, the heat leakage of the Dewar and the casing in the superconducting power equipment is applied to the wall in the form of a heat flow boundary, and the AC loss of the superconducting coil is accurately loaded on the superconducting coil as a thermal excitation. The superconducting tape is replaced by a material with similar thermal properties to the superconducting tape to simplify the thermal property model. The boundary type of the coolant inlet and outlet is set according to the principles of fluid mechanics and heat transfer and combined with the actual operating environment of the equipment. At the same time, steady-state simulation calculations are carried out by fully considering the influence of gravity, so as to obtain the temperature distribution of the superconducting coil and the coolant.

5. The electromagnetic-thermal-fluid coupling simulation method for superconducting power equipment based on an iterative algorithm according to claim 1, characterized in that: S4 specifically includes the following steps: The superconducting coil temperature distribution data obtained by S3 is used as feedback information and input into the electromagnetic characteristics simulation process with the superconducting coil in the basic model of S1 as the object, and used as the temperature condition for the superconducting coil transient electric field and current distribution simulation calculation again, and the steps of superconducting coil AC loss distribution calculation and superconducting coil and coolant temperature distribution calculation are repeated, thereby forming an iterative cycle mechanism of electromagnetic-thermal flow coupling simulation; During the iteration process, the electromagnetic simulation parameters are adaptively adjusted according to the temperature distribution results obtained in the previous cycle, and the heat flux distribution is recalculated based on the adjusted electromagnetic simulation results, and this process is repeated until the convergence conditions are met.

6. The electromagnetic-thermal coupling simulation method of superconducting power equipment based on an iterative algorithm according to claim 1, characterized in that: S5 specifically includes the following steps: According to the AC loss distribution data of the superconducting coil obtained in each cycle of the S4 iteration process, the total AC loss of the superconducting power equipment is determined by using a calculation method that is compatible with the structural characteristics and operation mode of the superconducting power equipment; At the same time, based on the total AC loss data determined by the two iterative calculations, its change rate is determined according to the predetermined calculation rules based on the electromagnetic-thermal flow coupling relationship and engineering application requirements. When the change rate is less than a preset threshold, the iteration is judged to be converged, and then the total AC loss value of the superconducting power equipment determined at this time and the corresponding temperature distribution data of the superconducting coil and the coolant are output.

7. The electromagnetic-thermal coupling simulation method of superconducting power equipment based on iterative algorithm according to claim 6, characterized in that: In S5, the convergence threshold in the iterative calculation process is set based on the type of superconducting power equipment, operating conditions, and required simulation accuracy.

8. An electronic device, comprising a memory and a processor, characterized in that: The processor is used to execute the program in the memory, so as to implement the electromagnetic-thermal-fluid coupling simulation method of superconducting power equipment based on an iterative algorithm as described in any one of claims 1 to 7.

9. A storage medium containing computer executable instructions, characterized in that: The storage medium of the computer executable instructions is used to execute the electromagnetic-thermal-fluid coupling simulation method of a superconducting power device based on an iterative algorithm as claimed in any one of claims 1 to 7 when executed by a computer processor.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the electromagnetic-thermal-fluid coupling simulation method for superconducting power equipment based on an iterative algorithm as described in any one of claims 1 to 7 is implemented.

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