Submarine cable data processing method and device, storage medium and electronic equipment

Abstract

The invention discloses a submarine cable data processing method and device, a storage medium and electronic equipment, and relates to the field of power transmission, and the method comprises the steps: obtaining a submarine cable project file; constructing an engineering simulation model of the submarine cable according to the submarine cable engineering file; constructing N armor layer equivalent models according to the engineering simulation model of the submarine cable; determining corresponding cable circulation distribution data of the submarine cable when each armor layer equivalent model is applied through simulation measurement and calculation; and determining a target armor layer equivalent model from the N armor layer equivalent models according to corresponding cable ring current distribution data when each armor layer equivalent model is applied to the submarine cable, and taking a matching condition of a galvanized steel wire and a copper wire of the target armor layer equivalent model as reference design information of the submarine cable. The technical problem that in the prior art, the submarine cable armor layer material ratio cannot be effectively optimized to reduce the circulating current loss and improve the cable current-carrying capacity is solved.

Description

Technical Field

[0001] This application relates to the field of power transmission technology, and more specifically, to a method, apparatus, storage medium, and electronic device for processing submarine cable data. Background Technology

[0002] In existing submarine cable technology, the selection and proportioning of armor materials have a crucial impact on cable performance. Submarine cables require armor layers to ensure their mechanical strength. Furthermore, due to the unique operating environment of submarine cables, in actual production, the metal sheaths and armor joints at both ends of the submarine cable are connected in parallel and directly grounded. This generates a considerable current in both the metal sheath and the armor layer, accompanied by significant losses, causing the outer sheath of the submarine cable to heat up, hindering conductor heat dissipation, and limiting the current-carrying capacity of the submarine cable.

[0003] In related technologies, many projects often employ techniques such as stripping the armor steel wires from the landing section of the cable to reduce losses in the landing section of a single-core submarine cable and increase transmission capacity. However, while the steel wire armor layer enhances the strength of the submarine cable and is part of its structure, stripping the armor avoids armor layer losses and optimizes heat dissipation, it cannot fundamentally guarantee the mechanical strength of the submarine cable. Moreover, due to the influence of tides, completely stripping the armor layer from the landing section would lead to a decrease in mechanical strength, and partial stripping would severely limit the current carrying capacity during low tide. Changing the armor material to reduce armor losses, such as using all copper flat wire, is another option. However, copper is much more expensive than steel. While this could increase the current carrying capacity of the landing section, using copper flat wire throughout the submarine laying section would significantly increase the project cost.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This application provides a method, apparatus, storage medium, and electronic device for processing submarine cable data, to at least solve the technical problem in the prior art that the material ratio of the armor layer of submarine cables cannot be effectively optimized to reduce circulating current loss and increase the current carrying capacity of the cable.

[0006] According to one aspect of the embodiments of this application, a method for processing submarine cable data is provided, comprising: acquiring submarine cable engineering documents, wherein the submarine cable engineering documents include at least the structural parameters, laying method, grounding method, and maximum load of the submarine cable; constructing an engineering simulation model of the submarine cable based on the submarine cable engineering documents; constructing N equivalent armor layer models based on the engineering simulation model of the submarine cable, wherein N is an integer greater than 1, and different equivalent armor layer models are used to simulate cable armor layers with different ratios of galvanized steel wire and copper wire; determining the cable circulation current distribution data corresponding to each equivalent armor layer model of the submarine cable through simulation calculation based on the engineering simulation model, wherein the cable circulation current distribution data includes at least the circulation current distribution data corresponding to the metal sheath and armor layer of the submarine cable respectively; determining a target equivalent armor layer model from the N equivalent armor layer models based on the cable circulation current distribution data corresponding to each equivalent armor layer model of the submarine cable, and using the ratio of galvanized steel wire and copper wire of the target equivalent armor layer model as reference design information for the submarine cable.

[0007] Optionally, based on the cable circulation current distribution data corresponding to each armor layer equivalent model of the submarine cable, a target armor layer equivalent model is determined from N armor layer equivalent models. This includes: determining the cable eddy current distribution data corresponding to each armor layer equivalent model of the submarine cable through simulation calculation based on the engineering simulation model, wherein the cable eddy current distribution data includes at least the circulation current distribution data corresponding to the armor layer of the submarine cable; and determining the target armor layer equivalent model from N armor layer equivalent models based on the cable circulation current distribution data and cable eddy current distribution data corresponding to each armor layer equivalent model of the submarine cable.

[0008] Optionally, after using the ratio of galvanized steel wire to copper wire in the equivalent model of the target armor layer as reference design information for the submarine cable, the data processing method for the submarine cable further includes: based on the cable circulating current distribution data corresponding to the application of the i-th armor layer equivalent model, determining the metal sheath circulating current magnitude, armor layer circulating current magnitude, metal sheath circulating current loss value, armor layer circulating current loss value, and total circulating current loss value of the submarine cable corresponding to each armor layer equivalent model, where i is an integer greater than or equal to 1; based on the metal sheath circulating current magnitude, armor layer circulating current magnitude, metal sheath circulating current loss value, armor layer circulating current loss value, and total circulating current loss value of the submarine cable, determining the inductance value of the sheath inductance of the submarine cable when using the i-th armor layer equivalent model as the target armor layer equivalent model, where the sheath inductance is the inductance connected in series on both sides of the metal sheath of the submarine cable.

[0009] Optionally, the method for processing submarine cable data further includes: determining the number of segments of the metal sheath and the number of segments of the armor layer of the submarine cable based on the design length of the submarine cable, wherein each segment of the metal sheath and the armor layer is grounded to the seabed, and the design length of the submarine cable is positively correlated with the number of segments of the metal sheath and the number of segments of the armor layer.

[0010] Optionally, the method for processing submarine cable data also includes: if the designed length of the submarine cable is detected to be greater than the preset length, determining that the material type of the submarine cable is semi-conductive polyethylene.

[0011] Optionally, an engineering simulation model of the submarine cable is constructed based on the submarine cable engineering documents, including: constructing an initial engineering model of the submarine cable based on various engineering parameters in the submarine cable engineering documents, wherein the initial engineering model includes: structural parameters of the submarine cable, grounding configuration, and electrical parameters of the surrounding environment; setting simulation parameters that match the cable operating conditions in the submarine cable engineering documents, wherein the simulation parameters include: simulation time length, power supply configuration parameters, analysis frequency range, and load characteristic parameters; and applying the simulation parameters to the initial engineering model to obtain the engineering simulation model of the submarine cable.

[0012] Optionally, N equivalent armor layer models are constructed based on the engineering simulation model of the submarine cable, including: constructing an initial equivalent armor layer model based on the engineering simulation model, wherein the initial equivalent armor layer model is used to simulate the initial ratio of galvanized steel wire and copper wire in the armor layer, including the resistivity and permeability parameters of galvanized steel wire and copper wire; performing N-1 target operations based on the initial equivalent armor layer model to obtain N-1 new equivalent armor layer models, wherein each target operation is used to generate a new equivalent armor layer model by changing the quantity ratio and arrangement of copper wire and galvanized steel wire based on the initial equivalent armor layer model.

[0013] Optionally, based on the engineering simulation model, the cable circulating current distribution data corresponding to the application of each armor layer equivalent model of the submarine cable is determined through simulation calculation. This includes: setting cable operating environment conditions for each armor layer equivalent model, wherein the cable operating environment conditions include: power specifications, frequency characteristics, and short-circuit fault scenarios; performing simulation calculations on the engineering simulation model and each armor layer equivalent model based on the cable operating environment conditions to obtain the cable circulating current distribution data corresponding to the application of each armor layer equivalent model of the submarine cable. The cable circulating current distribution data includes at least the current characteristics of the submarine cable that change over time under steady-state and transient conditions, and the current characteristics include current magnitude and current direction.

[0014] According to another aspect of the embodiments of this application, a submarine cable data processing apparatus is also provided, comprising: an engineering file acquisition unit for acquiring submarine cable engineering files, wherein the submarine cable engineering files include at least the structural parameters, laying method, grounding method, and maximum load of the submarine cable; a simulation model construction unit for constructing an engineering simulation model of the submarine cable based on the submarine cable engineering files; and an equivalent model construction unit for constructing N armor layer equivalent models based on the submarine cable engineering simulation model, wherein N is an integer greater than 1, and different armor layer equivalent models are used to simulate different ratios of galvanized steel wire and copper wire. The system comprises: a cable armor layer; a cable data determination unit, used to determine the cable circulation distribution data corresponding to each armor layer equivalent model of the submarine cable through simulation calculation based on the engineering simulation model; the cable circulation distribution data includes at least the circulation distribution data corresponding to the metal sheath and armor layer of the submarine cable; and a target model processing unit, used to determine the target armor layer equivalent model from N armor layer equivalent models based on the cable circulation distribution data corresponding to each armor layer equivalent model of the submarine cable, and to use the ratio of galvanized steel wire to copper wire in the target armor layer equivalent model as reference design information for the submarine cable.

[0015] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, which stores a computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located performs the above-described method for processing submarine cable data.

[0016] According to another aspect of the embodiments of this application, an electronic device is also provided, including one or more processors and a memory, the memory being used to store one or more programs, wherein when the one or more programs are executed by one or more processors, the one or more processors cause the one or more processors to perform the above-described method for processing submarine cable data.

[0017] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program or instructions, which, when executed by a processor, implement the above-described method for processing submarine cable data.

[0018] In this application, firstly, submarine cable engineering documents are obtained, which include at least the structural parameters, laying method, grounding method, and maximum load of the submarine cable. Then, an engineering simulation model of the submarine cable is constructed based on these documents, and N equivalent armor layer models are built based on this model. Different equivalent armor layer models are used to simulate cable armor layers with different ratios of galvanized steel wire to copper wire. Next, based on the engineering simulation model, the cable circulation current distribution data corresponding to each equivalent armor layer model is determined through simulation calculations. This data includes at least the circulation current distribution data corresponding to the metal sheath and the armor layer of the submarine cable. Finally, based on the cable circulation current distribution data corresponding to each equivalent armor layer model, a target equivalent armor layer model is determined from the N models, and the ratio of galvanized steel wire to copper wire in the target model is used as reference design information for the submarine cable.

[0019] As described above, this application first obtains submarine cable engineering documents, which contain key information such as cable structural parameters, laying methods, grounding methods, and maximum loads, providing fundamental data for constructing an accurate engineering simulation model. Using this data from the submarine cable engineering documents, a detailed submarine cable engineering simulation model can be created, capable of simulating the cable's behavior under actual operating conditions. Next, based on the submarine cable engineering simulation model, multiple equivalent armor layer models are constructed, each representing a cable armor layer with different ratios of galvanized steel wire and copper wire. These equivalent armor layer models allow users to evaluate the specific impact of different material ratios on cable performance, especially on circulating current loss and current carrying capacity.

[0020] Through simulation calculations, the circulating current distribution data of the metallic sheath and armor layer of the submarine cable can be determined under each armor layer equivalent model. This allows for the analysis and comparison of the impact of different armor layer material ratios on cable performance. Ultimately, by comparing the circulating current distribution data of different armor layer equivalent models, the optimal armor layer equivalent model can be identified—that is, the model that minimizes circulating current loss and maximizes cable current carrying capacity. Using the ratio of galvanized steel wire to copper wire in this target armor layer equivalent model as a design reference can directly guide the armor layer design of submarine cables. This facilitates the reduction of circulating current loss and the increase of cable current carrying capacity, not only improving cable performance but also potentially reducing material costs and improving economic feasibility. This solves the technical problem of the inability to effectively optimize the material ratio of submarine cable armor layers to reduce circulating current loss and increase cable current carrying capacity in existing technologies. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of an optional method for processing submarine cable data according to an embodiment of this application; Figure 2 This is a schematic cross-sectional view of an optional submarine cable according to an embodiment of this application; Figure 3 This is a schematic diagram showing the distribution of interlayer current between the metal sheath and the armor when an optional semiconducting inner sheath is used, according to an embodiment of this application. Figure 4 This is a schematic diagram of an optional submarine cable data processing apparatus according to an embodiment of this application.

[0022] in: 1. Conductor; 2. Conductor shield; 3. Insulation; 4. Insulation shield; 5. Semiconductor resistive water expansion tape; 6. Lead sheath; 7. Polyethylene sheath; 8. Impregnated rope; 9. Galvanized steel wire armor; 10. Optical cable. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0025] According to an embodiment of this application, a method embodiment for processing submarine cable data is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0026] According to the embodiments of this application, a submarine cable data processing system can be used as the execution subject of the submarine cable data processing method of this application embodiment. The submarine cable data processing system is hereinafter referred to as the system. The system can be a software system or an embedded system combining software and hardware. Of course, the execution subject of the method in the embodiments of this application can also be other forms of execution subject, such as devices, equipment, etc. It should be known by those skilled in the art that this application does not particularly limit the specific form of the execution subject of the method.

[0027] Figure 1 This is a method for processing submarine cable data according to embodiments of this application, such as... Figure 1 As shown, the method includes the following steps: Step S101: Obtain submarine cable engineering documents, which include at least the structural parameters, laying method, grounding method, and maximum load of the submarine cable.

[0028] Optionally, obtaining submarine cable engineering documents contains key information about the submarine cable. Among these, the structural parameters characterize the cable's physical construction details, such as conductor cross-sectional area, insulation thickness, sheath material, and the material and structure of the armor layer. These structural parameters directly determine the cable's electrical performance and mechanical strength. For example, the conductor cross-sectional area affects the cable's current-carrying capacity, while the material and structure of the armor layer relate to the cable's resistance to external forces and its loss level. The laying method describes the specific method of laying the cable on the submarine, which may include direct burial, duct laying, or overhead laying. Different laying methods can affect the cable's heat dissipation conditions and stress conditions. The grounding method involves the grounding configuration at both ends or along the cable route, such as single-end grounding, two-end grounding, or cross-interconnected grounding, which directly affects the circulating current distribution in the cable's metallic sheath and armor layer, thus affecting the cable's loss and current-carrying capacity.

[0029] Optionally, the maximum load characterizes the maximum current load that a submarine cable can withstand during normal operation, i.e., its current carrying capacity. This can be used to assess the cable's current-carrying capacity and design cable systems. Obtaining the maximum load helps determine the highest temperature the cable may experience during operation, ensuring that the cable's insulation materials and structure operate within a safe temperature range and preventing insulation aging or damage due to overheating. Simultaneously, maximum load information can also be used to optimize cable structural parameters and laying methods. For example, by rationally configuring the armor layer material and structure, circulating current loss can be effectively reduced, improving the cable's current-carrying capacity and operating efficiency while meeting the maximum load requirements.

[0030] Step S102: Construct an engineering simulation model of the submarine cable based on the submarine cable engineering documents.

[0031] Optionally, an engineering simulation model of the submarine cable can be constructed based on the engineering documents. This model utilizes detailed information provided in the engineering documents, such as the cable's structural parameters, laying method, grounding method, and maximum load, to create a virtual engineering simulation model of the submarine cable using simulation software. The engineering simulation model of the submarine cable can simulate the electrical behavior and physical characteristics of the cable during actual operation. For example, by inputting parameters such as the cable's conductor cross-sectional area, insulation thickness, sheath material, and armor material and structure, the simulation model can accurately reflect the cable's electrical performance, including current distribution, voltage drop, and circulating current loss. Simultaneously, setting parameters for the laying method and grounding method can simulate the cable's operating state under different laying environments, such as heat dissipation during direct burial or circulating current distribution under different grounding methods.

[0032] By constructing engineering simulation models of submarine cables, it is convenient to analyze and optimize their performance in a virtual environment. These models allow for the simulation and comparison of different armor layer material ratios, laying schemes, and grounding methods, thereby predicting their impact on cable current carrying capacity and losses. For example, by changing the ratio of steel wires to copper wires in the armor layer, the engineering simulation model of the submarine cable can calculate the circulating current distribution and losses under different ratios, thus determining the optimal material ratio scheme. This not only saves the cost and time of actual testing but also allows for the early identification of potential problems during the design phase, optimizing the design of submarine cables and improving their operational efficiency and reliability.

[0033] Step S103: Construct N equivalent armor layer models based on the engineering simulation model of the submarine cable, where N is an integer greater than 1. Different equivalent armor layer models are used to simulate cable armor layers with different ratios of galvanized steel wire and copper wire.

[0034] Optionally, N equivalent armor layer models are constructed based on the engineering simulation model of the submarine cable. These models represent the cable armor layer under different combinations of galvanized steel wire and copper wire. For example, one equivalent armor layer model can be constructed containing 55 galvanized steel wires and 2 copper wires, another can contain 50 galvanized steel wires and 5 copper wires, and so on. Each equivalent model can simulate different armor layer structures by changing the number of steel and copper wires, thereby studying the impact of different ratios on the armor layer performance.

[0035] By constructing these equivalent models of different armor layers, we can deeply analyze and compare the performance of armor layers under different ratios, such as circulating current distribution, loss characteristics, and impact on current carrying capacity. For example, through simulation calculations, we can discover that certain ratios can effectively reduce the circulating current loss of the armor layer, thereby increasing the current carrying capacity of the cable. This helps to find the optimal ratio of steel wire to copper wire to achieve the goals of reducing losses and increasing current carrying capacity, while also taking cost factors into account, facilitating the scientific and rational design of submarine cables.

[0036] Step S104: Based on the engineering simulation model, determine the cable circulation distribution data corresponding to each armor layer when applying the equivalent model of the submarine cable through simulation calculation. The cable circulation distribution data includes at least the circulation distribution data corresponding to the metal sheath and armor layer of the submarine cable.

[0037] Optionally, based on the engineering simulation model, the cable circulation distribution data corresponding to each armor layer equivalent model is determined through simulation calculations. This data is used to characterize the cable circulation distribution under these armor layer equivalent models by performing simulation calculations on each different armor layer equivalent model using the already constructed submarine cable engineering simulation model. Specifically, by inputting different armor layer equivalent models into the engineering simulation model, such as different ratios of galvanized steel wire and copper wire, the current distribution in the cable's metal sheath and armor layer under these different configurations can be simulated. This circulation distribution data can reflect in detail the flow path, magnitude, and direction of the current in the metal sheath and armor layer, thereby helping to analyze the impact of different armor layer configurations on cable performance.

[0038] Optionally, the cable circulating current distribution data should include at least the circulating current distribution data corresponding to the metal sheath and armor layers of the submarine cable. This emphasizes the detail and comprehensiveness of the circulating current distribution data because the circulating current in both the metal sheath and armor layers affects the total loss and current carrying capacity of the cable. During simulation calculations, it is necessary to focus not only on the circulating current in the armor layer but also on the circulating current in the metal sheath. By obtaining the circulating current distribution data of the metal sheath and armor layers separately, the impact of different armor layer equivalent models on the overall cable performance can be more accurately evaluated, thus providing a basis for optimizing the armor layer design. For example, by analyzing these cable circulating current distribution data, it can be found that certain armor layer configurations can significantly reduce the circulating current in the metal sheath, thereby reducing losses and increasing the current carrying capacity of the cable.

[0039] Optionally, to analyze the circulation characteristics of submarine cables, a reasonable and reliable model needs to be established. High-voltage cross-linked polyethylene submarine cables mainly consist of four components: conductor, insulation layer, sheath, and armor layer. The sheath includes both metallic and non-metallic sheaths. The conductor, metallic sheath, and armor layer all possess good electrical conductivity, and electromagnetic coupling effects exist between them. Considering the electrical and magnetic conductivity characteristics of each functional layer of the cable, such as the insulation, non-metallic sheath, semi-conductive layer, and water-blocking layer, as well as the electromagnetic properties of the earth, the constructed submarine cable model is a multi-dimensional model.

[0040] Specifically, the engineering simulation model for submarine cables can include three cable modeling methods: the general impedance model, the power frequency impedance model, and the simplified power frequency impedance model. Among these, the general impedance model is the most accurate, complex, and closest to the real system. It can be based on simulation platforms such as electromagnetic transient simulation models, and the appropriate component equivalent algorithms can be selected according to the analysis objectives to achieve transient and power frequency calculations. The power frequency impedance model considers the cable's power frequency characteristics, ignores the capacitance effect, and treats the ground current loop as an equivalent conductor. Mathematical calculation software is used to calculate and analyze the established model matrix, enabling calculations for normal power frequency and short-circuit power frequency. The simplified power frequency impedance model is the simplest of the three methods. It ignores the capacitance effect, treats the ground current loop as an equivalent conductor, and assumes that the current is known, all single-phase short-circuit current flows through the return line or sheath, and the three interconnected sections are equal in length.

[0041] While simplified power frequency impedance models can be directly calculated using mathematical algorithms, their application to modeling multi-segment cross-connected systems and even overhead cable hybrid transmission systems yields significant deviations and fails to effectively estimate the ground current at each grounding point. For a single cross-connected system or a single-ended grounded system with a return line, a power frequency impedance model can be established and calculated using mathematical software. However, for transmission and transformation systems composed of multiple cross-connections, the established power frequency impedance model becomes extremely complex, lacks strong regularity, cannot be modularized, and is not conducive to programming calculations. Therefore, the nodal voltage method is needed to process the power frequency impedance matrix, identify the regularity of multiple cross-connections, and simplify the model to achieve modeling of large systems. In contrast, modeling based on electromagnetic transient simulation software, due to its graphical processing method, does not suffer from the complexity of large system models and can conveniently model transmission and transformation systems with multiple cross-connections. To compare and verify the feasibility of the two methods, embodiments of this application use mathematical calculation software and electromagnetic transient simulation model software to establish power frequency equivalent models and simulation models for some simple land cables, and compare and analyze the two models.

[0042] While simplified power frequency impedance models can be directly calculated using mathematical algorithms, their application to model multi-segment interconnected systems and even hybrid transmission systems involving overhead, terrestrial, and submarine cables yields significant deviations. Using mathematical calculation software to establish a submarine cable simulation model results in a highly complex power frequency impedance model with weak regularity and complex modular processing, hindering programming calculations. Furthermore, considering the long-distance transmission of submarine cables and the unavoidable capacitance effect, this approach is also unsuitable for the submarine cable modeling in this application's embodiments. However, modeling based on electromagnetic transient simulation software, which employs a graphical processing method, avoids the complexity issues of large-scale system models and can conveniently model multiple interconnected transmission and transformation systems. Therefore, this application's embodiments will utilize electromagnetic transient simulation software to model the line engineering, focusing on analyzing the circulating current characteristics of the sheath and armor layers, and proposing corresponding improvement measures.

[0043] Step S105: Based on the cable circulation distribution data corresponding to each armor layer equivalent model when applying the equivalent model of the submarine cable, determine the target armor layer equivalent model from the N armor layer equivalent models, and use the ratio of galvanized steel wire to copper wire in the target armor layer equivalent model as the reference design information for the submarine cable.

[0044] Optionally, based on the cable circulation current distribution data corresponding to each armor layer equivalent model applied to the submarine cable, a target armor layer equivalent model is determined from N armor layer equivalent models. This target model represents a comprehensive evaluation based on the cable circulation current distribution data corresponding to each model after completing the simulation calculations for all armor layer equivalent models. This cable circulation current distribution data includes key indicators such as the magnitude and distribution of circulation current in the metal sheath and armor layer, and the resulting losses. By comparing and analyzing these cable circulation current distribution data, the armor layer equivalent model that performs optimally in specific performance indicators such as minimum loss and maximum current carrying capacity can be identified and designated as the target armor layer equivalent model. For example, if an armor layer equivalent model shows the lowest circulation current loss and the highest current carrying capacity in the simulation, while also meeting other engineering requirements such as mechanical strength, then this armor layer equivalent model can be selected as the target armor layer equivalent model.

[0045] Optionally, the ratio of galvanized steel wire to copper wire in the equivalent model of the target armor layer can be used as reference design information for submarine cables. Once the equivalent model of the target armor layer is determined, the specific ratio of galvanized steel wire to copper wire in this model will be used as an important reference for submarine cable design. This ratio is the optimal solution obtained after comprehensively considering factors such as the electrical performance, mechanical performance, and cost-effectiveness of the cable. In the actual design and manufacturing process of submarine cables, users can use this reference design information to determine the specific material ratio of the armor layer, thereby ensuring that the cable can achieve the expected performance indicators in actual applications, such as increasing current carrying capacity and reducing losses, while also ensuring the mechanical strength and economy of the cable.

[0046] This application adopts a design based on adding some copper wire to the steel wire armor, aiming to optimize the armor layer structure of the submarine cable by optimizing the overall impact of circulating current and eddy current loss distribution in the armor layer and metal sheath on the current carrying capacity of the submarine cable. Circulating current analysis yields the optimal copper-to-steel wire ratio in the submarine cable armor layer, achieving a structural design with maximum current carrying capacity. Armor materials are classified as ferromagnetic and non-ferromagnetic. For example, among commonly used armor materials, galvanized steel wire is magnetic, while stainless steel wire and copper wire are non-ferromagnetic. The losses in the sheath are mainly circulating current losses, with eddy current losses being very small and negligible. When the relative permeability is 1500, the eddy current loss in the armor layer is essentially equal to the circulating current loss. This application, through the construction and simulation analysis of multiple armor layer models, scientifically determines the optimal ratio of galvanized steel wire to copper wire, providing an optimization strategy for the structural design of submarine cables and significantly enhancing the cable's performance and economic feasibility.

[0047] In one optional embodiment, based on the cable circulation distribution data corresponding to each armor layer equivalent model applied to the submarine cable, a target armor layer equivalent model is determined from N armor layer equivalent models. This includes: the submarine cable data processing system determining the cable eddy current distribution data corresponding to each armor layer equivalent model applied to the submarine cable through simulation calculations based on an engineering simulation model. The cable eddy current distribution data includes at least the circulation distribution data corresponding to the armor layer of the submarine cable. Then, based on the cable circulation distribution data and cable eddy current distribution data corresponding to each armor layer equivalent model applied to the submarine cable, the target armor layer equivalent model is determined from the N armor layer equivalent models.

[0048] Optionally, the submarine cable data processing system utilizes engineering simulation models to perform simulation calculations to determine the cable eddy current distribution data when applying equivalent models for each armor layer. This cable eddy current distribution data includes at least the circulating current distribution within the armor layer. Specifically, the submarine cable data processing system simulates the current distribution within the armor layer under different configurations by inputting equivalent models for different armor layers, such as varying ratios of galvanized steel wire and copper wire. This current distribution data provides detailed information on the flow path, magnitude, and direction of the current within the armor layer, thereby aiding in the analysis of the impact of different armor layer configurations on cable performance. For example, simulation calculations can reveal that certain armor layer configurations can effectively reduce circulating current losses within the armor layer, thereby increasing the cable's current carrying capacity.

[0049] After acquiring the cable circulation current distribution data and cable eddy current distribution data corresponding to each armor layer equivalent model, the submarine cable data processing system further analyzes this data to determine the optimal armor layer equivalent model. This process involves a comprehensive evaluation of the performance indicators of different models, such as loss and current carrying capacity. By comparing and analyzing these cable circulation current distribution data and cable eddy current distribution data, the submarine cable data processing system can identify the armor layer equivalent model that performs best in specific performance indicators and determine it as the target armor layer equivalent model. For example, if an armor layer equivalent model shows the lowest circulation loss and the highest current carrying capacity in the simulation, while also meeting other engineering requirements such as mechanical strength, then this armor layer equivalent model will be selected as the target armor layer equivalent model. Finally, the ratio of galvanized steel wire to copper wire in this armor layer equivalent model will be used as important reference information for submarine cable design.

[0050] Optionally, after selecting the modeling method for the engineering simulation model of the submarine cable, the model can be verified. For example, a power frequency impedance model can be established using mathematical calculation software. The impedance matrix of the cable can be obtained through software calculation, and then a cable model based on an electromagnetic transient simulation model can be established. The structural parameters of the established model can be viewed by checking the submarine cable engineering file in the system files. By comparison, it can be seen that the impedance matrix of the cable model established using mathematical calculation software and the power model established using simulation platforms such as electromagnetic transient simulation model software have a parameter error of less than 0.5%, and the two models can be considered completely equivalent. In addition, it is not difficult to find that the power components included in the electromagnetic transient simulation model software equate the ground impedance to the self-impedance in the cable components, treating the ground as an equipotential body. By setting relevant parameters, the models of each power component can be established, and the entire power transmission and transformation engineering model can be built by assembling blocks.

[0051] Finally, by plotting multiple data columns, the short-circuit current to ground of the established two-terminal grounded + return line model can be obtained as approximately 11.5A, sheath current (approximately 250A), return line current (approximately 780A), and conductor current (2000A). To further verify the correctness of the power frequency equivalent model established using mathematical calculation software and the simulation model established based on the electromagnetic transient simulation model, the operating conditions of cross-interconnection with return line, two-terminal direct grounding with return line, and single-terminal grounding with return line were compared, as shown in Table 1: Table 1

[0052] A comparison with the calculation results of the power frequency impedance model established based on mathematical calculation software shows that the calculation results obtained by the two models are basically consistent.

[0053] Optionally, modeling can be performed after model verification. Taking a 110kV overhead, terrestrial, and submarine cable line project as an example, the terrestrial cable adopts a cross-interconnection and direct grounding method at both ends. Specifically, the cable metal sheath at the substation gas-insulated metal-enclosed switchgear terminal and the cable terminal outdoor terminal is grounded via a three-wire grounding box; at the insulation joint, the three-phase cable cores are transposed once, and simultaneously, the three-phase cable metal sheaths are transposed once through a cross-interconnection box, and then grounded through the sheath protector inside the cross-interconnection box. The newly built terrestrial cable is laid in ducts; the newly built submarine cable is 3.8km long, of which the unarmored section is laid vertically in a cable trench.

[0054] Considering the characteristics of overhead conductors, five equivalent models can be established in series. For land cables, three cross-connected cable segments can be connected in series, using a core transposition method. Simultaneously, a single submarine cable model and a model of the unarmored section of the submarine cable are established. This application's embodiment focuses on analyzing the sheath and armor layer circulation currents; therefore, the armor-stripped portion of the landing section is ignored, and the submarine cable uses a direct grounding method at both ends.

[0055] See Figure 2 The image shows a cross-section of a submarine cable. The submarine cable includes multiple sequentially nested annular layers. For example, the submarine cable may include, from the center to the outer perimeter, a conductor 1, a conductor shield 2, insulation 3, insulation shield 4, a semi-conductive resistive water expansion strip 5, a lead sheath 6, a polyethylene sheath 7, an impregnated rope 8, and a galvanized steel wire armor 9. The impregnated rope 8 may be provided in multiple layers and may be disposed on the inner and outer sides of the galvanized steel wire armor 9. The submarine cable may also include an optical cable 10, which may be located inside the galvanized steel wire armor 9 and may be threaded on the impregnated rope 8.

[0056] In an optional embodiment, after using the ratio of galvanized steel wire to copper wire in the equivalent model of the target armor layer as reference design information for the submarine cable, the submarine cable data processing method further includes: the submarine cable data processing system can determine the circulating current magnitude of the metal sheath, the circulating current magnitude of the armor layer, the circulating current loss value of the metal sheath, the circulating current loss value of the armor layer, and the total circulating current loss value of the submarine cable when applying each equivalent armor layer model, based on the cable circulating current distribution data corresponding to the application of the i-th equivalent armor layer model, where i is an integer greater than or equal to 1. Then, based on the circulating current magnitude of the metal sheath, the circulating current magnitude of the armor layer, the circulating current loss value of the metal sheath, the circulating current loss value of the armor layer, and the total circulating current loss value of the submarine cable, the inductance value of the sheath inductance of the submarine cable when using the i-th equivalent armor layer model as the target equivalent armor layer model is determined, where the sheath inductance is the inductance connected in series on both sides of the metal sheath of the submarine cable.

[0057] Optionally, when analyzing submarine cable performance, the submarine cable data processing system will calculate in detail the circulating current magnitude and corresponding loss values ​​of the metal sheath and armor layer, as well as the total circulating current loss value of the entire submarine cable, based on the cable circulating current distribution data when applying the equivalent model of the i-th armor layer. Specifically, the submarine cable data processing system obtains the circulating current magnitude in the metal sheath and armor layer through simulation calculations. These circulating current magnitudes directly reflect the current distribution in the sheath and armor layer. Simultaneously, the submarine cable data processing system also calculates the circulating current loss values ​​of the metal sheath and armor layer. These circulating current loss values ​​are derived from the circulating current magnitude and the resistance of the sheath and armor layer, reflecting the heat loss generated when the current flows in the sheath and armor layer. The total circulating current loss value characterizes the sum of the losses of the metal sheath and armor layer, directly related to the cable's operating efficiency and energy consumption, facilitating the evaluation of the performance of different armor layer equivalent models.

[0058] Optionally, after determining the circulating current magnitude of the metal sheath, the circulating current magnitude of the armor layer, the circulating current loss value of the metal sheath, the circulating current loss value of the armor layer, and the total circulating current loss value of the submarine cable, the submarine cable data processing system further determines the inductance value of the sheath inductance for the submarine cable when the i-th armor layer equivalent model is used as the target armor layer equivalent model. The sheath inductance characterizes the inductance connected in series on both sides of the metal sheath of the submarine cable, and its function is to reduce losses by limiting the circulating current in the sheath. By analyzing the circulating current magnitude and loss value, the submarine cable data processing system calculates a suitable inductance value to ensure that the circulating current in the sheath is effectively controlled under this armor layer configuration, thereby further optimizing the cable performance. This not only considers the impact of the armor layer material ratio on cable performance but also achieves a better operating state by adjusting the sheath inductance, ensuring that the cable can achieve optimal current carrying capacity and minimum loss in practical applications.

[0059] In an optional embodiment, the method for processing submarine cable data further includes: the submarine cable data processing system can determine the number of segments of the metal sheath and the number of segments of the armor layer of the submarine cable according to the design length of the submarine cable, wherein each segment of the metal sheath and the armor layer is grounded to the seabed, the design length of the submarine cable is positively correlated with the number of segments of the metal sheath, and the design length of the submarine cable is positively correlated with the number of segments of the armor layer.

[0060] Optionally, when designing submarine cables, the submarine cable data processing system can determine the number of segments for the metal sheath and armor layer based on the cable's design length. The cable's length directly affects its electrical performance and thermal stability. Specifically, longer submarine cables generate greater induced voltage and circulating current during operation, potentially leading to excessively high voltage differences between the metal sheath and armor layer, thus increasing the risk of breakdown. To reduce this risk, the submarine cable data processing system can calculate an appropriate number of segments based on the cable's design length, ensuring that the metal sheath and armor layer of each segment are grounded to the seabed. This grounding connection effectively reduces the induced voltage in the sheath and armor layer, decreases circulating current losses, and improves the cable's operational safety and reliability.

[0061] Optionally, the design length of a submarine cable is positively correlated with the number of segments in its metal sheath and armor layer. That is, the longer the cable, the more segments are required. This is because longer cables need more grounding connection points to distribute induced voltage and circulating current, thereby ensuring the electrical performance and thermal stability of the entire cable system. For example, shorter submarine cables may require fewer segments and grounding connection points; while longer cables require more segments and grounding connection points to effectively control induced voltage and circulating current. This allows the submarine cable data processing system to optimize the number of segments in the metal sheath and armor layer based on the specific design length of the cable.

[0062] In an optional embodiment, the method for processing submarine cable data further includes: the submarine cable data processing system can determine that the material type of the submarine cable is semi-conductive polyethylene material when it detects that the designed length of the submarine cable is greater than a preset length.

[0063] Optionally, the submarine cable data processing system has the function of detecting the design length of the submarine cable. When the submarine cable data processing system detects that the design length of the submarine cable exceeds a preset threshold length, it will automatically trigger the material type selection logic. The preset length can be set according to engineering experience and safety standards to determine whether special materials are needed to meet the electrical and mechanical performance requirements of the cable.

[0064] In this situation, the submarine cable data processing system can determine that the submarine cable is made of semi-conductive polyethylene. The reason for choosing semi-conductive polyethylene is its electrical properties. Semi-conductive polyethylene can effectively prevent excessively high induced potentials on the metallic sheath, and in the event of a short circuit in the middle of the submarine cable, it can avoid the risk of breakdown of the inner sheath due to excessive potential difference, thus ensuring the electrical safety and reliability of the submarine cable during long-distance laying.

[0065] In one optional embodiment, an engineering simulation model of the submarine cable is constructed based on the submarine cable engineering documents. This includes: a submarine cable data processing system constructing an initial engineering model of the submarine cable based on various engineering parameters in the submarine cable engineering documents. The initial engineering model includes the structural parameters of the submarine cable, grounding configuration, and electrical parameters of the surrounding environment. Then, simulation parameters matching the cable operating conditions in the submarine cable engineering documents are set. These simulation parameters include the simulation time length, power supply configuration parameters, analysis frequency range, and load characteristic parameters. Finally, the simulation parameters are applied to the initial engineering model to obtain the engineering simulation model of the submarine cable.

[0066] Optionally, the submarine cable data processing system first constructs an initial engineering model based on the various engineering parameters in the submarine cable engineering documents. This process involves detailed input of structural parameters of the submarine cable, such as the cable cross-section and insulation thickness, grounding configurations such as grounding method and grounding location, and electrical parameters of the surrounding environment, such as soil resistivity and seawater conductivity, so that they can collectively form an initial model that can reflect the basic characteristics of the submarine cable.

[0067] After constructing the initial engineering model, the submarine cable data processing system can set simulation parameters that match the cable operating conditions in the submarine cable engineering documents. These simulation parameters may include simulation time length to determine the duration of the simulation process, power configuration parameters such as voltage level and power type, analysis frequency range to evaluate cable performance at different frequencies, and load characteristic parameters such as load size and load type. By applying these simulation parameters to the initial engineering model, the submarine cable data processing system can perform a series of complex calculations and simulations, ultimately generating an engineering simulation model of the submarine cable. This engineering simulation model can accurately simulate the electrical behavior of the submarine cable under actual operating conditions.

[0068] Optionally, circulating current and eddy current losses are key factors determining the heating of submarine cables and affecting their current carrying capacity. Simulation analysis of the established submarine cable model helps to understand the influence of different armor layers on submarine cable losses, thus providing a theoretical basis for optimizing submarine cable structures. For example, to compare the impact of different armor layers on circulating current, the following compares the circulating current conditions of submarine cables with three types of armor: copper wire armor, galvanized steel wire armor, and stainless steel wire armor.

[0069] In the engineering simulation model of submarine cables, the armor layer is assumed to be a metal ring, while from... Figure 2 The cross-sectional diagram of the submarine cable shows that the armor layer of the submarine cable is made of a single layer of wound metal wire. To make the model more accurate, the cross-section of the submarine cable can be converted according to formula (1): Formula (1) Where k represents the conversion ratio; Used to represent the area of ​​a metal ring; This is used to represent the actual area of ​​the armor layer steel wire. The actual area of ​​the armor layer steel wire is equal to the product of the number of steel wires and the cross-sectional area of ​​a single steel wire. The area of ​​the steel wire armor is directly proportional to the number of steel wires. The number of steel wires needs to be determined using the outer diameter dimension, which can be determined based on the commonly used steel wire diameter of 5mm or 6mm provided by the processor.

[0070] The number of steel wires n can be referred to formula (2): Formula (2) As can be seen, the submarine cable armor layer in this embodiment of the application has a maximum of 57 steel wires laid, and the armor layer conversion factor can be obtained accordingly.

[0071] Therefore, the resistivity of the armor layer is set. Considering that the mutual inductance between submarine cables is related to their size, the cable size is not changed when modeling the submarine cables; only the resistivity is calculated. See Table 2 for reference. Table 2

[0072] Through simulation calculations, the circulating currents of the sheath and armor layer when the armor layer is made of three different materials can be obtained as shown in Table 3, such as copper, galvanized steel wire (relative permeability is taken as 1, i.e., magnetic permeability is ignored), and stainless steel wire: Table 3

[0073] Considering factors such as the gaps between the steel wires in the armor layer, the equivalent relative permeability of the galvanized steel wire is related to the structure. The circulation distributions at relative permeabilities of 1, 300, 600, and 1500 are shown below to determine the influence of relative permeability on the circulation distribution. See Table 4 for reference. Table 4

[0074] It can be seen that the armor layer current decreases as the resistivity of the armor layer material increases. By comparison, it can be seen that the sum of the sheath circulating current and the armor layer circulating current is approximately equal to the near-core current (peak value 890A), which means that the sheath layer and the armor layer can be considered as approximately equivalent to a current shunt model.

[0075] The losses in the sheath and armor layer are direct factors affecting current carrying capacity, and the losses are proportional to the resistance. The sheath resistance can be obtained from the resistivity, referring to formula (3): Formula (3) in, Used to indicate sheath resistance; Used to represent the resistivity of lead sheaths; Used to indicate the length of the lead sheath; Used to indicate the cross-sectional area of ​​the lead sheath.

[0076] Similarly, the resistance of the armor layer can be obtained, see Table 5: Table 5

[0077] Therefore, the total single-phase circulating current loss can be obtained, see Table 6: Table 6

[0078] When considering the relative permeability of galvanized steel wire, the circulating current loss is obtained, see Table 7: Table 7

[0079] As can be seen from the above, the metallic sheath and armor layer of a submarine cable can be considered as an equivalent parallel current-sharing model of resistance. The lower the resistivity of the armor layer, the lower the total circulating current loss. Therefore, the higher the relative permeability of the armor layer, the greater the circulating current in the sheath, and the greater the total circulating current loss.

[0080] Without considering the permeability, the total circulating current loss of galvanized steel wire armor is significantly less than that of stainless steel wire armor. However, if the relative permeability of galvanized steel wire is considered to be 300, the total circulating current loss of galvanized steel wire armor is basically the same as that of stainless steel wire armor. If the permeability is calculated to be 600, the total circulating current loss of galvanized steel wire armor is even slightly greater than that of stainless steel wire armor.

[0081] Optionally, armor materials can be classified as ferromagnetic or non-ferromagnetic. For example, among commonly used armor materials, galvanized steel wire is magnetic, while stainless steel wire and copper wire are non-ferromagnetic. The losses in the sheath are mainly circulating losses, with eddy current losses being very small and negligible. When the relative permeability is 1500, the eddy current losses in the armor layer are essentially equal to the circulating losses. Meanwhile, the spacing between the galvanized steel wires has a significant impact on eddy current losses; when the spacing reaches 0.03 mm, the eddy current losses are reduced to 3% of the eddy current losses without spacing.

[0082] Eddy current losses in the sheath can be ignored. Galvanized steel wire is used as the armor layer. Considering the cable structure, the calculated spacing of the galvanized steel wires is approximately 0.03 mm. The relative permeability of the galvanized steel wire can be assumed to be 121, and the eddy current loss in the armor layer is taken as 3% of the circulating current loss in the armor layer (approximately 8 kW). Refer to Table 8 for the galvanized steel wire armor circulating current loss after correcting for the relative permeability.

[0083] Table 8

[0084] To further reduce eddy current losses in the armor layer, a magnetic shielding method can be adopted, which involves placing copper wires or other non-magnetic materials at intervals within the galvanized steel wire layer. Adding copper wires for magnetic shielding is particularly noteworthy; this not only reduces circulating current losses but also lowers the overall resistivity of the armor layer, thereby reducing the total circulating current loss.

[0085] In one optional embodiment, N equivalent armor layer models are constructed based on the engineering simulation model of the submarine cable. This includes: the submarine cable data processing system constructs an initial equivalent armor layer model based on the engineering simulation model. The initial equivalent armor layer model is used to simulate the initial ratio of galvanized steel wire to copper wire in the armor layer, including the resistivity and permeability parameters of the galvanized steel wire and copper wire. Then, based on the initial equivalent armor layer model, N-1 target operations are performed to obtain N-1 new equivalent armor layer models. Each target operation is used to generate a new equivalent armor layer model by changing the quantity ratio and arrangement of copper wire and galvanized steel wire based on the initial equivalent armor layer model.

[0086] Optionally, based on the constructed engineering simulation model, the submarine cable data processing system first creates an initial equivalent model of the armor layer. This initial equivalent model simulates the initial ratio of galvanized steel wire to copper wire in the armor layer, and considers the resistivity and permeability parameters of these two materials in detail. The resistivity parameter reflects the degree to which the material impedes current, while the permeability parameter is related to the magnetic permeability of the material. Through these parameters, the initial equivalent model of the armor layer can accurately simulate the electrical characteristics of the armor layer under the initial ratio.

[0087] Optionally, after creating the initial equivalent armor layer model, the submarine cable data processing system performs N-1 target operations, each based on the initial equivalent armor layer model. These target operations generate new equivalent armor layer models by changing the ratio of copper wires to galvanized steel wires and their arrangement. For example, the number of copper wires can be increased or decreased, or the order of the copper and galvanized steel wires can be changed, thus generating different armor layer structures. Each operation produces a new equivalent armor layer model, ultimately resulting in N-1 new equivalent armor layer models. These new equivalent armor layer models will be used for further simulation analysis to evaluate the armor layer performance under different ratios and arrangements, thereby determining the optimal armor layer design.

[0088] For example, in a certain 110kV overhead, terrestrial cable, and submarine cable line project, the 110kV-800... For submarine cables with cross-sections, the armor layer scheme of 55 galvanized steel wires + 2 copper wires proposed in the embodiments of this application is adopted. Simulation analysis verifies that after the armor layer structure is optimized by the method proposed in this application, the current carrying capacity of the submarine cable is increased by about 20%. By using the sheath through resistance or reactance, the single-phase total loss can be further reduced by about 12.5%.

[0089] In one optional embodiment, based on an engineering simulation model, the cable circulating current distribution data corresponding to the application of each armor layer equivalent model is determined through simulation calculation. This includes: the submarine cable data processing system can set cable operating environment conditions for each armor layer equivalent model, wherein the cable operating environment conditions include: power specifications, frequency characteristics, and short-circuit fault scenarios. Then, based on the cable operating environment conditions, simulation calculations are performed on the engineering simulation model and each armor layer equivalent model to obtain the cable circulating current distribution data corresponding to the application of each armor layer equivalent model. The cable circulating current distribution data at least includes the current characteristics of the submarine cable under steady-state and transient conditions that evolve over time, and the current characteristics include current magnitude and current direction.

[0090] Optionally, when simulating the equivalent model of the armor layer, the submarine cable data processing system first sets specific cable operating environment conditions for each armor layer equivalent model. These operating environment conditions include power specifications such as voltage level and power type, frequency characteristics such as power frequency and high frequency, and short-circuit fault scenarios such as single-phase short circuit and three-phase short circuit. These operating environment conditions are set to simulate various electrical conditions that submarine cables may encounter in actual use, ensuring that the simulation results accurately reflect the cable's performance under different operating conditions.

[0091] Optionally, after setting the cable operating environment conditions, the submarine cable data processing system will perform detailed simulation calculations on the engineering simulation model and the equivalent model of each armor layer based on these conditions. Through simulation, the submarine cable data processing system can obtain the cable circulating current distribution data corresponding to the application of the equivalent model of each armor layer. This cable circulating current distribution data includes not only the circulating current distribution of the cable under steady-state conditions, but also the current characteristics that change over time under transient conditions such as when a short-circuit fault occurs. These current characteristics specifically include the magnitude and direction of the current, which can help users understand in detail the current distribution of different armor layer designs under various operating conditions.

[0092] Alternatively, circulating current and eddy current losses are the main factors affecting the current carrying capacity of submarine cables. Analysis of the circulating current in submarine cables reveals that copper wire armor minimizes the total circulating current loss. However, considering that copper wire armor is significantly more expensive than galvanized steel wire, galvanized steel wire is commonly used for the armor layer of submarine cables in practical engineering. Galvanized steel wire is a magnetic material and therefore exhibits some eddy current loss.

[0093] The armor layer uses a combination of galvanized steel wire and copper wire. This serves two purposes: magnetic shielding and reducing overall circulating current loss. However, considering the increased cost of copper wire, and taking into account the secondary magnetic shielding and the cable dimensions, a configuration of 55 galvanized steel wires and 2 copper wires is chosen. This results in a calculated overall resistivity of 11.1E-8Ω. m, the area after conversion is 14.2E-8Ω m, the equivalent relative permeability can also be calculated to be approximately 23.

[0094] Therefore, the relevant parameters for the armor using 55 galvanized steel wires + 2 copper wires obtained from the simulation are shown in Table 9: Table 9

[0095] Considering the impact of eddy current losses, the eddy current losses after magnetic shielding are approximately 60% of those without magnetic shielding, which is 4.8kW. Eddy current losses are less than circulating current losses. Therefore, the total single-phase loss is 106.8kW, approximately 60% of the total single-phase loss of 177kW without copper wire. Furthermore, the reduced losses from the metal sheath and armor layer also contribute to increased current carrying capacity.

[0096] Based on the above analysis, if the armor layer uses 2 copper wires + 55 galvanized steel wires, compared to 800... The three-phase loss of the fully galvanized steel wire armored submarine cable can be compared with that of the fully galvanized steel wire armored submarine cable. See Table 10: Table 10

[0097] It can be seen that an annual saving of approximately 237,400 yuan can be achieved by adding copper wire to galvanized steel wire, which can greatly reduce the total loss.

[0098] 800 Substituting the circulating current loss and eddy current loss calculated from the cross-sectional simulation model into the current carrying capacity calculation, the current carrying capacity of the armor layer using galvanized steel wire is calculated to be 680A, while the current carrying capacity after adopting the optimized structure proposed in this application is 816A, an increase of approximately 136A. Simultaneously, it is necessary to verify the thermal stability of the copper wire under short-circuit conditions. Considering a peak current of 5410A in the armor layer and a short-circuit time of 1.2s, the effective current of the copper wire can be calculated to be 889A, with a minimum cross-sectional area of ​​7.15. It is much smaller than the cross-sectional area of ​​two copper wires, which is 56.5. It meets the requirements of the regulations.

[0099] Optionally, reducing the circulating current in the sheath can reduce the total circulating current loss, thereby increasing the current carrying capacity of the submarine cable. As the previous analysis also shows, using a series resistor can further reduce the current in the sheath, thus reducing the total single-phase loss of the submarine cable. Refer to Table 11 for the relevant parameters when a 2-ohm resistor is connected in series in the sheath.

[0100] Table 11

[0101] As can be seen from the above, the total single-phase loss is 133kW, which is about 75% of the total single-phase loss of 177kW without copper wire. However, inserting a series resistor will generate an additional voltage on the sheath, increasing the induced voltage on the sheath. Therefore, equivalent resistors can be inserted in series at both input points of the sheath instead of only one end to reduce the induced voltage.

[0102] Alternatively, series resistors can effectively limit circulating current in the sheath and reduce the total circulating current loss of the submarine cable. However, due to the presence of circulating current, the loss on the resistor is relatively large during normal operation, and the current on the resistor will be very large during short-circuit faults. The selection of the resistor and heat dissipation measures need to be considered, and the loss on the resistor will be included in the line loss, resulting in waste. It is not difficult to imagine that current limiting can also be achieved by using series reactors, and the total active power loss will be greatly reduced.

[0103] Refer to Table 12 for the relevant parameters when 1mH inductors are connected in series on both sides of the sheath: Table 12

[0104] As can be seen from the above, it is approximately 79.7% of the total single-phase loss of 177kW without copper wire.

[0105] Refer to Table 13 for the relevant parameters when 3mH inductors are connected in series on both sides of the sheath: Table 13

[0106] As can be seen from the above, it is approximately 67.2% of the total single-phase loss of 177kW without copper wire.

[0107] It is evident that adding 3mH inductors on both sides of the sheath can further reduce the total single-phase loss by approximately 12.5%. If the submarine cable is long, the inductors may cause oscillations during short-circuit faults. To suppress current oscillations, the submarine cable sheath and armor layer can be connected to the seabed in segments. For ease of analysis, this simulation model can be divided into two segments, which can reduce the capacitive effect of long-distance submarine cables and suppress oscillations. However, since the inductors are only connected at the sheath entry points at both ends, the current-limiting effect of the inductors on the middle section of the submarine cable sheath is limited. Another approach is to replace the inner sheath layer with semi-conductive polyethylene. Since the sheath layer and armor layer are connected through a semi-conductive medium, distributed grounding can also suppress oscillations.

[0108] Alternatively, the advantage of using a semiconductive material as a liner for distributed grounding of the metal sheath is that, under the same metal sheath loss, it can prevent excessively high induced potential on the metal sheath, but the circulating current in the sheath and armor layer is still similar to that of the insulating inner sheath.

[0109] See Figure 3 This paper illustrates the current distribution between the metallic sheath and armor layers when a semiconducting inner sheath is used. Specifically, the cross-sectional structure of a submarine cable may include a semiconducting pad, a metallic sheath, a conductor, and an insulation layer. Distributed grounding of the metallic sheath through the semiconducting pad helps to achieve uniform current distribution and opposite-direction cancellation, reducing cable losses during operation and increasing the cable's current carrying capacity. The current loop formed between the metallic sheath and the semiconducting pad helps to suppress overvoltage on the cable sheath, thereby enhancing the cable's operational safety and reliability. During normal operation and short circuits outside the submarine cable line, the potential rise of both the metallic sheath and the armor layer changes linearly. The potential difference between them at any point in the submarine cable segment is zero, and there is no problem with inner sheath breakdown. However, during short circuits within the submarine cable line, the potential difference between the metallic sheath and the armor layer is large, and the potential difference increases with the length of the line, even exceeding the insulation withstand voltage level of the inner sheath, leading to large-area breakdown of the inner sheath.

[0110] If we consider that the inner sheath of the submarine cable is made of insulating material, and consider the effective values ​​of the interlayer voltage between the metallic sheath and the armor when a short circuit occurs at different points on the submarine cable, refer to Table 14: Table 14

[0111] It is evident that the voltage difference between the metallic sheath and the armor layer reaches its maximum when a short circuit occurs in the middle of the submarine cable. Table 15 shows the voltage differences between the metallic sheath and the armor layer when a short circuit occurs in the middle of different submarine cable lengths. Table 15

[0112] Calculations show that when the submarine cable is 16km long, the effective voltage difference is 10223V, which is greater than 10kV and may cause the inner sheath to break down. Therefore, a semi-conductive inner sheath is considered.

[0113] This application's embodiments start with the circulating loss and eddy current loss, which are important factors limiting the current carrying capacity of submarine cables. An engineering simulation model of the submarine cable is established, the circulating characteristics of the sheath and armor layers of the submarine cable are analyzed, the eddy current loss characteristics of the submarine cable are briefly analyzed, and an optimization scheme for the submarine cable structure is proposed based on the obtained rules. The feasibility of the optimization scheme is verified through simulation.

[0114] Analysis of the established engineering simulation model of submarine cables yielded the following conclusions: the sum of the circulating current in the sheath and the circulating current in the armor layer of the submarine cable is approximately equal to the core current; when using magnetic materials such as galvanized steel wire as the armor layer, gradually increasing the relative permeability will decrease the circulating current in the armor layer and increase the total circulating current loss of the submarine cable. However, because the gaps in the armor layer itself can significantly reduce the magnetic permeability of the armor layer, the circulating current in the galvanized steel wire armor layer used in engineering is larger than the theoretical value, and the total circulating current loss is not too large. By incorporating copper wire into the galvanized steel wire, it can both provide magnetic shielding and reduce the overall resistivity, increasing the circulating current in the armor layer and reducing the total circulating current loss. Comparative analysis shows that even when the armor layer is not very tight, adding copper wire to provide magnetic shielding will still reduce the relative permeability, thereby reducing some of the total circulating current loss. For submarine cables, the proportion of eddy current loss is relatively small. The main function of adding copper wire to the galvanized steel wire is to reduce the total circulating current loss, thereby increasing the current carrying capacity of the submarine cable. Analysis shows that the main function of galvanized steel wire + copper wire is to significantly reduce circulating current loss, resulting in excellent economic benefits. Furthermore, reduced loss also improves current carrying capacity, therefore, galvanized steel wire + copper wire is recommended. The reason for using a semi-conductive inner sheath in submarine cables is analyzed: the semi-conductive layer avoids the risk of large-area breakdown of the inner sheath caused by a short circuit in the middle of a submarine cable with an insulated inner sheath. Simulations show that if an insulated inner sheath is used, a short circuit in the middle of the submarine cable beyond a certain length will cause large-area breakdown of the inner sheath. To further reduce sheath circulating current, this application embodiment also uses series resistance and inductance methods, analyzing their advantages and disadvantages. Finally, through comparative analysis and practical considerations, an optimized scheme using 55 galvanized steel wires + 2 copper wires for the submarine cable structure, with a semi-conductive inner sheath, is proposed, and the thermal stability of the copper wire during a short circuit is verified.

[0115] See Figure 4According to another aspect of the embodiments of this application, a submarine cable data processing device is also provided, including: an engineering file acquisition unit 401, a simulation model construction unit 402, an equivalent model construction unit 403, a cable data determination unit 404, and a target model processing unit 405.

[0116] The system includes: an engineering document acquisition unit 401 for acquiring submarine cable engineering documents, which include at least the structural parameters, laying method, grounding method, and maximum load of the submarine cable; a simulation model construction unit 402 for constructing an engineering simulation model of the submarine cable based on the engineering documents; an equivalent model construction unit 403 for constructing N equivalent armor layer models based on the engineering simulation model of the submarine cable, where N is an integer greater than 1, and different equivalent armor layer models are used to simulate cable armor layers with different ratios of galvanized steel wire and copper wire; and a cable data determination unit. 404 is used to determine the cable circulation distribution data corresponding to each armor layer equivalent model of the submarine cable through simulation calculation based on the engineering simulation model. The cable circulation distribution data includes at least the circulation distribution data corresponding to the metal sheath and armor layer of the submarine cable respectively. The target model processing unit 405 is used to determine the target armor layer equivalent model from N armor layer equivalent models based on the cable circulation distribution data corresponding to each armor layer equivalent model of the submarine cable, and use the ratio of galvanized steel wire to copper wire in the target armor layer equivalent model as the reference design information of the submarine cable.

[0117] Optionally, the target model processing unit 405 includes: an eddy current distribution determination subunit, used to determine the cable eddy current distribution data corresponding to each armor layer equivalent model of the submarine cable by simulation calculation based on the engineering simulation model, wherein the cable eddy current distribution data includes at least the circulation distribution data corresponding to the armor layer of the submarine cable; and a target model determination subunit, used to determine the target armor layer equivalent model from N armor layer equivalent models based on the cable circulation distribution data and cable eddy current distribution data corresponding to each armor layer equivalent model of the submarine cable.

[0118] Optionally, the submarine cable data processing device further includes: a circulating current parameter determination unit, used to determine the circulating current magnitude of the metal sheath, the circulating current magnitude of the armor layer, the circulating current loss value of the metal sheath, the circulating current loss value of the armor layer, and the total circulating current loss value of the submarine cable when applying each armor layer equivalent model, based on the cable circulating current distribution data corresponding to the application of the i-th armor layer equivalent model of the submarine cable, where i is an integer greater than or equal to 1; and a sheath inductance determination unit, used to determine the inductance value of the sheath inductance of the submarine cable when the i-th armor layer equivalent model is used as the target armor layer equivalent model, based on the circulating current magnitude of the metal sheath, the circulating current magnitude of the armor layer, the circulating current loss value of the metal sheath, the circulating current loss value of the armor layer, and the total circulating current loss value of the submarine cable, where the sheath inductance is the inductance connected in series on both sides of the metal sheath of the submarine cable.

[0119] Optionally, the submarine cable data processing device further includes: a segment number determination unit, used to determine the number of segments of the metal sheath and the number of segments of the armor layer of the submarine cable according to the design length of the submarine cable, wherein each segment of the metal sheath and the armor layer is grounded to the seabed, the design length of the submarine cable is positively correlated with the number of segments of the metal sheath, and the design length of the submarine cable is positively correlated with the number of segments of the armor layer.

[0120] Optionally, the submarine cable data processing device further includes a material type determination unit, used to determine that the material type of the submarine cable is semi-conductive polyethylene when the designed length of the submarine cable is detected to be greater than a preset length.

[0121] Optionally, the simulation model construction unit 402 includes: an initial engineering model construction subunit, used to construct an initial engineering model of the submarine cable based on various engineering parameters in the submarine cable engineering file, wherein the initial engineering model includes: structural parameters of the submarine cable, grounding configuration, and electrical parameters of the surrounding environment; a simulation parameter setting subunit, used to set simulation parameters that match the cable operating conditions in the submarine cable engineering file, wherein the simulation parameters include: simulation time length, power supply configuration parameters, analysis frequency range, and load characteristic parameters; and an engineering simulation model determination subunit, used to apply the simulation parameters to the initial engineering model to obtain the engineering simulation model of the submarine cable.

[0122] Optionally, the equivalent model construction unit 403 includes: an initial equivalent model construction subunit, used to construct an initial armor layer equivalent model based on the engineering simulation model, wherein the initial armor layer equivalent model is used to simulate the initial ratio of galvanized steel wire and copper wire in the armor layer, including the resistivity and permeability parameters of galvanized steel wire and copper wire; and a target operation processing subunit, used to perform N-1 target operations based on the initial armor layer equivalent model to obtain N-1 new armor layer equivalent models, wherein each target operation is used to generate a new equivalent armor layer model by changing the quantity ratio and arrangement of copper wire and galvanized steel wire based on the initial armor layer equivalent model.

[0123] Optionally, the cable data determination unit 404 includes: an operating environment setting subunit, used to set cable operating environment conditions for each armor layer equivalent model, wherein the cable operating environment conditions include: power specifications, frequency characteristics, and short-circuit fault scenarios; and a simulation calculation subunit, used to perform simulation calculations on the engineering simulation model and each armor layer equivalent model based on the cable operating environment conditions, to obtain the cable circulating current distribution data corresponding to the submarine cable when applying each armor layer equivalent model, wherein the cable circulating current distribution data includes at least the current characteristics of the submarine cable that change over time under steady-state and transient conditions, and the current characteristics include current magnitude and current direction.

[0124] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, which stores a computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located performs the above-described method for processing submarine cable data.

[0125] According to another aspect of the embodiments of this application, an electronic device is also provided, including one or more processors and a memory, the memory being used to store one or more programs, wherein when the one or more programs are executed by one or more processors, the one or more processors cause the one or more processors to perform the above-described method for processing submarine cable data.

[0126] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program or instructions, which, when executed by a processor, implement the above-described method for processing submarine cable data.

[0127] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0128] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0129] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0130] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0131] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0132] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0133] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for processing submarine cable data, characterized in that, include: Obtain submarine cable engineering documents, wherein the submarine cable engineering documents include at least the structural parameters, laying method, grounding method and maximum load of the submarine cable; An engineering simulation model of the submarine cable is constructed based on the submarine cable engineering documents. Based on the engineering simulation model of the submarine cable, N equivalent armor layer models are constructed, where N is an integer greater than 1. Different equivalent armor layer models are used to simulate cable armor layers with different ratios of galvanized steel wire and copper wire. Based on the engineering simulation model, the cable circulation distribution data corresponding to each armor layer of the submarine cable is determined by simulation calculation. The cable circulation distribution data includes at least the circulation distribution data corresponding to the metal sheath and armor layer of the submarine cable. Based on the cable circulation distribution data corresponding to each armor layer equivalent model of the submarine cable, a target armor layer equivalent model is determined from the N armor layer equivalent models, and the ratio of galvanized steel wire to copper wire in the target armor layer equivalent model is used as the reference design information for the submarine cable.

2. The method for processing submarine cable data according to claim 1, characterized in that, Based on the cable circulation distribution data corresponding to each armor layer equivalent model applied to the submarine cable, the target armor layer equivalent model is determined from the N armor layer equivalent models, including: Based on the engineering simulation model, the cable eddy current distribution data corresponding to each armor layer of the submarine cable is determined by simulation calculation. The cable eddy current distribution data includes at least the circulation distribution data corresponding to the armor layer of the submarine cable. Based on the cable circulation distribution data and cable eddy current distribution data corresponding to each armor layer equivalent model of the submarine cable, the target armor layer equivalent model is determined from the N armor layer equivalent models.

3. The method for processing submarine cable data according to claim 1, characterized in that, After using the ratio of galvanized steel wire to copper wire in the equivalent model of the target armor layer as reference design information for the submarine cable, the data processing method for the submarine cable further includes: Based on the cable circulation distribution data corresponding to the application of the equivalent model of the i-th armor layer of the submarine cable, the metal sheath circulation current size, armor layer circulation current size, metal sheath circulation current loss value, armor layer circulation current loss value and total circulation current loss value of the submarine cable are determined when each armor layer equivalent model is applied, where i is an integer greater than or equal to 1. Based on the circulating current magnitude of the metal sheath, the circulating current magnitude of the armor layer, the circulating current loss value of the metal sheath, the circulating current loss value of the armor layer, and the total circulating current loss value of the submarine cable, the inductance value of the sheath inductance of the submarine cable is determined when the equivalent model of the i-th armor layer is used as the equivalent model of the target armor layer, wherein the sheath inductance is the inductance connected in series on both sides of the metal sheath of the submarine cable.

4. The method for processing submarine cable data according to claim 1, characterized in that, The method for processing submarine cable data also includes: The number of segments in the metal sheath and the number of segments in the armor layer of the submarine cable are determined according to the design length of the submarine cable. Each segment of the metal sheath and the armor layer is grounded to the seabed. The design length of the submarine cable is positively correlated with the number of segments in the metal sheath and the number of segments in the armor layer.

5. The method for processing submarine cable data according to claim 1, characterized in that, The method for processing submarine cable data also includes: If the designed length of the submarine cable is found to be greater than the preset length, the material type of the submarine cable is determined to be semi-conductive polyethylene.

6. The method for processing submarine cable data according to claim 1, characterized in that, Based on the aforementioned submarine cable engineering documents, an engineering simulation model of the submarine cable is constructed, including: An initial engineering model of the submarine cable is constructed based on the various engineering parameters in the submarine cable engineering documents. The initial engineering model includes: the structural parameters of the submarine cable, the grounding configuration, and the electrical parameters of the surrounding environment. Set simulation parameters that match the cable operating conditions in the submarine cable engineering documents, wherein the simulation parameters include: simulation time length, power supply configuration parameters, analysis frequency range, and load characteristic parameters; The simulation parameters are applied to the initial engineering model to obtain the engineering simulation model of the submarine cable.

7. The method for processing submarine cable data according to claim 1, characterized in that, Based on the engineering simulation model of the submarine cable, N equivalent models of the armor layer are constructed, including: An initial equivalent model of the armor layer is constructed based on the engineering simulation model. The initial equivalent model of the armor layer is used to simulate the initial ratio of galvanized steel wire and copper wire in the armor layer, including the resistivity and permeability parameters of galvanized steel wire and copper wire. Based on the initial armor layer equivalent model, N-1 target operations are performed to obtain N-1 new armor layer equivalent models. Each target operation is used to generate a new equivalent armor layer model by changing the quantity ratio and arrangement of copper wire and galvanized steel wire based on the initial armor layer equivalent model.

8. The method for processing submarine cable data according to claim 1, characterized in that, Based on the engineering simulation model, the cable circulation distribution data corresponding to each armor layer of the submarine cable is determined through simulation calculations, including: For each armor layer equivalent model, cable operating environment conditions are set, including: power specifications, frequency characteristics, and short-circuit fault scenarios. Based on the cable operating environment conditions, the engineering simulation model and the equivalent model of each armor layer are simulated and calculated to obtain the cable circulation current distribution data corresponding to the submarine cable when applying the equivalent model of each armor layer. The cable circulation current distribution data includes at least the current characteristics of the submarine cable that change with time under steady-state and transient conditions, and the current characteristics include current magnitude and current direction.

9. A device for processing submarine cable data, characterized in that, include: The engineering document acquisition unit is used to acquire submarine cable engineering documents, wherein the submarine cable engineering documents include at least the structural parameters, laying method, grounding method and maximum load of the submarine cable; The simulation model construction unit is used to construct an engineering simulation model of the submarine cable based on the submarine cable engineering files. The equivalent model construction unit is used to construct N armor layer equivalent models based on the engineering simulation model of the submarine cable, where N is an integer greater than 1. Different armor layer equivalent models are used to simulate cable armor layers with different ratios of galvanized steel wire and copper wire. The cable data determination unit is used to determine the cable circulation distribution data of the submarine cable when applying the equivalent model of each armor layer by means of simulation calculation based on the engineering simulation model. The cable circulation distribution data includes at least the circulation distribution data corresponding to the metal sheath and armor layer of the submarine cable respectively. The target model processing unit is used to determine the target armor layer equivalent model from the N armor layer equivalent models based on the cable circulation distribution data corresponding to each armor layer equivalent model of the submarine cable, and to use the ratio of galvanized steel wire to copper wire in the target armor layer equivalent model as the reference design information of the submarine cable.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein when the computer program is executed, the device containing the computer-readable storage medium performs the method for processing submarine cable data as described in any one of claims 1 to 8.

11. An electronic device, characterized in that, It includes one or more processors and a memory, the memory being used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to perform the method for processing submarine cable data as described in any one of claims 1 to 8.

12. A computer program product, characterized in that, It includes a computer program or instructions that, when executed by a processor, implement the method for processing submarine cable data according to any one of claims 1 to 8.

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