Method for calculating internal core current of dry-type direct current capacitor

Abstract

The application provides a dry-type DC capacitor internal core current calculation method, which comprises the following steps: constructing a branch for each capacitor core in the dry-type DC capacitor according to a current inflow path, and generating an equivalent circuit model corresponding to each branch; calculating the parameters of each element in each equivalent circuit model, wherein the total inductance value of the inductance element is calculated in combination with the electromagnetic coupling relationship in the dry-type DC capacitor; and calculating the current value of each capacitor core according to the current voltage acting on the dry-type DC capacitor, and the structure of each equivalent circuit model and the parameters of each element corresponding to each equivalent circuit model. The method considers the electromagnetic coupling relationship in the dry-type DC capacitor, can calculate the current value of each capacitor core in the capacitor, and is beneficial to guarantee the reliability of the capacitor.

Description

Technical Field

[0001] This application relates to the field of capacitor technology, and in particular to a method for calculating the core current of a dry DC capacitor. Background Technology

[0002] Currently, dry-type DC capacitors (also known as metallized film capacitors) are widely used in various fields due to their significant advantages such as small size, light weight, self-healing, and no risk of oil leakage or flammability. The reliability of dry-type DC capacitors plays a crucial role in the operation of the equipment in which they are used.

[0003] Dry-type DC capacitors have a complex structure, consisting of multiple capacitor cores. When high-frequency current flows through the capacitor, the current distribution among these cores becomes uneven and inconsistent. The overall reliability of the capacitor depends on the combined performance of all its internal capacitor cores; therefore, the current flowing through each core must be considered.

[0004] However, related technologies typically treat the entire dry-type DC capacitor as a single unit, ignoring internal variations and only considering the voltage and current at the capacitor ports. They assume the voltage and current across the capacitor cores are uniform, lacking a method for calculating the current across different capacitor core components. This results in poor reliability assessments of dry-type DC capacitors in these technologies, leading to potential safety hazards in the equipment.

[0005] Therefore, accurately calculating the specific current value of each capacitor core inside a dry DC capacitor has become an urgent problem to be solved. Summary of the Invention

[0006] This application aims to at least partially address one of the technical problems in the related art.

[0007] Therefore, the first objective of this application is to propose a method for calculating the core current of a dry DC capacitor. This method takes into account the electromagnetic coupling relationship inside the dry DC capacitor and can calculate the current value of each capacitor core inside the capacitor, which is beneficial to ensuring the reliability of the capacitor and solves the problem of how to calculate the specific value of the current on each capacitor core inside a dry DC capacitor.

[0008] The second objective of this application is to provide a system for calculating the core current inside a dry DC capacitor;

[0009] The third objective of this application is to provide a non-transitory computer-readable storage medium.

[0010] To achieve the above objectives, a first aspect of this application provides a method for calculating the core current of a dry-type DC capacitor, the method comprising the following steps:

[0011] Based on the current inflow path, a branch is constructed for each capacitor core inside the dry DC capacitor, and an equivalent circuit model corresponding to each branch is generated.

[0012] Calculate the parameters of each element in each of the equivalent circuit models, wherein the total inductance of the inductor element is calculated in conjunction with the electromagnetic coupling relationship inside the dry DC capacitor;

[0013] Based on the current voltage applied to the dry DC capacitor, the structure of each equivalent circuit model, and the parameters of each corresponding element, the current value of each capacitor core is calculated.

[0014] Optionally, in one embodiment of this application, the equivalent circuit model includes: a resistive element, a self-inductance element, a mutual inductance element, a capacitive element, and a leakage conductance element, wherein the second end of the resistive element is connected to the first end of the self-inductance element, and the second end of the self-inductance element is connected to the first end of the mutual inductance element; the second end of the mutual inductance element is connected to the first end of the capacitive element and the first end of the leakage conductance element; the first end of the resistive element, the second end of the capacitive element, and the second end of the leakage conductance element are the input terminals of the equivalent circuit model.

[0015] Optionally, in one embodiment of this application, calculating the total inductance value of the inductor element in conjunction with the electromagnetic coupling relationship inside the dry DC capacitor includes: calculating the self-inductance value of the inductor element; calculating the sum of the mutual inductance values ​​between the current branch and other branches in the dry DC capacitor (excluding the current branch); and adding the self-inductance value to the sum of the mutual inductance values ​​between the current branch and other branches to obtain the total inductance value of the current branch.

[0016] Optionally, in one embodiment of this application, the mutual inductance value between any of the other branches and the current branch is calculated using the following formula:

[0017]

[0018] Among them, M ij Let r be the mutual inductance value, r be the distance between the two branches, and l be the mutual inductance value. i Let l be the inductance of the current branch. j Let μ be the inductance of the j-th branch, where j represents any of the other branches, and μ is the permeability.

[0019] Optionally, in one embodiment of this application, a dry-type DC capacitor includes: a plurality of capacitor cores, a plurality of copper busbars, and a plurality of terminals, wherein the plurality of capacitor cores are connected in series and parallel through the plurality of copper busbars and metal wires, and a predetermined number of capacitor cores are connected in series in a column through a copper busbar; the terminals are used to introduce current into the corresponding copper busbar; the copper busbar is used to introduce current into each capacitor core in the column.

[0020] Optionally, in one embodiment of this application, after calculating the current value of each capacitor core, the method further includes: comparing the current value of each capacitor core to determine the target capacitor core to be adjusted; adjusting the parameters of the target capacitor core; and adjusting the parameters of the copper busbar corresponding to the target capacitor core.

[0021] To achieve the above objectives, a second aspect of this application also proposes a system for calculating the core current of a dry-type DC capacitor, comprising the following modules:

[0022] The generation module is used to construct a branch for each capacitor core inside the dry DC capacitor according to the current inflow path, and generate an equivalent circuit model corresponding to each branch.

[0023] The first calculation module is used to calculate the parameters of each element in each of the equivalent circuit models, wherein the total inductance value of the inductor element is calculated in combination with the electromagnetic coupling relationship inside the dry DC capacitor.

[0024] The second calculation module is used to calculate the current value of each capacitor core based on the current voltage applied to the dry DC capacitor, the structure of each equivalent circuit model, and the parameters of each corresponding element.

[0025] Optionally, in one embodiment of this application, the first calculation module is specifically used for: calculating the self-inductance value of the self-inductor element; calculating the sum of the mutual inductance values ​​of the other branches in the dry DC capacitor (excluding the current branch) and the current branch; and adding the self-inductance value to the sum of the mutual inductance values ​​of the other branches to the current branch to obtain the total inductance value of the current branch.

[0026] To implement the above embodiments, a third aspect of this application also proposes a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the method for calculating the core current of a dry DC capacitor as described in the above embodiments.

[0027] The technical solutions provided by the embodiments of this application offer at least the following beneficial effects: This application, by combining the electromagnetic coupling relationship within a dry-type DC capacitor, establishes an equivalent circuit model containing different core branches within the capacitor. Based on this equivalent circuit model, the specific current value on each branch capacitor core at different frequencies can be quantitatively calculated. Therefore, based on the accurate calculated current values ​​on the capacitor cores, the dry-type DC capacitor can be optimized in a targeted manner. By adjusting the parameters of the internal components, the current distribution on each core can be made uniform, enhancing the reliability of the capacitor. Furthermore, the reliability of the capacitor can be accurately assessed in applications, ensuring the normal and safe operation of the equipment in which the capacitor is located.

[0028] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0029] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0030] Figure 1 A flowchart illustrating a method for calculating the core current of a dry DC capacitor according to an embodiment of this application;

[0031] Figure 2 This is a schematic diagram of the structure of a specific dry-type DC capacitor proposed in an embodiment of this application;

[0032] Figure 3 This is a schematic diagram of the structure of an equivalent circuit model proposed in an embodiment of this application;

[0033] Figure 4 A flowchart illustrating a method for calculating inductance based on electromagnetic coupling relationships, as proposed in an embodiment of this application;

[0034] Figure 5 This is a schematic diagram illustrating the current distribution on different capacitor cores according to an embodiment of this application;

[0035] Figure 6 This is a schematic diagram of the structure of a dry-type DC capacitor internal core current calculation system proposed in an embodiment of this application. Detailed Implementation

[0036] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0037] It is important to note that the reliability of capacitors directly impacts the reliability of the equipment and even the entire project. For example, in the power generation field, converter valves are crucial equipment in new energy power generation and flexible DC transmission projects. They are mainly composed of power electronic switches (such as IGBTs) and dry-type DC capacitors. As a core component of the converter valve, the capacitor accounts for a large proportion in terms of quantity, size, and weight, directly affecting the quality and safety of power conversion. The reliability of the capacitor directly affects the reliability of the converter valve and even the entire transmission project. In practical applications, the voltage and current across the capacitor will change due to the operation of the power electronic switches. Under different topologies and control methods, the repetitive operation frequency of the power electronic switches ranges from several Hz to several kHz; and during the instantaneous switching on and off, the current frequency can reach several MHz. Therefore, the capacitor will be subjected to currents of different frequencies.

[0038] In related technologies, the high-frequency operating conditions brought about by converter valves are not considered. Evaluations are often conducted only under DC and AC power frequency conditions, resulting in inaccurate assessments of capacitors used in converter valves. Furthermore, the entire dry-type DC capacitor is typically treated as a single unit, ignoring internal dispersion, leading to poor accuracy in capacitor reliability assessments. While some solutions can somewhat uniformize the high-frequency current distribution across capacitor cores—for example, adding a transition copper strip to the middle of the core assembly connecting copper strip to achieve slightly more uniform current distribution at high frequencies; or varying the metal plating thickness of different areas of the capacitor core to ensure overall stability under high-frequency, high-current conditions—these solutions remain based on intuitive experience, lacking theoretical guidance and failing to obtain specific current values ​​for each capacitor core element. This is detrimental to the reliability of dry-type DC capacitors and the converter valves and other related equipment.

[0039] Therefore, this application proposes a method for calculating the core current of a dry DC capacitor. This method takes into account the electromagnetic coupling relationship inside the dry DC capacitor and can accurately calculate the current value of each capacitor core inside the capacitor.

[0040] The following description, with reference to the accompanying drawings, illustrates a method and system for calculating the core current of a dry-type DC capacitor according to an embodiment of the present invention.

[0041] Figure 1 This is a flowchart illustrating a method for calculating the core current of a dry-type DC capacitor according to an embodiment of this application, as shown below. Figure 1 As shown, the method includes the following steps:

[0042] Step S101: Construct a branch for each capacitor core inside the dry DC capacitor according to the current inflow path, and generate the equivalent circuit model corresponding to each branch.

[0043] The dry-type DC capacitor of this application is composed of hundreds of capacitor core components connected in series and parallel via metal leads and other components.

[0044] As an example, a dry-type DC capacitor consists of hundreds of capacitor core elements connected in series and parallel via metal wires and copper busbars. Figure 2 This is a schematic diagram of the structure of a specific dry-type DC capacitor proposed in an embodiment of this application, as shown below. Figure 2 As shown, the capacitor includes: multiple capacitor cores 10, multiple copper busbars 20, and multiple terminals 30.

[0045] In this configuration, multiple capacitor cores 20 are connected in series and parallel via multiple copper busbars 20 and metal wires. A preset number of capacitor cores 10 are connected in series in a column via a copper busbar 20, and the capacitor cores in each column are connected in parallel. The preset number of capacitor cores 10 in a column can be set according to actual needs, for example, such as... Figure 2 As shown, a column contains four capacitor cores 10. Each column of capacitors corresponds to a copper busbar 20 and a terminal 30.

[0046] Terminal 30 is used to introduce current into the corresponding copper busbar 20, and the copper busbar 20 is used to introduce current into each capacitor core 10 in this column. That is, external current flows into the busbar through the terminal, and then into each capacitor core through the copper busbar and metal leads.

[0047] Understandably, because the terminals are on one side of the capacitor, the paths of current flowing from the terminals to different capacitor cores differ. For example, the length and direction of different paths vary, and the copper busbars impede the current in each path differently; understandably, the longer the path, the greater the impediment. At high frequencies, these differences become particularly pronounced.

[0048] Therefore, due to the different paths of current flow into the capacitor core caused by the capacitor's structure, this application constructs a branch for each capacitor core inside the dry-type DC capacitor based on the current flow path and generates an equivalent circuit model corresponding to each branch. In one embodiment of this application, the branch includes the entire path from the initial end of the copper busbar to the capacitor core, and an equivalent circuit model is constructed for each component involved in this path.

[0049] That is, this application intends to calculate the current on different capacitor cores by establishing an equivalent circuit model of the capacitor's internal circuit. A branch is established for each capacitor core, and each capacitor core can be generally equivalent to a capacitor.

[0050] As one possible implementation method, Figure 3 This is a schematic diagram of an equivalent circuit model proposed in an embodiment of this application, such as... Figure 3As shown, the equivalent circuit model includes: a resistor (R)1, a self-inductance element (L)2, a mutual inductance element (M)3, a capacitor (C)4, and a leakage conductivity element (G)5.

[0051] In this circuit model, the second terminal of resistor 1 is connected to the first terminal of inductor 2, and the second terminal of inductor 2 is connected to the first terminal of mutual inductor 3. The second terminal of mutual inductor 3 is connected to the first terminal of capacitor 4 and the first terminal of leakage conductance element 5. The first terminal of resistor 1, the second terminal of capacitor 4, and the second terminal of leakage conductance element 5 are the input terminals of this circuit model, through which external current is connected.

[0052] Step S102: Calculate the parameters of each component in each equivalent circuit model, wherein the total inductance of the inductor is calculated in combination with the electromagnetic coupling relationship inside the dry DC capacitor.

[0053] Specifically, the parameters of each equivalent element in the equivalent circuit model are calculated based on the parameters of the copper busbars, capacitor cores, and other components in the branch.

[0054] Continue to refer to Figure 3 In the example shown, the parameter values ​​of resistor 1 and leakage conductor 5 can be determined based on the shape and material parameters of the copper busbar in the current branch, and the capacitance value of capacitor 4 can be determined based on the parameters of the copper busbar and capacitor core in the current branch.

[0055] Furthermore, when calculating the inductance value of inductor elements, since the current in each branch is affected by the current in other parts, the electromagnetic coupling relationship inside the capacitor needs to be fully considered. That is, when calculating the inductance value in the equivalent circuit model, this application needs to consider the mutual inductance of other branches to this branch, in addition to the self-inductance of the branch itself. The total inductance value of the inductor elements in the branch is obtained based on the self-inductance value of inductor element 2 and the mutual inductance value of mutual inductor element 3.

[0056] To more clearly illustrate the specific implementation process of calculating the total inductance value of inductor components based on the electromagnetic coupling relationship within a dry-type DC capacitor, the following example demonstrates a method for calculating inductance value proposed in one embodiment of this application. This method is applicable to applications such as... Figure 3 The equivalent circuit model is shown. Figure 4 This is a flowchart illustrating a method for calculating inductance based on electromagnetic coupling relationships, as proposed in an embodiment of this application. Figure 4 As shown, the method includes the following steps:

[0057] Step S201: Calculate the self-inductance value of the self-inductor element.

[0058] Specifically, the method for calculating the self-inductance value can refer to the methods in related technologies. For example, the self-inductance coefficient can be calculated based on the material parameters of each component in the branch, and the self-inductance value L of the current branch can be calculated based on the self-inductance coefficient. ii .

[0059] Step S202: Calculate the sum of the mutual inductance values ​​between the current branch and all other branches of the dry-type DC capacitor except the current branch.

[0060] Specifically, first calculate the mutual inductance between the current branch and each of the other branches of the capacitor, excluding the current branch. Then, add the mutual inductance values ​​between all the other branches and the current branch.

[0061] As an example, This represents the sum of the mutual inductance effects of other branches on this branch, where N is the total number of other branches, and j represents any one of the other branches. When calculating the mutual inductance between each of the other branches and the current branch, the principle of calculating the inductance between two metallic conductors can be referenced, and it can be calculated using the following formula:

[0062]

[0063] Among them, M ij Let r be the mutual inductance value, r be the distance between the two branches, and l be the mutual inductance value. i Let l be the inductance of the current branch. j Let μ be the inductance of the j-th branch, where j represents any of the other branches, and μ is the permeability.

[0064] Step S203: Add the self-inductance value to the sum of the mutual inductance values ​​of the other branches to the current branch to obtain the total inductance value of the current branch.

[0065] Specifically, the total inductance of the current branch can be calculated using the following formula:

[0066]

[0067] Among them, L ii This is the self-sensitivity of the aforementioned branch. It is the sum of the mutual inductance effects of the other branches on this branch.

[0068] Therefore, this application can sequentially calculate the parameters of each equivalent element in the equivalent circuit model. Among them, the inductance value of the inductor element is calculated considering the electromagnetic coupling relationship inside the capacitor. After the calculation of each parameter is completed, a complete equivalent circuit model is generated.

[0069] Step S103: Calculate the current value of each capacitor core based on the current voltage applied to the dry DC capacitor, the structure of each equivalent circuit model, and the parameters of each corresponding component.

[0070] Specifically, based on the structure of the equivalent circuit model and the parameters of each equivalent element, the formula for calculating the current in that branch can be obtained. Substituting the external input voltage, the current in the current branch can be calculated, thus obtaining the current value of the capacitor core in the branch. Then, by sequentially calculating the equivalent circuit models corresponding to each branch, the current value of each capacitor core can be obtained.

[0071] As an example, to Figure 2 The dry-type DC capacitor shown is given an input standard lightning voltage. The current values ​​at different times under the action of the standard lightning voltage wave are calculated, and current curves are generated. The current results on four different cores (C1 to C4) in the same column are shown below. Figure 5 As shown. By Figure 5 The changes in current on different cores in a column under lightning strike can be obtained. Figure 5 The horizontal axis represents time, and the vertical axis represents current.

[0072] Furthermore, to enhance the reliability of the capacitor, the current of each core inside the initially designed dry-type DC capacitor can be calculated using the calculation method of this application during the capacitor design stage, and the capacitor can be adjusted based on the calculation results. That is, in one embodiment of this application, after calculating the current value of each capacitor core, the method further includes: comparing the current values ​​of each capacitor core to determine the target capacitor core to be adjusted, then adjusting the parameters of the target capacitor core, and adjusting the parameters of the copper busbar corresponding to the target capacitor core.

[0073] Specifically, in this embodiment, after calculating the current value of each capacitor core, the current values ​​of each capacitor core are compared, including the differences in current changes among the capacitor cores under the same voltage for a certain period of time. The capacitor cores whose current distribution differs significantly from other capacitor cores, resulting in uneven overall current distribution, are identified as target capacitor cores. Then, adjustments are made to the target capacitor cores so that the current distribution in the branch containing the target capacitor core approximates that of other branches. In practice, this includes adjusting the parameters of the target capacitor core and its corresponding copper busbar.

[0074] For example, adjusting the area of ​​the copper busbars involved in the branch can change the parameters of the components in the equivalent circuit model corresponding to the current branch by increasing or decreasing the area of ​​the copper busbars in the branch, thereby changing the current flowing through the target capacitor core. As another adjustment method, the parameters of the target capacitor core itself can also be adjusted. For example, the dimensions and material parameters of the core shaft, base film, and other components of the target capacitor core can be adjusted to ensure that the current flowing through the target capacitor core is within the allowable error range of the current on other normal capacitor cores, so as to make the current distribution on each core uniform.

[0075] In one embodiment of this application, in the practical application of dry-type DC capacitors, the internal core current calculation method of this application can also be used to assess the reliability of the dry-type DC capacitors. After calculating the current value of each capacitor core, it is determined whether there are any abnormal capacitor cores. If a target capacitor core with an abnormal current is diagnosed, a reliability assessment result is generated, and a timely warning is issued to relevant personnel to facilitate timely maintenance of the dry-type DC capacitors and ensure the normal operation of equipment such as converter valves where the dry-type DC capacitors are located.

[0076] In summary, the method for calculating the core current of a dry-type DC capacitor according to the embodiments of this application, combined with the electromagnetic coupling relationship inside the dry-type DC capacitor, establishes an equivalent circuit model containing different core branches inside the capacitor. Based on the equivalent circuit model, the specific current value on each branch capacitor core at different frequencies can be quantitatively calculated. Therefore, based on the accurate current value calculated on the capacitor core, the dry-type DC capacitor can be optimized in a targeted manner. By adjusting the parameters of the internal components, the current distribution on each core can be made uniform, enhancing the reliability of the capacitor. In application, the reliability of the capacitor can be accurately evaluated, ensuring the normal and safe operation of the equipment in which the capacitor is located.

[0077] To achieve the above embodiments, this application also proposes a system for calculating the core current inside a dry-type DC capacitor. Figure 6 This is a schematic diagram of the structure of a dry-type DC capacitor internal core current calculation system proposed in an embodiment of this application, as shown below. Figure 6 As shown, the system includes: a generation module 100, a first calculation module 200, and a second calculation module 300.

[0078] The generation module 100 is used to construct a branch for each capacitor core inside the dry DC capacitor according to the current inflow path, and generate the equivalent circuit model corresponding to each branch.

[0079] The first calculation module 200 is used to calculate the parameters of each element in each equivalent circuit model, wherein the total inductance value of the inductor element is calculated in combination with the electromagnetic coupling relationship inside the dry DC capacitor.

[0080] The second calculation module 300 is used to calculate the current value of each capacitor core based on the current voltage acting on the dry DC capacitor, the structure of each equivalent circuit model, and the parameters of each corresponding component.

[0081] Optionally, in one embodiment of this application, the equivalent circuit model includes: a resistive element, a self-inductance element, a mutual inductance element, a capacitor element, and a leakage conductance element, wherein the second end of the resistive element is connected to the first end of the self-inductance element, and the second end of the self-inductance element is connected to the first end of the mutual inductance element; the second end of the mutual inductance element is connected to the first end of the capacitor element and the first end of the leakage conductance element; the first end of the resistive element, the second end of the capacitor element, and the second end of the leakage conductance element are the input terminals of the equivalent circuit model.

[0082] Optionally, in one embodiment of this application, the first calculation module 200 is specifically used for: calculating the self-inductance value of the self-inductor; calculating the sum of the mutual inductance values ​​of the other branches in the dry DC capacitor and the current branch; and adding the self-inductance value to the sum of the mutual inductance values ​​of the other branches and the current branch to obtain the total inductance value of the current branch.

[0083] Optionally, in one embodiment of this application, the first calculation module 200 is specifically used to calculate the mutual inductance value between any of the other branches and the current branch using the following formula:

[0084]

[0085] Among them, M ij Let r be the mutual inductance value, r be the distance between the two branches, and l be the mutual inductance value. i Let l be the inductance of the current branch. j Let μ be the inductance of the j-th branch, where j represents any of the other branches, and μ is the permeability.

[0086] Optionally, in one embodiment of this application, a dry DC capacitor includes: multiple capacitor cores, multiple copper busbars, and multiple terminals, wherein the multiple capacitor cores are connected in series and parallel through multiple copper busbars and metal wires, and a preset number of capacitor cores are connected in series in a column through one of the copper busbars; terminals are used to introduce current into the corresponding copper busbars; and copper busbars are used to introduce current into each capacitor core in the column.

[0087] Optionally, in one embodiment of this application, the system further includes an adjustment module for comparing the current value of each capacitor core to determine the target capacitor core to be adjusted; adjusting the parameters of the target capacitor core; and adjusting the parameters of the copper busbar corresponding to the target capacitor core.

[0088] It should be noted that the explanation of the aforementioned embodiment of the method for calculating the core current of a dry-type DC capacitor also applies to the system of this embodiment, and will not be repeated here.

[0089] In summary, the dry-type DC capacitor internal core current calculation system of this application, combined with the electromagnetic coupling relationship inside the dry-type DC capacitor, establishes an equivalent circuit model containing different core branches inside the capacitor. Based on the equivalent circuit model, the specific current value on each branch capacitor core at different frequencies can be quantitatively calculated. Therefore, based on the accurate current value calculated on the capacitor core, the dry-type DC capacitor can be optimized in a targeted manner. By adjusting the parameters of internal components, the current distribution on each core can be made uniform, enhancing the reliability of the capacitor. In application, the reliability of the capacitor can be accurately evaluated, ensuring the normal and safe operation of the equipment in which the capacitor is located.

[0090] To implement the above embodiments, this application also proposes a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the method for calculating the core current of a dry DC capacitor as described in any of the above embodiments.

[0091] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0092] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0093] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0094] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0095] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0096] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0097] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0098] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A method for calculating the core current of a dry-type DC capacitor, characterized in that, Includes the following steps: Based on the current inflow path, a branch is constructed for each capacitor core inside the dry DC capacitor, and an equivalent circuit model corresponding to each branch is generated. Calculate the parameters of each element in each of the equivalent circuit models, wherein calculating the parameters of each element in each of the equivalent circuit models includes: calculating the total inductance value of the inductor element, which is obtained by calculating the sum of the self-inductance value of the self-inductor element and the mutual inductance value of the mutual inductor element in the equivalent circuit model; Based on the current voltage applied to the dry DC capacitor, the structure of each equivalent circuit model, and the parameters of each corresponding element, the current value of each capacitor core is calculated.

2. The calculation method according to claim 1, characterized in that, The equivalent circuit model includes: resistive elements, self-inductance elements, mutual inductance elements, capacitive elements, and leakage conductance elements, wherein, The second end of the resistive element is connected to the first end of the self-inductor element, and the second end of the self-inductor element is connected to the first end of the mutual inductor element; The second end of the mutual inductance element is connected to the first end of the capacitor element and the first end of the leakage conductance element. The first end of the resistive element, the second end of the capacitive element, and the second end of the leakage conductivity element are the input terminals of the equivalent circuit model.

3. The calculation method according to claim 1, characterized in that, The mutual inductance between any of the other branches and the current branch is calculated using the following formula: in, Mutual inductance value, The distance between the two branch roads. For the inductance of the current branch, For the first j The inductance of the branch circuit, j Indicates any one of the other branches. is the magnetic permeability.

4. The calculation method according to claim 1, characterized in that, The dry-type DC capacitor includes: multiple capacitor cores, multiple copper busbars, and multiple terminals, wherein, Multiple capacitor cores are connected in series and parallel through multiple copper busbars and metal wires, and a predetermined number of capacitor cores are connected in series in a row through one copper busbar; The terminal is used to introduce current into the corresponding copper busbar; The copper busbar is used to introduce current into each of the capacitor cores in this column.

5. The calculation method according to claim 4, characterized in that, After calculating the current value for each capacitor core, the method further includes: Compare the current value of each capacitor core to determine the target capacitor core to be adjusted; Adjust the parameters of the target capacitor core, and adjust the parameters of the copper busbar corresponding to the target capacitor core.

6. A system for calculating the core current of a dry-type DC capacitor, characterized in that, Includes the following modules: The generation module is used to construct a branch for each capacitor core inside the dry DC capacitor according to the current inflow path, and generate an equivalent circuit model corresponding to each branch. The first calculation module is used to calculate the parameters of each element in each of the equivalent circuit models, wherein calculating the parameters of each element in each of the equivalent circuit models includes: calculating the total inductance value of the inductor element, wherein the total inductance value is obtained by calculating the sum of the self-inductance value of the self-inductor element and the mutual inductance value of the mutual inductor element in the equivalent circuit model; The second calculation module is used to calculate the current value of each capacitor core based on the current voltage applied to the dry DC capacitor, the structure of each equivalent circuit model, and the parameters of each corresponding element.

7. The computing system according to claim 6, characterized in that, The equivalent circuit model includes: resistive elements, self-inductance elements, mutual inductance elements, capacitive elements, and leakage conductance elements, wherein, The second end of the resistive element is connected to the first end of the self-inductor element, and the second end of the self-inductor element is connected to the first end of the mutual inductor element; The second end of the mutual inductance element is connected to the first end of the capacitor element and the first end of the leakage conductance element. The first end of the resistive element, the second end of the capacitive element, and the second end of the leakage conductivity element are the input terminals of the equivalent circuit model.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method for calculating the internal core current of a dry DC capacitor as described in any one of claims 1-5.

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