Passive harmonic filter based on common iron core structure and design method and system thereof

Abstract

The application relates to the technical field of filter structure design, and discloses a passive harmonic filter based on a common iron core structure and a design method and system thereof, which can configure filter parameters based on a basic magnetic circuit structure of the filter, specifically, determining an inductance value of the basic magnetic circuit structure according to application parameter information of the filter; determining the number of turns of a filter branch reactor coil in the basic magnetic circuit structure according to the basic magnetic circuit structure, the inductance value and the number of turns of a main loop reactor coil in the basic magnetic circuit structure; determining air gap configuration parameters according to the basic magnetic circuit structure, the number of turns of the main loop reactor coil and the number of turns of the filter branch reactor coil; and determining a final structure result of the filter according to the foregoing information. It can be seen that the application can improve the comprehensiveness and rationality of the passive harmonic filter structure design method, and improve the accuracy, pertinence and fitting of the final structure result of the filter.

Description

Technical Field

[0001] This invention relates to the field of filter structure design technology, and in particular to a passive harmonic filter based on a common core structure and its design method and system. Background Technology

[0002] With the rapid development of power electronics technology, the widespread application of nonlinear loads in power systems has led to increasingly serious harmonic pollution problems in power grids. Harmonics can not only cause equipment failures but also lead to relay protection malfunctions, communication interference, and even system collapse. Therefore, passive harmonic filters are crucial as core devices for suppressing harmonics and purifying the power grid.

[0003] Currently, the main design approach for passive harmonic filters is to directly use a traditional fixed magnetic circuit distribution as the passive harmonic filter structure. This makes it difficult to dynamically adapt to changes in harmonic characteristics under different operating conditions. Furthermore, under overload or transient harmonic impacts, traditional core materials are prone to magnetic saturation, leading to a sharp drop in inductance, filter performance failure, and even equipment damage. In addition, the traditional use of independent reactors and filters results in a large overall device size, high material costs, and heavy weight, leading to poor application performance of existing passive harmonic filters. Therefore, providing a new passive harmonic filter structure design approach to optimize the application performance of passive harmonic filters is particularly important. Summary of the Invention

[0004] This invention provides a passive harmonic filter based on a common core structure, along with its design method and system. This improves the design rationality and accuracy of passive harmonic filters based on a common core structure, thereby enhancing the precision and relevance of passive harmonic filters and optimizing their application performance and stability.

[0005] To address the aforementioned technical problems, the first aspect of this invention discloses a design method for a passive harmonic filter based on a common-core structure. The method is used to configure parameters of a target filter, which is a passive harmonic filter. Its basic magnetic circuit structure includes: a main circuit, a filtering branch, and a core with the target shape. The main circuit and the filtering branch each include a main circuit reactor and a filtering branch reactor, respectively. The main circuit reactor and the filtering branch reactor share a common core structure. The method includes:

[0006] Based on the application parameter information of the target filter, determine the target inductance value information of the basic magnetic circuit structure;

[0007] The number of turns of the first coil of the main circuit reactor is determined, and the number of turns of the second coil of the filter branch reactor is determined based on the basic magnetic circuit structure, the target inductance value information and the number of turns of the first coil;

[0008] Based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and the preset magnetic core coil state constraints, the target air gap configuration parameters of the target filter are determined.

[0009] The final structural result of the target filter is determined based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and the target air gap configuration parameters.

[0010] As an optional implementation, in the first aspect of the present invention, the target structure is an EI type structure, the iron core is provided with a central column; the main circuit reactor is formed by winding a flat copper wire type coil on the inner layer of the central column; the filter branch reactor is formed by winding a round copper wire type coil on the outer layer of the central column, and the main circuit reactor and the filter branch reactor are separated by an insulating material.

[0011] As an optional implementation, in a first aspect of the invention, determining the number of turns of the second coil of the filter branch reactor based on the basic magnetic circuit structure, the target inductance value information, and the number of turns of the first coil includes:

[0012] Based on the basic magnetic circuit structure, determine the target inductance value and number of turns relationship between the main circuit reactor and the filter branch reactor in the target filter;

[0013] Based on the target inductance value information, determine the first inductance value of the main circuit reactor and the second inductance value of the filter branch reactor;

[0014] The number of turns of the second coil of the filter branch reactor is determined based on the target inductance value and the number of turns relationship, the number of turns of the first coil, the first inductance value, and the second inductance value.

[0015] As an optional implementation, in the first aspect of the present invention, determining the target inductance value and turns relationship between the main circuit reactor and the filter branch reactor in the target filter based on the basic magnetic circuit structure includes:

[0016] Based on the basic magnetic circuit structure and the preset magnetomotive force relationship conditions, the total air gap thickness relationship between the main circuit reactor and the filter branch reactor in the target filter is determined. The total air gap thickness relationship includes the fact that the total air gap thickness is the same when the main circuit reactor and the filter branch reactor have a shared core structure.

[0017] Based on the total air gap thickness relationship, determine the target inductance value and number of turns relationship between the main circuit reactor and the filter branch reactor;

[0018] Furthermore, the formula relating the target inductance value and the number of turns includes:

[0019] N1 2 / L1=N f 2 / L f ;

[0020] Where N1 is the number of turns of the first coil, L1 is the value of the first inductance, and N f L is the number of turns of the second coil. f This is the second inductance value.

[0021] As an optional implementation, in the first aspect of the present invention, determining the target air gap configuration parameters of the target filter based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and preset magnetic core coil state limiting conditions includes:

[0022] Based on the determined first fundamental current information of the main circuit reactor and the preset first current coefficient scheme, the first maximized current result is determined, and based on the first maximized current result and the preset magnetic core saturation and coil over-temperature limiting conditions, the first magnetic flux density parameter configuration information and the first temperature rise parameter configuration information of the main circuit reactor are determined.

[0023] Based on the determined second fundamental current information and harmonic current information of the filter branch reactor, and the preset second current coefficient scheme, the second maximized current result is determined. Based on the second maximized current result and the preset magnetic core saturation and coil over-temperature limiting conditions, the second magnetic flux density parameter configuration information and the second temperature rise parameter configuration information of the filter branch reactor are determined.

[0024] Based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, the configuration information of the first magnetic flux density parameter, the configuration information of the first temperature rise parameter, the configuration information of the second magnetic flux density parameter, and the configuration information of the second temperature rise parameter, the target air gap configuration parameters of the target filter are determined.

[0025] As an optional implementation, in a first aspect of the present invention, determining the target air gap configuration parameters of the target filter based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, the first magnetic flux density parameter configuration information, the first temperature rise parameter configuration information, the second magnetic flux density parameter configuration information, and the second temperature rise parameter configuration information includes:

[0026] Based on the aforementioned basic magnetic circuit structure, determine the geometric dimensions of the iron core;

[0027] Based on the first magnetic flux density parameter configuration information, the first temperature rise parameter configuration information, the first number of coil turns, and the core geometric dimensions, the coil air gap configuration scheme of the main circuit reactor is determined.

[0028] Based on the configuration information of the second magnetic flux density parameter, the configuration information of the second temperature rise parameter, the number of turns of the second coil, and the geometric dimensions of the iron core, the air gap configuration scheme of the filter branch reactor is determined.

[0029] Based on the coil air gap configuration scheme of the main circuit reactor and the coil air gap configuration scheme of the filter branch reactor, the target air gap configuration parameters of the target filter are determined.

[0030] As an optional implementation, in the first aspect of the present invention, the application parameter information includes at least one or more of the following: demand filtering harmonic order information, load rated power information, grid voltage information, first fundamental frequency information and first fundamental current information of the main circuit, and demand compensation reactive power information.

[0031] And, determining the target inductance value information of the basic magnetic circuit structure based on the application parameter information of the target filter includes:

[0032] Based on the required reactive power compensation information and the grid voltage information, determine the filter capacitor information corresponding to the filter branch in the target filter;

[0033] Based on the required harmonic order information and the first fundamental frequency information, the tuning frequency information of the filtering branch is determined.

[0034] Based on the tuning frequency information, the filter capacitor information, and the preset theoretical value of the total impedance of the filter branch at the tuning frequency, the second inductance value of the filter branch reactor is determined.

[0035] The first inductance value of the main circuit reactor is determined based on the grid voltage information, the first fundamental frequency information, and the first fundamental current information.

[0036] Based on the first inductance value and the second inductance value, the target inductance value information of the basic magnetic circuit structure is determined.

[0037] The second aspect of this invention discloses a design system for a passive harmonic filter based on a common-core structure. The system is used to execute the design method for a passive harmonic filter based on a common-core structure disclosed in the first aspect of this invention, and the system includes:

[0038] An inductance value determination module is used to determine the target inductance value information of the basic magnetic circuit structure based on the application parameter information of the target filter.

[0039] The coil turns determination module is used to determine the number of turns of the first coil of the main circuit reactor, and to determine the number of turns of the second coil of the filter branch reactor based on the basic magnetic circuit structure, the target inductance value information and the number of turns of the first coil.

[0040] The air gap configuration determination module is used to determine the target air gap configuration parameters of the target filter based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and preset magnetic core coil state limiting conditions.

[0041] The final structure determination module is used to determine the final structure result of the target filter based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and the target air gap configuration parameters.

[0042] As an optional implementation, in the second aspect of the present invention, the target structure is an EI type structure, the iron core is provided with a central column; the main circuit reactor is formed by winding a flat copper wire type coil on the inner layer of the central column; the filter branch reactor is formed by winding a round copper wire type coil on the outer layer of the central column, and the main circuit reactor and the filter branch reactor are separated by an insulating material.

[0043] As an optional implementation, in a second aspect of the present invention, the method by which the coil turns determination module determines the second coil turns of the filter branch reactor based on the basic magnetic circuit structure, the target inductance value information, and the first coil turns specifically includes:

[0044] Based on the basic magnetic circuit structure, determine the target inductance value and number of turns relationship between the main circuit reactor and the filter branch reactor in the target filter;

[0045] Based on the target inductance value information, determine the first inductance value of the main circuit reactor and the second inductance value of the filter branch reactor;

[0046] The number of turns of the second coil of the filter branch reactor is determined based on the target inductance value and the number of turns relationship, the number of turns of the first coil, the first inductance value, and the second inductance value.

[0047] As an optional implementation, in the second aspect of the present invention, the method by which the coil turns determination module determines the target inductance value and turns relationship between the main circuit reactor and the filter branch reactor in the target filter based on the basic magnetic circuit structure specifically includes:

[0048] Based on the basic magnetic circuit structure and the preset magnetomotive force relationship conditions, the total air gap thickness relationship between the main circuit reactor and the filter branch reactor in the target filter is determined. The total air gap thickness relationship includes the fact that the total air gap thickness is the same when the main circuit reactor and the filter branch reactor have a shared core structure.

[0049] Based on the total air gap thickness relationship, determine the target inductance value and number of turns relationship between the main circuit reactor and the filter branch reactor;

[0050] Furthermore, the formula relating the target inductance value and the number of turns includes:

[0051] N1 2 / L1=N f 2 / L f ;

[0052] Where N1 is the number of turns of the first coil, L1 is the value of the first inductance, and N f L is the number of turns of the second coil. f This is the second inductance value.

[0053] As an optional implementation, in a second aspect of the present invention, the air gap configuration determining module determines the target air gap configuration parameters of the target filter based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and preset magnetic core coil state limitations, specifically including:

[0054] Based on the determined first fundamental current information of the main circuit reactor and the preset first current coefficient scheme, the first maximized current result is determined, and based on the first maximized current result and the preset magnetic core saturation and coil over-temperature limiting conditions, the first magnetic flux density parameter configuration information and the first temperature rise parameter configuration information of the main circuit reactor are determined.

[0055] Based on the determined second fundamental current information and harmonic current information of the filter branch reactor, and the preset second current coefficient scheme, the second maximized current result is determined. Based on the second maximized current result and the preset magnetic core saturation and coil over-temperature limiting conditions, the second magnetic flux density parameter configuration information and the second temperature rise parameter configuration information of the filter branch reactor are determined.

[0056] Based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, the configuration information of the first magnetic flux density parameter, the configuration information of the first temperature rise parameter, the configuration information of the second magnetic flux density parameter, and the configuration information of the second temperature rise parameter, the target air gap configuration parameters of the target filter are determined.

[0057] As an optional implementation, in a second aspect of the present invention, the air gap configuration determining module determines the target air gap configuration parameters of the target filter based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, the first magnetic flux density parameter configuration information, the first temperature rise parameter configuration information, the second magnetic flux density parameter configuration information, and the second temperature rise parameter configuration information, specifically including the following methods:

[0058] Based on the aforementioned basic magnetic circuit structure, determine the geometric dimensions of the iron core;

[0059] Based on the first magnetic flux density parameter configuration information, the first temperature rise parameter configuration information, the first number of coil turns, and the core geometric dimensions, the coil air gap configuration scheme of the main circuit reactor is determined.

[0060] Based on the configuration information of the second magnetic flux density parameter, the configuration information of the second temperature rise parameter, the number of turns of the second coil, and the geometric dimensions of the iron core, the air gap configuration scheme of the filter branch reactor is determined.

[0061] Based on the coil air gap configuration scheme of the main circuit reactor and the coil air gap configuration scheme of the filter branch reactor, the target air gap configuration parameters of the target filter are determined.

[0062] As an optional implementation, in the second aspect of the present invention, the application parameter information includes at least one or more of the following: demand filtering harmonic order information, load rated power information, grid voltage information, first fundamental frequency information and first fundamental current information of the main circuit, and demand compensation reactive power information.

[0063] Furthermore, the method by which the inductance value determination module determines the target inductance value information of the basic magnetic circuit structure based on the application parameter information specifically includes:

[0064] Based on the required reactive power compensation information and the grid voltage information, determine the filter capacitor information corresponding to the filter branch in the target filter;

[0065] Based on the required harmonic order information and the first fundamental frequency information, the tuning frequency information of the filtering branch is determined.

[0066] Based on the tuning frequency information, the filter capacitor information, and the preset theoretical value of the total impedance of the filter branch at the tuning frequency, the second inductance value of the filter branch reactor is determined.

[0067] The first inductance value of the main circuit reactor is determined based on the grid voltage information, the first fundamental frequency information, and the first fundamental current information.

[0068] Based on the first inductance value and the second inductance value, the target inductance value information of the basic magnetic circuit structure is determined.

[0069] A third aspect of this invention discloses another design system for a passive harmonic filter based on a common-core structure, the system comprising:

[0070] Memory containing executable program code;

[0071] A processor coupled to the memory;

[0072] The processor calls the executable program code stored in the memory to execute the design method of the passive harmonic filter based on the common core structure disclosed in the first aspect of the present invention.

[0073] The fourth aspect of the present invention discloses a computer storage medium storing computer instructions, which, when invoked, are used to execute the design method of the passive harmonic filter based on a common core structure disclosed in the first aspect of the present invention.

[0074] The fifth aspect of this invention discloses a passive harmonic filter based on a common core structure, the passive harmonic filter including a main circuit and a filter branch connected in parallel with the main circuit, the passive harmonic filter being electrically connected in parallel between the power grid and the load;

[0075] The main circuit includes a main circuit reactor, and the filter branch includes a filter branch reactor. The inductor coil of the main circuit reactor and the inductor coil of the filter branch reactor are coaxially wound and stacked on the same iron core center column.

[0076] The input terminal of the main circuit reactor is electrically connected to the power grid, and the output terminal of the main circuit reactor is electrically connected in parallel to the filter branch reactor.

[0077] The passive harmonic filter is designed based on the design method of the passive harmonic filter based on the common core structure disclosed in the first aspect, and the structural design operation is performed to obtain the final structural result.

[0078] As an optional implementation, in a sixth aspect of the invention, the filter branch further includes a filter capacitor connected in series with the filter branch reactor;

[0079] The target structure of the iron core includes an EI type structure. The iron core includes a three-phase magnetic circuit. The inductor coil of the main circuit reactor is wound on the inner layer of the iron core center column by enameled or silk-insulated flat copper wire. The inductor coil of the filter branch reactor is wound on the outer layer of the iron core center column by enameled or silk-insulated round copper wire. The spacer between the inductor coil of the main circuit reactor and the inductor coil of the filter branch reactor is an insulating material.

[0080] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0081] In this embodiment of the invention, the solution is used to configure the parameters of a target filter, which is a passive harmonic filter. Its basic magnetic circuit structure includes a main circuit, a filter branch, and a core with a target shape. The main circuit and the filter branch each include a main circuit reactor and a filter branch reactor, respectively, and the main circuit reactor and the filter branch reactor share a common core structure. Based on the application parameter information of the target filter, the target inductance value of the basic magnetic circuit structure is determined. The number of turns of the first coil of the main circuit reactor is determined, and based on the basic magnetic circuit structure, the target inductance value, and the number of turns of the first coil, the number of turns of the second coil of the filter branch reactor is determined. Based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and preset core coil state limitations, the target air gap configuration parameters of the target filter are determined. Based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and the target air gap configuration parameters, the final structural result of the target filter is determined. As can be seen, this invention can provide a design method for passive harmonic filters based on a common core structure. By determining the basic magnetic circuit structure of the filter to be designed, the number of turns of the first coil of the main circuit, the number of turns of the second coil of the filter magnetic circuit, and the target air gap configuration parameters, the final structural result of the filter can be determined. This is beneficial to improving the comprehensiveness and rationality of the passive harmonic filter structural design method, and thus to improving the accuracy, relevance, and fit of the final structural result of the determined passive harmonic filter. In this way, it is beneficial to improve the application stability and optimize the application performance of the passive harmonic filter. Attached Figure Description

[0082] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0083] Figure 1 This is a flowchart illustrating a design method for a passive harmonic filter based on a common core structure disclosed in an embodiment of the present invention.

[0084] Figure 2 This is a schematic diagram of the design system of a passive harmonic filter based on a common core structure disclosed in an embodiment of the present invention;

[0085] Figure 3 This is a schematic diagram of the design system of another passive harmonic filter based on a common core structure disclosed in an embodiment of the present invention;

[0086] Figure 4 This is a schematic diagram of the basic circuit principle of a passive harmonic filter based on a common core structure disclosed in an embodiment of the present invention;

[0087] Figure 5 This is a schematic diagram of a passive harmonic filter based on a common core structure disclosed in an embodiment of the present invention;

[0088] Figure 6 This is a schematic diagram of the equivalent circuit model of a passive harmonic filter based on a common core structure disclosed in an embodiment of the present invention. Detailed Implementation

[0089] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0090] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or end that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or ends.

[0091] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0092] This invention discloses a passive harmonic filter based on a common-core structure, along with its design method and system. It provides a design approach for passive harmonic filters based on a common-core structure. By determining the basic magnetic circuit structure of the filter to be designed, the number of turns of the first coil in the main circuit, the number of turns of the second coil in the filter magnetic circuit, and the target air gap configuration parameters, the final structural result of the filter is determined. This improves the comprehensiveness and rationality of the passive harmonic filter structural design method, thereby enhancing the accuracy, relevance, and fit of the determined final structural result of the passive harmonic filter. This ultimately improves the application stability and optimizes the application performance of the passive harmonic filter. Detailed descriptions follow.

[0093] Example 1

[0094] Please see Figure 1 , Figure 1 This is a flowchart illustrating a design method for a passive harmonic filter based on a common-core structure disclosed in an embodiment of the present invention. Figure 1 The described method can be applied to the design system of passive harmonic filters based on a common-core structure. This system may include a server, which can be a local server or a cloud server; this embodiment of the invention is not limited to any particular server. Figure 1 The described method is used to configure the parameters of a target filter, which is a passive harmonic filter. Its basic magnetic circuit structure includes a main circuit, a filter branch, and a core with the target shape. The main circuit and filter branch each include a main circuit reactor and a filter branch reactor, respectively. The main circuit reactor and the filter branch reactor share a common core structure. This invention is not limited in its embodiments. Figure 1 As shown, the design method of this passive harmonic filter based on a common core structure includes the following operations:

[0095] 101. Based on the application parameter information of the target filter, determine the target inductance value information of the basic magnetic circuit structure.

[0096] Optionally, the target filter includes a main circuit reactor, a filter branch reactor, and a filter capacitor in the filter branch; however, this embodiment of the invention does not impose any limitations.

[0097] Optionally, the target inductance value information includes at least the inductance value of the main circuit reactor and the inductance value of the filter branch reactor, but this embodiment of the invention does not limit it.

[0098] 102. Determine the number of turns of the first coil of the main circuit reactor, and determine the number of turns of the second coil of the filter branch reactor based on the basic magnetic circuit structure, target inductance value information and the number of turns of the first coil.

[0099] 103. Determine the target air gap configuration parameters of the target filter according to the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and the preset magnetic core coil state limiting conditions.

[0100] Optionally, the target air gap configuration parameters of the target filter can be understood as the number of air gaps, the positions of the air gaps, the sizes of the air gaps, etc. provided on the iron core column of the target filter, which are not limited in the embodiments of the present invention.

[0101] 104. Determine the final structural result of the target filter according to the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and the target air gap configuration parameters.

[0102] Optionally, establish a coupled inductor model and analyze the electrical decoupling conditions, and equivalent the common iron core structure to a two-winding transformer model or a coupled inductor model. The coupling degree between the main circuit reactor and the filter branch reactor is represented by the coupling coefficient k (0 < k < 1); where the main circuit current flows through the main circuit reactor coil and generates a main magnetic flux in the iron core, and the filter branch current flows through the filter branch reactor coil and generates a magnetic flux in the iron core, and the two magnetic fluxes are superimposed on each other in the iron core; further, to ensure the normal operation of the filter, it is necessary to avoid adverse effects caused by magnetic coupling between the two circuits. Therefore, the key to this solution is to make the magnetomotive forces (MMFs) generated by the two coils cancel each other out or be significantly weakened at the fundamental frequency, that is, to achieve "magnetic potential balance". Further, the design goal is to make the coupling coefficient k approach 0, or to make the electromotive force induced by the fundamental current in the main circuit reactor on the filter branch reactor extremely small through a clever wiring method, and vice versa, so as to achieve approximate electrical decoupling of the two inductors, which is not limited in the embodiments of the present invention.

[0103] Optionally, for the iron core magnetic circuit of the filter, assume that the number of turns of the main circuit reactor coil is N1, then the current passing through it is i1(t) (mainly the fundamental current), and the number of turns of the filter branch reactor coil is N fThe current flowing through it is if(t) (mainly the h-th harmonic current), therefore the total magnetomotive force in the iron core is F = N1×i1(t)+Nf×if(t). To achieve magnetic circuit desaturation and reduce mutual influence, ideally the total magnetomotive force F≈0. However, since i1(t) and if(t) have different frequencies, they cannot cancel each other out at all times, but can partially cancel each other out. Therefore, the following innovative application is made: This scheme pursues the balance of the fundamental magnetomotive force, that is, to make the magnetomotive force generated by the fundamental current component (if any) of the filter branch reactor coil equal in magnitude and opposite in direction to the magnetomotive force generated by the fundamental current of the main circuit reactor coil. Since the fundamental current of the filter branch is very small due to the series capacitor, by adjusting the turns ratio, the main circuit... The fundamental current of the reactor induces a fundamental voltage in the reactor coil of the filter branch that is much smaller than the fundamental voltage of the power grid, thus ensuring that the fundamental current of the filter branch is extremely small and does not affect the reactive power compensation function, while also not generating significant fundamental magnetic flux excitation on the iron core. Furthermore, the final inductance value is determined by the number of coil turns, the geometry of the iron core, and the air gap of the magnetic circuit. By precisely adjusting the size of the air gap of each coil, the self-inductance value of each coil can be finely adjusted while achieving the magnetomotive force balance design, so that it meets the target inductance value information initially calculated based on the application parameter information. This embodiment of the invention does not limit this.

[0104] As can be seen, the design method for passive harmonic filters based on a common core structure described in the embodiments of the present invention can provide a design approach for passive harmonic filters based on a common core structure. By determining the basic magnetic circuit structure of the filter to be designed, the number of turns of the first coil of the main circuit, the number of turns of the second coil of the filter magnetic circuit, and the target air gap configuration parameters, the final structural result of the filter is determined. This is beneficial to improving the comprehensiveness and rationality of the passive harmonic filter structural design approach, and thus beneficial to improving the accuracy, relevance, and fit of the determined final structural result of the passive harmonic filter. Consequently, it is beneficial to improve the application stability and optimize the application performance of the passive harmonic filter.

[0105] In an optional embodiment, the target structure is an EI type structure, with a central column in the iron core; the main circuit reactor is formed by winding a flat copper wire type coil on the inner layer of the central column; the filter branch reactor is formed by winding a round copper wire type coil on the outer layer of the central column, and the main circuit reactor and the filter branch reactor are separated by an insulating material.

[0106] Optionally, the core material can be, but is not limited to, silicon steel sheet material 35WW250; this embodiment of the invention does not impose any limitations.

[0107] Optionally, the inductor coil of the main circuit reactor is wound with enameled or silk-insulated flat copper wire in the inner layer of the target iron core, which is not limited in the embodiments of the present invention.

[0108] Optionally, the inductor coil of the filter branch reactor is wound with enameled or silk-insulated round copper wire on the outer layer of the target iron core, which is not limited in the embodiments of the present invention.

[0109] Optionally, the inductor coil of the main circuit reactor and the inductor coil of the filter branch reactor are wound on the same column. Further, the layers of the inductor coil of the main circuit reactor and the inductor coil of the filter branch reactor can be isolated by DMD insulating paper. This embodiment of the invention does not limit the scope of the invention.

[0110] It is evident that this optional embodiment can propose the type of copper wire for the main circuit reactor and the winding layers and the type of spacer material for the filter, which is beneficial to improving the comprehensiveness and rationality of the filter's magnetic circuit structure, and thus to improving the accuracy and reliability of the determined filter's magnetic circuit structure.

[0111] In another optional embodiment, the above application parameter information includes at least one or more of the following: demand filtering harmonic order information, load rated power information, grid voltage information, first fundamental frequency information and first fundamental current information of the main circuit, and demand compensation reactive power information.

[0112] Furthermore, the determination of the target inductance value of the basic magnetic circuit structure based on the application parameter information of the target filter may include:

[0113] Based on the reactive power compensation information and grid voltage information, determine the filter capacitor information corresponding to the filter branch in the target filter.

[0114] Based on the required harmonic order information and first fundamental frequency information, determine the tuning frequency information of the filter branch;

[0115] Based on the tuning frequency information, filter capacitor information, and the preset theoretical value of the total impedance of the filter branch at the tuning frequency, determine the second inductance value of the filter branch reactor.

[0116] The first inductance value of the main circuit reactor is determined based on the grid voltage information, the first fundamental frequency information, and the first fundamental current information.

[0117] Based on the first inductance value and the second inductance value, the target inductance value information of the basic magnetic circuit structure is determined.

[0118] Optionally, based on the demand compensation reactive power information and grid voltage information, the filter capacitor information corresponding to the filter branch in the target filter is determined. For example: assuming the load rated power is 18.5kW, since the fundamental wave demand compensation reactive power does not exceed 20% of the load rated power, the demand compensation reactive power information is Q=3.5kvar, and the grid voltage information is U... n =400V, based on the formula C=Q / (2πf×U) n2 The filter capacitor information C is calculated. f ≈70μF, but this embodiment of the invention is not limited.

[0119] Optionally, the above-mentioned harmonic order information and first fundamental frequency information to be filtered out are used to determine the tuning frequency information of the filtering branch. For example: assuming the required harmonic order information to be filtered out is h=5 and the first fundamental frequency information is f1=250Hz, based on the formula h1=(93%~98%)×h and the formula f h1 = h1×f1, thus obtaining the tuning frequency information f of the filter branch. h1 =242Hz (approximately 96.8% × 250Hz), which is not limited in the embodiments of the present invention.

[0120] Optionally, the second inductance value of the filter branch reactor is determined based on the tuning frequency information, filter capacitor information, and the preset theoretical value of the total impedance of the filter branch at the tuning frequency. For example, since the theoretical total impedance of the filter branch at the tuning frequency is zero (i.e., the theoretical value of the total impedance of the filter branch at the tuning frequency), the formula ω is obtained. h1 ×L f =1 / (ω h1 ×C f ), where ω h1 =2π×f h1 Therefore, we obtain the formula 2πf h1 ×L f =1 / (2πf h1 ×C f Furthermore, the second inductance value L of the filter branch reactor is obtained. f ≈6.19mH, but the embodiments of the present invention are not limited.

[0121] Optionally, the first inductance value of the main circuit reactor is determined based on the grid voltage information, the first fundamental frequency information, and the first fundamental current information. For example, since the inductance value of the main circuit reactor is generally taken as 10% to 15% of the fundamental phase voltage, the formula L1 = U is obtained. n / √3 / (2πf×I n ) ×12%, further based on the aforementioned L1 formula and assumed values, the first inductance value of the main circuit reactor is obtained as L1=2.52mH. This embodiment of the invention is not limited.

[0122] As can be seen, this optional embodiment can provide a method for determining the first inductance value of the main circuit reactor and a method for determining the second inductance value of the filter branch reactor. This is beneficial to improving the pertinence and fit of the method for determining the first inductance value and the second inductance value, and to improving the diversity and flexibility of the inductance value determination method. In turn, it is beneficial to improve the accuracy and reliability of the determined first inductance value and the second inductance value, thereby improving the accuracy and fit of the filter structure result determined subsequently based on the target inductance value information.

[0123] In yet another optional embodiment, determining the number of turns of the second coil of the filter branch reactor based on the basic magnetic circuit structure, the target inductance value information, and the number of turns of the first coil may include:

[0124] Based on the basic magnetic circuit structure, determine the target inductance value and number of turns relationship between the main circuit reactor and the filter branch reactor in the target filter;

[0125] Based on the target inductance value information, determine the first inductance value of the main circuit reactor and the second inductance value of the filter branch reactor;

[0126] Based on the target inductance value and the number of turns relationship, the number of turns of the first coil, the first inductance value, and the second inductance value, determine the number of turns of the second coil of the filter branch reactor.

[0127] Optionally, since the main circuit reactor and the filter branch reactor share the same iron core and have the same total air gap thickness, the formula N1 corresponding to the target inductance value and number of turns is obtained. 2 / L1=N f 2 / L f Furthermore, let's assume: the first coil of the main circuit reactor has N1 = 30 turns, the first inductance of the main circuit reactor has L1 = 2.52mH, and the second inductance of the filter branch reactor has L... f ≈6.19mH, then the number of turns N of the second coil of the filter branch reactor can be calculated using the formula. f ≈47 turns, but this embodiment of the invention is not limited.

[0128] As can be seen, this optional embodiment can determine the target inductance value and the number of turns relationship based on the basic magnetic circuit structure, and then determine the number of turns of the second coil of the filter branch reactor based on the target inductance value and the number of turns relationship, the number of turns of the first coil, the first inductance value, and the second inductance value. This is beneficial to improving the comprehensiveness, rationality, pertinence, and fit of the method for determining the number of turns of the second coil of the filter branch reactor, thereby improving the accuracy and reliability of the determined number of turns of the second coil. This is beneficial to optimizing the operation effect of the subsequent filter based on the number of turns of the second coil and meeting the operation requirements.

[0129] In another optional embodiment, determining the target inductance value and turns relationship between the main circuit reactor and the filter branch reactor in the target filter based on the basic magnetic circuit structure may include:

[0130] Based on the basic magnetic circuit structure and the preset magnetomotive force relationship, the relationship between the total air gap thickness of the main circuit reactor and the filter branch reactor in the target filter is determined. The total air gap thickness relationship includes the fact that the total air gap thickness of the main circuit reactor and the filter branch reactor is the same when they share a common iron core structure.

[0131] Based on the total air gap thickness, determine the target inductance value and number of turns relationship between the main circuit reactor and the filter branch reactor.

[0132] As can be seen, this optional embodiment can determine the total air gap thickness relationship based on the basic magnetic circuit structure and preset magnetomotive force relationship conditions, thereby determining the target inductance value and number of turns relationship. This is beneficial to improving the comprehensiveness and rationality of the method for determining the target inductance value and number of turns relationship, and thus improving the accuracy, reliability and pertinence of the determined target inductance value and number of turns relationship.

[0133] In another optional embodiment, the formula corresponding to the above-mentioned target inductance value and number of turns may include:

[0134] N1 2 / L1=N f 2 / L f ;

[0135] Where N1 is the number of turns of the first coil, L1 is the value of the first inductance, and N f L represents the number of turns in the second coil. f This is the second inductance value.

[0136] It is evident that this optional embodiment can provide a specific formula for representing the relationship between the target inductance value and the number of turns, which is beneficial to improving the effectiveness and rationality of the determined target inductance value and the number of turns relationship, and to improving the scientificity and creativity of the formula corresponding to the target inductance value and the number of turns relationship.

[0137] In yet another optional embodiment, determining the target air gap configuration parameters of the target filter based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and preset magnetic core coil state constraints may include:

[0138] Based on the determined first fundamental current information of the main circuit reactor and the preset first current coefficient scheme, the first maximum current result is determined, and based on the first maximum current result and the preset magnetic core saturation and coil over-temperature limiting conditions, the first magnetic flux density parameter configuration information and the first temperature rise parameter configuration information of the main circuit reactor are determined.

[0139] Based on the determined second fundamental current information and harmonic current information of the filter branch reactor, and the preset second current coefficient scheme, the second maximum current result is determined. Based on the second maximum current result and the preset magnetic core saturation and coil over-temperature limiting conditions, the second magnetic flux density parameter configuration information and the second temperature rise parameter configuration information of the filter branch reactor are determined.

[0140] Based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, the configuration information of the first magnetic flux density parameter, the configuration information of the first temperature rise parameter, the configuration information of the second magnetic flux density parameter, and the configuration information of the second temperature rise parameter, the target air gap configuration parameters of the target filter are determined.

[0141] Optionally, the first fundamental current information and the first current coefficient scheme of the main circuit reactor mentioned above can be illustrated as follows: the first current coefficient scheme is 1.1×I1, the first fundamental current information is I1, and the first maximized current result is obtained. This embodiment of the invention does not limit the scope of the invention.

[0142] Optionally, the configuration information of the first maximum current result, the first magnetic flux density parameter of the main circuit reactor, and the configuration information of the first temperature rise parameter are illustrated for example: assuming the first maximum current result is 38.5A, then the configuration information of the first magnetic flux density parameter is B1≤0.85Tesla, and the configuration information of the first temperature rise parameter is ΔT1≤60K. This embodiment of the invention does not limit these parameters.

[0143] Optionally, the above-mentioned second fundamental current information, harmonic current information, and second current coefficient scheme are illustrated with an example: Filter branch reactor L f The second current coefficient scheme is based on the maximum value of the superposition of the branch fundamental current and harmonic current, i.e., (I) f 2 +(30%I1) 2 ) 0.5 Among them, the second fundamental current information I f The second maximized current result is obtained by taking the harmonic current information I1. This embodiment of the invention is not limited.

[0144] Alternatively, the second fundamental current information can be determined by the filter capacitor information and the rated voltage of the filter capacitor, but this embodiment of the invention does not limit this.

[0145] Optionally, the configuration information of the second maximized current result, the second magnetic flux density parameter of the filter branch reactor, and the second temperature rise parameter, as described above, can be illustrated as follows: assuming the second maximized current result is 11.7A, then the configuration information of the second magnetic flux density parameter is B. f1 ≤0.2Tesla, the second temperature rise parameter configuration information is △T f ≤30K, but this embodiment of the invention is not limited thereto.

[0146] Optionally, through the above design scheme, most of the magnetic flux generated by the strong fundamental current in the main circuit reactor is canceled out by the coil ampere-turns of the filter branch reactor (although the current is small, the number of turns is large). The fundamental magnetic flux density in the iron core is very low and the iron loss is small. At the same time, the coupling of the two coils to the harmonic frequency is very weak, and they work basically independently. Furthermore, after the design scheme is put into use, the content of the fifth harmonic current in the system drops from 70% to below 15%, the reactive power compensation function is normal, and the temperature rise of the common core reactor meets the F-class insulation standard. This embodiment of the invention is not limited.

[0147] As can be seen, this optional embodiment can determine the first magnetic flux density parameter configuration information and the first temperature rise parameter configuration information of the main circuit reactor, as well as the second magnetic flux density parameter configuration information and the second temperature rise parameter configuration information of the filter branch reactor, thereby determining the target air gap configuration parameters. This is beneficial to improving the comprehensiveness and rationality of the method for determining the target air gap configuration parameters, and thus improving the accuracy, reliability, and specificity of the determined target air gap configuration parameters. This helps to prevent core oversaturation, coil overheating, and DC bias saturation. In addition, it is beneficial to improve the comprehensiveness and rationality of the method for determining the first magnetic flux density parameter configuration information and the first temperature rise parameter configuration information of the main circuit reactor, and thus improve the accuracy and reliability of the determined first magnetic flux density parameter configuration information and the first temperature rise parameter configuration information. Furthermore, it is beneficial to improve the comprehensiveness and rationality of the method for determining the second magnetic flux density parameter configuration information and the second temperature rise parameter configuration information of the filter branch reactor, and thus improve the accuracy and reliability of the determined second magnetic flux density parameter configuration information and the second temperature rise parameter configuration information.

[0148] In yet another optional embodiment, determining the target air gap configuration parameters of the target filter based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, the configuration information of the first magnetic flux density parameter, the configuration information of the first temperature rise parameter, the configuration information of the second magnetic flux density parameter, and the configuration information of the second temperature rise parameter may include:

[0149] Based on the basic magnetic circuit structure, determine the geometric dimensions of the iron core;

[0150] Based on the configuration information of the first magnetic flux density parameter, the configuration information of the first temperature rise parameter, the number of turns of the first coil, and the geometric dimensions of the iron core, the coil air gap configuration scheme of the main circuit reactor is determined.

[0151] Based on the configuration information of the second magnetic flux density parameter, the configuration information of the second temperature rise parameter, the number of turns of the second coil, and the geometric dimensions of the iron core, the air gap configuration scheme of the filter branch reactor is determined.

[0152] Based on the coil air gap configuration scheme of the main circuit reactor and the coil air gap configuration scheme of the filter branch reactor, the target air gap configuration parameters of the target filter are determined.

[0153] Optionally, one or more small air gaps can be provided in the core column of the iron core to adjust the inductance value of the main circuit reactor and indirectly adjust the inductance value of the filter branch reactor, as well as to prevent DC bias saturation. This embodiment of the invention does not limit the scope of the invention.

[0154] Optionally, the coil air gap configuration scheme may include, but is not limited to, coil position, number of coils, and coil size, etc., and the embodiments of the present invention do not limit it.

[0155] As can be seen, this optional embodiment can determine the coil air gap configuration scheme of the main circuit reactor and the coil air gap size configuration scheme of the filter branch reactor, thereby determining the target air gap configuration parameters of the filter. This is beneficial to improving the diversity, flexibility, pertinence, and rationality of the coil air gap configuration scheme determination method, and to improving the flexibility, pertinence, and fit of the determination parameters used to determine the coil air gap configuration scheme. In turn, it is beneficial to improve the accuracy, reliability, and pertinence of the determined coil air gap configuration scheme of the main circuit reactor and the coil air gap configuration scheme of the filter branch reactor, thereby improving the accuracy and reliability of the determined target air gap configuration parameters.

[0156] Example 2

[0157] Please see Figure 2 , Figure 2 This is a schematic diagram of the design system of a passive harmonic filter based on a common core structure disclosed in an embodiment of the present invention. Figure 2 The described system may include a server, which may be a local server or a cloud server; this embodiment of the invention does not impose any limitation. Figure 2 The described system can be used to perform the steps in the design method of the passive harmonic filter based on the common core structure described in Embodiment 1; such as Figure 2 As shown, the design system of this passive harmonic filter based on a common core structure can include:

[0158] The inductance value determination module 301 is used to determine the target inductance value information of the basic magnetic circuit structure based on the application parameter information of the target filter.

[0159] The coil turns determination module 302 is used to determine the number of turns of the first coil of the main circuit reactor, and to determine the number of turns of the second coil of the filter branch reactor based on the basic magnetic circuit structure, target inductance value information and the number of turns of the first coil.

[0160] The air gap configuration determination module 303 is used to determine the target air gap configuration parameters of the target filter based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and the preset magnetic core coil state constraints.

[0161] The final structure determination module 304 is used to determine the final structure result of the target filter based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and the target air gap configuration parameters.

[0162] It is evident that implementation Figure 2 The described design system for passive harmonic filters based on a common-core structure provides a design method for passive harmonic filters based on a common-core structure. By determining the basic magnetic circuit structure of the filter to be designed, the number of turns of the first coil in the main circuit, the number of turns of the second coil in the filter magnetic circuit, and the target air gap configuration parameters, the final structural result of the filter can be determined. This is beneficial to improving the comprehensiveness and rationality of the passive harmonic filter structural design method, and thus improving the accuracy, relevance, and fit of the final structural result of the determined passive harmonic filter. In this way, it is beneficial to improve the application stability and optimize the application performance of the passive harmonic filter.

[0163] In an optional embodiment, the target structure is an EI type structure, with a central column in the iron core; the main circuit reactor is formed by winding a flat copper wire type coil on the inner layer of the central column; the filter branch reactor is formed by winding a round copper wire type coil on the outer layer of the central column, and the main circuit reactor and the filter branch reactor are separated by an insulating material.

[0164] It is evident that implementation Figure 2 The described system can also propose the type of copper wire for the main circuit reactor and the winding layers and the type of spacer material for the filter, which helps to improve the comprehensiveness and rationality of the filter's magnetic circuit structure, and thus helps to improve the accuracy and reliability of the determined filter's magnetic circuit structure.

[0165] In another optional embodiment, the coil turns determination module 302 determines the second coil turns of the filter branch reactor based on the basic magnetic circuit structure, target inductance value information, and the first coil turns in a specific manner including:

[0166] Based on the basic magnetic circuit structure, determine the target inductance value and number of turns relationship between the main circuit reactor and the filter branch reactor in the target filter;

[0167] Based on the target inductance value information, determine the first inductance value of the main circuit reactor and the second inductance value of the filter branch reactor;

[0168] Based on the target inductance value and the number of turns relationship, the number of turns of the first coil, the first inductance value, and the second inductance value, determine the number of turns of the second coil of the filter branch reactor.

[0169] It is evident that implementation Figure 2 The described system can also determine the target inductance value and turns ratio based on the basic magnetic circuit structure, and then determine the number of turns of the second coil of the filter branch reactor based on the target inductance value and turns ratio, the number of turns of the first coil, the first inductance value, and the second inductance value. This helps to improve the comprehensiveness, rationality, pertinence, and fit of the method for determining the number of turns of the second coil of the filter branch reactor, thereby improving the accuracy and reliability of the determined number of turns of the second coil. This, in turn, helps to optimize the operation effect of subsequent filters based on the number of turns of the second coil and meet the operation requirements.

[0170] In another optional embodiment, the coil turns determination module 302 determines the target inductance value and turns relationship between the main circuit reactor and the filter branch reactor in the target filter based on the basic magnetic circuit structure, specifically including:

[0171] Based on the basic magnetic circuit structure and the preset magnetomotive force relationship, the relationship between the total air gap thickness of the main circuit reactor and the filter branch reactor in the target filter is determined. The total air gap thickness relationship includes the fact that the total air gap thickness of the main circuit reactor and the filter branch reactor is the same when they share a common iron core structure.

[0172] Based on the total air gap thickness, determine the target inductance value and number of turns relationship between the main circuit reactor and the filter branch reactor.

[0173] It is evident that implementation Figure 2 The described system can also determine the total air gap thickness relationship based on the basic magnetic circuit structure and preset magnetomotive force relationship conditions, thereby determining the target inductance value and number of turns relationship. This is beneficial to improving the comprehensiveness and rationality of the method for determining the target inductance value and number of turns relationship, and thus improving the accuracy, reliability and pertinence of the determined target inductance value and number of turns relationship.

[0174] In yet another optional embodiment, the formula relating the target inductance value and the number of turns includes:

[0175] N1 2 / L1=N f 2 / L f ;

[0176] Where N1 is the number of turns of the first coil, L1 is the value of the first inductance, and N f L represents the number of turns in the second coil. f This is the second inductance value.

[0177] It is evident that implementation Figure 2The described system can also provide specific formulas for the relationship between target inductance value and number of turns, which helps to improve the effectiveness and rationality of the determined target inductance value and number of turns relationship, and helps to improve the scientificity and creativity of the formulas corresponding to the target inductance value and number of turns relationship.

[0178] In another optional embodiment, the air gap configuration determination module 303 determines the target air gap configuration parameters of the target filter based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, and preset magnetic core coil state constraints, specifically including:

[0179] Based on the determined first fundamental current information of the main circuit reactor and the preset first current coefficient scheme, the first maximum current result is determined, and based on the first maximum current result and the preset magnetic core saturation and coil over-temperature limiting conditions, the first magnetic flux density parameter configuration information and the first temperature rise parameter configuration information of the main circuit reactor are determined.

[0180] Based on the determined second fundamental current information and harmonic current information of the filter branch reactor, and the preset second current coefficient scheme, the second maximum current result is determined. Based on the second maximum current result and the preset magnetic core saturation and coil over-temperature limiting conditions, the second magnetic flux density parameter configuration information and the second temperature rise parameter configuration information of the filter branch reactor are determined.

[0181] Based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, the configuration information of the first magnetic flux density parameter, the configuration information of the first temperature rise parameter, the configuration information of the second magnetic flux density parameter, and the configuration information of the second temperature rise parameter, the target air gap configuration parameters of the target filter are determined.

[0182] It is evident that implementation Figure 2 The described system can also determine the configuration information of the first magnetic flux density parameter and the first temperature rise parameter of the main circuit reactor, as well as the configuration information of the second magnetic flux density parameter and the second temperature rise parameter of the filter branch reactor, thereby determining the target air gap configuration parameters. This helps improve the comprehensiveness and rationality of the method for determining the target air gap configuration parameters, and thus improves the accuracy, reliability, and specificity of the determined target air gap configuration parameters. This helps prevent core oversaturation, coil overheating, and DC bias saturation. Furthermore, it improves the comprehensiveness and rationality of the method for determining the configuration information of the first magnetic flux density parameter and the first temperature rise parameter of the main circuit reactor, and thus improves the accuracy and reliability of the determined first magnetic flux density parameter and the first temperature rise parameter. Additionally, it improves the comprehensiveness and rationality of the method for determining the configuration information of the second magnetic flux density parameter and the second temperature rise parameter of the filter branch reactor, and thus improves the accuracy and reliability of the determined second magnetic flux density parameter and the second temperature rise parameter.

[0183] In another optional embodiment, the air gap configuration determination module 303 determines the target air gap configuration parameters of the target filter based on the basic magnetic circuit structure, the number of turns of the first coil, the number of turns of the second coil, the configuration information of the first magnetic flux density parameter, the configuration information of the first temperature rise parameter, the configuration information of the second magnetic flux density parameter, and the configuration information of the second temperature rise parameter. Specifically, this includes:

[0184] Based on the basic magnetic circuit structure, determine the geometric dimensions of the iron core;

[0185] Based on the configuration information of the first magnetic flux density parameter, the configuration information of the first temperature rise parameter, the number of turns of the first coil, and the geometric dimensions of the iron core, the coil air gap configuration scheme of the main circuit reactor is determined.

[0186] Based on the configuration information of the second magnetic flux density parameter, the configuration information of the second temperature rise parameter, the number of turns of the second coil, and the geometric dimensions of the iron core, the air gap configuration scheme of the filter branch reactor is determined.

[0187] Based on the coil air gap configuration scheme of the main circuit reactor and the coil air gap configuration scheme of the filter branch reactor, the target air gap configuration parameters of the target filter are determined.

[0188] It is evident that implementation Figure 2 The described system can also determine the coil air gap configuration scheme of the main circuit reactor and the coil air gap size configuration scheme of the filter branch reactor, thereby determining the target air gap configuration parameters of the filter. This is beneficial to improving the diversity, flexibility, pertinence, and rationality of the coil air gap configuration scheme determination method, and to improving the flexibility, pertinence, and fit of the determination parameters used to determine the coil air gap configuration scheme. In turn, it is beneficial to improve the accuracy, reliability, and pertinence of the determined coil air gap configuration scheme of the main circuit reactor and the coil air gap configuration scheme of the filter branch reactor, thereby improving the accuracy and reliability of the determined target air gap configuration parameters.

[0189] In another optional embodiment, the application parameter information includes at least one or more of the following: demand filtering harmonic order information, load rated power information, grid voltage information, first fundamental frequency information and first fundamental current information of the main circuit, and demand compensation reactive power information.

[0190] Furthermore, the inductance value determination module 301 determines the target inductance value information of the basic magnetic circuit structure based on the application parameter information of the target filter in the following specific ways:

[0191] Based on the reactive power compensation information and grid voltage information, determine the filter capacitor information corresponding to the filter branch in the target filter.

[0192] Based on the required harmonic order information and first fundamental frequency information, determine the tuning frequency information of the filter branch;

[0193] Based on the tuning frequency information, filter capacitor information, and the preset theoretical value of the total impedance of the filter branch at the tuning frequency, determine the second inductance value of the filter branch reactor.

[0194] The first inductance value of the main circuit reactor is determined based on the grid voltage information, the first fundamental frequency information, and the first fundamental current information.

[0195] Based on the first inductance value and the second inductance value, the target inductance value information of the basic magnetic circuit structure is determined.

[0196] It is evident that implementation Figure 2 The described system can also provide a method for determining the first inductance value of the main circuit reactor and a method for determining the second inductance value of the filter branch reactor. This is beneficial for improving the specificity and fit of the method for determining the first and second inductance values, as well as for increasing the diversity and flexibility of the inductance value determination method. This, in turn, helps to improve the accuracy and reliability of the determined first and second inductance values, thereby improving the accuracy and fit of the filter structure results subsequently determined based on the target inductance value information.

[0197] Example 3

[0198] Please see Figure 3 , Figure 3 This is a schematic diagram of the design system of another passive harmonic filter based on a common core structure disclosed in an embodiment of the present invention. Wherein, Figure 3 The described system may include a server, which may be a local server or a cloud server; this embodiment of the invention does not limit the scope. Figure 3 As shown, the system may include:

[0199] Memory 401 storing executable program code;

[0200] Processor 402 coupled to memory 401;

[0201] Furthermore, it may also include an input interface 403 coupled to the processor 402 and an output interface 404;

[0202] The processor 402 calls the executable program code stored in the memory 401 to execute the steps in the design method of the passive harmonic filter based on the common core structure described in Embodiment 1.

[0203] Example 4

[0204] This invention discloses a computer storage medium that stores a computer program for electronic data interchange, wherein the computer program causes a computer to execute the steps in the design method of a passive harmonic filter based on a common core structure as described in Embodiment 1.

[0205] Example 5

[0206] This invention discloses a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to cause a computer to perform the steps in the design method of a passive harmonic filter based on a common core structure described in Embodiment 1.

[0207] Example 6

[0208] This invention discloses a passive harmonic filter based on a common core structure. The passive harmonic filter includes a main circuit and a filter branch connected in parallel with the main circuit. The passive harmonic filter is electrically connected in parallel between the power grid and the load.

[0209] The main circuit includes a main circuit reactor, the filter branch includes a filter branch reactor, and the inductor coil of the main circuit reactor and the inductor coil of the filter branch reactor are coaxially wound and stacked on the same iron core center column.

[0210] The input terminal of the main circuit reactor is electrically connected to the power grid, and the output terminal of the main circuit reactor is electrically connected in parallel to the filter branch reactor.

[0211] The passive harmonic filter is designed based on the design method of the passive harmonic filter with a common core structure as described in Example 1. The structural design operation is performed to obtain the final structural result.

[0212] As can be seen, the common core structure of the main circuit reactor and the filter branch reactor proposed in this embodiment of the invention is beneficial to improving the novelty and specialness of the filter structure, highly integrating and reducing the size and weight of the filter, significantly reducing costs, avoiding magnetic interference and thus improving the working stability of the filter, enhancing the filtering effect of specific frequency bands and suppressing resonance to optimize potential performance, and achieving unified heat dissipation to improve the efficiency of thermal management.

[0213] In an optional embodiment, the aforementioned filter branch may further include a filter capacitor connected in series with the filter branch reactor; the target shape structure of the iron core includes an EI type shape structure, the iron core includes a three-phase magnetic circuit, the inductor coil of the main circuit reactor is wound in the inner layer of the iron core center column by enameled or silk-insulated flat copper wire, the inductor coil of the filter branch reactor is wound in the outer layer of the iron core center column by enameled or silk-insulated round copper wire, and the spacer layer between the inductor coil of the main circuit reactor and the inductor coil of the filter branch reactor is an insulating material.

[0214] Optionally, the main circuit reactor is a high-impedance inductor, mainly to suppress and reduce the impact of harmonics generated by nonlinear loads on the power grid; the filter branch reactor and filter capacitor form a tuned branch; series resonance is generated at the main specific harmonic frequency, absorbing most of its harmonic current waves, reducing the impact of load-side harmonics on the power quality of the power grid. This embodiment of the invention is not limited.

[0215] Optional, Figure 4 The diagram shown illustrates the basic circuit principle of the passive harmonic filter included in this scheme, comprising the main circuit reactor, the filter branch reactor, and the filter capacitor. This embodiment of the invention is not limited to any particular type.

[0216] Optional, Figure 5 The diagram shown illustrates the passive harmonic filter of this scheme, which uses an EI-type reactor with a common core and co-column winding. This embodiment of the invention is not limited to this one.

[0217] Optional, Figure 6 The diagram shown is an equivalent circuit model of the main circuit reactor and the filter branch reactor included in the passive harmonic filter of this scheme. This embodiment of the invention is not limited.

[0218] The device embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0219] Through the detailed description of the above embodiments, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, including read-only memory (ROM), random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), one-time programmable read-only memory (OTPROM), electrically-Erasable Programmable Read-Only Memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, disk storage, magnetic tape storage, or any other computer-readable medium that can be used to carry or store data.

[0220] Finally, it should be noted that the passive harmonic filter based on a common core structure and its design method and system disclosed in the embodiments of the present invention are merely preferred embodiments of the present invention, and are only used to illustrate the technical solutions of the present invention, not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A design method of a passive harmonic filter based on a common core structure, said method for configuring parameters of a target filter, said target filter being a passive harmonic filter, whose basic magnetic circuit structure comprises: The main circuit, the filter branch, and the core of the target form structure; The main circuit and the filter branch respectively include a main circuit reactor and a filter branch reactor, and the main circuit reactor and the filter branch reactor have a common core structure, characterized in that the method comprises: According to the application parameter information of the target filter, determine the target inductance value information of the basic magnetic circuit structure, the application parameter information at least includes one or more of the required harmonic filtering times information, the load rated power information, the grid voltage information, the first fundamental frequency information and the first fundamental current information of the main circuit, the required compensation reactive power information; Determine the first coil turns of the main circuit reactor, and according to the basic magnetic circuit structure, the target inductance value information and the first coil turns, determine the second coil turns of the filter branch reactor; According to the basic magnetic circuit structure, the first coil turns, the second coil turns and the preset magnetic core coil state limiting condition, determine the target air gap configuration parameter of the target filter; According to the basic magnetic circuit structure, the first coil turns, the second coil turns and the target air gap configuration parameter, determine the final structure result of the target filter; And, according to the application parameter information of the target filter, determine the target inductance value information of the basic magnetic circuit structure, including: According to the required compensation reactive power information and the grid voltage information, determine the filter capacitance information corresponding to the filter branch in the target filter; According to the required harmonic filtering times information and the first fundamental frequency information, determine the tuning frequency information of the filter branch; According to the tuning frequency information, the filter capacitance information and the preset total impedance theoretical value of the filter branch at the tuning frequency, determine the second inductance value of the filter branch reactor; According to the grid voltage information, the first fundamental frequency information and the first fundamental current information, determine the first inductance value of the main circuit reactor; According to the first inductance value and the second inductance value, determine the target inductance value information of the basic magnetic circuit structure.

2. The design method of a passive harmonic filter based on a common core structure according to claim 1, characterized in that, The target form structure is an EI type form structure, the core is provided with a center column; the main circuit reactor is formed by winding a flat copper wire type coil on the inner layer of the center column; the filter branch reactor is formed by winding a round copper wire type coil on the outer layer of the center column, and the main circuit reactor and the filter branch reactor are separated by an insulating separation material.

3. The design method of a passive harmonic filter based on a common core structure according to claim 1, characterized in that, According to the basic magnetic circuit structure, the target inductance value information and the first coil turns, determine the second coil turns of the filter branch reactor, including: According to the basic magnetic circuit structure, determine the target inductance value and the turns relationship corresponding to the main circuit reactor and the filter branch reactor in the target filter; According to the target inductance value information, determine the first inductance value of the main circuit reactor and the second inductance value of the filter branch reactor; According to the target inductance value and the turn number relationship, the first coil turn number, the first inductance value and the second inductance value, the second coil turn number of the filter branch reactor is determined.

4. The design method of a passive harmonic filter based on a common core structure according to claim 3, characterized in that, According to the basic magnetic circuit structure, the target inductance value and the turn number relationship corresponding to the main loop reactor and the filter branch reactor in the target filter are determined, including: According to the basic magnetic circuit structure and the preset magnetic potential relationship condition, the total air gap thickness relationship corresponding to the main loop reactor and the filter branch reactor in the target filter is determined, and when the main loop reactor and the filter branch reactor are in a shared core structure, the total air gap thickness corresponding to the main loop reactor and the filter branch reactor is the same; According to the total air gap thickness relationship, the target inductance value and the turn number relationship corresponding to the main loop reactor and the filter branch reactor are determined; And the target inductance value and the turn number relationship corresponding formula includes: N1 2 / L1 =N f 2 / L f ; wherein N1 is the first number of turns, L1 is the first inductance value, N f is the second number of turns, and L f is the second inductance value.

5. The design method of a passive harmonic filter based on a common core structure according to claim 1, characterized in that, According to the basic magnetic circuit structure, the first coil turn number, the second coil turn number and the preset magnetic core coil state limiting condition, the target air gap configuration parameter of the target filter is determined, including: According to the determined first fundamental current information of the main loop reactor and the preset first current coefficient scheme, a first maximum current result is determined, and according to the first maximum current result and the preset magnetic core saturation and coil over-temperature limiting condition, a first magnetic flux density parameter configuration information and a first temperature rise parameter configuration information of the main loop reactor are determined; According to the determined second fundamental current information and harmonic current information of the filter branch reactor, the preset second current coefficient scheme, a second maximum current result is determined, and according to the second maximum current result and the preset magnetic core saturation and coil over-temperature limiting condition, a second magnetic flux density parameter configuration information and a second temperature rise parameter configuration information of the filter branch reactor are determined; According to the basic magnetic circuit structure, the first coil turn number, the second coil turn number, the first magnetic flux density parameter configuration information, the first temperature rise parameter configuration information, the second magnetic flux density parameter configuration information and the second temperature rise parameter configuration information, the target air gap configuration parameter of the target filter is determined.

6. The design method of a passive harmonic filter based on a common core structure according to claim 5, characterized in that, According to the basic magnetic circuit structure, the first coil turn number, the second coil turn number, the first magnetic flux density parameter configuration information, the first temperature rise parameter configuration information, the second magnetic flux density parameter configuration information and the second temperature rise parameter configuration information, the target air gap configuration parameter of the target filter is determined, including: According to the basic magnetic circuit structure, the core geometric size information is determined; According to the first magnetic flux density parameter configuration information and the first temperature rise parameter configuration information, the first coil turn number and the core geometric size information, the coil air gap configuration scheme of the main loop reactor is determined; According to the second magnetic flux density parameter configuration information and the second temperature rise parameter configuration information, the second coil turn number and the core geometric size information, the coil air gap configuration scheme of the filter branch reactor is determined; According to the coil air gap configuration scheme of the main loop reactor and the coil air gap configuration scheme of the filter branch reactor, a target air gap configuration parameter of the target filter is determined.

7. A design system of a passive harmonic filter based on a common core structure, characterized by, The system is used to perform the design method of the passive harmonic filter based on the common core structure as claimed in any one of claims 1-6, and the system comprises: An inductance value determination module is configured to determine target inductance value information of the basic magnetic circuit structure according to application parameter information of the target filter; A coil turn number determination module is configured to determine a first coil turn number of the main loop reactor, and determine a second coil turn number of the filter branch reactor according to the basic magnetic circuit structure, the target inductance value information and the first coil turn number; An air gap configuration determination module is configured to determine a target air gap configuration parameter of the target filter according to the basic magnetic circuit structure, the first coil turn number, the second coil turn number and a preset magnetic core coil state limitation condition; A final structure determination module is configured to determine a final structure result of the target filter according to the basic magnetic circuit structure, the first coil turn number, the second coil turn number and the target air gap configuration parameter.

8. A design system of a passive harmonic filter based on a common core structure, characterized by, The system comprises: a memory storing executable program codes; a processor coupled with the memory; the processor invokes the executable program codes stored in the memory to perform the design method of the passive harmonic filter based on the common core structure as claimed in any one of claims 1-6.

9. A computer storage medium, characterized in that The computer storage medium stores computer instructions, which are invoked to perform the design method of the passive harmonic filter based on the common core structure as claimed in any one of claims 1-6.

10. A passive harmonic filter based on a common core structure, characterized by The passive harmonic filter comprises a main loop and a filter branch connected in parallel with the main loop, and the passive harmonic filter is connected in parallel between a power grid and a load; The main loop comprises a main loop reactor, and the filter branch comprises a filter branch reactor, and an inductance coil of the main loop reactor and an inductance coil of the filter branch reactor are coaxially and up-down stacked on a same core center column; an input end of the main loop reactor is electrically connected with the power grid, and an output end of the main loop reactor is electrically connected in parallel with the filter branch reactor; The passive harmonic filter performs a structure design operation to obtain a final structure result based on the design method of the passive harmonic filter based on the common core structure as claimed in any one of claims 1-6.

11. The common core structure based passive harmonic filter according to claim 10, characterized in that, The filter branch further comprises a filter capacitor connected in series with the filter branch reactor; The target morphological structure of the core comprises an EI type morphological structure, the core comprises a three-phase magnetic loop, the inductance coil of the main loop reactor is wound on an inner layer of the core center column by using enameled or silk-wound flat copper wire, the inductance coil of the filter branch reactor is wound on an outer layer of the core center column by using enameled or silk-wound round copper wire, and two interval layers corresponding to the inductance coil of the main loop reactor and the inductance coil of the filter branch reactor are insulating materials.

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