A method and computer device for calculating the inductance of a low-harmonic magnetically controlled reactor

Abstract

The present invention relates to the field of low harmonic magnetically controlled reactor inductance calculation, and specifically to a method and computer device for fine calculation of the inductance of a low harmonic magnetically controlled reactor. The technical solution includes: calculating the magnetic resistance in the AC magnetic circuit through the parameters of the low harmonic magnetically controlled reactor; using a block calculation method when calculating the magnetic resistance, first respectively calculating the AC iron core magnetic resistance in the non-orthogonal region, the magnetic resistance in the orthogonal region, and the magnetic resistance in the air gap, calculating the air gap magnetic resistance includes calculating the designed air gap magnetic resistance and calculating the air gap magnetic resistance at the splicing, and calculating the magnetic resistance in the orthogonal region includes calculating the iron core magnetic resistance in the orthogonal region and calculating the peripheral magnetic resistance in the orthogonal region; then calculating the total magnetic resistance of the low harmonic magnetically controlled reactor based on the calculated AC iron core magnetic resistance in the non-orthogonal region, the magnetic resistance in the orthogonal region, and the air gap magnetic resistance; calculating the inductance value of the low harmonic magnetically controlled reactor based on the obtained total magnetic resistance. The present invention is suitable for calculating the inductance of a low harmonic magnetically controlled reactor.

Description

Technical Field

[0001] The present invention relates to the field of low harmonic magnetically controlled reactor inductance calculation, and in particular to a method and a computer device for fine calculation of the inductance of a low harmonic magnetically controlled reactor. Background Art

[0002] As a basic component of power equipment, reactors are widely used in power system stability control, transformer resonant withstand voltage test, power flow regulation, motor soft start and fault current suppression.

[0003] Among them, CN114843088A proposes a novel low-harmonic magnetically controlled reactor and the structure of the reactor, but does not mention a method for calculating the inductance of the low-harmonic magnetically controlled reactor.

[0004] Patent CN111987704A proposes a method for calculating the inductance of a magnetic saturation DC fault current limiter taking into account permanent magnet leakage flux. By using the flux tube equivalent calculation principle, an equivalent magnetic permeability network of the fault current limiter is obtained, and the equivalent inductance value is calculated.

[0005] At present, there are few refined calculation methods for low-harmonic magnetically controlled reactors. Most low-harmonic magnetically controlled reactors are designed by first performing finite element simulation and then making corrections. There is an urgent need for a low-harmonic magnetically controlled reactor design method that can be designed from top to bottom according to design requirements. The key difficulty lies in the accurate calculation of the inductance value of the low-harmonic magnetically controlled reactor. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method and a computer device for calculating the inductance of a low-harmonic magnetically controlled reactor in detail, which greatly improves the accuracy of the calculation results of the inductance value of the low-harmonic magnetically controlled reactor.

[0007] The present invention adopts the following technical solutions to achieve the above-mentioned purpose. In a first aspect, the present invention provides a method for fine calculation of inductance of a low-harmonic magnetically controlled reactor, comprising:

[0008] Calculate the magnetic resistance in the AC magnetic circuit through the parameters of the low harmonic magnetic controlled reactor;

[0009] The block calculation method is adopted when calculating the magnetic resistance. First, the AC core magnetic resistance in the non-orthogonal region, the orthogonal region magnetic resistance and the air gap magnetic resistance are calculated separately. Then, the total magnetic resistance of the low-harmonic magnetic controlled reactor is calculated based on the calculated AC core magnetic resistance in the non-orthogonal region, the orthogonal region magnetic resistance and the air gap magnetic resistance.

[0010] The inductance value of the low harmonic magnetic controlled reactor is calculated based on the obtained total magnetic resistance.

[0011] Furthermore, the calculation of the AC core magnetic reluctance in the non-orthogonal region specifically includes:

[0012] The length of the AC core in the non-orthogonal region is l a1 , the magnetic permeability of the AC core in the non-orthogonal region is μ a1 , the cross-sectional area of ​​the AC core perpendicular to the magnetic flux direction is S a , then the AC core magnetic resistance in the non-orthogonal region is R mal for:

[0013] .

[0014] Furthermore, the calculation of the air gap reluctance specifically includes:

[0015] For the designed air gap part, the magnetic resistance is calculated as follows:

[0016] The length of the air gap is designed to be l g , the width of the magnetic flux diffraction is:

[0017] , h g To design the length of the core column on one side of the air gap, It indicates the width of the magnetic flux diffraction in the designed air gap;

[0018] Design the equivalent cross-sectional area of ​​the air gap for:

[0019] ,in a core and b core is the length and width of the AC core cross section;

[0020] The air gap is designed to be 2, and the magnetic resistance of the air gap is designed to be:

[0021] ,in μ 0 is the magnetic permeability of vacuum, R mg Represents the magnetic resistance of the designed air gap.

[0022] Furthermore, the calculation of the air gap magnetic resistance specifically includes:

[0023] For the air gap at the joint caused by actual installation, the magnetic resistance is calculated as follows:

[0024] The length of the air gap at the joint is l j , the width of the magnetic flux diffraction is:

[0025] , hj is the length of the core column on one side of the air gap at the joint, Indicates the width of the air gap flux diffraction at the joint;

[0026] Equivalent cross-sectional area of ​​the air gap at the joint for:

[0027] ;

[0028] There are 4 air gaps at the joints, so the magnetic resistance of the air gaps at the joints is:

[0029] , R mj Represents the magnetic resistance of the air gap at the joint.

[0030] Furthermore, the orthogonal region magnetic resistance includes the orthogonal region peripheral magnetic resistance and the orthogonal region core magnetic resistance. Calculating the orthogonal region core magnetic resistance specifically includes:

[0031] The magnetic permeability of the core in the orthogonal region is μ 2. The cross-sectional area of ​​the DC core in the orthogonal region in the direction perpendicular to the magnetic flux is S d , the length of the orthogonal region is l d , the low harmonic magnetically controlled reactor has two orthogonal regions, so the core magnetic resistance of the orthogonal region R md1 for:

[0032] .

[0033] Furthermore, calculating the magnetic resistance around the orthogonal region specifically includes:

[0034] The air around the orthogonal area is divided into a semicircular area and a semicircular ring area;

[0035] For the semicircular area, the first area and the second area have the same shape, so the magnetic permeance of the two areas is the same. The calculation formula of the magnetic permeance of the first area and the second area is:

[0036] , Λ A1 and Λ A2 represent the first region and the second region magnetic permeance respectively;

[0037] For the semicircular ring area, the calculation formulas for calculating the magnetic permeance of the third area and the fourth area are:

[0038]

[0039] in, and Represent the third and fourth region magnetic permeances, respectively.l acyoke1 and l acyoke2 is the upper and lower length of the iron yoke;

[0040] The first area, the second area, the third area and the fourth area are in parallel, so the total magnetic resistance of the four areas is R md2 for:

[0041] ;

[0042] Then the orthogonal region magnetic resistance is:

[0043] , R md represents the total magnetic resistance in the orthogonal region, Indicates a parallel relationship.

[0044] Furthermore, the inductance value of the low harmonic magnetically controlled reactor is:

[0045]

[0046] in N ac is the number of turns of a single AC coil connected to the circuit, and L is the inductance of the low harmonic magnetically controlled reactor.

[0047] In a second aspect, the present invention provides a computer device, including a memory, wherein the memory stores program instructions, and when the program instructions are run, the above-mentioned method for calculating the inductance refinement of a low-harmonic magnetically controlled reactor is executed.

[0048] The beneficial effects of the present invention are:

[0049] When calculating the magnetic resistance, the present invention adopts a block calculation method, firstly respectively calculates the AC iron core magnetic resistance in the non-orthogonal region, the orthogonal region magnetic resistance and the air gap magnetic resistance, and then calculates the total magnetic resistance of the low harmonic magnetic controlled reactor based on the calculated non-orthogonal region AC iron core magnetic resistance, orthogonal region magnetic resistance and air gap magnetic resistance, thereby improving the accuracy of the total magnetic resistance.

[0050] Compared with the prior art, the calculation of the present invention is more concise and efficient, and takes into account the leakage magnetic field in the air and the diffraction effect of the air gap, so the inductance of the low-harmonic magnetically controlled reactor is calculated more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a flow chart of a method for calculating the inductance refinement of a low harmonic magnetically controlled reactor provided by an embodiment of the present invention;

[0052] Figure 2 is a topological structure diagram of a low harmonic magnetically controlled reactor provided by an embodiment of the present invention;

[0053] Figure 3 is a schematic cross-sectional view of a low harmonic magnetically controlled reactor provided by an embodiment of the present invention;

[0054] Figure 4 is a schematic diagram of an equivalent magnetic circuit provided by an embodiment of the present invention;

[0055] Figure 5 is a schematic diagram of the air gap magnetic flux diffraction effect provided by an embodiment of the present invention;

[0056] Figure 6 2 is a schematic diagram of leakage magnetic flux distribution in the air provided in an embodiment of the present invention, (a) represents a semicircular area, and (b) represents a semicircular ring area. DETAILED DESCRIPTION

[0057] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0058] The present invention provides a method for calculating the inductance of a low harmonic magnetically controlled reactor in detail. Figure 1 As shown, including:

[0059] Calculate the magnetic resistance in the AC magnetic circuit through the parameters of the low harmonic magnetic controlled reactor;

[0060] The block calculation method is adopted when calculating the magnetic resistance. First, the AC core magnetic resistance in the non-orthogonal region, the orthogonal region magnetic resistance and the air gap magnetic resistance are calculated separately. Then, the total magnetic resistance of the low-harmonic magnetic controlled reactor is calculated based on the calculated AC core magnetic resistance in the non-orthogonal region, the orthogonal region magnetic resistance and the air gap magnetic resistance.

[0061] The inductance value of the low harmonic magnetic controlled reactor is calculated based on the obtained total magnetic resistance.

[0062] When calculating the air gap magnetic resistance, the present invention considers the influence of the designed air gap and the air gap at the joint on the magnetic resistance. The AC iron core and the DC iron core with the air gap at the joint are both composed of multiple rectangular iron core blocks. There is a small air gap at the joint of the iron core blocks. When calculating the inductance, the magnetic resistance of the small air gap is considered and substituted into the total magnetic permeability network.

[0063] The present invention takes into account the influence of the diffraction effect of the magnetic flux at the air gap of the iron core, and considers that when the magnetic flux passes through the air gap of the reactor, the magnetic flux passes through the air around the air gap, resulting in a change in the equivalent cross-sectional area of ​​the air gap.

[0064] When calculating the magnetic resistance of the orthogonal region, the present invention takes into account the magnetic resistance of the core part and the leakage magnetic field around the orthogonal region. The air around the orthogonal region is divided into two typical semicircular regions, and the equivalent magnetic permeability values ​​of each part are calculated and substituted into the total magnetic permeability network.

[0065] Specifically, the structure and cross-sectional diagram of the low harmonic magnetically controlled reactor are as follows: Figure 2 and Figure 3 As shown. The new low-harmonic magnetically controlled reactor adopts a structure in which the AC and DC cores are completely orthogonal, wherein the AC core is a closed core and the DC core adopts two identical C-shaped cores; the DC core is in the middle of the AC core and is orthogonal to the AC core to form a cross-type low-harmonic magnetically controlled reactor. The new low-harmonic magnetically controlled reactor also includes: an AC coil and a DC coil, wherein the AC coil includes two, the first AC coil and the second AC coil are respectively wound on the two side columns of the AC core, serving as the working winding of the reactor. The DC coil includes two, the first DC coil and the second DC coil are respectively wound on the two side columns of the DC core, serving as the control winding of the reactor, Figure 2 middle N ac is the number of turns of a single AC coil connected to the circuit, N dc It is the number of turns of a single DC coil connected to the circuit.

[0066] The inductance calculation principle of the present invention is:

[0067] The formula for calculating inductance is:

[0068]

[0069] The formula for calculating magnetic resistance is:

[0070]

[0071] Where, N represents the total number of turns of the low harmonic magnetically controlled reactor inductor. l represents length, S represents area, represents magnetic permeability;

[0072] According to the above formula, the magnetic resistance of the low harmonic magnetic controlled reactor can be calculated. The equivalent magnetic circuit diagram is as follows: Figure 4 As shown in Figure 2, the magnetic resistance in the magnetic circuit includes the AC core resistance in the non-orthogonal region, the air gap resistance, and the orthogonal region resistance.

[0073] For the non-orthogonal region AC core, calculate the magnetic resistance of this part, where the length of the AC core part is l a1 , the magnetic permeability of the non-orthogonal region of the AC core is μ a1 , S a It is the cross-sectional area of ​​the AC core perpendicular to the direction of magnetic flux.

[0074] The magnetic resistance of this part is calculated as:

[0075] , R malis the AC core reluctance in the non-orthogonal region.

[0076] The schematic diagram of the designed air gap and the air gap at the joint is as follows Figure 5 shown.

[0077] For the designed air gap part, the magnetic resistance is calculated as follows:

[0078] The length of the air gap is designed to be l g , the width of the magnetic flux diffraction is:

[0079] , h g To design the length of the core column on one side of the air gap, It indicates the width of the magnetic flux diffraction in the designed air gap;

[0080] Design the equivalent cross-sectional area of ​​the air gap for:

[0081] ,in a core and b core is the length and width of the AC core cross section;

[0082] If there are two air gaps, the magnetic reluctance of the air gap is:

[0083] ,in μ 0 is the magnetic permeability of vacuum, R mg Represents the magnetic resistance of the designed air gap.

[0084] For the air gap at the joint caused by actual installation, the magnetic resistance is calculated as follows:

[0085] The length of the air gap at the joint is l j , the width of the magnetic flux diffraction is:

[0086] , h j is the length of the core column on one side of the air gap at the joint, Indicates the width of the air gap flux diffraction at the joint;

[0087] Equivalent cross-sectional area of ​​the air gap at the joint for:

[0088] ;

[0089] There are four air gaps at the joints, and the magnetic resistance of the air gaps at the joints is:

[0090] , R mj Represents the magnetic resistance of the air gap at the joint.

[0091] The orthogonal region magnetic resistance includes the orthogonal region peripheral magnetic resistance and the orthogonal region iron core magnetic resistance, and the two magnetic resistances are in a parallel relationship.

[0092] Calculating the core reluctance in the orthogonal region specifically includes:

[0093] The magnetic permeability of the core in the orthogonal region is μ 2. The cross-sectional area of ​​the DC core in the orthogonal region in the direction perpendicular to the magnetic flux is S d , the length of the orthogonal region is l d , there are two orthogonal regions in the low harmonic magnetically controlled reactor, such as Figure 2 As shown, the gray upper and lower two small squares are the core magnetic resistance in the orthogonal region R md1 for:

[0094] ;

[0095] Calculate the magnetic resistance around the orthogonal region and divide the air around the orthogonal region into two typical regions. Figure 6 As shown in (a), for the semicircular area, since the shapes of area A1 and area A2 are the same, the magnetic permeance of the two areas is the same. Calculate the magnetic permeance Λ of the two areas A1 and Λ A2 The formula is:

[0096] ;

[0097] like Figure 6 As shown in (b), for the semicircular ring area, the formula for calculating the magnetic permeance of the A3 area and the A4 area is:

[0098]

[0099] l acyoke1 and l acyoke2 is the upper and lower length of the iron yoke.

[0100] The four regions are in parallel, so the total magnetic resistance of the four regions is R md2 Should be

[0101]

[0102] There are two orthogonal regions, so the total magnetic resistance of the orthogonal regions should be:

[0103] , Rmd represents the total magnetic resistance in the orthogonal region, Indicates a parallel relationship.

[0104] The inductance expression of low harmonic magnetic controlled reactor is:

[0105]

[0106] in N ac is the number of turns of a single AC coil connected to the circuit, L represents the inductance of the low-harmonic magnetically controlled reactor. There are two AC windings in the low-harmonic magnetically controlled reactor, so the total number of turns of the AC part of the orthogonal reactor is 2 N ac .

[0107] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A method for calculating the inductance of a low harmonic magnetically controlled reactor in detail, characterized in that: include: Calculate the magnetic resistance in the AC magnetic circuit through the parameters of the low harmonic magnetic controlled reactor; The block calculation method is adopted when calculating the magnetic resistance. First, the AC core magnetic resistance in the non-orthogonal region, the orthogonal region magnetic resistance and the air gap magnetic resistance are calculated separately. Then, the total magnetic resistance of the low-harmonic magnetic controlled reactor is calculated based on the calculated AC core magnetic resistance in the non-orthogonal region, the orthogonal region magnetic resistance and the air gap magnetic resistance. Calculate the inductance value of the low harmonic magnetically controlled reactor based on the obtained total magnetic resistance; The calculation of air gap reluctance specifically includes the reluctance of the designed air gap part and the reluctance of the air gap at the joint caused by the actual installation; For the designed air gap part, the magnetic resistance is calculated as follows: The length of the air gap is designed to be l g , the width of the magnetic flux diffraction is: , h g To design the length of the core column on one side of the air gap, It indicates the width of the magnetic flux diffraction in the designed air gap; Design the equivalent cross-sectional area of ​​the air gap for: ,in a core and b core is the length and width of the AC core cross section; The air gap is designed to be 2, and the magnetic resistance of the air gap is designed to be: ,in μ 0 is the magnetic permeability of vacuum, R mg represents the magnetic resistance of the designed air gap; The orthogonal region magnetic resistance includes the orthogonal region peripheral magnetic resistance and the orthogonal region core magnetic resistance; Calculating the magnetic resistance around the orthogonal region specifically includes: The air around the orthogonal area is divided into a semicircular area and a semicircular ring area; For the semicircular area, the first area and the second area have the same shape, so the magnetic permeance of the two areas is the same. The calculation formula of the magnetic permeance of the first area and the second area is: , Λ A1 and Λ A2 represent the first region and the second region magnetic permeance respectively, l d represents the length of the orthogonal region; For the semicircular ring area, the calculation formulas for calculating the magnetic permeance of the third area and the fourth area are: in, and Represent the third and fourth region magnetic permeances, respectively. l acyoke1 and l acyoke2 is the upper and lower length of the iron yoke; The first area, the second area, the third area and the fourth area are in parallel, so the total magnetic resistance of the four areas is R md2 for: ； There are two orthogonal regions, so the total magnetic resistance of the orthogonal regions is: , R md represents the total magnetic resistance in the orthogonal region, Indicates a parallel relationship, R md1 is the core reluctance in the orthogonal region.

2. The method for calculating the inductance of a low harmonic magnetically controlled reactor according to claim 1 is characterized in that: Calculating the core reluctance in the orthogonal region specifically includes: The magnetic permeability of the core in the orthogonal region is μ 2. The cross-sectional area of ​​the DC core in the orthogonal region in the direction perpendicular to the magnetic flux is S d , there are two orthogonal regions in the low harmonic magnetically controlled reactor, and the core magnetic resistance in the orthogonal region is: 。 3. The method for calculating the inductance of a low harmonic magnetically controlled reactor according to claim 2 is characterized in that: Calculating the AC core reluctance in the non-orthogonal region specifically includes: The length of the AC core in the non-orthogonal region is l a1 , the magnetic permeability of the AC core in the non-orthogonal region is μ a1 , the cross-sectional area of ​​the AC core perpendicular to the magnetic flux direction is S a , then the AC core magnetic resistance in the non-orthogonal region is R mal for: 。 4. The method for calculating the inductance of a low harmonic magnetically controlled reactor according to claim 3 is characterized in that: For the air gap at the joint caused by actual installation, the magnetic resistance is calculated as follows: The length of the air gap at the joint is l j , the width of the magnetic flux diffraction is: , h j is the length of the core column on one side of the air gap at the joint, Indicates the width of the air gap flux diffraction at the joint; Equivalent cross-sectional area of ​​the air gap at the joint for: ； There are 4 air gaps at the joints, so the magnetic resistance of the air gaps at the joints is: , R mj Represents the magnetic resistance of the air gap at the joint.

5. The method for calculating the inductance of a low harmonic magnetically controlled reactor according to claim 4 is characterized in that: The inductance value of the low harmonic magnetic controlled reactor is: in N ac is the number of turns of a single AC coil connected to the circuit, and L is the inductance of the low harmonic magnetically controlled reactor.

6. A computer device comprising a memory, wherein the memory stores program instructions, characterized in that: When the program instructions are executed, the method for fine-tuning the inductance calculation of the low-harmonic magnetically controlled reactor as described in any one of claims 1 to 5 is executed.

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