CN112487677B - A method and device for calculating reactor core loss - Google Patents

Abstract

The invention provides a method and a device for calculating the core loss of a reactor, wherein the method is characterized in that the core loss calculation is carried out by constructing a magnetic flux transient equation set, establishing an objective function and applying solution methods such as loop iteration, linear interpolation, fourier series decomposition and the like; and adopting finite element magnetic field numerical calculation to obtain reactor magnetic field distribution, adopting a preset data processing program to realize data acquisition and processing, finally obtaining the loss of each iron core cake, further obtaining the total loss of the reactor iron core through calculation, and realizing the reliable calculation of the iron core loss of the reactor.

Description

A method and device for calculating core loss of a reactor

Technical Field

The invention relates to the technical field of transformer design, and in particular to a method and device for calculating the core loss of a reactor.

Background Art

Reactors are widely used in power systems. Their main function is to limit the large current of the system and compensate for the distributed capacitance current of the system. For reactors, the accuracy of the calculation of core loss has always been a difficult design problem, especially for three-phase five-column core structures. The magnetic circuit is relatively complex, with many influencing factors. The magnetic field distributions of the main yoke, side yoke, and side column are also different, and there are harmonic components. It is relatively difficult to accurately calculate the core loss by traditional manual methods. In terms of testing, unlike transformer equipment, the reactor is a one-terminal component and cannot be tested at no load. During the test, only the total loss can be measured. All losses are included and cannot be separated, so that the core loss and stray loss of the product cannot be accurately checked, which may lead to a large deviation between the loss design value and the actual value. Therefore, how to accurately calculate the core loss of the three-phase five-column core structure reactor is of great significance to engineering designers for design verification, research and improvement of product performance reliability, and to ensure the safe and stable operation of the reactor.

Summary of the invention

In view of this, an embodiment of the present invention provides a method and device for calculating the core loss of a reactor, so as to realize the calculation of the core loss of the reactor.

To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

A method for calculating core loss of a reactor, comprising:

Obtaining an electromagnetic simulation calculation model of the reactor to be tested;

The electromagnetic simulation calculation model of the reactor is solved and calculated by using finite element magnetic field numerical calculation to obtain the magnetic field distribution of the reactor;

Extracting and obtaining the loss of each iron core disk in the reactor based on the magnetic field distribution of the reactor;

The effective cross-sectional areas of the main yoke, the side yoke and the side column of the reactor are calculated based on the core structure dimension data of the reactor;

Based on an equivalent planar magnetic circuit network matching the reactor, a group of magnetic flux transient equations is constructed;

Solve the flux instantaneous equations and derive the functional relationship between the yoke flux and time.

The objective function is established based on the functional relationship between the side yoke flux and time. Wherein, φ ₂ (t) is the main yoke flux of the reactor, φ ₁ (t) is the side yoke flux of the reactor, φ _m is the maximum total flux of the iron yoke of the reactor, w refers to the angular frequency, _Re2 (t) is the main yoke magnetic resistance at time t, _Re1 (t) is the side yoke magnetic resistance at time t, R _z (t) is the side column magnetic resistance at time t, R _j (t) is the magnetic resistance at the core joint angle at time t, _Be2 (t) is the main yoke magnetic density value at time t, and _Sp is the effective cross-sectional area of the main yoke or the effective cross-sectional area of the side yoke;

Based on the objective function, a functional relationship between the side yoke magnetic density value and the side column magnetic density value changing with time is calculated;

Based on the functional relationship between the side yoke and side column magnetic density values changing with time, the side yoke magnetic resistance, the main yoke magnetic resistance, the side column magnetic resistance, and the magnetic resistance at the core joint angle and the target function, the main yoke magnetic density value, the side yoke magnetic density value, and the side column magnetic density value of the reactor at different times are calculated;

Calculate the peak value of the Nth harmonic component in the main yoke magnetic density value, the side yoke magnetic density value, and the side column magnetic density value, wherein the Nth harmonic includes but is not limited to: fundamental wave, third harmonic and fifth harmonic;

Based on the preset B-P function relationship of silicon steel sheets, the unit loss value and total loss value of the side yoke, main yoke and side column under different harmonics are calculated by interpolation method;

The sum of the total loss values of the side yoke, the main yoke, the side column and the core loss is taken as the total core loss value of the reactor.

Optionally, in the above-mentioned method for calculating the core loss of the reactor, the loss of each core disk in the reactor is obtained based on the magnetic field distribution of the reactor, including:

Based on the magnetic field distribution of the reactor, a magnetic density value of a preset collection point on the iron core cake on the reactor is collected;

The magnetic flux of each acquisition point is calculated based on the magnetic density value of each acquisition point;

The unit magnetic flux of all the acquisition points corresponding to each core cake is summed up and divided by the effective cross-sectional area of the core cake to obtain the average magnetic flux density value of the core cake;

Based on the preset B-P function relationship of the silicon steel sheet, the unit loss value ΔP (B _ci ) of the core cake is calculated by using the interpolation method, and then the total core loss P _c is obtained.

Optionally, in the above reactor core loss calculation method, the reactor is a three-phase five-column core structure reactor, and the flux transient equation is:

Wherein: _Ra (t), _Rb (t), _Rc (t) are the magnetic resistances of the three-phase iron core columns A, B, C at time t respectively; _FA (t), _FB (t), _FC (t) are the three-phase magnetic pressure sources A, B, C at time t respectively; _φ1 (t), _φ3 (t), _φ4 (t) are the magnetic fluxes of each circuit of the equivalent planar magnetic circuit network at time t respectively.

Optionally, in the above reactor core loss calculation method, the functional relationship between the side yoke magnetic flux and time is:

Optionally, in the above reactor core loss calculation method, the functional relationship between the side yoke magnetic density value and the side column magnetic density value changing with time is respectively:

Wherein, the effective cross-sectional area of the reactor side column, the _Be1 (t) is the magnetic flux density value of the reactor side yoke at time t, and the _Bz (t) is the magnetic flux density value of the reactor side column at time t.

Optionally, in the above-mentioned reactor core loss calculation method, the functional relationship between the side yoke and side column magnetic density values changing with time, the yoke magnetic resistance, the main yoke magnetic resistance, the side column magnetic resistance, and the magnetic resistance at the core joint angle and the objective function are used to calculate the main yoke magnetic density value, the side yoke magnetic density value, and the side column magnetic density value of the reactor at different times, including:

According to the given silicon steel sheet B-μ relationship function (magnetic flux density and magnetic permeability relationship function of silicon steel sheet), solve the magnetic permeability of different magnetic circuits, and then calculate the side yoke magnetic resistance _Re1 (t), main yoke magnetic resistance _Re2 (t), side column magnetic resistance _Rz (t) and magnetic resistance at the core joint angle _Rj (t):

Among them, _Sz refers to the effective cross-sectional area of the reactor side column, _μe1 refers to the magnetic permeability of the side yoke, _μe2 refers to the magnetic permeability of the main yoke, _μj refers to the magnetic permeability at the angle of the core joint, _μz refers to the magnetic permeability of the side column, Mp refers to the distance from the center of the core to the inner side of the side column, TS refers to the thickness of the side column, Hp refers to the thickness of the upper and lower iron yokes, and Hw refers to the window height.

Substitute each partial magnetic resistance into the objective function f(t) to obtain the main yoke magnetic density value, side yoke magnetic density value, and side column magnetic density value of the reactor at different times.

Optionally, in the above-mentioned reactor core loss calculation method, the interpolation method is used to obtain the unit loss value and total loss value of the side yoke, main yoke and side column under different harmonics based on the preset silicon steel sheet B-P function relationship, including:

According to the given B-P function relationship of silicon steel sheet, the unit loss value of side yoke ΔP(maxB _e1j ), the unit loss value of main yoke ΔP(maxB _e2j ), the unit loss value of side column ΔP(maxB _zj ) and the total loss value of side yoke P _e1 , the total loss value of main yoke P _e2 , and the total loss value of side column P _z under different harmonics are obtained by interpolation method:

Among them: _Ge1 is the weight of the side yoke, _Gz is the weight of the side column, and _Ge2 is the weight of the main yoke.

A reactor core loss calculation device, comprising:

The core loss calculation unit is used to obtain the electromagnetic simulation calculation model of the reactor to be tested; solve the electromagnetic simulation calculation model of the reactor by finite element magnetic field numerical calculation to obtain the magnetic field distribution of the reactor; and extract the loss of each core in the reactor based on the magnetic field distribution of the reactor;

The iron yoke loss calculation unit is used to calculate the effective cross-sectional area of the main yoke, side yoke and side column of the reactor based on the core structure size data of the reactor; build a group of flux instantaneous equations based on an equivalent plane magnetic circuit network matching the reactor; solve the group of flux instantaneous equations to derive the functional relationship of the side yoke flux changing with time; establish an objective function based on the functional relationship of the side yoke flux changing with time Wherein, φ ₂ (t) is the main yoke flux of the reactor, φ ₁ (t) is the side yoke flux of the reactor, φ _m is the maximum total flux of the iron yoke of the reactor, w refers to the angular frequency, _Re2 (t) is the main yoke magnetic resistance at time t, _Re1 (t) is the side yoke magnetic resistance at time t, R _z (t) is the side column magnetic resistance at time t, R _j (t) is the magnetic resistance at the angle of the core joint at time t, _Be2 (t) is the main yoke magnetic density value at time t, S _p is the effective cross-sectional area of the main yoke or the effective cross-sectional area of the side yoke; based on the objective function, the functional relationship between the side yoke magnetic density value and the side column magnetic density value changing with time is calculated; based on the functional relationship between the side yoke and side column magnetic density values changing with time, the side yoke magnetic resistance, the main yoke magnetic resistance, the side column magnetic resistance, and the magnetic resistance at the angle of the core joint and the objective function, the main yoke magnetic density value, the side yoke magnetic density value, and the side column magnetic density value of the reactor at different times are calculated; the peak value of the Nth harmonic component in the main yoke magnetic density value, the side yoke magnetic density value, and the side column magnetic density value is calculated, and the Nth harmonic includes but is not limited to: fundamental wave, third harmonic and fifth harmonic; based on the preset silicon steel sheet B-P function relationship, the unit loss value and total loss value of the side yoke, main yoke, and side column under different harmonics are obtained by interpolation method;

The core loss calculation unit is used to take the sum of the total loss values of the side yoke, the main yoke, the side column and the core cake loss as the total core loss value of the reactor.

Optionally, in the above reactor core loss calculation device, when the core loss calculation unit extracts and obtains the core loss of each core in the reactor based on the magnetic field distribution of the reactor, it is specifically used to:

Based on the magnetic field distribution of the reactor, a magnetic density value of a preset collection point on the iron core cake on the reactor is collected;

The magnetic flux of each acquisition point is calculated based on the magnetic density value of each acquisition point;

The unit magnetic flux of all the acquisition points corresponding to each core cake is summed up and divided by the effective cross-sectional area of the core cake to obtain the average magnetic flux density value of the core cake;

Based on the preset B-P function relationship of the silicon steel sheet, the unit loss value ΔP (B _ci ) of the core cake is calculated by using the interpolation method, and then the total core loss P _c is obtained.

Optionally, in the above reactor core loss calculation device, the reactor is a three-phase five-column core structure reactor, and the flux transient equation is:

Wherein: _Ra (t), _Rb (t), _Rc (t) are the magnetic resistances of the three-phase iron core columns A, B, C at time t respectively; _FA (t), _FB (t), _FC (t) are the three-phase magnetic pressure sources A, B, C at time t respectively; _φ1 (t), _φ3 (t), _φ4 (t) are the magnetic fluxes of each circuit of the equivalent planar magnetic circuit network at time t respectively.

Optionally, in the above reactor core loss calculation device, the functional relationship of the side yoke magnetic flux changing with time is:

Optionally, in the above reactor core loss calculation device, the functional relationship between the side yoke magnetic density value and the side column magnetic density value changing with time is respectively:

Wherein, the effective cross-sectional area of the reactor side column, the _Be1 (t) is the magnetic flux density value of the reactor side yoke at time t, and the _Bz (t) is the magnetic flux density value of the reactor side column at time t.

Optionally, in the above-mentioned reactor core loss calculation device, the yoke loss calculation unit calculates the main yoke magnetic density value, the side yoke magnetic density value, and the side column magnetic density value of the reactor at different times based on the functional relationship between the side yoke and side column magnetic density values changing with time, the yoke magnetic resistance, the main yoke magnetic resistance, the side column magnetic resistance, and the magnetic resistance at the core joint angle and the objective function, and is specifically used to:

According to the given silicon steel sheet B-μ relationship function, solve the magnetic permeability of different magnetic circuits, and then calculate the side yoke reluctance _Re1 (t), main yoke reluctance _Re2 (t), side column reluctance _Rz (t) and the reluctance at the core joint angle _Rj (t):

Substitute each partial magnetic resistance into the objective function f(t) to obtain the main yoke magnetic density value, side yoke magnetic density value, and side column magnetic density value of the reactor at different times;

Among them, _Sz refers to the effective cross-sectional area of the reactor side column, _μe1 refers to the magnetic permeability of the side yoke, _μe2 refers to the magnetic permeability of the main yoke, _μj refers to the magnetic permeability at the angle of the core joint, _μz refers to the magnetic permeability of the side column, Mp refers to the distance from the center of the core to the inner side of the side column, TS refers to the thickness of the side column, Hp refers to the thickness of the upper and lower iron yokes, and Hw refers to the window height.

Optionally, in the above reactor core loss calculation device, the interpolation method is used to obtain the unit loss value and total loss value of the side yoke, main yoke and side column under different harmonics based on the preset silicon steel sheet B-P function relationship, including:

According to the given B-P function relationship of silicon steel sheet, the unit loss value of side yoke ΔP(maxB _e1j ), the unit loss value of main yoke ΔP(maxB _e2j ), the unit loss value of side column ΔP(maxB _zj ) and the total loss value of side yoke P _e1 , the total loss value of main yoke P _e2 , and the total loss value of side column P _z under different harmonics are obtained by interpolation method:

Among them: _Ge1 is the weight of the side yoke, _Gz is the weight of the side column, and _Ge2 is the weight of the main yoke.

Based on the above technical scheme, the above scheme provided by the embodiment of the present invention, in the scheme disclosed in the embodiment of the present application, when calculating the loss of the core cake of the reactor, the present invention adopts a finite element numerical calculation method to calculate the magnetic field distribution of the electromagnetic simulation calculation model of the reactor to be tested, and extracts the loss of each core cake in the reactor based on the magnetic field distribution of the reactor. When calculating the iron yoke loss, based on the equivalent planar magnetic circuit network matching the reactor, a group of instantaneous equations for magnetic flux is built, the group of instantaneous equations for magnetic flux is solved, and the functional relationship of the change of the side yoke magnetic flux with time is derived. Based on the functional relationship of the change of the side yoke magnetic flux with time, an objective function is established. Based on the objective function, the functional relationship of the change of the side yoke magnetic density value and the side column magnetic density value with time is calculated. Based on the functional relationship of the change of the side yoke and side column magnetic density values with time, the side yoke magnetic resistance, the main yoke magnetic resistance, and the side The column magnetic resistance, the magnetic resistance at the angle of the core joint and the objective function are used to calculate the main yoke magnetic density value, side yoke magnetic density value and side column magnetic density value of the reactor at different times; the peak value of the Nth harmonic component in the main yoke magnetic density value, side yoke magnetic density value and side column magnetic density value is calculated, and the Nth harmonic includes but is not limited to: fundamental wave, third harmonic and fifth harmonic; finally, based on the preset silicon steel sheet B-P function relationship, the unit loss value and total loss value of the side yoke, main yoke and side column under different harmonics are obtained by interpolation method.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

FIG1 is a flow chart of a method for calculating core loss of a reactor disclosed in an embodiment of the present application;

FIG2 is an electromagnetic simulation calculation model of a reactor shown in an embodiment of the present application;

FIG3 is a schematic diagram of a specific calculation process of the core loss disclosed in an embodiment of the present application;

FIG4 is a schematic diagram of the structure of a three-phase five-column iron core reactor;

FIG5 is a schematic diagram of the structure of an equivalent planar magnetic circuit network of a three-phase five-column iron core reactor;

FIG6 is a schematic diagram of the structure of a reactor core loss calculation device disclosed in an embodiment of the present application.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

In this context, the inventor proposed a method for calculating the core loss of the reactor, which is to calculate the iron yoke loss by building a group of flux instantaneous equations, establishing an objective function, and using loop iteration, linear interpolation, Fourier series decomposition and other solving methods; using finite element magnetic field numerical calculation to obtain the magnetic field distribution of the reactor, and using a preset data processing program to realize data collection and processing, and finally obtain the loss of each core cake. In addition, considering the influence of the process coefficient, the loss correction is performed according to the actual situation to make the core loss calculation more accurate.

Specifically, referring to FIG1 , the method for calculating the core loss of a reactor disclosed in an embodiment of the present application may include: calculating the core loss and calculating the iron yoke loss;

The core loss calculation is also called the core loss calculation, which includes:

Step S101: obtaining an electromagnetic simulation calculation model of the reactor to be tested;

In the technical solution disclosed in the embodiment of the present application, the reactor may be a three-phase five-column iron core structure reactor, or a reactor of other structures.

This step mainly involves establishing the numerical calculation model of the reactor and setting the material properties.

In this step, according to the structural characteristics and symmetry of the reactor, the solution area can be taken as half of the core symmetric center section. According to the actual size of the reactor core and coil, an axisymmetric electromagnetic simulation calculation model is established, as shown in Figure 2. When establishing the model, the core material and conductor material of the reactor need to be defined through the material editor.

Step S102: using finite element magnetic field numerical calculation to solve and calculate the electromagnetic simulation calculation model of the reactor to obtain the magnetic field distribution of the reactor;

In this step, a field-circuit coupling method is adopted to build a circuit connection diagram based on the electromagnetic simulation calculation model. Through the constructed circuit connection diagram, the electromagnetic field equation and the connection circuit equation composed of the external power supply are coupled, and the two-dimensional nonlinear time-harmonic field solution is calculated to obtain a magnetic field distribution that matches the electromagnetic simulation calculation model of the reactor.

Step S103: extracting and obtaining the loss of each iron core disk in the reactor based on the magnetic field distribution of the reactor;

In this step, after the magnetic field distribution of the reactor is calculated, the loss of each core cake in the reactor can be calculated based on the magnetic field distribution of the reactor. Specifically, referring to FIG. 3 , the calculation process of the core cake loss can include:

Step S201: collecting magnetic density values of preset collection points on the iron core disk of the reactor based on the magnetic field distribution of the reactor;

In this step, a single core cake in the reactor is taken as a unit, a path is selected, and collection points are set with a certain step length, and the magnetic density value of each collection point on each core cake is extracted respectively. The more collection points are set, the more accurate the calculation is. For example, in this scheme, the middle height position of each core cake of the reactor can be taken as the origin, and a path from the core inner radius _Rn to the core outer radius _Rw along the X-axis direction is taken, and the path passes through the origin. The core inner diameter _Rn is taken as the starting point 0.5Δδ away from the origin, and a certain length Δδ is used as the step length to set multiple collection points, and the magnetic density value B _ij of each collection point is extracted based on the magnetic field distribution.

Step S202: Calculate the magnetic flux of each acquisition point based on the magnetic density value of each acquisition point;

In this step, the magnetic density value of each collection point is processed, and the magnetic density value extracted from each collection point is multiplied by the corresponding unit area to obtain the unit magnetic flux of the collection point. Specifically, the magnetic density value _Bij extracted from the jth collection point of the i-th core cake is multiplied by the jth unit area to obtain the unit magnetic flux _ΔΦij of the collection point, that is, _ΔΦij = _Bij *2π*( _Rn +(j-1)*Δδ+0.5Δδ)*Δδ, wherein 2π*( _Rn +(j-1)*Δδ+0.5ΔρG)*Δρδ is the unit area of the jth collection point.

Step S203: summing up the unit magnetic flux ΔΦ _ij of all the acquisition points corresponding to each core cake and dividing it by the effective cross-sectional area S _c of the core cake to obtain the average magnetic flux value B _ci of the core cake;

Right now, The m is the number of sampling points of each core cake, and the m is an integer. In this solution, m=int((R _w -R _n )/Δδ).

Step S204: Based on the preset silicon steel sheet B-P function relationship (magnetic flux density and unit iron loss function relationship of silicon steel sheet), the core cake unit loss value ΔP (B _ci ) is calculated by interpolation method, and then the total core loss P _c is obtained;

In this step, after obtaining the average magnetic flux density B _ci of the core cake, the unit loss value ΔP (B _ci ) of the core cake is calculated based on the preset silicon steel sheet B-P function relationship curve by using the interpolation method, and then the total core loss P _c is obtained. Where: n is the total number of core cakes in the reactor; G _ci is the weight of the i-th core cake.

In this scheme, the calculation process of iron yoke loss includes:

Step S104: Calculating the effective cross-sectional areas of the main yoke, the side yoke and the side column of the reactor based on the core structure dimension data of the reactor;

In this step, the effective cross-sectional area of the reactor's main yoke _Sp , side yoke _Sp, and side post _Sz can be calculated based on the known core structure dimension data of the reactor. In general, the effective cross-sectional area of the side yoke of the reactor is the same as the effective cross-sectional area of the main yoke.

Step S105: constructing a magnetic flux instantaneous equation based on an equivalent planar magnetic circuit network matching the reactor;

In this step, it is assumed that the magnetic flux in the iron core column of the reactor is sinusoidal alternating and the three-phase magnetic flux is symmetrical. That is, the instantaneous values of the total magnetic flux φ _A , φ B, and φ C of the iron yoke of phase A, phase _B , and phase _C are: φ _A = φ _m sin (wt), φ _B = φ _m sin (wt-120), φ _C = φ _m sin (wt + 120), where φ _m is the maximum value of the total magnetic flux of the iron yoke. Then, according to the structure and magnetic circuit characteristics of the reactor, an equivalent planar magnetic circuit network of the reactor is established. Taking a three-phase five-column iron core reactor as an example, the structure of the three-phase five-column iron core reactor is shown in Figure 4. According to the structure and magnetic circuit characteristics of the three-phase five-column iron core reactor, the equivalent planar magnetic circuit network established is shown in Figure 5.

After establishing the equivalent planar magnetic circuit network, the instantaneous analysis method is used to divide the fundamental wave flowing through the iron core into N equal parts, and the basic laws of the magnetic circuit are applied to each time period. The reactor is a three-phase five-column iron core structure reactor, as shown in Figure 5. According to the equivalent planar magnetic circuit network, a group of instantaneous flux equations at any time t is constructed, which is the instantaneous flux equation.

The constructed flux instantaneous equations are:

Wherein: _Ra (t), _Rb (t), _Rc (t) are the magnetic resistances of the three-phase core columns A, B and C at time t respectively; _Re1 (t), _Re2 (t), _Rj (t), _Rz (t) are the magnetic resistances of the side yoke, main yoke, the angle of the core joint and the side columns at time t respectively; F _A (t), F _B (t), F _C (t) are the magnetic pressure sources of the three-phase A, B and C at time t respectively; the _φ1 (t), _φ3 (t), _φ4 (t) are the magnetic fluxes of each circuit of the equivalent planar magnetic circuit network at time t respectively; wherein _φ1 (t) is specifically the magnetic flux of the side yoke circuit of the equivalent planar magnetic circuit network at time t.

Step S106: Solve the flux instantaneous equations to derive the functional relationship between the return yoke flux and time;

In this step, the flux instantaneous equations are solved, and based on the three-phase flux symmetry principle, the return yoke flux function φ ₁ (t) at any time t can be obtained: That is, the functional relationship between the side yoke flux and time;

Step S107: establishing an objective function f(t)=φ _m sinwt-φ ₁ (t)-φ ₂ (t) based on the functional relationship of the side yoke flux changing with time, wherein φ ₂ (t) is the main yoke flux of the reactor, φ ₁ (t) is the side yoke flux of the reactor, and φ _m is the maximum total flux of the iron yoke of the reactor;

According to the characteristics of the magnetic circuit, the total magnetic flux of the iron yoke is composed of the main yoke magnetic flux φ ₂ (t) and the side yoke magnetic flux φ ₁ (t), and the objective function f(t) is established based on this:

f(t)＝φ _m sinwt-φ ₁ (t)-φ ₂ (t), further

Magnetic density value Magnetic density value Magnetic density value Magnetic density value Magnetic density value Magnetic density value

Step S108: Calculating the functional relationship between the side yoke magnetic flux density value and the side column magnetic flux density value changing with time based on the objective function;

In the reactor, since the magnetic flux flowing through the side yoke is the total magnetic flux minus the main yoke magnetic flux, the functional relationship between the side yoke magnetic flux value _Be1 (t) and the side column magnetic flux value _Bz (t) changing with time can be derived:

Step S109: Calculate the magnetic resistance of the side yoke, the main yoke, the side column, and the magnetic resistance at the angle of the core joint of the reactor;

In the reactor, due to the influence of the magnetization curve of the silicon steel sheet, the magnetic resistance of each part in the reactor also changes with time t, forming a nonlinear magnetic resistance. At time t, according to the pre-given silicon steel sheet B-μ relationship function, the magnetic permeability of different magnetic circuits in the reactor can be solved, and then the side yoke magnetic resistance _Re1 (t), main yoke magnetic resistance _Re2 (t), side column magnetic resistance _Rz (t) and magnetic resistance at the core joint angle _Rj (t) can be calculated. Specifically:

Step S110: based on the functional relationship of the side yoke and side column magnetic density values changing with time, the side yoke magnetic resistance, the main yoke magnetic resistance, the side column magnetic resistance, the magnetic resistance at the core joint angle and the target function, the main yoke magnetic density value, the side yoke magnetic density value, and the side column magnetic density value of the reactor at different times are calculated;

Specifically, when executing this step, the reliability of the objective function may be pre-judged. When judging the reliability of the objective function, the following method is used:

Substitute each obtained partial magnetic resistance (side yoke magnetic resistance _Re1 (t), main yoke magnetic resistance _Re2 (t), side column magnetic resistance _Rz (t) and magnetic resistance at the core joint angle _Rj (t)) into the objective function f(t), first initialize the main yoke magnetic density value _Be2 (t) at time t, and check whether the objective function f(t) = 0 holds. If it does not meet the requirements, re-correct the main yoke magnetic density value _Be2 (t), and then return to step S108 to recalculate, and continuously iterate until a suitable main yoke magnetic density value _Be2 (t) is found. This value is the main yoke magnetic density value at time t, and the side yoke magnetic density value at time t and the side column magnetic density value at time t can also be obtained.

Step S111: Calculate the peak value of the Nth harmonic component in the main yoke magnetic density value, the side yoke magnetic density value, and the side column magnetic density value, wherein the Nth harmonic includes but is not limited to: fundamental wave, third harmonic and fifth harmonic;

After calculating the main yoke magnetic density value, side yoke magnetic density value, and side column magnetic density value of the reactor's iron yoke (main yoke, side yoke, side column) at different times, the above steps obtain the magnetic density values at different times. Since the iron yoke contains harmonic components, in order to accurately calculate the iron yoke loss, the Fourier series can be used to solve the main yoke magnetic density value at time t, the side yoke magnetic density value at time t, and the magnetic density value of the side column magnetic density value at time t. The main harmonic components (fundamental wave, third harmonic, fifth harmonic) are separated, and the peak value of the magnetic density value under each harmonic component is solved, specifically:

Wherein: maxB _e11 , maxB _z1 , maxB _e21 are the peak values of the fundamental magnetic flux density value T of the side yoke, main yoke and side column respectively; maxB _e13 , maxB _z3 , maxB _e23 are the peak values of the magnetic flux density value T under the third harmonic of the side yoke, main yoke and side column respectively; maxB _e15 , maxB _z5 , maxB _e25 are the peak values of the magnetic flux density value T under the fifth harmonic of the side yoke, main yoke and side column respectively;

Step S112: Based on the preset B-P function relationship of the silicon steel sheet, the unit loss value and the total loss value of the side yoke, main yoke and side column under different harmonics are obtained by using the interpolation method;

In this step, after the peak values of the Nth harmonic components in the main yoke magnetic density value, the side yoke magnetic density value, and the side column magnetic density value are calculated, the unit loss values ΔP(maxB e1j ), ΔP(maxB _e2j ), ΔP(maxB _zj ) and the total loss values P _e1 , P _e2 , and P _z of the side yoke, main yoke, and side column under different harmonics are obtained by interpolation method according to the _given B-P function relationship of the silicon steel sheet. Specifically:

Among them: _Ge1 , _Gz , _Ge2 are the weights of the side yoke, side column and main yoke respectively.

Step S113: taking the sum of the total loss value of the side yoke, the main yoke, the side column and the core loss as the total core loss value of the reactor;

In this step, the total core loss is obtained by adding the core loss P _c , side yoke loss _Pe1 , side post loss _Pe2 and side post loss P _z obtained above.

In the scheme disclosed in the embodiment of the present application, when calculating the loss of the core disk of the reactor, the present invention uses a finite element numerical calculation method to calculate the magnetic field distribution of the electromagnetic simulation calculation model of the reactor to be tested, and extracts the loss of each core disk in the reactor based on the magnetic field distribution of the reactor. When calculating the iron yoke loss, based on the equivalent planar magnetic circuit network matching the reactor, a group of instantaneous equations for magnetic flux is constructed, the group of instantaneous equations for magnetic flux is solved, and the functional relationship of the change of the side yoke magnetic flux with time is derived. Based on the functional relationship of the change of the side yoke magnetic flux with time, an objective function is established. Based on the objective function, the functional relationship of the change of the side yoke magnetic density value and the side column magnetic density value with time is calculated. Based on the functional relationship of the change of the side yoke and side column magnetic density values with time, the side yoke magnetic resistance, the main yoke magnetic resistance, and the side The column magnetic resistance, the magnetic resistance at the angle of the core joint and the objective function are used to calculate the main yoke magnetic density value, side yoke magnetic density value and side column magnetic density value of the reactor at different times; the peak value of the Nth harmonic component in the main yoke magnetic density value, side yoke magnetic density value and side column magnetic density value is calculated, and the Nth harmonic includes but is not limited to: fundamental wave, third harmonic and fifth harmonic; finally, based on the preset silicon steel sheet B-P function relationship, the unit loss value and total loss value of the side yoke, main yoke and side column under different harmonics are obtained by interpolation method.

In the reactor, since the magnetic flux of the side yoke and the main yoke is a periodic function, but not a sinusoidal alternating magnetic flux, it means that the magnetic flux in the iron yoke does not only contain the fundamental sinusoidal magnetic flux, but also contains harmonic components. Therefore, in this scheme, in order to accurately calculate the iron yoke loss, since the magnetic flux of the side yoke and the main yoke is a periodic function, the magnetic density values of the main yoke, the side yoke and the side column can be expanded into a convergent Fourier series. Then, the Fourier solution is used to obtain the peak value of the magnetic density value under different harmonics (fundamental wave, third harmonic, fifth harmonic), and then the unit loss is obtained, and finally the core loss is obtained.

In actual engineering, the core joint form, core overlap width, number of laminations per stack, core joint size, and core clamping degree are different, which will affect the uneven distribution of magnetic flux. During the production and manufacturing process, the magnetization performance of the core silicon steel sheet will be affected during the shearing, stacking, pressing, and bumping process, and the magnetization curve data will also change to a certain extent. These factors will affect the change in the magnetic resistance of each section in the magnetic circuit. Therefore, it is necessary to use the matching reactor parameters when calculating the core loss based on the actual production situation and through experiments.

This embodiment discloses a device for calculating the core loss of a reactor. For the specific working contents of each unit in the device, please refer to the contents of the above-mentioned method embodiment. The device for calculating the core loss of a reactor provided in an embodiment of the present invention is described below. The device for calculating the core loss of a reactor described below and the method for calculating the core loss of a reactor described above can be referred to each other.

6 , the device may include a core loss calculation unit 100 , an iron yoke loss calculation unit 200 , and a core loss calculation unit 300 ;

The core loss calculation unit 100 is used to obtain an electromagnetic simulation calculation model of the reactor to be tested; solve and calculate the electromagnetic simulation calculation model of the reactor using finite element magnetic field numerical calculation to obtain the magnetic field distribution of the reactor; and extract the loss of each core in the reactor based on the magnetic field distribution of the reactor;

The iron yoke loss calculation unit 200 is used to calculate the effective cross-sectional area of the main yoke, the side yoke and the side column of the reactor based on the core structure size data of the reactor; to build a group of flux instantaneous equations based on an equivalent plane magnetic circuit network matching the reactor; to solve the group of flux instantaneous equations to derive the functional relationship of the side yoke flux changing with time; to establish an objective function based on the functional relationship of the side yoke flux changing with time Wherein, φ ₂ (t) is the main yoke flux of the reactor, φ ₁ (t) is the side yoke flux of the reactor, φ _m is the maximum total flux of the iron yoke of the reactor, w refers to the angular frequency..., _Re2 (t) is the main yoke magnetic resistance at time t, _Re1 (t) is the side yoke magnetic resistance at time t, _Rz (t) is the side column magnetic resistance at time t, _Rj (t) is the magnetic resistance at the angle of the core joint at time t, _Be2 (t) is the main yoke magnetic density value at time t, S _p is the effective cross-sectional area of the main yoke or the effective cross-sectional area of the side yoke; based on the objective function, the functional relationship between the side yoke magnetic density value and the side column magnetic density value changing with time is calculated; based on the functional relationship between the side yoke and side column magnetic density values changing with time, the side yoke magnetic resistance, the main yoke magnetic resistance, the side column magnetic resistance, and the magnetic resistance at the angle of the core joint and the objective function, the main yoke magnetic density value, the side yoke magnetic density value, and the side column magnetic density value of the reactor at different times are calculated; the peak value of the Nth harmonic component in the main yoke magnetic density value, the side yoke magnetic density value, and the side column magnetic density value is calculated, and the Nth harmonic includes but is not limited to: fundamental wave, third harmonic and fifth harmonic; based on the preset silicon steel sheet B-P function relationship, the unit loss value and total loss value of the side yoke, main yoke, and side column under different harmonics are obtained by interpolation method;

The core loss calculation unit 300 is used to take the sum of the total loss values of the side yoke, the main yoke, the side column and the core cake loss as the total core loss value of the reactor.

Corresponding to the above method, when the core loss calculation unit 100 extracts and obtains the losses of each core in the reactor based on the magnetic field distribution of the reactor, it is specifically used to:

Based on the magnetic field distribution of the reactor, a magnetic density value of a preset collection point on the iron core cake on the reactor is collected;

The magnetic flux of each acquisition point is calculated based on the magnetic density value of each acquisition point;

The unit magnetic flux of all the acquisition points corresponding to each core cake is summed up and divided by the effective cross-sectional area of the core cake to obtain the average magnetic flux density value of the core cake;

Based on the preset B-P function relationship of the silicon steel sheet, the unit loss value ΔP (B _ci ) of the core cake is calculated by using the interpolation method, and then the total core loss P _c is obtained.

Corresponding to the above method, the iron yoke loss calculation unit is specifically used to calculate the main yoke magnetic density value, the side yoke magnetic density value, and the side column magnetic density value of the reactor at different times based on the functional relationship between the side yoke and the side column magnetic density values changing with time, the yoke magnetic resistance, the main yoke magnetic resistance, the side column magnetic resistance, and the magnetic resistance at the angle of the core joint and the objective function:

According to the given silicon steel sheet B-μ relationship function, solve the magnetic permeability of different magnetic circuits, and then calculate the side yoke reluctance _Re1 (t), main yoke reluctance _Re2 (t), side column reluctance _Rz (t) and the reluctance at the core joint angle _Rj (t):

Substitute each partial magnetic resistance into the objective function f(t) to obtain the main yoke magnetic density value, side yoke magnetic density value, and side column magnetic density value of the reactor at different times;

Among them, _Sz refers to the effective cross-sectional area of the reactor side column, _μe1 refers to the magnetic permeability of the side yoke, _μe2 refers to the magnetic permeability of the main yoke, _μj refers to the magnetic permeability at the angle of the core joint, _μz refers to the magnetic permeability of the side column, Mp refers to the distance from the center of the core to the inner side of the side column, TS refers to the thickness of the side column, Hp refers to the thickness of the upper and lower iron yokes, and Hw refers to the window height.

Corresponding to the above method, the preset B-P function relationship of the silicon steel sheet is used to obtain the unit loss value and total loss value of the side yoke, main yoke and side column under different harmonics by interpolation method, including:

According to the given B-P function relationship of silicon steel sheet, the unit loss value of side yoke ΔP(maxB _e1j ), the unit loss value of main yoke ΔP(maxB _e2j ), the unit loss value of side column ΔP(maxB _zj ) and the total loss value of side yoke P _e1 , the total loss value of main yoke P _e2 , and the total loss value of side column P _z under different harmonics are obtained by interpolation method:

Among them: _Ge1 is the weight of the side yoke, _Gz is the weight of the side column, and _Ge2 is the weight of the main yoke.

For the convenience of description, the above system is described by dividing it into various modules according to its functions. Of course, when implementing the present invention, the functions of each module can be implemented in the same or multiple software and/or hardware.

Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

The professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims (14)

1. A method for calculating reactor core loss, which is characterized by including: Obtain the electromagnetic simulation calculation model of the reactor under test; Use finite element magnetic field numerical calculation to solve and calculate the electromagnetic simulation calculation model of the reactor to obtain the magnetic field distribution of the reactor; The loss of each iron core cake in the reactor is extracted based on the magnetic field distribution of the reactor; The effective cross-sectional area of the main yoke, side yoke and side column of the reactor is calculated based on the core structural size data of the reactor; Based on the equivalent planar magnetic circuit network matching the reactor, a system of instantaneous magnetic flux equations is constructed; Solve the instantaneous flux equations and derive the functional relationship of the side yoke flux with time; Establish an objective function based on the functional relationship between the side yoke flux and time. Among them, φ ₂ (t) is the main yoke magnetic flux of the reactor, φ ₁ (t) is the side yoke magnetic flux of the reactor, φ _m is the maximum total magnetic flux of the iron yoke of the reactor, and the w refers to is the angular frequency, the R _e2 (t) is the main yoke magnetic resistance at time t, the R _e1 (t) is the side yoke magnetic resistance at time t, the R _z (t) is the side column magnetic resistance at time t, so R _j (t) is the magnetic resistance at the angle of the core seam at time t, B _e2 (t) is the magnetic density value of the main yoke at time t, and S _p is the effective cross-sectional area of the main yoke or the effective cross-sectional area of the side yoke. ; Based on the objective function, the functional relationship expression of the side yoke magnetic density value and the side column magnetic density value changing with time is calculated; Based on the functional relationship between the magnetic density values of the side yoke and the side column changing with time, the magnetic resistance of the side yoke, the magnetic resistance of the main yoke, the magnetic resistance of the side column, the magnetic resistance at the angle of the core seam, and the above-mentioned objective function, the reactance is calculated The main yoke magnetic density value, side yoke magnetic density value, and side column magnetic density value of the device at different times; Calculate the peak value of the Nth harmonic component in the main yoke magnetic density value, side yoke magnetic density value, and side column magnetic density value. The Nth harmonic includes but is not limited to: fundamental wave, third harmonic, and fifth harmonic. harmonic; Based on the preset B-P function relationship of silicon steel sheets, the interpolation method is used to calculate the unit loss value and total loss value of the side yoke, main yoke and side column under different harmonics; The sum of the total loss value of the side yoke, main yoke, side column and core cake loss is taken as the total core loss value of the reactor. 2. The method for calculating the core loss of the reactor according to claim 1, characterized in that the loss of each core cake in the reactor is extracted based on the magnetic field distribution of the reactor, including: Collect the magnetic density value of a preset collection point on the iron core cake on the reactor based on the magnetic field distribution of the reactor; The magnetic flux of each collection point is calculated based on the magnetic density value of each collection point; After summing the unit magnetic flux of all collection points corresponding to each iron core cake, divide it by the effective cross-sectional area of the iron core cake to obtain the average magnetic density value of the iron core cake; Based on the preset B-P functional relationship of the silicon steel sheet, the interpolation method is used to calculate the unit loss value ΔP (B _ci ) of the core cake, and then the total core loss P _c is obtained. 3. The reactor core loss calculation method according to claim 2, characterized in that the reactor is a three-phase five-column core structure reactor, and the magnetic flux instantaneous equation is: Among them: R _a (t), R _b (t), R _c (t) are the magnetic resistance of the three-phase iron core columns A, B, and C at time t respectively; F _A (t), F _B (t), F _C (t) are respectively the three-phase magnetic pressure sources A, B, and C at time t, and φ ₁ (t), φ ₃ (t), and φ ₄ (t) are the loops of the equivalent planar magnetic circuit network at time t, respectively. magnetic flux. 4. The reactor core loss calculation method according to claim 3, characterized in that the functional relationship of the side yoke magnetic flux changing with time is: 5. The reactor core loss calculation method according to claim 4, characterized in that the functional relationship expressions based on the changes of the side yoke magnetic density value and the side column magnetic density value with time are respectively: Among them, the effective cross-sectional area of the reactor side column, the B _e1 (t) is the magnetic density value of the reactor side yoke at time t, and the B _z (t) is the magnetic density value of the reactor side column at time t. value. 6. The reactor core loss calculation method according to claim 5, characterized in that the functional relationship expression based on the time-dependent transformation of the magnetic density values of the side yoke and the side column, the yoke magnetic resistance, the main yoke magnetic resistance, the side column Using the magnetic resistance, the magnetic resistance at the angle of the core seam, and the objective function, we can calculate the main yoke magnetic density value, side yoke magnetic density value, and side column magnetic density value of the reactor at different times, including: According to the given silicon steel sheet B-μ relationship function, solve the magnetic permeability of different magnetic circuits, and then calculate the side yoke magnetic resistance R _e1 (t), the main yoke magnetic resistance R _e2 (t), and the side column magnetic resistance R _z (t) ) and the magnetic resistance R _j (t) at the angle between the core joints: Among them, the S _z refers to the effective cross-sectional area of the reactor side column, the μ _e1 refers to the side yoke magnetic permeability, μ _e2 refers to the main yoke magnetic permeability μ _j refers to the core joint angle The magnetic permeability μ _z refers to the magnetic permeability of the side pillars, Mp refers to the distance from the center of the core to the inside of the side pillars, TS refers to the thickness of the side pillars, Hp refers to the thickness of the upper and lower iron yokes, and the Hw refers to is the window height Substitute each part of the magnetic resistance into the objective function f(t) to obtain the main yoke magnetic density value, side yoke magnetic density value, and side column magnetic density value of the reactor at different times. 7. The reactor core loss calculation method according to claim 6, characterized in that, based on the preset silicon steel sheet BP functional relationship, the interpolation method is used to calculate the side yoke, main yoke, and side yoke under different harmonics. Column unit loss value and total loss value, including: According to the given silicon steel sheet B-P functional relationship, the interpolation method is used to calculate the side yoke unit loss value ΔP (maxB _e1j ), the main yoke unit loss value ΔP (maxB _e2j ), and the side column unit loss value ΔP ( maxB _zj ) and the total loss value of the side yoke P _e1 , the total loss value of the main yoke P _e2 , and the total loss value of the side column P _z : Among them: G _e1 is the weight of the side yoke, G _z is the weight of the side column, and G _e2 is the weight of the main yoke. 8. A reactor core loss calculation device, characterized by including: The iron core cake loss calculation unit is used to obtain the electromagnetic simulation calculation model of the reactor to be tested; use finite element magnetic field numerical calculation to solve and calculate the electromagnetic simulation calculation model of the reactor to obtain the magnetic field distribution of the reactor; based on the The magnetic field distribution of the reactor is extracted to obtain the loss of each iron core cake in the reactor; An iron yoke loss calculation unit is used to calculate the effective cross-sectional area of the main yoke, side yokes and side columns of the reactor based on the iron core structural size data of the reactor; based on the equivalent planar magnetic field matching the reactor circuit network, build the instantaneous flux equations; solve the flux instantaneous equations, and derive the functional relationship of the side yoke flux with time; establish the objective function based on the functional relationship of the side yoke flux with time Among them, φ ₂ (t) is the main yoke magnetic flux of the reactor, φ ₁ (t) is the side yoke magnetic flux of the reactor, φ _m is the maximum total magnetic flux of the iron yoke of the reactor, and the w refers to is the angular frequency, the R _e2 (t) is the main yoke magnetic resistance at time t, the R _e1 (t) is the side yoke magnetic resistance at time t, the R _z (t) is the side column magnetic resistance at time t, so R _j (t) is the magnetic resistance at the angle of the core seam at time t, B _e2 (t) is the magnetic density value of the main yoke at time t, and S _p is the effective cross-sectional area of the main yoke or the effective cross-sectional area of the side yoke. ; Based on the objective function, the functional relationship expression of the side yoke magnetic density value and the side column magnetic density value changing with time is calculated; the functional relationship expression based on the time changing side yoke and side column magnetic density value, side yoke magnetic resistance, main Using the yoke magnetic resistance, side column magnetic resistance, and the magnetic resistance at the angle of the core seam as well as the objective function, the main yoke magnetic density value, side yoke magnetic density value, and side column magnetic density value of the reactor at different times are calculated. ; Calculate the peak value of the Nth harmonic component in the main yoke magnetic density value, side yoke magnetic density value, and side column magnetic density value. The Nth harmonic includes but is not limited to: fundamental wave, third harmonic and fifth harmonic. Sub-harmonic; based on the preset B-P function relationship of silicon steel sheets, use the interpolation method to calculate the unit loss value and total loss value of the side yoke, main yoke and side column under different harmonics; The core loss calculation unit is used to calculate the sum of the total loss value of the side yoke, main yoke, and side pillars and the core cake loss as the total core loss value of the reactor. 9. The reactor core loss calculation device according to claim 8, characterized in that when the core cake loss calculation unit extracts the core cake loss of each core cake in the reactor based on the magnetic field distribution of the reactor, specifically Used for: Collect the magnetic density value of a preset collection point on the iron core cake on the reactor based on the magnetic field distribution of the reactor; The magnetic flux of each collection point is calculated based on the magnetic density value of each collection point; After summing the unit magnetic flux of all collection points corresponding to each iron core cake, divide it by the effective cross-sectional area of the iron core cake to obtain the average magnetic density value of the iron core cake; Based on the preset B-P functional relationship of the silicon steel sheet, the interpolation method is used to calculate the unit loss value ΔP (B _ci ) of the core cake, and then the total core loss P _c is obtained. 10. The reactor core loss calculation device according to claim 9, characterized in that the reactor is a three-phase five-column core structure reactor, and the magnetic flux instantaneous equation is: Among them: R _a (t), R _b (t), R _c (t) are the magnetic resistance of the three-phase iron core columns A, B, and C at time t respectively; F _A (t), F _B (t), F _C (t) are the three-phase magnetic pressure sources A, B, and C at time t, respectively. The φ ₁ (t), φ ₃ (t), and φ ₄ (t) are respectively the equivalent planar magnetic circuit network at time t. loop flux. 11. The reactor core loss calculation device according to claim 10, characterized in that the functional relationship of the side yoke magnetic flux changing with time is: 12. The reactor core loss calculation device according to claim 11, characterized in that the functional relationship expressions based on the changes of the side yoke magnetic density value and the side column magnetic density value with time are respectively: Among them, the effective cross-sectional area of the reactor side column, the B _e1 (t) is the magnetic density value of the reactor side yoke at time t, and the B _z (t) is the magnetic density value of the reactor side column at time t. value. 13. The reactor core loss calculation device according to claim 12, characterized in that the iron yoke loss calculation unit is based on the functional relationship expression of the side yoke and side column magnetic density values changing over time, the yoke reluctance, the main Using the yoke magnetic resistance, side column magnetic resistance, and the magnetic resistance at the angle of the core seam as well as the objective function, the main yoke magnetic density value, side yoke magnetic density value, and side column magnetic density value of the reactor at different times are calculated. When, it is specifically used for: According to the given silicon steel sheet B-μ relationship function, solve the magnetic permeability of different magnetic circuits, and then calculate the side yoke magnetic resistance R _e1 (t), the main yoke magnetic resistance R _e2 (t), and the side column magnetic resistance R _z (t) ) and the magnetic resistance R _j (t) at the angle between the core joints: Substitute each part of the magnetic resistance into the objective function f(t) to obtain the main yoke magnetic density value, side yoke magnetic density value, and side column magnetic density value of the reactor at different times; Among them, the S _z refers to the effective cross-sectional area of the reactor side column, the μ _s1 refers to the side yoke magnetic permeability, μ _s2 refers to the main yoke magnetic permeability μ _j refers to the core joint angle The magnetic permeability μ _z refers to the magnetic permeability of the side pillars, Mp refers to the distance from the center of the core to the inside of the side pillars, TS refers to the thickness of the side pillars, Hp refers to the thickness of the upper and lower iron yokes, and the Hw refers to is the window height. 14. The reactor core loss calculation device according to claim 13, characterized in that, based on the preset silicon steel sheet BP functional relationship, the interpolation method is used to calculate the side yoke, main yoke, side yoke under different harmonics. Column unit loss value and total loss value, including: According to the given silicon steel sheet B-P functional relationship, the interpolation method is used to calculate the side yoke unit loss value ΔP (maxB _e1j ), the main yoke unit loss value ΔP (maxB _e2j ), and the side column unit loss value ΔP ( maxB _zj ) and the total loss value of the side yoke P _e1 , the total loss value of the main yoke P _e2 , and the total loss value of the side column P _z : Among them: G _e1 is the weight of the side yoke, G _z is the weight of the side column, and G _e2 is the weight of the main yoke.