Modeling Method of Electromagnetic-Solid Coupled Ladder Circuit for Dynamic Characteristics of Switch Valve Electromagnet

Abstract

The present invention proposes a modeling method for an electro-magnetic-solid coupled trapezoidal circuit of the dynamic characteristics of a switching valve electromagnet, comprising the following steps: step S1, by analyzing the positional relationship between the shell, iron core, armature, and frame of the high-speed switching valve electromagnet, the distribution of the magnetic flux path generated by the coil in the electromagnet is deduced, thereby obtaining its magnetic circuit model; step S2, based on the relationship between the inductance and magnetic resistance of ferromagnetic materials and applying the duality theory of circuits and magnetic circuits, the magnetic circuit elements are converted into circuit elements, and an equivalent trapezoidal circuit model is derived that takes into account the strong eddy current effect of the electromagnet under high-frequency working conditions; step S3, establishing sub-models of each equivalent electronic component, constructing an equivalent circuit model of the electro-magnetic-solid multi-field coupling of the high-speed switching valve electromagnet, and obtaining high-frequency dynamic characteristic data of the high-speed switching valve electromagnet under different voltage control strategies. The present invention provides an accurate and practical simulation model for the control and optimization design of high-speed electromagnets, saving time and cost.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic simulation technology, in particular to a modeling method for an electromagnet dynamic characteristic electric-magnetic-solid coupled ladder circuit of a switching valve electromagnet. Background Art

[0002] Since the concept of Industry 4.0 was first proposed at the Hannover Industrial Fair, the rapid development of Internet technology has made the interconnection of all things increasingly possible. Under this wave, "digital hydraulics" technology has also made great progress. The development of high-performance digital hydraulic components will strongly promote technological development and industrial innovation in the field of fluid transmission and control, and has become one of the goals that the industry strives for.

[0003] Hydraulic valves are key control components in hydraulic systems, and high-performance hydraulic control valves are often one of the most expensive hydraulic components in the system. The emergence of digital valves is a typical representative of the development of hydraulic valve technology, which greatly improves the flexibility of control. As an important achievement of digital hydraulic valves, high-speed switching digital valves are a type of digital hydraulic valve that always works in fully open or fully closed state. Therefore, they have small pressure loss, low energy consumption, and are not sensitive to oil contamination. They can directly convert switching digital signals into flow signals, allowing digital signals to be directly combined with hydraulic systems. In recent years, high-speed switching valves have been a research hotspot in the hydraulic industry, and the research directions mainly focus on high-speed electromagnets, valve body structure and flow channel optimization, as well as high-speed switching valve drive control strategies and application expansion.

[0004] The electromagnet is the core component of the high-speed switching valve and the key driving part that drives the valve core to move. The performance of the electromagnet itself largely determines the static and dynamic performance of the high-speed switching valve. Therefore, the modeling research of the electro-mechanical converter is of great significance to the overall performance improvement of the high-speed switching valve.

[0005] Currently, the most commonly used modeling methods for high-speed switching valve solenoids can be divided into two categories. One method uses mathematical methods to describe and link the various physical field characteristics of the solenoid. Existing mathematical modeling methods are relatively crude, and in some cases the results obtained are somewhat different from reality. Another modeling method uses modeling and simulation software, namely finite element modeling, but this method is not suitable for transient response calculations due to the high computational time required.

[0006] Therefore, whether a simple and easy-to-use high-speed electromagnet fast simulation model can be established that takes into account the eddy current effect and is associated with the size and material properties of the iron core will become a key breakthrough point in the research and development of high-speed switching valve frequency response optimization and control. Summary of the Invention

[0007] The present invention proposes a modeling method for an electro-magnetic-solid coupled trapezoidal circuit of the dynamic characteristics of a switching valve electromagnet, which is a modeling method for quickly analyzing the dynamic characteristics of a high-speed switching valve electromagnet. The present invention aims to overcome the defects of traditional mathematical modeling methods and finite element modeling methods when modeling high-speed electromagnets. Based on actual physical laws, the present invention considers the eddy current effects generated during magnetic field changes and establishes a transient simulation model of electro-magnetic-solid multi-field coupling. The motion characteristics of the electromagnet are accurately predicted, and electromagnetic field data of different parts of each component can be obtained in all aspects. An accurate and practical simulation model is provided for the control and optimization design of high-speed electromagnets, saving time and cost.

[0008] The present invention adopts the following technical solutions.

[0009] A modeling method for an electromagnet dynamic characteristic electric-magnetic-solid coupled ladder circuit of a switch valve is used to quickly analyze the electromagnet dynamic characteristic of a high-speed switch valve, comprising the following steps:

[0010] Step S1: Analyze the positional relationship among the housing, core, armature, and frame of the high-speed switching valve electromagnet to deduce the distribution of the magnetic flux path generated by the coil in the electromagnet, thereby obtaining its magnetic circuit model;

[0011] Step S2: Based on the relationship between the inductance and magnetic resistance of ferromagnetic materials and applying the duality theory of circuits and magnetic circuits, the magnetic circuit components are converted into circuit components, and an equivalent trapezoidal circuit model is derived that takes into account the strong eddy current effect of the electromagnet under high-frequency working conditions;

[0012] Step S3: Establish each equivalent electronic component sub-model, build an equivalent circuit model of the electric-magnetic-solid multi-field coupling of the high-speed switch valve electromagnet, and obtain high-frequency dynamic characteristic data of the high-speed switch valve electromagnet under different voltage control strategies.

[0013] After the electromagnet is subjected to voltage and current is generated in the coil, the magnetic lines of force pass through the yoke, the iron core, the air gap, the armature in sequence, and then return to the yoke to complete the closure. When the magnetic flux in the ferromagnetic material of the electromagnet can be considered to be uniformly distributed, the entire electromagnet is divided into several magnetic circuit sections. Since the internal magnetic flux in the yoke is divided into vertical and horizontal according to different directions, it is divided into an upper magnetic yoke and a side magnetic yoke. Since the iron core and the frame are in close contact, they share the same magnetic circuit section. Under the action of the additional magnetic isolation ring in the middle of the frame, it is divided into an upper iron core, a middle iron core, and a lower iron core. Similarly, the armature is divided into an upper armature, a middle armature, and a lower armature according to the different cross-sectional areas of the magnetic flux.

[0014] Step S1 specifically includes the following steps:

[0015] Step S1.1, concentrate the magnetomotive force distributed in the core onto multiple core segments, and divide the entire core into several magnetic circuit segments when the magnetic flux in each core segment can be considered to be uniformly distributed;

[0016] Step S1.2: Each magnetic circuit segment can be regarded as a magnetic flux tube, and it is assumed that the leakage flux distributed on the magnetic circuit segment flows in and out from the end points of the magnetic circuit segment; wherein, is the excitation resistance of the side yoke, is the excitation resistance of the lower core, is the excitation resistance of the iron core, is the leakage magnetic resistance distributed in the core, is the excitation resistance of the upper core, is the leakage magnetic resistance of the magnetic isolation ring, is the air gap reluctance, is the excitation resistance of the lower armature, is the excitation resistance of the armature, is the excitation resistance of the lower armature, is the magnetic leakage resistance of the hollow space inside the armature, is the excitation resistance of the upper magnetic yoke;

[0017] Step S1.3: Connect the magnetic flux tubes of the ferromagnetic material magnetic field and the leakage magnetic field according to their spatial positions, and regard them as equivalent magnetic circuits corresponding to the magnetic fields.

[0018] The step S2 specifically includes the following steps:

[0019] Step S2.1, set a node at each network port of the magnetic circuit, and then select the closed curve formed by the outermost magnetic branch to infinity to form a mesh;

[0020] Step S2.2: Use a straight line to connect each node and mesh according to the dual transformation rule. The magnetic resistance passed by the connecting line is transformed into air leakage inductance, displacement variable inductance, and ferromagnetic model according to the different properties of the corresponding domain; the magnetomotive force element is transformed into a current source element.

[0021] Step S2.3: Replace the current source with a coil resistance and a voltage source in series to create an equivalent circuit model.

[0022] The dual transformation rules in step S2.2 include:

[0023] A1. Any two mesh nodes can only be connected through magnetic circuit elements;

[0024] A2. Each magnetic circuit element can only be passed through by a connecting wire once;

[0025] A3. All components of the magnetic circuit must be passed through by connecting wires;

[0026] A4. Each mesh node is connected at least twice.

[0027] The air leakage inductance in step S2.2 is calculated based on the size of the air domain, specifically: Formula 1;

[0028] Where N is the number of coil turns, r is the radius of the air domain, μ0 is the vacuum permeability, and h is the height of the air domain.

[0029] The displacement motion inductance relationship in step S2.2 is obtained by establishing the motion equation and the voltage balance equation, specifically:

[0030] Formula 2;

[0031] Where m is the mass of the moving parts such as the armature; x is the displacement of the armature; F sp =F0+kx is the spring force; F0 is the spring preload; k is the spring stiffness; is the friction resistance; v is the damping coefficient; is the acceleration of the moving part; F m is the electromagnetic force, which is expressed as:

[0032] Formula 3;

[0033] Where, φ s is the magnetic flux through the armature, S is the area of ​​the armature;

[0034] Assuming that the voltage across the electromagnet coil of the high-speed switching valve is U, the total magnetic flux changes during the current change, thereby generating an induced electromotive force. Kirchhoff's voltage equation is expressed as: Formula 4;

[0035] Where U is the voltage across the coil; I is the coil current; N is the number of coil turns; φ is the magnetic flux generated by a single turn of current;

[0036] Finally, the calculation formula of the displacement variable linear inductor can be obtained, which is expressed as:

[0037] Formula 5;

[0038] Where S is the area of ​​the armature, and δ is the relative distance between the armature and the core, which can be expressed as:

[0039] δ=x max -x formula six;

[0040] Where x max is the maximum displacement of the valve core.

[0041] In step S2.2: the ferromagnetic model takes into account that the ferromagnetic material has a certain thickness, and the electric field inside it is not uniformly distributed due to the skin effect. The electric field and magnetic field gradually decrease from one side of the coil to the other side. The material is divided into several concentric rings, and in each layer, the resistance is used to represent the eddy current loss of the iron core, and the nonlinear inductance represents the nonlinear magnetization characteristics of the iron core. They are combined in series and parallel to form a ladder circuit that takes into account the eddy current effect.

[0042] The resistance calculation formula used to express the eddy current loss of each layer of ferromagnetic material is expressed as:

[0043] Formula 7;

[0044] Where ρ is the resistivity of the material, l e is the path length of the eddy current, S e is the cross-sectional area of ​​the eddy current.

[0045] The inductance calculation formula used to express the nonlinear magnetization characteristics of the iron core is expressed as:

[0046] Formula 8;

[0047] Where Lu is the unsaturated inductance value, parameter α determines the shape of the curve of the simulation result, and β is the flux saturation value.

[0048] In step S3, with the help of the VoltageSensor module in the Simscape library of the Simulink simulation platform, the electromagnetic force data of the moving parts of the high-speed electromagnet are obtained, the displacement equation of the moving parts is constructed, and then the inductance data is obtained by calculating the distance of the air gap and input into the VariableInductor to obtain the displacement-varying inductor. Inductor is used as the fixed inductance of air leakage flux, the magnetizing characteristic inductance is established using the ControlledCurrentSource and matlabfcn modules, and the eddy current loss resistance is represented by Resistor. They are connected in series and parallel to form a ladder circuit model; finally, the construction of the electromagnet multi-physics field model is completed, the voltage control strategy is input through SignalBuilder, and the dynamic characteristics of the electromagnet are obtained through simulation analysis.

[0049] The present invention is a modeling method for an electro-magnetic-solid coupled trapezoidal circuit for rapid analysis of the dynamic characteristics of a high-speed switching valve electromagnet. The method first analyzes the positional relationship between the housing, core, armature, and skeleton of the high-speed switching valve electromagnet to deduce the distribution of the magnetic flux path generated by the coil in the electromagnet, thereby obtaining its magnetic circuit model. Based on the relationship between the inductance and magnetic resistance of ferromagnetic materials, and applying the duality theory of circuits and magnetic circuits to convert magnetic circuit elements into circuit elements, an equivalent trapezoidal circuit model is derived that takes into account the strong eddy current effect of the electromagnet under high-frequency working conditions. Each equivalent electronic component sub-model is established, and an equivalent circuit model of the electro-magnetic-solid multi-field coupling of the high-speed switching valve electromagnet is constructed to obtain high-frequency dynamic characteristic data of the high-speed switching valve electromagnet under different voltage control strategies. Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1) The electric-magnetic-solid multi-physics field coupling model of the high-speed switching valve electromagnet established in the present invention is different from traditional mathematical modeling methods such as the magnetic circuit segmentation method. It introduces a trapezoidal network to describe the eddy current response inside the ferromagnetic material. It truly simulates the process of interaction between the magnetic field and eddy current field based on actual physical laws, thereby improving the accuracy of the transient simulation of the electromagnet.

[0051] 2) As a non-iterative simulation method, the present invention offers faster computation speed and shorter solution times than finite element modeling methods. Furthermore, the parametric modeling approach, where all parameters are determined by the electromagnet's structural dimensions and material properties, combined with an optimization algorithm, can accelerate the electromagnet's optimization design cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0053] Attachment Figure 1 A schematic diagram of a flow chart of an embodiment of the present invention;

[0054] Attachment Figure 2 A schematic diagram of a high-speed switching valve and its electromagnet according to an embodiment of the present invention;

[0055] Attachment Figure 3 A schematic diagram of a magnetic circuit drawn for an embodiment of the present invention;

[0056] Attachment Figure 4 This is a schematic diagram of an equivalent circuit derived from an embodiment of the present invention;

[0057] Attachment Figure 5 Schematic diagram of the layered and ladder-shaped circuit model of the electromagnetic side yoke portion according to an embodiment of the present invention;

[0058] Attachment Figure 6 Schematic diagram of a single-layer eddy current loss resistor according to an embodiment of the present invention;

[0059] Attachment Figure 7 This is a schematic diagram showing a comparison of the magnetic properties of the material 1J50 according to Example 1 of the present invention;

[0060] Attachment Figure 8a The first diagram is a schematic diagram showing the construction of the electronic component models according to the embodiment of the present invention;

[0061] Attachment Figure 8b A second diagram illustrating the construction of electronic component models according to an embodiment of the present invention;

[0062] Attachment Figure 8c The third diagram is a schematic diagram showing the construction of the electronic component models according to the embodiment of the present invention;

[0063] Attachment Figure 8d FIG4 is a schematic diagram showing the construction of electronic component models according to an embodiment of the present invention;

[0064] Attachment Figure 8e Figure 5 is a schematic diagram showing the construction of electronic component models according to an embodiment of the present invention;

[0065] Attachment Figure 8f Figure 6 is a schematic diagram showing the construction of electronic component models according to an embodiment of the present invention;

[0066] Attachment Figure 8g FIG7 is a schematic diagram showing the construction of electronic component models according to an embodiment of the present invention;

[0067] Attachment Figure 9 Schematic diagram of a multi-physics field simulation model built in Simulink according to an embodiment of the present invention;

[0068] Attachment Figure 10a Schematic diagram of input voltage strategy according to an embodiment of the present invention;

[0069] Attachment Figure 10b Schematic diagram of dynamic characteristic results obtained by running the simulation model of an embodiment of the present invention. DETAILED DESCRIPTION

[0070] like Figure 1 As shown, a modeling method of an electromagnet-solid coupled ladder circuit for dynamic characteristics of a switching valve electromagnet is used to quickly analyze the dynamic characteristics of the electromagnet of a high-speed switching valve, including the following steps:

[0071] Step S1: Analyze the positional relationship among the housing, core, armature, and frame of the high-speed switching valve electromagnet to deduce the distribution of the magnetic flux path generated by the coil in the electromagnet, thereby obtaining its magnetic circuit model;

[0072] Step S2: Based on the relationship between the inductance and magnetic resistance of ferromagnetic materials and applying the duality theory of circuits and magnetic circuits, the magnetic circuit components are converted into circuit components, and an equivalent trapezoidal circuit model is derived that takes into account the strong eddy current effect of the electromagnet under high-frequency working conditions;

[0073] Step S3: Establish each equivalent electronic component sub-model, build an equivalent circuit model of the electric-magnetic-solid multi-field coupling of the high-speed switch valve electromagnet, and obtain high-frequency dynamic characteristic data of the high-speed switch valve electromagnet under different voltage control strategies.

[0074] Take the electromagnet of a high-speed switch valve (combined with Figure 2 ) as an example, after the electromagnet is applied with voltage to generate current in the coil, the magnetic lines of force pass through the yoke, the iron core, the air gap, the armature in sequence, and then return to the yoke to complete the closure. When the magnetic flux in the ferromagnetic material of the electromagnet can be considered to be uniformly distributed, the entire electromagnet is divided into several magnetic circuit sections. Since the internal magnetic flux in the yoke is divided into vertical and horizontal according to different directions, it is divided into an upper magnetic yoke and a side magnetic yoke. Since the iron core and the frame are in close contact, they share the same magnetic circuit section. Under the action of the additional magnetic isolation ring in the middle of the frame, it is divided into an upper iron core, a middle iron core, and a lower iron core. Similarly, the armature is divided into an upper armature, a middle armature, and a lower armature according to the different magnetic flux cross-sectional areas.

[0075] Step S1 specifically includes the following steps:

[0076] Step S1.1, concentrate the magnetomotive force distributed in the core onto multiple core segments, and divide the entire core into several magnetic circuit segments when the magnetic flux in each core segment can be considered to be uniformly distributed;

[0077] Step S1.2: Each magnetic circuit segment can be regarded as a magnetic flux tube, and it is assumed that the leakage flux distributed on the magnetic circuit segment flows in and out from the end points of the magnetic circuit segment; wherein, is the excitation resistance of the side yoke, is the excitation resistance of the lower core, is the excitation resistance of the iron core, is the leakage magnetic resistance distributed in the core, is the excitation resistance of the upper core, is the leakage magnetic resistance of the magnetic isolation ring, is the air gap reluctance, is the excitation resistance of the lower armature, is the excitation resistance of the armature, is the excitation resistance of the lower armature, is the magnetic leakage resistance of the hollow space inside the armature, is the excitation resistance of the upper magnetic yoke;

[0078] Step S1.3: Connect the magnetic flux tubes of the ferromagnetic material magnetic field and the leakage magnetic field according to their spatial positions, and regard them as equivalent magnetic circuits corresponding to the magnetic fields.

[0079] like Figure 4 As shown, step S2 specifically includes the following steps:

[0080] Step S2.1, set a node at each network port of the magnetic circuit, and then select the closed curve formed by the outermost magnetic branch to infinity to form a mesh;

[0081] Step S2.2: Use a straight line to connect each node and mesh according to the dual transformation rule. The magnetic resistance passed by the connecting line is transformed into air leakage inductance, displacement variable inductance, and ferromagnetic model according to the different properties of the corresponding domain; the magnetomotive force element is transformed into a current source element.

[0082] Step S2.3: Replace the current source with a coil resistance and a voltage source in series to create an equivalent circuit model.

[0083] The dual transformation rules in step S2.2 include:

[0084] A1. Any two mesh nodes can only be connected through magnetic circuit elements;

[0085] A2. Each magnetic circuit element can only be passed through by a connecting wire once;

[0086] A3. All components of the magnetic circuit must be passed through by connecting wires;

[0087] A4. Each mesh node is connected at least twice.

[0088] The air leakage inductance in step S2.2 is calculated based on the size of the air domain, specifically: Formula 1;

[0089] Where N is the number of coil turns, r is the radius of the air domain, μ0 is the vacuum permeability, and h is the height of the air domain.

[0090] The displacement motion inductance relationship in step S2.2 is obtained by establishing the motion equation and the voltage balance equation, specifically:

[0091] Formula 2;

[0092] Where m is the mass of the moving parts such as the armature; x is the displacement of the armature; F sp =F0+kx is the spring force; F0 is the spring preload; k is the spring stiffness; is the friction resistance; v is the damping coefficient; is the acceleration of the moving part; F m is the electromagnetic force, which is expressed as:

[0093] Formula 3;

[0094] Where, φ s is the magnetic flux through the armature, S is the area of ​​the armature;

[0095] Assuming that the voltage across the electromagnet coil of the high-speed switching valve is U, the total magnetic flux changes during the current change, thereby generating an induced electromotive force. Kirchhoff's voltage equation is expressed as: Formula 4;

[0096] Where U is the voltage across the coil; I is the coil current; N is the number of coil turns; φ is the magnetic flux generated by a single turn of current;

[0097] Finally, the calculation formula of the displacement variable linear inductor can be obtained, which is expressed as:

[0098] Formula 5;

[0099] Where S is the area of ​​the armature, and δ is the relative distance between the armature and the core, which can be expressed as:

[0100] δ=x max -x formula six;

[0101] Where x max is the maximum displacement of the valve core.

[0102] With side yoke (combined Figure 5 ) as an example, in step S2.2: the ferromagnetic model takes into account that the ferromagnetic material has a certain thickness, and the electric field inside it is not uniformly distributed due to the skin effect. The electric field and magnetic field gradually decrease from one side of the coil to the other side, and the material is divided into several concentric rings. In each layer, the resistance is used to represent the eddy current loss of the iron core, and the nonlinear inductance is used to represent the nonlinear magnetization characteristics of the iron core. They are combined in series and parallel to form a ladder circuit that considers the eddy current effect.

[0103] The resistance calculation formula used to express the eddy current loss of each layer of ferromagnetic material (combined with Figure 6 ), expressed as: Formula 7;

[0104] Where ρ is the resistivity of the material, l e is the path length of the eddy current, S e is the cross-sectional area of ​​the eddy current.

[0105] The inductance calculation formula used to express the nonlinear magnetization characteristics of the iron core is expressed as:

[0106] Formula 8;

[0107] Where Lu is the unsaturated inductance value, parameter α determines the shape of the curve of the simulation result, and β is the flux saturation value.

[0108] like Figure 7 This is a comparison chart of the magnetization test curve and simulation curve of ferromagnetic material 1J50.

[0109] In step S3, with the help of the VoltageSensor module in the Simscape library of the Simulink simulation platform, the electromagnetic force data of the moving parts of the high-speed electromagnet are obtained, the displacement equation of the moving parts is constructed, and then the inductance data is obtained by calculating the air gap distance and input into the VariableInductor to obtain the displacement-varying inductor. Inductor is used as the fixed inductance of air leakage flux, the magnetizing characteristic inductance is established using the ControlledCurrentSource and matlabfcn modules, and the eddy current loss resistance is represented by Resistor. They are connected in series and parallel to form a ladder circuit model; finally, the construction of the electromagnet multi-physics field model is completed, the voltage control strategy is input through SignalBuilder, and the dynamic characteristics of the electromagnet are obtained through simulation analysis.

Claims

1. Dynamic Characteristics of Switch Valve Electromagnets A modeling method for an electromagnet-solid coupled ladder circuit is used to analyze the dynamic characteristics of high-speed switch valve electromagnets. The following features are present: The following steps are included: Step S1: Analyze the positional relationship between the high-speed switch valve electromagnet core, armature, and frame to deduce the distribution of the magnetic flux path generated by the coil in the electromagnet, thereby obtaining its magnetic circuit model; Step S2: Based on the relationship between the inductance and magnetic resistance of ferromagnetic materials and applying the duality theory of circuits and magnetic circuits, the magnetic circuit components are converted into circuit components, and an equivalent trapezoidal circuit model of the strong eddy current effect of the electromagnet under high-frequency working conditions is derived; The step S2 specifically includes the following steps: Step S2.1, set a node at each network port of the magnetic circuit, and then select nodes from the closed curve formed by the outermost magnetic branch to infinity to form a mesh; Step S2.2: Connect each node and mesh with a straight line according to the dual transformation rule. The magnetic resistance passed by the connecting line is transformed into air leakage inductance, displacement variable inductance, and ferromagnetic model according to the properties of the corresponding domain; the magnetomotive force element is transformed into a current source element; In step S2.2: the ferromagnetic model takes into account the thickness of the ferromagnetic material. Due to the skin effect, the electric field inside the ferromagnetic material is not uniformly distributed, and the electric and magnetic fields gradually decrease from one side of the coil to the other. The material is divided into several concentric rings. In each layer, the eddy current loss of the iron core is represented by resistance, and the nonlinear magnetization characteristics of the iron core are represented by nonlinear inductance. These are combined in series and parallel to form a ladder circuit that takes into account the eddy current effect. The resistance calculation formula used to express the eddy current loss of each layer of ferromagnetic material is expressed as: Where ρ is the resistivity of the material, l e is the path length of the eddy current, S e is the cross-sectional area of ​​eddy current flow; Step S2.3: Replace the current source with a coil resistor and a voltage source in series to create an equivalent circuit model. The dual transformation rules in step S2.2 include: A1. Any two mesh nodes can only be connected through magnetic circuit elements; A2. Each magnetic circuit element can only be passed through by a connecting wire once; A3. All components of the magnetic circuit must be passed through by connecting wires; A4. Each mesh node is connected at least twice; The air leakage inductance in step S2.2 is calculated based on the size of the air domain, specifically: Where N is the number of coil turns, r is the radius of the air domain, μ0 is the vacuum magnetic permeability, and h is the height of the air domain. Step S3: Establish sub-models of each equivalent electronic component, build an equivalent circuit model of the electric-magnetic-solid multi-field coupling of the high-speed switching valve electromagnet, and obtain high-frequency dynamic characteristic data of the high-speed switching valve electromagnet under different voltage control strategies.

2. The modeling method of the electro-magnetic-solid coupled ladder circuit of the dynamic characteristics of the switch valve electromagnet according to claim 1 is characterized by: Step S1 specifically includes the following steps: Step S1.1, concentrate the magnetomotive force distributed in the core onto multiple core segments, and divide the entire core into several magnetic circuit segments when the magnetic flux in each core segment can be considered to be uniformly distributed; Step S1.2: Each magnetic circuit segment is considered as a magnetic flux tube, and it is assumed that the leakage flux distributed on the magnetic circuit segment flows in and out from the end points of the magnetic circuit segment; wherein, is the excitation resistance of the side yoke, is the excitation resistance of the lower core, is the excitation resistance of the iron core, is the leakage magnetic resistance distributed in the core, is the excitation resistance of the upper core, is the leakage magnetic resistance of the magnetic isolation ring, is the air gap reluctance, is the excitation resistance of the lower armature, is the excitation resistance of the armature, is the excitation resistance of the upper armature, is the magnetic leakage resistance of the hollow space inside the armature, is the excitation resistance of the upper magnetic yoke; Step S1.3: Connect the magnetic flux tubes of the ferromagnetic material magnetic field and the leakage magnetic field according to their spatial positions, and regard them as equivalent magnetic circuits corresponding to the magnetic fields.

3. The modeling method of the electro-magnetic-solid coupled ladder circuit of the dynamic characteristics of the switch valve electromagnet according to claim 1 is characterized by: The displacement variable inductance relationship in step S2.2 is obtained by establishing the motion equation and the voltage balance equation, specifically: Where m is the mass of the armature moving part; x is the armature displacement; F sp =F0+kx is the spring force; F0 is the spring preload; k is the spring stiffness; is the friction resistance; v is the damping coefficient; is the acceleration of the moving part; F m is the electromagnetic force, which is expressed as: Where, φ s is the magnetic flux through the armature, S is the area of ​​the armature; Assuming that the voltage across the electromagnet coil of the high-speed switching valve is U, the total magnetic flux changes during the current change, thereby generating an induced electromotive force. Kirchhoff's voltage equation is expressed as: Where U is the voltage across the coil; I is the coil current; N is the number of coil turns; φ is the magnetic flux generated by a single turn of current; Finally, the calculation formula of the displacement variable linear inductor can be obtained, which is expressed as: Where S is the area of ​​the armature, and δ is the relative distance between the armature and the core, which can be expressed as: δ=x max -x Formula 6; Where x max is the maximum displacement of the valve core.

4. The modeling method of the electro-magnetic-solid coupled ladder circuit of the dynamic characteristics of the switch valve electromagnet according to claim 1 is characterized by: The inductance calculation formula used to express the nonlinear magnetization characteristics of the iron core is expressed as: Where Lu is the unsaturated inductance value, parameter α determines the shape of the curve of the simulation result, and β is the flux saturation value.

5. The modeling method of the electromagnet-solid coupled ladder circuit for the dynamic characteristics of the switch valve electromagnet according to claim 1, characterized in that: In step S3, with the help of the Voltage Sensor module in the Simscape library of the Simulink simulation platform, the electromagnetic force data of the moving parts of the high-speed electromagnet are obtained, and the displacement equation of the moving parts is constructed. The inductance data is then calculated by calculating the air gap distance and input into the Variable Inductor to obtain the displacement-varying inductor. The Inductor is used as the fixed inductance of air leakage flux, and the magnetizing characteristic inductance is established using the Controlled Current Source and MATLAB FCN modules. The eddy current loss resistance is represented by Resistor, and they are connected in series and parallel to form a ladder circuit model. Finally, the construction of the electromagnet multi-physics field model is completed, and the voltage control strategy is input through Signal Builder. The dynamic characteristics of the electromagnet are obtained by simulation analysis.

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