Optimization Design Method and Device of Electromagnetic Coil Based on Voltage Control Strategy Matching

Abstract

The present invention discloses an optimized design device and method for an electromagnetic coil based on voltage control strategy matching. The coil and the switching valve are arranged in a magnetic conductive bracket, the coil is sleeved on the outer periphery of the switching valve, and the port of the switching valve is connected to an oil circuit assembly; the method includes obtaining the structural dimension parameters of the switching valve; establishing an equivalent magnetic circuit model of the switching valve group; performing simulation on the coil to obtain the functional relationship between the input power and the coil volume and the coil temperature rise; constructing an electromagnetic coil model, and simulating to obtain the opening time and closing time of the switching valve and the power consumption of the electromagnetic coil under different coil structural dimensions; generating a target optimization function and the constraint conditions of the target optimization function; solving the target optimization function to obtain the optimal design scheme of the coil structure. In the present invention, by obtaining known parameters, establishing a magnetic circuit model, and calculating model parameters, the final coil parameters of the outer diameter, inner diameter, height, and wire diameter are obtained, so that the high-speed switching valve can take into account the power consumption of the electromagnet module while meeting the functional requirements.

Description

Technical Field

[0001] The present invention belongs to the field of electromagnetic coil design of high-speed switching valves, and particularly relates to an optimized design device and method for electromagnetic coils based on voltage control strategy matching. Background Art

[0002] Compared with electro-hydraulic servo or proportional valves, digital hydraulic systems have multiple advantages, such as low throttling loss, low cost, high reliability, and better realization of small system drive or actuator. As the core component of a digital hydraulic system, its dynamic characteristics determine the performance of the digital hydraulic system. There have been many digital valves that use multiple high-speed switching valves (HSVs) instead of electro-hydraulic proportional spool valves to improve the performance of actuators or main valves. As the core component of digital valves, there are still continuous challenges in developing high-performance HSVs with several indispensable characteristics such as low temperature rise, miniaturization, and fast response.

[0003] Compared with structural parameter optimization, voltage control strategies can improve the dynamic response of high-speed switching valves by changing the control signal. In the prior art, experts have established the relationship between the driving voltage and the response time of HSVs and studied the influence of the driving voltage on the dynamic characteristics of HSVs; someone has proposed an improved dual-voltage method to reduce the opening and closing times; on this basis, some scholars have designed a three-voltage control strategy to improve the response characteristics during the closing stage of the switching valve; for large-range variations in the supply oil pressure, a three-voltage control method for an adaptive oil source based on pulse width modulation (PWM) signal technology has been designed to improve and maintain the dynamic performance of HSVs under different pressures; further, in order to reduce the opening time of high-speed switching valves, a four-voltage control algorithm has been proposed, and its dynamic characteristics are better than those of other traditional control methods.

[0004] The parameters of the electromagnetic coil have a significant impact on the dynamic characteristics of HSVs. Currently, almost all studies have focused on optimizing the coil parameters of single-coil solenoid-type HSVs, and there are few reports on optimizing the coils of multi-coil integrated switching valves. Moreover, the influence of different voltage control strategies on coil parameter optimization has not been considered during the optimization process. Summary of the Invention

[0005] In order to solve the problems existing in the background art, the purpose of the present invention is to provide an optimized design device and method for electromagnetic coils based on voltage control strategy matching, so as to obtain the optimal electromagnetic coil parameters for different voltage control strategies.

[0006] The technical solution adopted by the present invention is as follows:

[0007] 1. An optimized design device for electromagnetic coils based on voltage control strategy matching:

[0008] It mainly consists of four switching valves, four coils, a magnetic conductive bracket and a valve seat; the magnetic conductive bracket is installed on the valve seat, and the valve seat is used to place the external oil circuit components; the coils and the switching valves are both arranged inside the magnetic conductive bracket, each coil is sleeved on the outer periphery of each switching valve, and the ports of the switching valves are connected to the external oil circuit components; there is thermal conductive silicone grease between the coils and the magnetic conductive bracket, and the heat generated by the coils is conducted to the magnetic conductive bracket through the thermal conductive silicone grease, thereby accelerating the heat dissipation of the coils to reduce the temperature rise of the coils.

[0009] The oil circuit components include an oil source, an oil tank and a main valve; the inlets of the first switching valve NC1 and the third switching valve NC3 are both connected to the oil source, the outlets of the first switching valve NC1 and the third switching valve NC3 are respectively connected to the left chamber and the right chamber of the main valve, the inlets of the second switching valve NC2 and the fourth switching valve NC4 are respectively connected to the left chamber and the right chamber of the main valve, the outlets of the second switching valve NC2 and the fourth switching valve NC4 are both connected to the oil tank, the outlet of the first switching valve NC1 is connected to the inlet of the second switching valve NC2, and the outlet of the third switching valve NC3 is connected to the inlet of the fourth switching valve NC4.

[0010] A displacement sensor for measuring the displacement of the main valve spool is also connected to the main valve.

[0011] II. An optimized design method for electromagnetic coils based on voltage control strategy matching, comprising the following steps:

[0012] Step S1: First, obtain the structural dimension parameters of the switching valve and the magnetic conductive bracket; the structural dimension parameters of the switching valve include the armature diameter, the main air gap of the armature, the lateral air gap of the armature and the armature length.

[0013] Step S2: According to the structural dimension parameters of the switching valve and the magnetic conductive bracket, establish an equivalent magnetic circuit model EMC of the switching valve group, and use the equivalent magnetic circuit model EMC to obtain the magnetic resistance of the switching valve.

[0014] Step S3: Simulate the coil to obtain the relationship between the coil temperature rise and the input power and the coil volume, and obtain the functional relationship P set = f(V,ΔT) by fitting.

[0015] Step S4: Construct an electromagnetic coil model based on the response surface method, and simulate to obtain the opening time t on and the closing time t off of the switching valve with different coil structural dimensions, as well as the power consumption P in of the electromagnetic coil; generate an objective optimization function with the opening and closing times of the switching valve as independent variables and the constraint conditions of the objective optimization function; solve the objective optimization function under the constraint conditions to obtain the optimal design scheme of the coil structure.

[0016] Step 3 includes the following steps:

[0017] Step S3.1: First, establish a 3D model of the overall device in finite element software, and perform mesh division, define boundary conditions, and the heat dissipation coefficient h for the 3D model n ;

[0018] The heat dissipation coefficient h in step S3.1 n is obtained by the following formula:

[0019]

[0020] In the formula, k p is the thermal conductivity; L is the characteristic length of the device wall; g is the acceleration due to gravity; α is the coefficient of thermal expansion; v is the dynamic viscosity; P r is the Prandtl number; dT is the temperature difference between the wall temperature and the fluid surface temperature; C and n are both empirical constants, C takes 0.59, and n takes 0.25;

[0021] Step S3.2: Then, use the steady-state thermal simulation module to perform simulation on the 3D model to obtain the relationship between the coil temperature rise ΔT and the coil input power P set , coil volume V, and fit the objective function relationship P set with the input power P set as the dependent variable and the coil volume V and coil temperature rise ΔT as the independent variables, P

[0022] Step 4 specifically includes the following steps:

[0023] Step 4.1: First, according to the structural dimension parameters of the switching valve group in step S1, establish a geometric model of the switching valve group in the simulation software; then, establish a coil function model in the design variable module of the simulation software, where the independent variables of the coil function model are the coil structural dimension parameters, and the dependent variables are the allowable input coil power P set , coil resistance R, and the number of coil turns N; the coil structural dimension parameters include the coil inner diameter R in , coil outer diameter R out , and coil height L k ;

[0024] Step 4.2: Define the material properties of the switching valve group;

[0025] Step 4.3: Define the motion attributes of the switching valve armature, including the motion stroke, armature mass, pre-pressure, and motion damping force;

[0026] Step 4.4: Define the coil excitation source as a voltage excitation, and determine the piecewise function of the switching valve excitation voltage according to the preset voltage control strategy;

[0027] Step 4.5: Then, obtain the opening time t on and closing time t off of the switching valve, as well as the power consumption P in of the electromagnetic coil through simulation calculation;

[0028] Step 4.6: Utilize the opening time t on and closing time t off of the switching valve, the allowable input coil power P set , and the coil structure size parameters to construct the target optimization function of the coil size and the constraint conditions corresponding to the target optimization function; Based on the constraint conditions, solve the target optimization function to obtain the optimal coil structure size that meets the constraint conditions and has the highest opening and closing comprehensive efficiency of the switching valve; Generate an optimized design scheme for the electromagnetic coil according to the obtained optimal coil structure size.

[0029] The coil function model in the above Step 4.1 is:

[0030] P set = f(V,ΔT)

[0031]

[0032] In the above formula, b k and the outer diameter d c of the enameled wire are expressed as follows:

[0033] b k = R out - R in

[0034] d c = 7.7918×0.8967 WNU + 0.001

[0035] The expression of the coil resistance R is as follows:

[0036]

[0037] d b = 8.025×0.8907 WNU + 0.001

[0038] where f k is the filling coefficient, WNU is the enameled wire gauge; ρ is the resistivity of the enameled wire.

[0039] The piecewise function of the switching valve excitation voltage in the above Step 4.4 is as follows:

[0040]

[0041] U h = 1.1I off R

[0042] U pre = 0.9I pre R

[0043] wherein, I on is the opening current of the switching valve; I off is the closing current of the switching valve; N is the number of turns of the coil; L on is the inductance under the opening of the switching valve; L off is the inductance under the closing of the switching valve; The preloading force of the switching valve; P s is the oil pressure at the inlet of the switching valve; P 0 is the oil pressure at the outlet of the high-speed switching valve; A is the cross-sectional area of the pressure inlet of the switching valve; C d and C v represent the flow coefficient and the flow velocity coefficient respectively; A 0 is the opening area of the valve port of the switching valve; θ is the jet angle of the switching valve; K is the spring stiffness coefficient of the switching valve; δ off and δ on represent the main armature air gaps under the closing and opening of the switching valve respectively; λ is an empirical coefficient, taking 0.85; U h is the holding voltage; U pre is the preloading voltage; I pre is the preloading current of the switching valve; R is the coil resistance;

[0044] In the above formula, the inductance L on under the opening of the switching valve and the inductance L off under the closing of the switching valve are obtained through the following formula:

[0045] L on = N 2 / R m,on

[0046] L off = N 2 / R m,off

[0047] wherein, R m,on and R m,off represent the reluctances under the opening and closing of the switching valve respectively.

[0048] The target optimization function of the coil in step 4.6 is:

[0049] max f d = max[f 1(u) + f 2 (u)]

[0050]

[0051] wherein, f d represents the combined opening and closing efficiency of the switching valve; f 1 (u) represents the opening efficiency of the switching valve; f 2 (u) represents the closing efficiency of the switching valve; max[] represents the maximum value function;

[0052] The expression of the constraint condition is as follows:

[0053]

[0054] wherein, k 1 (u) represents the power consumption P of the electromagnetic coil obtained by simulation in and the ratio to the allowable input power P set of.

[0055] The present invention aims to improve the opening and closing efficiency and maintenance convenience of the switching valve through a modular structure form and an optimized electromagnetic coil design. The core part of the device includes four switching valves, four electromagnetic coils, thermal conductive silicone grease, a magnetic conductive bracket, and a valve seat; these components work together to achieve efficient control of the external oil circuit components. The oil circuit components consist of an oil source, an oil tank, and a main valve, and the switching valve realizes fine regulation of the fluid power system by precisely controlling the connection with the oil circuit components.

[0056] The development process mainly includes the following key steps:

[0057] Step 1, obtaining the structural dimension parameters of the device: First, collect the dimension parameters of the switching valve and the magnetic conductive bracket, which are the basis for establishing the equivalent magnetic circuit model.

[0058] Step 2, establishing the equivalent magnetic circuit model of the device and obtaining the magnetic resistance: According to the structural dimension parameters of the switching valve and the magnetic conductive bracket, establish the equivalent magnetic circuit model EMC of the switching valve group.

[0059] Step 3, coil simulation and temperature rise analysis: Simulate the coil, analyze the relationship between its temperature rise and input power and volume, and determine the functional relationship between these parameters through data fitting.

[0060] Step 4, optimized design and simulation verification: Construct an electromagnetic coil model based on the response surface method, simulate the opening time, closing time, and power consumption under different structural dimensions, and optimize the design according to the opening and closing efficiency to finally obtain the optimal coil structural dimensions.

[0061] The beneficial effects of the present invention are:

[0062] 1. Under the condition of meeting the coil temperature rise, the method of the present invention aims at the dynamic response of the switching valve for different coil voltage control strategies to obtain matching optimal electromagnetic coil parameters.

[0063] 2. The present invention proposes an electromagnetic coil optimization method for multi-coil integration based on the response surface method, which improves the design accuracy and efficiency of the multi-coil integrated switching valve.

[0064] 3. By sealing four coils on the magnetic conductive bracket and using thermal conductive silicone grease in the present invention, the device can effectively accelerate the heat dissipation of the coil, reduce the temperature rise, and thus extend the service life of the coil. In addition, compared with the traditional single-coil design, the modular structure of the present invention greatly reduces the maintenance cost and complexity, because the split structure of the coil and the valve body makes it possible to replace the damaged parts separately without replacing the whole device. Description of the Drawings

[0065] Figure 1 is a schematic diagram of the structure of a digital hydraulic valve;

[0066] Figure 2 is the magnetic circuit model of the switching valve group;

[0067] Figure 3 is the coil temperature rise surface;

[0068] Figure 4 is the Pareto front optimization result under different control strategies; among them, (a) is the relationship diagram of the objective function of the switching valve closing and opening under single voltage control; (b) is the comparison diagram of the calculation results of the response surface method and the finite element method under single voltage control; (c) is the relationship diagram of the objective function of the switching valve closing and opening under three-voltage control; (d) is the comparison diagram of the calculation results of the response surface method and the finite element method under three-voltage control; (e) is the relationship diagram of the objective function of the switching valve closing and opening under four-voltage control; (f) is the comparison diagram of the calculation results of the response surface method and the finite element method under four-voltage control;

[0069] Figure 5 is the result diagram of the opening and closing times of the optimal coil obtained under the single voltage control strategy under different voltage controls; among them, (a) is the relationship diagram of the spool displacement, external control signal and time; (b) is the bar chart of the spool opening, closing and opening and closing times under different voltage control strategies;

[0070] Figure 6 is the result diagram of the opening and closing times of the optimal coil obtained under the three-voltage control strategy under different voltage controls; among them, (a) is the relationship diagram of the spool displacement, external control signal and time; (b) is the bar chart of the spool opening, closing and opening and closing times under different voltage control strategies;

[0071] Figure 7It is a result diagram of the opening and closing times of the optimal coil obtained under the four-voltage control strategy at different voltage controls; among them, (a) is a diagram showing the relationship between spool displacement, external control signal and time; (b) is a bar chart of the spool opening, closing and opening / closing times under different voltage control strategies.

[0072] Figure 8 It is a result diagram of the opening and closing times of the proportional coil at different voltage controls; among them, (a) is a diagram showing the relationship between spool displacement, external control signal and time; (b) is a bar chart of the spool opening, closing and opening / closing times under different voltage control strategies.

[0073] Figure 9 It is a three-voltage control flow chart. Specific implementation manner

[0074] The present invention will be described in detail below in conjunction with specific implementation cases. The following implementation cases will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form.

[0075] The method of the present invention uses an electromagnetic coil optimization design device, such as Figure 1 shown. The device mainly consists of four high-speed switching valves, four coils, thermal grease, a magnetic conduction bracket and a valve seat; the magnetic conduction bracket is installed on the valve seat, and the valve seat is used to place the external oil circuit components; the coils and the switching valves are both arranged inside the magnetic conduction bracket, each coil is detachably sleeved on the outer periphery of each switching valve, and the ports of the switching valves are connected to the external oil circuit components; the thermal grease is arranged between the electromagnetic coil and the magnetic conduction bracket;

[0076] The oil circuit components include an oil source, an oil tank and a main valve; the inlets of the first switching valve NC1 and the third switching valve NC3 are both connected to the oil source, the outlets of the first switching valve NC1 and the third switching valve NC3 are respectively connected to the left chamber and the right chamber of the main valve, the inlets of the second switching valve NC2 and the fourth switching valve NC4 are respectively connected to the left chamber and the right chamber of the main valve, the outlets of the second switching valve NC2 and the fourth switching valve NC4 are both connected to the oil tank, the outlet of the first switching valve NC1 is connected to the inlet of the second switching valve NC2, and the outlet of the third switching valve NC3 is connected to the inlet of the fourth switching valve NC4; a sensor for measuring the spool displacement of the main valve is also arranged on the main valve;

[0077] The switching valves NC1, NC2, NC3 and NC4 are all normally closed valves and all adopt spring reset.

[0078] The device seals the four coils and the magnetic conductive support together through thermal conductive silicone grease, and can quickly conduct the heat generated by the four coils to the magnetic conductive support through the thermal conductive silicone grease, thereby accelerating the heat dissipation of the coils and reducing their temperature rise. In addition, compared with the traditional single-coil solenoid type, which has the disadvantage that the whole valve needs to be replaced when the coil is damaged, this modular structure form is easier to maintain because the coil and the valve body adopt a split structure.

[0079] The method includes the following steps:

[0080] Step S1: First, obtain the structural dimension parameters of the switching valve and the magnetic conductive support; the structural dimension parameters of the switching valve include the armature diameter, the main air gap of the armature, the lateral air gap of the armature, and the armature length, and the structural dimension parameters of the magnetic conductive support include the three-dimensional dimensions such as the length, width, height, and thickness of the magnetic conductive support;

[0081] Step S2: According to the structural dimension parameters of the switching valve and the magnetic conductive support, establish an equivalent magnetic circuit model EMC of the switching valve group. The switching valve group mainly includes four switching valves and a magnetic conductive support, and use the equivalent magnetic circuit model EMC to obtain the magnetic resistance in the open / closed state of the switching valve;

[0082] Step S3: Carry out simulation on the coil to obtain the relationship between the coil temperature rise and the input power and the coil volume, and obtain the functional relationship P = f(V,ΔT) between the input power and the coil volume and the coil temperature rise through fitting;

[0083] Step S4: Construct an electromagnetic coil model based on the response surface method, and simulate to obtain the opening time t on and closing time t off of the switching valve under different coil structural dimensions under the preset voltage control strategy, in and the power consumption P

[0084] Step 3 includes the following steps:

[0085] Step S3.1: First, establish a three-dimensional model of the overall device in the finite element software, and carry out mesh generation, define boundary conditions, and the heat dissipation coefficient h n in the steady-state thermal simulation module in the finite element software;

[0086] The heat dissipation coefficient h n in Step S3.1 is obtained by the following formula:

[0087]

[0088] In the formula, k pis the thermal conductivity; L is the characteristic length of the device wall; g is the acceleration due to gravity; α is the coefficient of thermal expansion; v is the dynamic viscosity; P r is the Prandtl number; dT is the temperature difference between the wall temperature and the fluid surface temperature; C and n are both empirical constants, C is taken as 0.59, and n is taken as 0.25;

[0089] Step S3.2: Then, use the steady-state thermal simulation module to simulate the three-dimensional model to obtain the relationship between the coil temperature rise ΔT of the coil under different coil input powers P set and coil volumes V, and fit the objective function relationship with the input power P set as the dependent variable and the coil volume V and the coil temperature rise ΔT as the independent variables P set = f(V, ΔT).

[0090] In the Cartesian coordinate system, with the coil input power P set as the X-axis coordinate value, the coil volume V as the Y-axis coordinate value, and the coil temperature rise ΔT as the Z-axis coordinate value, a number of discrete points can be collected through simulation, and then the discrete points are fitted to obtain the objective function surface P set = f(V, ΔT);

[0091] Step 4 specifically includes the following steps:

[0092] Step 4.1: First, according to the structural dimension parameters of the switching valve group in Step S1, establish a geometric model of the switching valve group in the simulation software; then, establish a coil function model in the design variable module of the simulation software. The independent variables of the coil function model are the coil structural dimension parameters, and the dependent variables are the allowable input coil power P set , coil resistance R, and the number of coil turns N; the coil structural dimension parameters include the inner diameter R in of the coil, the outer diameter R out of the coil, and the coil height L k ;

[0093] Step 4.2: Define the simulation domain and the material properties of the switching valve group;

[0094] Step 4.3: Define the movement attributes of the switching valve armature, including the movement stroke, armature mass, pre-pressure, and movement damping force;

[0095] Step 4.4: Define the coil excitation source as voltage excitation, and determine the piecewise function of the switching valve excitation voltage according to the preset voltage control strategy;

[0096] The voltage control strategy adopts one of single-voltage control, dual-voltage control, triple-voltage control, and quadruple-voltage control.

[0097] Step 4.5. Next, obtain the opening time t on and closing time t off of the switching valve, as well as the power consumption P in of the electromagnetic coil;

[0098] In Step 4.6, use the opening time t on and closing time t off of the switching valve, the allowed input coil power P set and the coil structure size parameters to construct the target optimization function of the coil size and the constraint conditions corresponding to the target optimization function; based on the constraint conditions, solve the target optimization function to obtain the optimal coil structure size that meets the constraint conditions and has the highest opening and closing comprehensive efficiency of the switching valve; according to the obtained optimal coil structure size, generate an optimized design scheme for the electromagnetic coil.

[0099] The coil function model in Step 4.1 is:

[0100] P set = f(V,ΔT)

[0101]

[0102] In the above formula, b k and the outer diameter d c of the enameled wire are expressed as follows:

[0103] b k = R out - R in

[0104] d c = 7.7918×0.8967 WNU + 0.001

[0105]

[0106] d b = 8.025×0.8907 WNU + 0.001

[0107] where f k is the filling coefficient, WNU is the enameled wire gauge; ρ is the wire density of the enameled wire.

[0108] In specific implementation, when three-voltage control is adopted, the piecewise function expression of the excitation voltage of the switching valve is as follows:

[0109]

[0110] Specifically, see Figure 9 the three-voltage control strategy process; where U is the real-time voltage across the coil; U sis the supply power voltage; I is the real-time current flowing through the coil;

[0111] The expressions of the parameters in the piecewise function are as follows:

[0112]

[0113] U h = 1.1I off R

[0114] U pre = 0.9I pre R

[0115] where, I on is the opening current of the switching valve; I off is the closing current of the switching valve; N is the number of turns of the coil; L on is the inductance under the opening of the switching valve; L off is the inductance under the closing of the switching valve; P s is the oil pressure at the inlet of the switching valve; P 0 is the oil pressure at the outlet of the high-speed switching valve; A is the cross-sectional area of the pressure inlet of the switching valve; A 0 is the valve port opening area of the switching valve; C d and C v respectively represent the flow coefficient and the velocity coefficient; θ is the jet angle of the switching valve; K is the spring stiffness coefficient of the switching valve; is the preloading force of the switching valve, and its expression is as follows: x 0 is the pre-compression of the spring; δ off and δ on respectively represent the main armature air gap under the closing and opening of the switching valve; λ is an empirical coefficient, taking 0.85; U h is the holding voltage; U pre is the preloading voltage; I pre is the preloading current of the switching valve; R is the coil resistance;

[0116] In the above formula, the inductance L on under the opening of the switching valve and the inductance L off under the closing of the switching valve are obtained through the following formula:

[0117] L on = N 2 / R m,on

[0118] L off = N 2 / R m,off

[0119] where, R m,on and R m,offRespectively represent the reluctance with the switching valve open and closed.

[0120]

[0121]

[0122] In the formula, s is the effective cross-sectional area of the armature; μ c is the magnetic permeability of the magnetic conductive material; μ 0 is the magnetic permeability of air; x 0 is the initial air gap of the armature, x e is the final air gap of the armature; l c is the magnetic path length;

[0123] Under different voltage control strategies, the piecewise function expression of the excitation voltage of the switching valve can be selected according to the conventional formulas in the art. Only the opening current I on , closing current I off , holding voltage U h , and preloading voltage U pre These four unknowns are involved. Therefore, solving the above four unknowns can achieve the control of the switching valve.

[0124] The target optimization function of the coil in step 4.6 is:

[0125] max f d = max[f 1 (u) + f 2 (u)]

[0126]

[0127] Among them, f d represents the comprehensive opening and closing efficiency of the switching valve; f 1 (u) represents the opening efficiency of the switching valve; f 2 (u) represents the closing efficiency of the switching valve; max[] represents the maximum value function;

[0128] The expression of the constraint condition is as follows:

[0129]

[0130] Among them, k 1 (u) represents the ratio of the power consumption P in of the electromagnetic coil obtained by simulation to the allowable input power P set .

[0131] Specific embodiment: Taking a 4-switch valve bridge as an example, where the valve bodies of the 4 switching valves have the same size, the solution method is introduced as follows:

[0132] Step S1: Obtain the structural dimension parameters and materials of the switching valve and the magnetic conductive bracket; the known structural dimension parameters include the outer diameter of the valve body being 9 mm, the diameter of the armature being 5.6 mm, the main air gap of the armature being 0.5 mm, the lateral air gap of the armature being 0.05 mm, the length of the armature being 15 mm, the stroke of the armature being 0.35 mm, and the material being DT4C.

[0133] Step S2: According to the structural dimension parameters and material properties of the switching valve and the magnetic conductive bracket, establish an equivalent magnetic circuit model EMC of the switching valve group, as Figure 2 shown;

[0134] Step S3: Conduct simulation on the coil to obtain the relationship between the coil temperature rise and the input power and coil volume, and obtain the functional relationship P = f(V,ΔT) between the input power, coil volume, and coil temperature rise through fitting;

[0135] Using the cftool fitting tool in MATALB, obtain Figure 3 the functional expression of the surface:

[0136] P(V,ΔT) = -0.3259 + 0.0001077V + 0.07728ΔT - 5.498×10 -8 V 2 + 3.74×10 -6 VΔT + 0.000246ΔT 2

[0137] Step S4: Construct an electromagnetic coil model based on the response surface method, and simulate to obtain the opening time t on and closing time t off of the switching valve under different coil structural dimensions, as well as the power consumption P in of the electromagnetic coil; according to the allowable power consumption P set of the switching valve, generate an objective optimization function with the opening and closing times of the switching valve as independent variables and the constraint conditions of the objective optimization function; solve the optimization objective function under the function conditions to obtain the optimal design scheme of the coil structure.

[0138] The range of the coil structure dimension parameters in the coil function model is:

[0139] Coil outer diameter R out : 6.25 - 7.1; Coil height L k : 20 - 45; Coil enameled wire gauge WNU: 25 - 40.

[0140] The Pareto front optimization results for different voltage control strategies are as Figure 4As shown, the Pareto front coil parameters obtained by the response surface method are input into the finite element analysis software to calculate the opening and closing times of the coil. The comparison results show that for the calculation results based on any voltage control strategy, the relative error of the opening time of the switching valve is less than 15%, and the relative error of the calculated closing time is less than 6%. The calculation efficiency is improved while meeting the calculation accuracy requirements of engineering design.

[0141] Finally, the optimal coil parameters based on different voltage control strategies are shown in Table 1 below.

[0142] Table 1 Optimized parameters of electromagnetic coils based on different voltage control strategies

[0143]

[0144] Furthermore, based on the optimal coil parameters, the effects of subsequent different voltage control strategies on the opening and closing times of the switching valve are studied.

[0145] Figure 5 For the optimal coil type A obtained based on single voltage control, the effects on the performance of the switching valve under subsequent three-voltage and four-voltage control strategies. When three-voltage control is adopted, the closing time decreases by 50% (from 2 ms to 1 ms), the opening time remains unchanged, and the input power decreases by 31.7%. After further adopting four-voltage control, the opening time will also decrease by 36% (from 5.5 ms to 3.5 ms).

[0146] Figure 6 For the optimal coil type B obtained based on three-voltage control, the effects on the performance of the switching valve under subsequent single-voltage and four-voltage control strategies. When single-voltage control is adopted, the closing time will increase by 250% (from 1 ms to 3.5 ms), the opening time remains unchanged, and the input power will increase by 432%, resulting in coil burnout. When four-voltage control is adopted, the opening time will decrease by 20% (from 2.5 ms to 2 ms), while the closing time remains unchanged.

[0147] Figure 7 For the optimal coil type C obtained based on four-voltage control, the effects on the performance of the switching valve under subsequent single-voltage and three-voltage control strategies. When single-voltage control is adopted, the opening time will increase by 150% (from 1 ms to 2.5 ms), the closing time will increase by 250% (from 1 ms to 3.5 ms), and the input power will increase by 998.8%, which will lead to coil burnout. When three-voltage control is adopted, the opening time will increase by 150% (from 1 ms to 2.5 ms), the closing time remains unchanged, and the input power will decrease by 17.5%.

[0148] Figure 8Under the prior art, the opening and closing times of the proportional coil under the single-voltage control strategy, the three-voltage control strategy, and the four-voltage control strategy are 10 ms, 8 ms, and 6 ms respectively. Compared with the coil A using this method: 1) Under the single-voltage control strategy, the opening time increases by 9% (from 5.5 ms to 6 ms), and the closing time increases by 200% (from 1.4 ms to 4 ms); 2) Under the three-voltage control strategy, the opening time increases by 9% (from 5.5 ms to 6 ms), and the closing time increases by 40% (from 1 ms to 1.4 ms); 3) Under the four-voltage control strategy, the opening time increases by 14.2% (from 3.5 ms to 4.5 ms), and the closing time increases by 40% (from 1 ms to 1.4 ms).

[0149] The above are only the preferred embodiments of the present invention. It should be noted that improvements and refinements can be made without departing from the working principle of the present invention, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An electromagnetic coil optimization design method based on voltage control strategy matching, characterized in that: The steps include: Step S1, first, obtaining the structural dimension parameters of the switch valve and the magnetic conductive bracket; the structural dimension parameters of the switch valve include the armature diameter, the armature main air gap, the armature lateral air gap and the armature length; Step S2, establishing an equivalent magnetic circuit model EMC of the switch valve group according to the structural size parameters of the switch valve and the magnetic conductive bracket, and obtaining the magnetic resistance of the switch valve using the equivalent magnetic circuit model EMC; Step S3: simulate the coil to obtain the relationship between the coil temperature rise and the input power and coil volume, and obtain the functional relationship P between the input power, coil volume and coil temperature rise by fitting. set =f(V,ΔT); Step S4: construct an electromagnetic coil model based on the response surface method, and simulate and obtain the opening time t of the switch valve with different coil structure sizes. on and closing time t off ., and the power consumption of the electromagnetic coil P in ; Generate a target optimization function with the opening and closing time of the switch valve as an independent variable and constraints of the target optimization function; solve the target optimization function under the constraints to obtain an optimal design solution for the coil structure; The step S4 specifically includes the following steps: Step S4.1: First, according to the structural dimension parameters of the switch valve group in step S1, a geometric model of the switch valve group is established in the simulation software; then, a coil function model is established in the design variable module of the simulation software, wherein the independent variable of the coil function model is the coil structural dimension parameter, and the dependent variable is the coil power P allowed to be input. set , coil resistance R and coil turns N; the coil structure size parameters include the coil inner diameter R in , coil outer diameter R out and coil height L k ; Step S4.2, defining the material properties of the switch valve group; Step S4.3, defining the motion properties of the switch valve armature, including motion stroke, armature mass, pre-pressure, and motion damping force; Step S4.4, defining the coil excitation source as voltage excitation, and determining the piecewise function of the switch valve excitation voltage according to a preset voltage control strategy; Step S4.5: Next, obtain the opening time t of the switch valve through simulation calculation. on and closing time t off ., and the power consumption of the electromagnetic coil P in ; Step S4.6: Using the opening time t of the switch valve on and closing time t off .、Allowable coil input power P set and coil structure size parameters, constructing a target optimization function for coil size and constraints corresponding to the target optimization function; Based on the constraints, the target optimization function is solved to obtain the optimal coil structure size that satisfies the constraints and has the highest comprehensive opening and closing efficiency of the switch valve; based on the obtained optimal coil structure size, an electromagnetic coil optimization design scheme is generated; The coil function model in step S4.1 is: P set =f(V,ΔT) In the above formula, b k And the outer diameter of the enameled wire d c The expression is as follows: b k =R out -R in d c ＝7.7918×0.8967 WNU +0.001 The expression of coil resistance R is as follows: d b ＝8.025×0.8907 WNU +0.001 Among them, f k is the filling factor, WNU is the wire number of the enameled wire; ρ is the resistivity of the enameled wire.

2. The electromagnetic coil optimization design method based on voltage control strategy matching according to claim 1 is characterized in that: The step S3 comprises the following steps: Step S3.1: First, a three-dimensional model of the entire device is established in the finite element software, and the three-dimensional model is meshed, and boundary conditions and heat dissipation coefficient h are defined. n ; The heat dissipation coefficient h in step S3.1 n The following formula is used to obtain: In the formula, k p is the thermal conductivity; L is the characteristic length of the device wall; g is the gravitational acceleration; α is the thermal expansion coefficient; v is the dynamic viscosity; P r is the Prandtl number; dT is the temperature difference between the wall temperature and the fluid surface temperature; C and n are both empirical constants, C is 0.59, and n is 0.25; Step S3.2: Next, the three-dimensional model is simulated using the steady-state thermal simulation module to obtain the coil at different coil input powers P. set , the change relationship of coil temperature rise ΔT under the condition of coil volume V, and fit the input power P set The objective function relationship P is the dependent variable, the coil volume V and the coil temperature rise ΔT are the independent variables. set =f(V,ΔT).

3. The electromagnetic coil optimization design method based on voltage control strategy matching according to claim 1 is characterized in that: The piecewise function of the switching valve excitation voltage in step S4.4 is as follows: U h =1.1I off R And pre =0.9I pre R Among them, I on is the opening current of the switch valve; I off is the closing current of the switch valve; N is the number of coil turns; L on is the inductance of the switch valve when it is open; L off is the inductance of the switch valve when it is closed; Preload force of the switch valve; P s is the oil pressure at the inlet of the switch valve; P0 is the oil pressure at the outlet of the high-speed switch valve; A is the cross-sectional area of ​​the pressure inlet of the switch valve; C d and C v They represent the flow coefficient and flow velocity coefficient respectively; A0 is the opening area of ​​the switch valve; θ is the jet angle of the switch valve; K is the spring stiffness coefficient of the switch valve; δ off and δ on They represent the main air gap of the armature when the switch valve is closed and opened respectively; λ is the empirical coefficient, which is taken as 0.85; U h To maintain voltage; U pre is the preload voltage; I pre is the preload current of the switch valve; R is the coil resistance; In the above formula, the inductance L when the switch valve is open is on and the inductance L when the switch valve is closed off It is obtained by the following formula: L on =N 2 / R m,on L off =N 2 / R m,off Among them, R m,on and R m,off Represent the magnetic resistance when the switch valve is opened and closed, respectively.

4. The electromagnetic coil optimization design method based on voltage control strategy matching according to claim 1 is characterized in that: The target optimization function of the coil in step S4.6 is: max f d =max[f1(u)+f2(u)] Among them, f d represents the comprehensive efficiency of the opening and closing of the switch valve; f1(u) represents the opening efficiency of the switch valve; f2(u) represents the closing efficiency of the switch valve; max[] represents the maximum value function; The constraint condition is expressed as follows: Where k1(u) represents the power consumption P of the electromagnetic coil obtained by simulation. in With the allowable input power P set ratio.

5. An electromagnetic coil optimization design device for implementing the electromagnetic coil optimization design method based on voltage control strategy matching according to any one of claims 1 to 4, characterized in that: It is mainly composed of four switch valves, four coils, a magnetic bracket and a valve seat; the magnetic bracket is installed on the valve seat, and the valve seat is used to place the external oil circuit component; the coil and the switch valve are arranged inside the magnetic bracket, and each coil is sleeved on the outer periphery of each switch valve, and the port of the switch valve is connected to the external oil circuit component; thermal conductive silicone grease is provided between the coil and the magnetic bracket, and the heat generated by the coil is conducted to the magnetic bracket through the thermal conductive silicone grease, thereby accelerating the heat dissipation of the coil to reduce the temperature rise of the coil.

6. The electromagnetic coil optimization design device according to claim 5, characterized in that: The oil circuit assembly includes an oil source, an oil tank and a main valve; the inlet of the first switch valve NC1 and the inlet of the third switch valve NC3 are both connected to the oil source, the outlet of the first switch valve NC1 and the outlet of the third switch valve NC3 are respectively connected to the left chamber and the right chamber of the main valve, the inlet of the second switch valve NC2 and the inlet of the fourth switch valve NC4 are respectively connected to the left chamber and the right chamber of the main valve, the outlet of the second switch valve NC2 and the outlet of the fourth switch valve NC4 are both connected to the oil tank, the outlet of the first switch valve NC1 is connected to the inlet of the second switch valve NC2, and the outlet of the third switch valve NC3 is connected to the inlet of the fourth switch valve NC4.

7. The electromagnetic coil optimization design device according to claim 6, characterized in that: The main valve is also connected with a displacement sensor for measuring the displacement of the valve core of the main valve.

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