Quantitative magnetizing device and system and adjusting control method

Abstract

The invention discloses a quantitative magnetizing device, a quantitative magnetizing system and an adjusting control method, and relates to the technical field of quantitative magnetizing, constant current is used for quantitative magnetizing, the process of slowly increasing the current is avoided, the magnetism of a material can be obviously changed, and the influence of a critical magnetic field is not considered. Error understanding of the magnetizing process or the characteristics of the magnetic material may be caused, especially in the case where the magnetic state of the material may vary with an applied magnetic field. The influence of a critical magnetic field is ignored, so that the understanding of the magnetizing process of the magnetic material is not accurate, and the performance and the application effect of the magnetic material are influenced. The magnetizing process is optimized by accurately controlling a current growth model, and excessive heating or nonlinear response is avoided. And the slope of the initial magnetization section is selected as a reference, so that the stability and efficiency of the material at the temperature close to Curie temperature can be improved. Meanwhile, the constant current is used for magnetizing, so that the stability of the magnetic field intensity can be ensured, the hysteresis loss is reduced, and the accuracy and repeatability of the experiment are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of quantitative magnetization, and more specifically, to a regulation and control method for quantitative magnetization. Background Art

[0002] As one of the core technologies for magnetic material processing, quantitative magnetization technology is of great significance to improving product performance and production efficiency. With the advancement of materials science and the development of automation and intelligent technology, quantitative magnetization technology will be more accurate and efficient, further promoting the development of various magnetic applications. Quantitative magnetization is a technology that enables magnetic materials or equipment to achieve predetermined magnetic properties by precisely controlling the magnetization process. It is widely used in motor manufacturing, permanent magnet material production, sensor manufacturing, medical equipment and other fields. The realization of quantitative magnetization usually relies on advanced automation control technologies, such as PID control, digital control, closed-loop feedback, etc., to ensure the accuracy and stability of the magnetization process.

[0003] The prior art has the following deficiencies:

[0004] Quantitative magnetization uses constant current for magnetization without a process of slowly increasing the current, which may cause the magnetism of the material to change significantly. It also does not take into account the influence of the critical magnetic field, which may lead to a misunderstanding of the magnetization process or the characteristics of the magnetic material, especially when the magnetic state of the material may change with the applied magnetic field. Ignoring the influence of the critical magnetic field may lead to an inaccurate understanding of the magnetization process of the magnetic material, affecting its performance and application effect.

[0005] In view of the above problems, the present invention proposes a solution. Summary of the invention

[0006] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a regulation control method and system capable of quantitative magnetization to solve the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A quantitative magnetization regulating and controlling method comprises the following steps:

[0009] Step S1, recording the temperature of the material and the environment at various times, using a magnetometer to measure the magnetization intensity of the material and the external magnetic field intensity respectively, and using a digital ammeter to monitor the current in real time.

[0010] Step S2, calculating the critical magnetic field of the material through the magnetization intensity of the material and the external magnetic field intensity, and judging whether the magnetization intensity of the material is close to saturation, and analyzing whether the thermal power input and output of the material are balanced through thermal balance.

[0011] Step S3, determining the target current in this case according to the critical magnetic field and the Curie temperature of the material.

[0012] Step S4, selecting a current growth model according to the target current and the slope of the initial magnetization segment in the magnetization curve, so that the current can achieve an early growth, and then use a constant current for magnetization after reaching the target current.

[0013] In a preferred embodiment, step S1 includes the following contents:

[0014] Use temperature sensors to record the temperature of the current material and the current environment in real time, use superconducting quantum interference devices to measure the magnetization intensity of the material and the strength of the externally applied magnetic field, and connect the synchronous measurement with the data acquisition system to record the magnetic field data and temperature data in real time;

[0015] Use a digital ammeter to monitor the current in real time, connect it directly to the computer using a USB interface, and read the data through the software.

[0016] In a preferred embodiment, step S2 includes the following contents:

[0017] The relationship between the magnetization intensity of the material and the external magnetic field intensity is expressed as: M = xH; when it reaches the saturation state, the magnetization intensity M sat reaches the maximum value, at which time the external magnetic field H c The corresponding magnetization is given by:

[0018] The magnetization curve is obtained by the magnetization intensity and the external magnetic field intensity to determine whether the critical magnetic field is reached: gradually increase the external magnetic field and measure the magnetization intensity of the material. When the magnetization intensity reaches the saturation state, the increase of the external magnetic field will not cause a significant change in the magnetization intensity. The external magnetic field at this time is the critical magnetic field. At this time, the critical magnetic field is reached. In this case, the measured current is the target current I1 determined based on the critical magnetic field.

[0019] Design a temperature control model design;

[0020] Thermal balance analysis: In steady state, the thermal power input and output of the material should be balanced, that is: P out =P in ;

[0021] The thermal power input is calculated from the material's resistance and the current: P in =I 2 R;

[0022] The thermal power output is calculated using the following heat transfer model: P out =hA(TT env ), where: h is the convection heat transfer coefficient, A is the surface area of ​​the material, Tenv is the ambient temperature, T is the current temperature of the material;

[0023] Temperature change rate: The temperature change rate over time is estimated by differential calculation. The temperature change over time is calculated by real-time temperature data. Between two consecutive time points t1 and t2, the temperatures are T(t1) and T(t2) respectively. The approximate value of the temperature change rate is estimated by the following differential calculation formula:

[0024] Relationship between thermal power and temperature change rate: The temperature change rate is expressed by the mass, specific heat capacity and temperature change of the object: Where: m is the mass of the object, c is the specific heat capacity of the object, is the temperature change rate;

[0025] When P in -P out >0, P in >P out , the temperature of the object will increase,

[0026] When P in -P out When P < 0 in <P out , the temperature of the object will decrease,

[0027] When P in -P out =0, P in =P out , the system reaches thermal equilibrium,

[0028] In a preferred embodiment, step S3 includes the following contents:

[0029] When the difference between thermal power input and output is zero, P in -P out = 0, that is, P in =P out , reaching the Curie temperature of the material, in which case the current is the target current I2 determined according to the temperature;

[0030] The target current I1 determined according to the critical magnetic field is compared with the target current I2 determined according to the temperature, and the smaller value is taken as the target current for subsequent operations.

[0031] In a preferred embodiment, step S4 includes the following contents:

[0032] Obtaining magnetization curve data: The magnetization curve consists of the relationship between the magnetic field intensity H and the magnetic induction intensity B, that is, B = f(H);

[0033] The initial current is I0, calculated in unit time: that is, the magnetic induction intensity B(t) and the magnetic field intensity H(t) are calculated in unit time t. The formula for the initial magnetization segment slope can be expressed as:

[0034] After receiving the target current of the quantitative magnetization device and the slope of the initial magnetization section, the target current of the quantitative magnetization device and the slope of the initial magnetization section are defined as input variables, and they are divided into different fuzzy sets respectively;

[0035] The growth model is defined as the output variable and divided into fuzzy sets;

[0036] Fuzzy rules are formulated to describe the impact of the target current of the quantitative magnetization device and the definition of the slope of the initial magnetization segment on the growth model;

[0037] Carry out fuzzy reasoning according to fuzzy rules to determine the growth model selection of quantitative magnetization device;

[0038] Combined with the above, when the charging time is short and the slope of the magnetization curve is steep during the magnetization process, a linear current growth model is used to control the current for magnetization: the initial current is I0, the target current is I f , the total time of the magnetization process is T, and the change of current over time is expressed by the following formula: Finally, the target current I is reached at t = T f ;

[0039] When the charging time is long and the slope of the magnetization curve is small during the re-magnetization process, the exponential current growth model is used to control the current for magnetization. The exponential growth formula can be written as: I(t) = I0 + (I f -I0)·(1-e -λt ), where: I(t) is the current at time t, I0 is the initial current, I f is the target current, λ is the adjustment rate, and t is the current time.

[0040] A quantitative magnetization regulating and controlling system comprises: an information acquisition module, a data processing module, a statistical analysis module and a model building module.

[0041] Information acquisition module: records the temperature of the material and the environment at all times, uses a magnetometer to measure the magnetization intensity of the material and the external magnetic field intensity respectively, and uses a digital ammeter to monitor the current in real time;

[0042] Data processing module: calculates the critical magnetic field of the material through the magnetization intensity of the material and the external magnetic field intensity, and determines whether the current magnetization intensity of the material is close to saturation, and analyzes whether the thermal power input and output of the material are balanced through thermal balance;

[0043] Statistical analysis module: determines the target current in this case based on the critical magnetic field and Curie temperature of the material;

[0044] Model building module: Select the current growth model according to the target current and the slope of the initial magnetization segment in the magnetization curve, so that the current can achieve early growth, and then use constant current for magnetization after reaching the target current.

[0045] A quantitative magnetizing device comprises a power supply and an electromagnetic coil. The power supply is used to provide a stable current source and control the current size and waveform; the electromagnetic coil is used to generate a magnetic field.

[0046] The technical effects and advantages of the quantitative magnetization regulation control method and system of the present invention are as follows: the magnetization process is optimized by accurately controlling the current growth model to avoid overheating or nonlinear response. Selecting the slope of the initial magnetization segment as a reference helps to improve the stability and efficiency of the material when it is close to the Curie temperature. At the same time, using constant current for magnetization can ensure the stability of the magnetic field intensity and reduce hysteresis loss, thereby improving the accuracy and repeatability of the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 The invention discloses a regulation and control method capable of quantitative magnetization.

[0048] Figure 2 The invention discloses a regulating and controlling system capable of quantitative magnetization. DETAILED DESCRIPTION

[0049] 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.

[0050] The present invention is collected.

[0051] Example 1

[0052] The present invention Figure 1 As shown, a regulation and control method for quantitative magnetization is provided, comprising the following steps:

[0053] Step S1, recording the temperature of the material and the environment at various times, using a magnetometer to measure the magnetization intensity of the material and the external magnetic field intensity respectively, and using a digital ammeter to monitor the current in real time.

[0054] Step S2, calculating the critical magnetic field of the material through the magnetization intensity of the material and the external magnetic field intensity, and judging whether the magnetization intensity of the material is close to saturation, and analyzing whether the thermal power input and output of the material are balanced through thermal balance.

[0055] Step S3, determining the target current in this case according to the critical magnetic field and the Curie temperature of the material.

[0056] Step S4, selecting a current growth model according to the target current and the slope of the initial magnetization segment in the magnetization curve, so that the current can achieve an early growth, and then use a constant current for magnetization after reaching the target current.

[0057] The specific implementation is as follows:

[0058] In step S1, the temperature at each time is recorded, and the magnetization intensity of the material and the external magnetic field intensity are measured using a magnetometer, including:

[0059] Temperature recording: The temperature of the current material and the current environment is recorded in real time through the temperature sensor. The temperature of the material is an important factor in the performance of the magnetic material. Especially when the material approaches or exceeds its Curie temperature, the magnetism of the material will change significantly. Therefore, real-time temperature monitoring is very important.

[0060] Measurement of magnetization intensity and external magnetic field intensity: The superconducting quantum interference device (SQU ID) is used to measure the magnetization intensity of the material and the external applied magnetic field intensity. It can detect extremely weak magnetic field changes and is a non-contact magnetic field measurement tool. Therefore, it can be used to measure the magnetism of the sample without direct contact with the sample, avoiding magnetic field interference caused by contact.

[0061] SQU ID can be used in conjunction with a temperature sensor to record temperature changes T in real time, and perform synchronous measurements and connect to a data acquisition system to record magnetic field data and temperature data in real time.

[0062] Real-time monitoring of current: Use a digital ammeter to monitor the current in real time, connect it directly to the computer using a USB interface, and read the data through the software for subsequent use and analysis. The digital ammeter is used to monitor the current passing through the material. The current is closely related to the magnetization process of the material. During the magnetization process, the current directly affects the external magnetic field and the magnetization degree of the material.

[0063] In step S2, the critical magnetic field of the material is calculated by the magnetization intensity of the material and the external magnetic field intensity, and it is determined whether the magnetization intensity of the material is close to saturation. The thermal balance is used to analyze whether the thermal power input and output of the material are balanced. The specific contents include:

[0064] The critical magnetic field refers to the point at which the magnetization curve begins to change significantly at a certain temperature. It is an important indicator of the saturation magnetization intensity of the material. It is the external magnetic field intensity at which the magnetization intensity of the material reaches saturation. For ferromagnetic materials or certain types of strong magnetic materials, it is usually related to the magnetic saturation intensity of the material and the magnetic permeability of the material. In some materials, especially ferromagnetic materials, the critical magnetic field is related to temperature and will decrease with increasing temperature.

[0065] Saturation magnetization intensity: refers to the magnetization intensity of the material reaching its maximum value when the external magnetic field increases to a certain value. At this time, the magnetization intensity of the magnetic material no longer increases with the increase of the external magnetic field. That is, under the action of a strong external magnetic field, all magnetic moments will be aligned to the maximum extent, so that the magnetization intensity of the material reaches a maximum value.

[0066] The relationship between the magnetization intensity of a material and the external magnetic field intensity can be expressed as: M = xH; where: M is the magnetization intensity of the material, x is the magnetic susceptibility, and H is the external magnetic field intensity.

[0067] When the saturation state is reached, the magnetization intensity M sat reaches the maximum value, at which time the external magnetic field H c The corresponding magnetization intensity can be given by the following formula: Where: M sat is the saturation magnetization of the material, and x is the magnetic susceptibility of the material.

[0068] Calculation example: Assume there is a ferromagnetic material with a saturation magnetization intensity M sat =1.0×10 6 A / m, magnetic susceptibility x = 1000, then the critical magnetic field can be calculated as:

[0069] Determine whether the critical magnetic field is reached by the magnetization curve method:

[0070] The magnetization curve (i.e., hysteresis loop) usually shows the relationship between the material's magnetization intensity M and the external magnetic field H. When the external magnetic field increases, the magnetization intensity also increases. As the external magnetic field increases further, the magnetization intensity tends to saturation and reaches an upper limit. The magnetization curve usually shows that at a larger magnetic field value, the magnetization intensity no longer increases significantly, which is the critical magnetic field or saturation magnetic field.

[0071] Gradually increase the external magnetic field and measure the magnetization intensity of the material. When the magnetization intensity reaches saturation, further increase of the external magnetic field will not cause a significant change in the magnetization intensity. The external magnetic field at this time is the critical magnetic field. Once the magnetization intensity of the material reaches saturation, further increase of the external magnetic field will not cause a significant increase in the magnetization intensity. At this time, it can be considered that the critical magnetic field has been reached. In this case, the measured current is the target current I1 determined based on the critical magnetic field.

[0072] In order to control the temperature and always keep it at the Curie temperature T of the material C , design a temperature control model so that the temperature can be maintained near this temperature as it changes over time.

[0073] Thermal balance analysis: In steady state, the thermal power input and output of the material should be balanced, that is: P out =P in ; Among them: P in is the input thermal power, P out is the output thermal power, and the input thermal power is calculated by the resistance of the material itself and the current: P in =I 2 R.

[0074] Assuming that heat is dissipated by natural convection or other heat dissipation mechanisms, the following heat conduction model can be used to estimate the output thermal power: P out =hA(TT env ), where: h is the convection heat transfer coefficient, A is the surface area of ​​the material, T env is the ambient temperature and T is the current temperature of the material.

[0075] Temperature change rate: It indicates the rate of change of temperature over time. It is defined as the derivative of temperature over time, that is: However, in practical applications, the derivative cannot be calculated directly. Instead, the rate of change of temperature over time is estimated by differential calculation. The temperature change over time is usually calculated by real-time temperature data. Assuming that between two consecutive time points t1 and t2, the temperatures are T(t1) and T(t2) respectively, the approximate value of the temperature change rate can be estimated by the following differential calculation formula: Here, T(t1) and T(t2) are the temperatures at time points t1 and t2, respectively, and Δt=t2-t1 is the time interval between the two time points.

[0076] For example: t1 = 0, t2 = 1, T(t1) = 20, T(t2) = 22

[0077] From t1=0 to t2=1, the temperature change rate is:

[0078] Curie temperature refers to the temperature at which certain substances (especially ferromagnetic materials and antiferromagnetic materials) undergo a transition from ferromagnetism or antiferromagnetism to paramagnetism. When a substance is heated to the Curie temperature, its magnetism will undergo a fundamental change. The Curie temperature is determined by the lattice structure and atomic interactions of the substance, and it is closely related to the magnetic properties of the material. After exceeding the Curie temperature, the material no longer has the ability to spontaneously magnetize and becomes a paramagnetic material, that is, it will produce weak magnetization under an external magnetic field.

[0079] For example: The Curie temperature of iron (Fe) is about 770℃ (1040K), that is, when iron is heated to this temperature, it loses its ferromagnetism and becomes paramagnetic. The Curie temperature of nickel (Ni) is about 358℃ (631K). The Curie temperature of cobalt (Co) is about 1121℃ (1394K).

[0080] Relationship between thermal power and temperature change rate: According to the law of conservation of heat, the temperature change of an object is closely related to the energy change inside it. The temperature change rate can be expressed by the mass, specific heat capacity and temperature change of the object: Where: m is the mass of the object, c is the specific heat capacity of the object, is the rate of temperature change.

[0081] When P in -P out >0, P in >P out , the temperature of the object will increase,

[0082] When P in -P out When P < 0 in <P out , the temperature of the object will decrease,

[0083] When P in -P out =0, P in =P out , the system reaches thermal equilibrium,

[0084] In step S3, the target current in this case is determined according to the critical magnetic field of the material and the Curie temperature of the material, and the specific contents include:

[0085] In order to keep the temperature at the Curie temperature of the material, the current intensity during magnetization must be accurately controlled. Temperature control can be achieved by adjusting the current in real time. Using real-time feedback control, ensure that the temperature is stable near the set value. in -P out = 0, that is, P in =Pout , reaching the Curie temperature of the material, the current in this case is the target current I2 determined according to the temperature.

[0086] The target current I1 determined according to the critical magnetic field is compared with the target current I2 determined according to the temperature, and the smaller value is taken as the target current for subsequent operations.

[0087] In step S4, a current growth model is selected according to the target current and the slope of the initial magnetization segment in the magnetization curve, so that the current can achieve an early growth, and then a constant current is used for magnetization after reaching the target current. The specific contents include:

[0088] Linear growth is suitable for situations where the current needs to be increased simply and gradually. It is easy to implement and stable, changes evenly, and is relatively easy to control. When the target current to be achieved is small, a linear model can be used to reach the target current faster. Exponential growth is suitable for current increase processes that need to start relatively slowly and then accelerate, which can improve the efficiency of the magnetization process. When the target current to be achieved is large, the magnetization intensity may not increase linearly, but gradually accelerates. The magnetization intensity usually accelerates over time until the battery reaches a certain saturation state.

[0089] Observation of magnetization curve: In the initial stage of magnetization process, the reaction speed of magnetic material is closely related to the shape of its magnetization curve. To judge whether it is slow, we can observe from the slope of the initial magnetization segment: In the magnetization process, if the slope of the initial segment of the magnetization curve (i.e. the part when the material just begins to magnetize) is slow, it means that the magnetic material reacts slowly in the initial stage. On the contrary, if the slope is steep, it means that the material is more likely to respond to the external magnetic field.

[0090] Obtaining magnetization curve data: The magnetization curve consists of the relationship between the magnetic field intensity H and the magnetic induction intensity B, that is, B = f(H), where H is the external magnetic field intensity and B is the magnetic induction intensity of the material. If the initial current is set to I0, the formula can be expressed as: Calculation in unit time: that is, calculation of magnetic induction intensity B(t) and magnetic field intensity H(t) in unit time t: (ΔB=B(t)-0=B(t), similarly ΔH=H(t)-0=H(t)).

[0091] Set the threshold of the initial magnetization segment slope to S threshold , the slope is less than the set threshold S threshold, the material reacts slowly in the initial stage of magnetization. At this time, the exponential growth model will be smoother and gradually accelerate the current increase until the target current is reached. If the slope is greater than the set threshold, it means that the material reacts relatively quickly. The linear current growth model is used to control the current for magnetization, which means that the material responds quickly to the external magnetic field and is suitable for using the linear growth model to evenly increase the current.

[0092] After receiving the target current of the quantitative magnetization device and the slope of the initial magnetization section, the target current of the quantitative magnetization device and the slope of the initial magnetization section are defined as input variables, and they are divided into different fuzzy sets respectively.

[0093] For example, "Low", "Medium", "High" for target current, "Low", "Medium", "High" for initial magnetization segment slope.

[0094] Define the growth model as the output variable, partitioning it into fuzzy sets, for example, "Linear", "Exponential" for the growth model.

[0095] Formulate a set of fuzzy rules to describe the impact of different input variables on output variables. The definition of rules can be based on professional knowledge or obtained through data analysis and experiments. For example:

[0096] The charging time is marked as T, the slope of the initial magnetization segment is marked as S, and the growth model is marked as G. growth Then we can define

[0097] Rule 1:IF(T is Low)AND(S is High)THEN(G growth is Linear

[0098] Rule 2:IF(Tis High)AND(S is Low)THEN(G growth is Exponential ...

[0100] Fuzzy reasoning is performed based on fuzzy rules to determine the growth model solution.

[0101] It should be noted that the division of fuzzy sets can be adjusted according to actual conditions. For example, although the present embodiment takes three fuzzy sets as examples, in fact, the charging time and the initial magnetization segment slope can be divided into more than three sets according to the growth model to facilitate better precise adjustment.

[0102] Furthermore, for the judgment of the overall time coefficient and the initial magnetization segment slope, the threshold can be set according to the actual situation. For example, when the target current exceeds 100 amperes, it is marked as "High", and when the initial magnetization segment slope exceeds It is marked as "H i gh" and so on, which will not be elaborated here.

[0103] Combined with the above, when the charging time is short and the slope of the magnetization curve is steeper during the re-magnetization process, the initial magnetization reaction is faster and the current grows evenly. It is more suitable to use a linear current growth model to control the current for magnetization:

[0104] Assume that the initial current is I0 and the target current is I f , the total time of the magnetization process is T, we can express the change of current over time by the following formula: Where: I t is the current at time t (unit: ampere), I0 is the initial current at the beginning of magnetization (unit: ampere), I f is the target current at the end of magnetization (unit: ampere), t is the current time (unit: second), and T is the total time of the magnetization process (unit: second). This formula indicates that the current increases linearly with time and finally reaches the target current I at t = T. f .

[0105] When the charging time is long and the slope of the magnetization curve is small during the re-magnetization process, the initial magnetization reaction is slow and the current gradually accelerates. It is more suitable to use the exponential current growth model to control the current for magnetization:

[0106] This model is suitable for the initial current growth is slow, and then gradually accelerate to approach the target current. The formula for exponential growth can be written as: I(t) = I0 + (I f -I0)·(1-e -λt ), where: I(t) is the current at time t (in amperes), I0 is the initial current (in amperes), I f is the target current (in amperes), λ is the adjustment rate, which controls the speed at which the current increases, and t is the current time (in seconds). In this formula, λ controls the rate at which the current increases. A larger λ value causes the current to increase rapidly, while a smaller λ value causes the current to increase gradually, reaching the target current more smoothly.

[0107] Example 2

[0108] Figure 2 The invention provides a quantitative magnetization regulating and controlling system, which comprises an information acquisition module, a data processing module, a statistical analysis module and a model building module.

[0109] Information acquisition module: records the temperature of the material and the environment at various times, uses a magnetometer to measure the magnetization intensity of the material and the external magnetic field intensity respectively, and uses a digital ammeter to monitor the current in real time.

[0110] Data processing module: Calculate the critical magnetic field of the material through the magnetization intensity of the material and the external magnetic field intensity, and judge whether the current magnetization intensity of the material is close to saturation, and analyze whether the thermal power input and output of the material are balanced through thermal balance.

[0111] Statistical analysis module: Determine the target current in this case based on the critical magnetic field and Curie temperature of the material.

[0112] A quantitative magnetizing device comprises a power supply and an electromagnetic coil. The power supply is used to provide a stable current source and control the current size and waveform; the electromagnetic coil is used to generate a magnetic field.

[0113] Model building module: Select the current growth model according to the target current and the slope of the initial magnetization segment in the magnetization curve, so that the current can achieve early growth, and then use constant current for magnetization after reaching the target current.

[0114] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0115] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product.

[0116] 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.

[0117] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0118] Those of ordinary skill in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application of the technical solution and the invention constraints. Professional and technical personnel can 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 this application.

[0119] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0120] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0121] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A quantitative magnetization regulation and control method, characterized in that: Includes steps: Step S1, recording the temperature of the material and the environment at each time, using a magnetometer to measure the magnetization intensity of the material and the external magnetic field intensity respectively, and using a digital ammeter to monitor the current in real time; Step S2, calculating the critical magnetic field of the material by the magnetization intensity of the material and the external magnetic field intensity, and judging whether the magnetization intensity of the material is close to saturation, and analyzing whether the thermal power input and output of the material are balanced by thermal balance; Step S3, determining the target current in this case according to the critical magnetic field of the material and the Curie temperature of the material; Step S4, selecting a current growth model according to the target current and the slope of the initial magnetization segment in the magnetization curve, so that the current can achieve an early growth, and then use a constant current for magnetization after reaching the target current.

2. A quantitative magnetization regulating and controlling method according to claim 1, characterized in that: Use temperature sensors to record the temperature of the current material and the current environment in real time, use superconducting quantum interference devices to measure the magnetization intensity of the material and the strength of the externally applied magnetic field, and connect the synchronous measurement with the data acquisition system to record the magnetic field data and temperature data in real time; Use a digital ammeter to monitor the current in real time, connect it directly to the computer using a USB interface, and read the data through the software.

3. A quantitative magnetization regulating and controlling method according to claim 2, characterized in that: The relationship between the magnetization intensity of the material and the external magnetic field intensity is expressed as: M = xH; when it reaches the saturation state, the magnetization intensity M sat reaches the maximum value, at which time the external magnetic field H c The corresponding magnetization is given by: The magnetization curve is obtained by the magnetization intensity and the external magnetic field intensity to determine whether the critical magnetic field is reached: gradually increase the external magnetic field and measure the magnetization intensity of the material. When the magnetization intensity reaches the saturation state, the increase of the external magnetic field will not cause a significant change in the magnetization intensity. The external magnetic field at this time is the critical magnetic field. At this time, the critical magnetic field is reached. In this case, the measured current is the target current I1 determined based on the critical magnetic field. Design a temperature control model design; Thermal balance analysis: In steady state, the thermal power input and output of the material should be balanced, that is: P out =P in ; The thermal power input is calculated from the material's resistance and the current: P in =I 2 R; The thermal power output is calculated using the following heat transfer model: P out =hA(TT env ), where: h is the convection heat transfer coefficient, A is the surface area of ​​the material, T env is the ambient temperature, T is the current temperature of the material; Temperature change rate: The temperature change rate over time is estimated by differential calculation. The temperature change over time is calculated by real-time temperature data. Between two consecutive time points t1 and t2, the temperatures are T(t1) and T(t2) respectively. The approximate value of the temperature change rate is estimated by the following differential calculation formula: Relationship between thermal power and temperature change rate: The temperature change rate is expressed by the mass, specific heat capacity and temperature change of the object: Where: m is the mass of the object, c is the specific heat capacity of the object, is the temperature change rate; When P in -P out >0, P in >P out , the temperature of the object will increase, When P in -P out When P < 0 in <P out , the temperature of the object will decrease, When P in -P out =0, P in =P out , the system reaches thermal equilibrium, 4. A quantitative magnetization control method according to claim 3, characterized in that ； When the difference between thermal power input and output is zero, P in -P out = 0, that is, P in =P out , reaching the Curie temperature of the material, in which case the current is the target current I2 determined according to the temperature; The target current I1 determined according to the critical magnetic field is compared with the target current I2 determined according to the temperature, and the smaller value is taken as the target current for subsequent operations.

5. A quantitative magnetization regulating and controlling method according to claim 4, characterized in that: Obtaining magnetization curve data: The magnetization curve consists of the relationship between the magnetic field intensity H and the magnetic induction intensity B, that is, B = f(H); The initial current is I0, calculated in unit time: that is, the magnetic induction intensity B(t) and the magnetic field intensity H(t) are calculated in unit time t. The formula for the initial magnetization segment slope can be expressed as: After receiving the target current of the quantitative magnetization device and the slope of the initial magnetization section, the target current of the quantitative magnetization device and the slope of the initial magnetization section are defined as input variables, and they are divided into different fuzzy sets respectively; The growth model is defined as the output variable and divided into fuzzy sets; Fuzzy rules are formulated to describe the impact of the target current of the quantitative magnetization device and the definition of the slope of the initial magnetization segment on the growth model; Carry out fuzzy reasoning according to fuzzy rules to determine the growth model selection of quantitative magnetization device; Combined with the above, when the charging time is short and the slope of the magnetization curve is steep during the magnetization process, a linear current growth model is used to control the current for magnetization: the initial current is I0, the target current is I f , the total time of the magnetization process is T, and the change of current over time is expressed by the following formula: Finally, the target current I is reached at t = T f ; When the charging time is long and the slope of the magnetization curve is small during the re-magnetization process, the exponential current growth model is used to control the current for magnetization. The exponential growth formula can be written as: I(t) = I0 + (I f -I0)·(1-e -λt ), where: I(t) is the current at time t, I0 is the initial current, I f is the target current, λ is the adjustment rate, and t is the current time.

6. A quantitative magnetization regulating and controlling system, used to implement a quantitative magnetization regulating and controlling method according to any one of claims 1 to 5, characterized in that: include: Information acquisition module, data processing module, statistical analysis module and model building module; Information acquisition module: records the temperature of the material and the environment at all times, uses a magnetometer to measure the magnetization intensity of the material and the external magnetic field intensity respectively, and uses a digital ammeter to monitor the current in real time; Data processing module: calculates the critical magnetic field of the material through the magnetization intensity of the material and the external magnetic field intensity, and determines whether the current magnetization intensity of the material is close to saturation, and analyzes whether the thermal power input and output of the material are balanced through thermal balance; Statistical analysis module: determines the target current in this case based on the critical magnetic field and Curie temperature of the material; Model building module: Select the current growth model according to the target current and the slope of the initial magnetization segment in the magnetization curve, so that the current can achieve early growth, and then use constant current for magnetization after reaching the target current.

7. A quantitative magnetization device, used to implement a quantitative magnetization regulation and control method as claimed in any one of claims 1 to 5, characterized in that: The device comprises a power source and an electromagnetic coil. The power source is used to provide a stable current source and control the current size and waveform; the electromagnetic coil is used to generate a magnetic field.

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