Measuring device and determining method for hysteresis characteristic of electrical steel sheet

Abstract

The invention relates to an electrical steel sheet hysteresis characteristic measurement device and a determination method, relates to the field of magnetic material hysteresis characteristics, and can improve the reliability of an electrical steel sheet hysteresis characteristic measurement result. The device comprises an excitation module, a signal measuring module, a temperature control module and a stress applying module. The excitation module comprises an excitation coil and an excitation winding framework; the excitation coil surrounds the periphery of the excitation winding framework and is used for providing an excitation magnetic field for the electrical steel sheet; the temperature control module comprises a heating sheet used for providing heat for the electrical steel sheet; the stress applying module comprises a stress push rod used for providing stress for the electrical steel sheet; the signal measurement module comprises a magnetic field intensity coil and a magnetic flux density coil; the magnetic flux density coil surrounds the periphery of the excitation winding framework; the coil specification of the magnetic field intensity coil is matched with the specification of the electrical steel sheet; and the signal measurement module is used for measuring the magnetic flux density and the magnetic field intensity of the electrical steel sheet under different heat and stress conditions.

Description

Technical Field

[0001] The present application relates to the technical field of hysteresis characteristics of magnetic materials, and in particular to a device for measuring and determining the hysteresis characteristics of electrical steel sheets. Background Art

[0002] During actual service, electrical steel sheets are often subject to the combined influence of multiple physical fields, such as temperature fluctuations and stress. These factors can lead to significant differences between the actual magnetic properties of electrical steel sheets and those obtained using standard testing methods. Therefore, when measuring the magnetic properties of electrical steel sheet magnetic materials, the influence of external parameters such as temperature and stress must be considered.

[0003] Currently, in commonly used magnetic property measurement methods, the magnetic path length is often difficult to accurately determine and the sample preparation process is cumbersome. In addition, current research on the magnetic property measurements of electrical steel sheets under the coupling of multiple physical fields focuses on the influence of a single physical field, such as loading temperature through a constant temperature heating box, or loading stress through pneumatic and hydraulic devices. As a result, when measuring the magnetic properties of electrical steel sheets, the measurement results are inaccurate and unreliable. Summary of the Invention

[0004] Based on this, it is necessary to provide a device and method for measuring the hysteresis characteristics of electrical steel sheets to address the above technical problems.

[0005] In a first aspect, the present application provides a device for measuring the hysteresis characteristics of an electrical steel sheet, comprising an excitation module, a signal measurement module, a temperature control module, and a stress application module;

[0006] The excitation module includes an excitation coil and an excitation winding frame; the excitation coil is surrounded by the periphery of the excitation winding frame and is used to provide an excitation magnetic field for the electrical steel sheet when the electrical steel sheet is located in the measurement space formed by the excitation winding frame;

[0007] The temperature control module includes a heating plate; the heating plate is located in the measurement space and is used to provide heat to the electrical steel sheet while the excitation magnetic field acts on the electrical steel sheet;

[0008] The stress applying module includes a stress push rod; the stress push rod is configured to use a reserved application channel of the measurement space formed by the excitation winding skeleton to apply stress to the electrical steel sheet located in the measurement space, so as to perform a hysteresis characteristic measurement of the electrical steel sheet in the measurement space with the physical characteristics of the excitation magnetic field, heat loading, and stress application coupled when the excitation magnetic field and heat loading are simultaneously applied to the electrical steel sheet;

[0009] The signal measurement module includes a magnetic field strength coil and a magnetic flux density coil; the magnetic flux density coil surrounds the periphery of the excitation winding skeleton; the magnetic field strength coil is located in the measurement space and is configured to obtain the magnetic field strength in a non-exposed manner, and the coil specifications of the magnetic field strength coil match the specifications of the electrical steel sheet; the signal measurement module is linked with the excitation module, the temperature control module and the stress application module, and is used to measure the magnetic flux density and the magnetic field strength of the electrical steel sheet under different conditions of the heat and the stress when the electrical steel sheet is in the excitation magnetic field.

[0010] In one embodiment, the magnetic field strength coil is placed in the measurement space through a coil sealing box; the coil sealing box includes a magnetic field strength coil positioning plate;

[0011] The magnetic field strength coil includes a first magnetic field strength coil and a second magnetic field strength coil;

[0012] The magnetic field strength coil positioning plate includes a plurality of positioning side surfaces; the first magnetic field strength coil and the second magnetic field strength coil are fixed on different positioning side surfaces.

[0013] In one embodiment, the heating plate is placed in the measurement space via a heating plate fixing box;

[0014] A plurality of heating plates are evenly arranged above the heating plate fixing box, receiving electric energy transmitted by the wiring in the heating plate fixing box and converting the electric energy into heat energy to complete the heat loading of the electrical steel sheet.

[0015] In one embodiment, a temperature measuring wire groove is provided in the heating plate fixing box for carrying a temperature measuring wire to control the temperature of the heating plate.

[0016] In one embodiment, the device includes an electrical steel sheet clamping module; the electrical steel sheet clamping module includes a clamping unit, and the clamping unit includes a push-pull clamp, a first clamping body, a second clamping body, a third clamping body, and a fourth clamping body;

[0017] The push-pull clamp is used to fix the electrical steel sheet in a space formed by the first clamp body, the second clamp body, the third clamp body and the fourth clamp body, and the space is aligned with the position of the electrical steel sheet on the excitation winding skeleton.

[0018] In one embodiment, the electrical steel sheet clamping module includes a sliding unit, which includes a slider, a slider guide and a sliding platform; the sliding unit is connected to the clamping unit through the sliding platform, so that the slider drives the clamping unit to slide on the slider guide.

[0019] In one embodiment, the stress applying module is connected to the sliding unit of the electrical steel sheet clamping module to apply stress to the electrical steel sheet;

[0020] The stress applying module further includes a stress sensor and a push rod fixing box composed of a stress fixing plate; the stress push rod is connected to the stress sensor and fixed in the push rod fixing box to obtain stress data of the electrical steel sheet.

[0021] In one embodiment, the push rod fixing box is composed of a plurality of push rod fixing plates, and the push rod fixing plates include heat dissipation holes.

[0022] In one embodiment, the device includes a magnetic conductive module; the magnetic conductive module includes a plurality of symmetrical iron yokes to form a magnetic field introduction path for the electrical steel sheet when the excitation coil generates a magnetic field excitation.

[0023] In a second aspect, the present application further provides a method for determining the hysteresis characteristics of an electrical steel sheet, comprising:

[0024] Obtaining the temperature, external stress, and magnetic field strength of the environment in which the electrical steel sheet is located; the temperature, external stress, and magnetic field strength are detected by the electrical steel sheet hysteresis characteristic measuring device as described in any one of the above;

[0025] determining a relationship between a magnetic field intensity and a magnetization intensity of a single hysteresis operator in the electrical steel sheet when the magnetic structure of the electrical steel sheet is stable under the temperature and applied stress; wherein the magnetic structure stability is characterized by minimization of a free energy of a hysteresis operator in the electrical steel sheet;

[0026] Determining a hysteresis angle of the magnetization intensity relative to the magnetic field intensity in each hysteresis operator based on the relationship between the magnetic field intensity and the magnetization intensity; the hysteresis angle has different performance values ​​in different environments and external stresses;

[0027] According to the hysteresis angle, the polarization influence of the hysteresis operator on the magnetic field of the magnetic field strength is accumulated to obtain the relationship between the magnetic flux density in the electrical steel sheet and the magnetic field strength, and the hysteresis characteristics of the electrical steel sheet are determined according to the relationship between the magnetic flux density and the magnetic field strength.

[0028] The above-mentioned device and method for measuring the hysteresis characteristics of electrical steel sheets ensure the stability and adjustability of the excitation magnetic field of the electrical steel sheets during the measurement process through the excitation coil and excitation winding skeleton in the excitation module. The heating plate in the temperature control module is precisely set in the measurement space to provide the required heat for the electrical steel sheets, providing a uniform and stable temperature loading environment. The stress application module uses a stress push rod to accurately control the uniformity of the stress loading stress applied to the electrical steel sheets. The magnetic flux density coil surrounds the periphery of the excitation winding skeleton, while the magnetic field strength coil is accurately placed in the measurement space, accurately matching the specifications of the electrical steel sheets, ensuring the accurate acquisition of magnetic field strength and magnetic flux density data. With the coordinated action of each module, multiple factors such as temperature, stress, and magnetic field are ensured to be controllable and stable during the experiment, and the measurement accuracy of the hysteresis characteristics of electrical steel sheets is improved under the premise of high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 1 is a structural block diagram of a device for measuring hysteresis characteristics of an electrical steel sheet according to an embodiment;

[0031] Figure 2 Schematic diagram of the planar structure of the magnetic field strength coil in one embodiment;

[0032] Figure 3 A schematic diagram of the placement of magnetic field strength coils in one embodiment;

[0033] Figure 4 Schematic diagram of the structure inside the excitation winding skeleton in one embodiment;

[0034] Figure 5 is a schematic diagram of a temperature control module in one embodiment;

[0035] Figure 6 This is a schematic structural diagram of a fixed clamp module in one embodiment;

[0036] Figure 7 2. It is a structural diagram of a movable jaw module in one embodiment;

[0037] Figure 8 is a schematic structural diagram of a stress applying module in one embodiment;

[0038] Figure 9Schematic diagram of the structure of a magnetic conductive module in one embodiment;

[0039] Figure 10 A schematic diagram of sealing and fixing the excitation coil in one embodiment;

[0040] Figure 11 Schematic diagram of the structure of a device for measuring hysteresis characteristics of electrical steel sheets in another embodiment;

[0041] Figure 12 1 is a flow chart of a method for determining hysteresis characteristics of an electrical steel sheet according to one embodiment;

[0042] Figure 13 Schematic diagram of a flow chart of a method for determining hysteresis characteristics of an electrical steel sheet in another embodiment;

[0043] Figure 14 A schematic diagram of a magnetization structure arrangement in one embodiment;

[0044] Figure 15 Schematic diagram of a flow chart of a method for determining hysteresis characteristics of an electrical steel sheet under different excitation magnetic fields in one embodiment;

[0045] Figure 16 A schematic diagram showing a comparison between an alternating magnetization simulation result and a measurement result in one embodiment;

[0046] Figure 17 A schematic diagram showing a comparison between an alternating magnetization simulation result and a measurement result in another embodiment;

[0047] Figure 18 Schematic diagram comparing the circular rotation magnetization simulation results and the measurement results in one embodiment.

[0048] Explanation of the reference numerals: 1-stand, 2-fixed clamp module, 20-push-pull clamp, 21-first clamp body, 22-second clamp body, 23-third clamp body, 24-fourth clamp body, 25-fixed clamp base plate, 26-fixed clamp base plate column, 3-movable clamp module, 30-push-pull clamp, 31-first clamp body, 32-second clamp body, 33-third clamp body, 34-fourth clamp body, 35-movable clamp base plate, 36-movable clamp base plate column, 37-slider, 38-slider guide rail, 39-sliding platform, 4-excitation and measurement module Block, 40-excitation winding skeleton, 41-coil sealing box, 42-magnetic field strength coil positioning plate, 43A-first magnetic field strength coil, 43B-second magnetic field strength coil, 5-magnetic conductivity module, 50-C-type iron yoke, 51-upper C-type iron yoke mounting plate, 52-C-type iron yoke fixing block, 53-lifting push rod, 6-stress application module, 60-electric push rod, 61-stress sensor, 62-push rod fixing plate, 7-temperature control module, 70-heating plate fixing box, 71-heating plate, 72-temperature measurement wire trough, 8-electrical steel sheet. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0050] In order to enable those skilled in the art to better understand the present application, the relevant technologies are first introduced below.

[0051] Electrical steel sheets are the foundational material for key magnetic components in electrical equipment like transformers. Their magnetic properties directly impact the energy efficiency and operational reliability of these devices. Understanding the magnetization and loss characteristics of the core of electrical steel sheets is a crucial prerequisite for designing high-quality, high-efficiency transformers. Therefore, accurately measuring and modeling the magnetic properties of electrical steel sheets is crucial for improving the design and performance analysis of transformers and other electrical equipment.

[0052] The actual operation of electrical equipment such as transformers is subject to complex magnetic field environments, resulting in diverse and unpredictable magnetic field types and operating conditions. Transformers may be affected not only by the coupling of multiple physical fields, such as temperature and stress, but also by magnetic fields from different directions, including alternating and rotating magnetic fields. Therefore, when studying the magnetic properties of electrical steel sheets, in addition to considering the coupling of multiple physical fields, such as temperature and stress, it is also necessary to fully consider the impact of different excitation conditions on their magnetic properties, thereby effectively improving the energy efficiency and quality of electrical equipment.

[0053] At present, the main methods for measuring magnetic properties include the Epstein square circle method and the single-piece measurement method. According to IEC and relevant domestic standards, the Epstein square circle method is widely used to measure the alternating magnetic properties of soft magnetic materials. However, the Epstein square circle method has certain limitations, such as the difficulty in accurately determining the magnetic path length and the cumbersome sample preparation process. To this end, Japanese scholars Yamamoto et al. proposed a single-piece measurement method, which is relatively simple in sample preparation and is only suitable for measuring the magnetic properties of thin-gauge oriented electrical steel sheets in transformer products. There is an urgent need for a measurement device suitable for the hysteresis characteristics of electrical steel sheets under complex excitation conditions.

[0054] In an exemplary embodiment, Figure 1 As shown, the present application provides a device for measuring the hysteresis characteristics of an electrical steel sheet, which includes an excitation module, a signal measurement module, a temperature control module, and a stress application module.

[0055] Among them, the excitation module includes an excitation coil and an excitation winding frame; the excitation coil is surrounded by the periphery of the excitation winding frame, and is used to provide an excitation magnetic field for the electrical steel sheet when the electrical steel sheet is located in the measurement space formed by the excitation winding frame.

[0056] The excitation module, consisting of an excitation coil and an excitation winding bobbin, provides an excitation magnetic field during measurements of electrical steel sheets. The excitation coil is a wire structure wound around a bobbin. When AC or DC current is applied, it generates a magnetic field around it. The excitation winding bobbin supports the coil and ensures a stable magnetic field distribution within the measurement volume. This module creates a controlled magnetization environment, ensuring consistent magnetic excitation input during measurement of the electrical steel sheets and preventing interference from ambient magnetic fields.

[0057] The temperature control module includes a heating plate; the heating plate is located in the measuring space and is used to provide heat to the electrical steel sheet while the excitation magnetic field acts on the electrical steel sheet.

[0058] The temperature control module primarily consists of a heater. These heaters can be resistor wire heaters or ceramic heaters, and their size and shape are designed to fit within the measurement space formed by the excitation winding skeleton and effectively transfer heat to the electrical steel sheet. The heater can be placed in close contact with the surface of the electrical steel sheet or in contact with it through a medium with good thermal conductivity. The temperature control module can also include a temperature sensor (such as a thermocouple or thermistor) and a temperature controller to monitor the temperature within the measurement space in real time and precisely control the heater's output power based on the set target temperature, thereby applying heat to the electrical steel sheet. The heater can be made of a material with stable resistivity and stable performance in a magnetic field to avoid interference with magnetic field measurements.

[0059] The stress application module includes a stress push rod; the stress push rod is configured to use a reserved application channel of the measurement space formed by the excitation winding skeleton to provide stress to the electrical steel sheet located in the measurement space, so as to perform hysteresis characteristic measurement of the electrical steel sheet in the measurement space with physical characteristics coupled with the excitation magnetic field, heat loading and stress application when the excitation magnetic field and heat loading are simultaneously applied to the electrical steel sheet.

[0060] The stress application module includes a stress push rod, which applies controllable mechanical stress to the electrical steel sheet. The stress push rod can be electrically controlled to apply tensile or compressive stress, simulating the mechanical forces experienced by the electrical steel sheet during service in transformers or motors. This is used to study the effects of stress on hysteresis properties and optimize the material design and processing of the electrical steel sheet. A predetermined application channel is provided within the measurement space. The location and dimensions of this channel allow the stress push rod to pass smoothly through and act on the electrical steel sheet within the measurement space. The contact surface between the stress push rod and the electrical steel sheet can be designed with a specific shape (such as a flat surface or with a clamping structure) to ensure uniform stress transfer. The signal measurement module includes a magnetic field strength coil and a magnetic flux density coil. The magnetic flux density coil surrounds the periphery of the excitation winding bobbin. The magnetic field strength coil is located within the measurement space and is configured to acquire magnetic field strength in a non-exposed manner. The coil specifications of the magnetic field strength coil match those of the electrical steel sheet.

[0061] The signal measurement module includes a magnetic field strength coil and a magnetic flux density coil, which measure magnetic field strength and magnetic flux density, respectively. The magnetic flux density coil, which surrounds the excitation winding bobbin, acquires magnetic flux density information within the electrical steel sheet through electromagnetic induction. The magnetic field strength coil can be placed directly within the measurement space and is compatible with the electrical steel sheet specifications.

[0062] For example, matching the specifications of the electrical steel sheet can be understood as the size of the magnetic field strength coil being the same as or similar to the size of the electrical steel sheet (e.g., the degree of similarity is greater than a threshold). In an optional embodiment, the specifications of the magnetic field strength coil can be adjusted based on the specifications of the electrical steel sheet. If the specifications of the electrical steel sheet to be measured increase, the magnetic field strength coil can be increased to match the specifications of the electrical steel sheet to measure uniform magnetic field strength values ​​across a larger sample area, rather than localized magnetic characteristics of the sample. A multi-coil structure is used to simultaneously acquire magnetic field and magnetic flux, thereby achieving high-precision measurement of hysteresis characteristics. In an optional embodiment, for electrical steel sheets of different specifications, the appropriate magnetic field strength coil is matched based on the size of the current electrical steel sheet to ensure accurate signal acquisition. The magnetic field strength coil can acquire magnetic field strength in a non-exposed manner. Specifically, the magnetic field strength coil can be encapsulated in a coil enclosure. The coil enclosure is typically made of non-magnetic, insulating material to protect the coil from environmental factors and secure it in a specific position within the measurement space, such as near the surface of the electrical steel sheet. In this way, the magnetic field strength coil can sense the magnetic field strength around the electrical steel sheet without directly contacting the electrical steel sheet, thus avoiding interference that may be caused by physical contact.

[0063] The signal measurement module is linked with the excitation module, temperature control module and stress application module to measure the magnetic flux density and magnetic field strength of the electrical steel sheet under different heat and stress conditions when the electrical steel sheet is in an excitation magnetic field.

[0064] In one exemplary embodiment, during measurement, an AC current flows through the excitation coil of the excitation module, generating a periodically varying alternating magnetic field. The excitation coil surrounds the excitation winding bobbin, ensuring uniform magnetic field distribution within the measurement volume and maintaining a stable excitation magnetic field around the electrical steel sheet. In one embodiment, the excitation current magnitude and frequency are adjustable to accommodate varying hysteresis measurement requirements.

[0065] Next, the temperature control module activates the heating plate, heating the electrical steel sheet to the set temperature. The heating plate can be a ceramic heating element, attached to the measurement space to ensure uniform heating of the sample, and closed-loop control is performed using a temperature sensor. This process is used to study the hysteresis characteristics of electrical steel sheets at different temperatures. In an optional embodiment, multiple heating plates are provided to heat the electrical steel sheet, preventing breakage due to localized overheating and uneven heating when the electrical steel sheet is large.

[0066] The stress application module then applies a set stress to the electrical steel sheet using a stress push rod through a reserved application channel in the excitation winding bobbin. This stress can be either axial tensile or compressive, allowing for investigation of the effect of mechanical stress on the hysteresis loop. The stress push rod is electrically driven to precisely control the loading force, while a stress sensor monitors the real-time stress value to ensure accurate measurement data. An adjustable clamping mechanism secures the electrical steel sheet to ensure uniform stress distribution.

[0067] Finally, the signal measurement module collects the hysteresis data of the electrical steel sheet. The magnetic flux density coil is wrapped around the periphery of the excitation winding skeleton, and the magnetic flux density is measured by induced electromotive force; the magnetic field strength coil is placed in the measurement space, and on the premise of determining the sample specifications, it is determined whether to increase or decrease the coil specifications to directly measure the complete magnetic field strength of the electrical steel sheet to obtain the hysteresis characteristics of the electrical steel sheet. For example, the magnetic flux density coil and the magnetic field strength coil in the signal measurement module synchronously measure the magnetic flux density and magnetic field strength of the electrical steel sheet. By changing the magnitude and frequency of the excitation current, and controlling the magnitude of temperature and stress, the hysteresis loop data of the electrical steel sheet under different physical property coupling conditions can be obtained to obtain the hysteresis characteristics of the electrical steel sheet.

[0068] In this embodiment, the excitation coil and the excitation winding skeleton in the excitation module ensure the stability and adjustability of the excitation magnetic field of the electrical steel sheet during the measurement process. The heating plate in the temperature control module is precisely set in the measurement space to provide the required heat for the electrical steel sheet, providing a uniform and stable temperature loading environment. The stress application module uses a stress push rod through the application channel reserved by the excitation winding skeleton to apply controllable stress to the electrical steel sheet in the measurement space, and the uniformity of the stress loading stress applied to the electrical steel sheet. The magnetic flux density coil surrounds the periphery of the excitation winding skeleton, and the magnetic field strength coil is accurately placed in the measurement space to obtain the magnetic field strength in a non-exposed manner, which helps to protect the coil from the direct influence of temperature and stress, ensure the accuracy and reliability of the magnetic field strength measurement, accurately match the specifications of the electrical steel sheet, and ensure the accurate acquisition of the magnetic field strength and magnetic flux density data. By integrating the excitation module, temperature control module, and stress application module, the present application can simultaneously apply an excitation magnetic field to the electrical steel sheet, control its temperature, and apply mechanical stress. This multi-physical field coupling is closer to the service environment of the electrical steel sheet in actual applications (such as transformers and other electrical equipment), making the measured hysteresis characteristic data more accurate.

[0069] In an exemplary embodiment, the magnetic field strength coil is placed in the measurement space through a coil sealing box; the coil sealing box includes a magnetic field strength coil positioning plate; the magnetic field strength coil includes a first magnetic field strength coil and a second magnetic field strength coil; the magnetic field strength coil positioning plate includes multiple positioning sides; the first magnetic field strength coil and the second magnetic field strength coil are fixed to different positioning sides.

[0070] Specifically, the coil sealing box can be made of high-strength, heat-resistant materials, and its interior is designed with a specialized support structure to mount and secure the magnetic field strength coil. This sealing box not only effectively prevents interference from external physical factors such as moisture and external magnetic fields on the coil, but also ensures that the magnetic field strength coil maintains a stable operating state during the experiment.

[0071] When looking down at the coil sealing box, Figure 2 As shown, the magnetic field strength coil positioning plate 42 can be set in the coil sealing box 41 and provide multiple positioning sides. Each side is designed with multiple positioning holes for accurately fixing the first magnetic field strength coil 43A and the second magnetic field strength coil 43B to ensure that they are located in different areas within the measurement space. In one embodiment, as Figure 3As shown, first magnetic field strength coil 43A is fixed to one side of magnetic field strength coil positioning plate 42, positioned in the upper area of ​​the measurement space, to collect signals from the upper magnetic field. Second magnetic field strength coil 43B is fixed to the other side of magnetic field strength coil positioning plate 42, positioned in the lower area, to measure signals from the lower magnetic field. Working together, these two coils provide comprehensive magnetic field strength data, enabling a precise representation of the spatial distribution of the magnetic field.

[0072] During assembly, 502 glue is used to temporarily secure first and second magnetic field strength coils 43A, 43B to their correct positions within coil sealing box 41, preventing displacement or movement during subsequent operations that could affect measurement. Once secured, the coils are enclosed within the sealed box, and heat-resistant sealant is used to fill any remaining space within the box, sealing the entire assembly.

[0073] In this embodiment, the arrangement of upper and lower magnetic field strength coils allows for simultaneous acquisition of magnetic field data from both upper and lower regions, ensuring comprehensive coverage of the measurement range. This configuration not only enables comprehensive magnetic field distribution data to be obtained during magnetic field strength measurement, but also improves data acquisition accuracy. Furthermore, through precise fixation and optimized sealing design, measurement errors caused by device instability are reduced, improving the repeatability and consistency of measurement data and thus ensuring the reliability of measurement results.

[0074] In an exemplary embodiment, the heating plate is placed in the measurement space through a heating plate fixing box; multiple heating plates are evenly arranged above the heating plate fixing box, receiving electrical energy transmitted by the wiring in the heating plate fixing box and converting the electrical energy into thermal energy to complete the thermal loading of the electrical steel sheet.

[0075] The heater, which can be a ceramic heater, provides a uniform heat load to the electrical steel sheet during measurement, simulating actual operating temperature conditions. The heater mounting box mounts and supports the heater, providing power supply circuitry and thermal isolation.

[0076] Specifically, at the horizontal viewing angle of the measurement space, Figure 4 As shown, the measurement space is surrounded by the excitation winding frame. In the temperature control module, the ceramic heating plate 71 can be placed flat on the top of the heating plate fixing box 70. The ceramic heating plate generates heat when powered on, providing the required heat load to the electrical steel sheet. The surface temperature of the heating plate is stable and can maintain uniform heat output for a long time, ensuring that the electrical steel sheet is heated evenly. Optionally, as Figure 5 As shown, the ceramic heating plate 71 is evenly divided into multiple pieces and placed above the heating plate fixing box 70 to avoid overheating in the middle and further ensure that the electrical steel sheet is heated evenly.

[0077] The interior of the heating plate fixing box 70 is designed with a 320mmx104mmx4mm chamber, which is specifically used to install and fix the ceramic heating plate 71 and provide it with a power line channel. The design of the box also takes into account the optimization of heat conduction. The surrounding free space is filled with glass fiber, which effectively reduces the heat diffusion to the parts that do not need to be heated. In order to improve the high temperature resistance, the heating plate fixing box is sealed with a 250°C temperature-resistant sealant on all sides to ensure that heat does not leak out during the heating process, and the temperature conduction is slowed down to the winding skeleton, thereby improving the temperature control accuracy of the measurement system. During the operation of the device, the ceramic heating plate 71 will convert electrical energy into thermal energy through electric current, and transfer the heat evenly to the electrical steel sheet. In this process, due to the design of the heating plate fixing box 70, the heat is concentrated in the heating plate area, and the isolation of the sealant prevents the heat from affecting other components, ensuring that the electrical steel sheet is heated evenly and the thermal loading process is stable.

[0078] In this embodiment, the efficient heat conversion of the ceramic heater and the precise design of the heater fixing box provide stable and uniform heat loading, ensuring the accuracy, reliability and long-term stability in the measurement of the hysteresis characteristics of the electrical steel sheet.

[0079] In an exemplary embodiment, a temperature measuring wire groove is provided in the heating plate fixing box for carrying a temperature measuring wire to control the temperature of the heating plate.

[0080] Looking down at the temperature control module, Figure 5 As shown, the temperature measurement cable trough 72 is a structure used to carry the temperature sensor circuit. It provides a fixed channel for the temperature measurement cable and ensures the stability of temperature data transmission. The temperature measurement cable is used to monitor the temperature of the heater plate 71 or the surrounding area in real time. By working together with the temperature measurement cable trough 72, the temperature measurement cable ensures the temperature control accuracy of the heater plate, thereby ensuring the temperature stability of the measurement environment.

[0081] In one embodiment, Figure 4 As shown, the excitation winding skeleton is also provided with a wiring lead-in port for routing the temperature measuring wire lead-out line and transmitting temperature data.

[0082] In this embodiment, a temperature measuring wire groove 72 is provided in the heating plate fixing box 70 to provide a stable channel for the temperature measuring wire, which makes the transmission of temperature data more stable, provides a reliable temperature control basis for the measurement system, and ensures that the heating plate 71 operates at a stable temperature.

[0083] In an exemplary embodiment, the device includes an electrical steel sheet clamping module; the electrical steel sheet clamping module includes a clamping unit, and the clamping unit includes a push-pull clamp, a first clamping body, a second clamping body, a third clamping body and a fourth clamping body; the push-pull clamp is used to fix the electrical steel sheet in the space formed by the first clamping body, the second clamping body, the third clamping body and the fourth clamping body, and the space is aligned with the position of the electrical steel sheet on the excitation winding skeleton.

[0084] For example, the clamping unit is part of the electrical steel sheet clamping module and includes multiple clamping components for clamping and securing the electrical steel sheet. The clamping unit uses a push-pull clamp and multiple clamp bodies to precisely clamp the electrical steel sheet, ensuring that it does not shift in position.

[0085] In one embodiment, the electrical steel sheet clamping module includes a fixed clamp module and a movable clamp module. Figure 6 As shown, the clamping unit is arranged in the fixed clamp module 2, and the push-pull clamp 20 firmly clamps the electrical steel sheet in the space surrounded by the first clamp body 21, the second clamp body 22, the third clamp body 23 and the fourth clamp body 24 through a push-pull action. The design of each clamp body ensures uniform clamping force on the electrical steel sheet, avoiding any deformation or displacement of the electrical steel sheet during the measurement process. The push-pull clamp 20 fixes the electrical steel sheet in the space surrounded by the clamp bodies through sliding and clamping operations, and ensures its firm position by controlling the clamping force. This design can ensure the docking accuracy of the electrical steel sheet with the excitation winding skeleton during the measurement process, thereby ensuring the accuracy of the measurement data. The electrical steel sheet clamping module 2 forms a fixed clamp base through the fixed clamp base plate 25 and the fixed clamp base plate column 26, providing stable support. The fixed clamp base is fixedly connected to the stand by bolts to form a solid overall structure, ensuring the stability and reliability of the clamping module during the measurement process.

[0086] In this embodiment, through the precise design of the push-pull clamp and multiple clamp bodies, this embodiment ensures that the electrical steel sheet is stably clamped during the magnetic field measurement process, avoids position deviation caused by external force or vibration, and thus ensures high accuracy of the measurement data.

[0087] In an exemplary embodiment, the electrical steel sheet clamping module includes a sliding unit, which includes a slider, a slider guide and a sliding platform; the sliding unit is connected to the clamping unit through the sliding platform so that the slider drives the clamping unit to slide on the slider guide.

[0088] Specifically, if Figure 7As shown, in the movable clamp module of the electrical steel sheet clamping module, the sliding unit consists of a slider 37, a slider guide 38, and a sliding platform 39, providing a smooth motion trajectory for adjusting the position of the electrical steel sheet. The slider 37 is part of the sliding unit and is designed to work with the slider guide 38 to provide stable sliding. The slider is responsible for moving the clamping unit to the desired position, ensuring that the electrical steel sheet is precisely aligned during measurement. The slider guide 38 is a component that works in conjunction with the slider 37, providing a smooth and stable track. The slider guide is fixed to the base of the device and guides the slider for smooth sliding on the track, ensuring that the sliding unit does not jam or deflect during operation. The sliding platform 39 is the base platform of the sliding unit and works with the slider guide 38 and slider 37 to ensure stable sliding of the slider. Through its connection to the clamping unit 3, the sliding platform enables the clamping unit to slide horizontally when needed, thereby precisely adjusting the position of the electrical steel sheet.

[0089] Optionally, the push-pull quick clamp 30 in the clamping unit of the movable clamp enables the first clamping body 31, the second clamping body 32, the third clamping body 33 and the fourth clamping body 34 to tightly surround and fix the electrical steel sheet through a push-pull action. The design of these clamping bodies ensures uniform clamping force and avoids deformation or position displacement of the electrical steel sheet. The movable clamp base plate 35 and the movable clamp base plate column 36 together constitute the support structure of the clamping unit. The movable clamp base plate 35 and the column 36 are connected by bolts to provide a stable foundation. The clamping unit can slide smoothly on the guide rail through the cooperation of the slider 37, the slider guide rail 38 and the sliding platform 39. It is fixed to the stand by bolts to ensure that the module will not be displaced or the structure will be loose during operation. By fixing the slider guide rail 38 to the base formed by the movable clamp base plate 35 and the movable clamp base plate column 36, a stable movable clamp module 3 is finally formed to ensure that the device has precise operating performance.

[0090] In this embodiment, through the design of the sliding unit and the cooperation between the slider and the slider guide, smooth and precise sliding adjustment is achieved, ensuring the position accuracy of the electrical steel sheet in the measurement space.

[0091] In an exemplary embodiment, the stress applying module is connected to the sliding unit of the electrical steel sheet clamping module to apply stress to the electrical steel sheet; the stress applying module also includes a stress sensor and a push rod fixing box composed of a stress fixing plate; the stress push rod is connected to the stress sensor and fixed in the push rod fixing box to obtain stress data of the electrical steel sheet.

[0092] The stress push rod applies tensile or compressive stress to the electrical steel sheet accurately through mechanical control and can be an electric push rod.

[0093] Specifically, if Figure 8As shown, the stress application module is connected to the electrical steel sheet clamping module via a sliding unit. The function of the sliding unit is to precisely adjust the position of the electrical steel sheet to ensure that the electrical steel sheet is precisely aligned when stress is applied. The stress application module is fixed by a push rod fixing plate 62 to ensure that the stress-loading electric push rod 60 and the stress sensor 61 maintain a stable position during the stress application process, thereby ensuring the accuracy of the measurement data. The stress-loading electric push rod is connected to the push rod fixing box via the push rod fixing plate 62 to ensure stable stress application and avoid errors. The stress sensor 61 is connected to the stress-loading electric push rod 60 for real-time monitoring of the stress on the electrical steel sheet.

[0094] In this embodiment, through the cooperation of the stress loading electric push rod 60 and the stress sensor 61, stress can be accurately applied to the electrical steel sheet, and stress data can be monitored in real time to ensure accuracy and uniformity during the stress application process.

[0095] In an exemplary embodiment, the push rod fixing box is composed of a plurality of push rod fixing plates, and the push rod fixing plates include heat dissipation holes.

[0096] For example, the push rod mounting plate is provided with heat dissipation holes. The holes provide airflow channels through their opening design, accelerating heat dissipation. The size and distribution of each heat dissipation hole are optimized to ensure that the heat generated during device operation can be efficiently dissipated.

[0097] In this embodiment, the design of the heat dissipation holes can ensure the stability of the device during the stress application process, and prevent device damage or inaccurate measurement due to temperature increase.

[0098] In an optional embodiment, the stress application module also includes a stress display that provides real-time readings of force changes during measurement. The stress sensor 62 employed can detect ±2000N, is compact and easy to install, and has a sensitivity of 1.3mV / V. Both the stress sensor 62 and the stress display have a measuring range that covers both tension and compression.

[0099] In an exemplary embodiment, the device includes a magnetic conductive module; the magnetic conductive module includes a plurality of symmetrical iron yokes to form a magnetic field introduction path for the electrical steel sheet when the excitation coil generates a magnetic field excitation.

[0100] The magnetic permeability module is a device used to form a magnetic field introduction path for the electrical steel sheet under the excitation of the magnetic field generated by the excitation coil. This module uses a symmetrical iron yoke to introduce and concentrate the magnetic field, ensuring that the magnetic field can act evenly on the electrical steel sheet, improving the efficiency and accuracy of the magnetic field excitation. The symmetrical iron yoke is the magnetic field introduction component in the magnetic permeability module. It can evenly distribute and guide the magnetic field, ensuring that the electrical steel sheet can effectively transmit magnetic force when excited by the magnetic field. The symmetrical iron yoke can be implemented as a C-shaped iron yoke. The symmetrical iron yoke is designed as a symmetrical structure to ensure uniform magnetic field transmission.

[0101] Specifically, if Figure 9 As shown, multiple C-shaped iron yokes 50 are designed to be arranged symmetrically and are stably fixed by the upper C-shaped iron yoke mounting plate 51 and the C-shaped iron yoke fixing block 52. The stand provides solid support for the C-shaped iron yoke 50, ensuring that the iron yoke remains stable when the magnetic field is applied. Each C-shaped iron yoke 50 can evenly guide the magnetic field when the excitation coil generates a magnetic field, and ensure that the magnetic field can be evenly distributed on the electrical steel sheet. The lifting push rod 53 adjusts the position of the C-shaped iron yoke. When placing the electrical steel sheet 8, it can accurately control the upper and lower positions of the C-shaped iron yoke to ensure that the electrical steel sheet is accurately connected to the magnetic field introduction path, thereby optimizing the magnetic field excitation effect.

[0102] In this embodiment, the magnetic conductive module design effectively improves the accuracy and stability of the hysteresis characteristic measurement of electrical steel sheets, provides a more uniform and accurate magnetic field introduction path for magnetic field excitation, and ensures high efficiency and reliability during the measurement process.

[0103] In a specific embodiment, the magnetic coil is sealed and fixed as Figure 10 As shown, screw holes are reserved at the four corners of the sealing bottom plate 44, through which the sealing bottom plate 44 is firmly connected to the column 45. The sealing side plate 46 is designed to be inserted into the side of the excitation winding skeleton 40 and temporarily fixed with glue to ensure its accurate positioning. During the assembly process, the sealing side plate 46 and the sealing bottom plate 44 fixed with glue together form a stable sealing structure with the excitation winding skeleton 40. This structure effectively encloses the excitation coil 4 and the magnetic flux density coil 41, ensuring that they are not affected by changes in temperature and humidity of the external environment during operation. After the entire structure is assembled, a sealant with a temperature resistance of 250°C is filled into the tripod-shaped structure to further enhance the sealing and fixation.

[0104] In an exemplary embodiment, the hysteresis characteristic detection device of the electrical steel sheet is as follows Figure 11As shown, the device can be used to measure the hysteresis characteristics of electrical steel sheets, specifically including a stand 1, an electrical steel sheet clamping module (fixed clamp module 2, movable clamp module 3), an excitation and measurement module 4 (excitation module, signal measurement module), a magnetic permeability module 5, a stress application module 6, and a temperature control module 7. The device is used to perform the following steps:

[0105] An appropriately sized electrical steel sheet is selected as the measurement sample, ensuring its surface is clean and undamaged to facilitate subsequent magnetic property measurements. The entire measurement apparatus is placed on a test stand 1, and the electrical steel sheet is secured within the measurement space formed by the excitation winding frame using the fixed clamp module 2 and the movable clamp module 3. The electrical steel sheet is surrounded and secured by the first, second, third, and fourth clamps of the fixed clamp module 2, securing one side of the sheet and maintaining alignment within the measurement space of the excitation winding frame. The other side of the sheet is then secured by the first, second, third, and fourth clamps of the movable clamp module 3. Simultaneously, the slider, slider guide, and sliding platform of the movable clamp module 3 are adjusted to ensure that the clamping unit can slide freely along the guide rails, ensuring that the electrical steel sheet is fully positioned within the measurement space. The lifting push rod of the magnetic conductivity module 5 adjusts the electrical steel sheet up and down, ensuring that it fully enters the alternating magnetic field formed by the excitation coil for complete magnetic conductivity. The heating function is activated by the temperature control module 7. Set the required operating temperature and provide thermal energy to the electrical steel sheet through the ceramic heating sheet. The ceramic heating sheets are evenly distributed above the heating sheet fixing box to heat the electrical steel sheet to the set temperature and ensure temperature uniformity. Start the stress application module 6 and apply the required tensile or compressive stress to the electrical steel sheet through the electric push rod. The stress value is monitored in real time by the stress sensor, and the stress is loaded to the electrical steel sheet to ensure that the stress is applied evenly and controllable. The required alternating magnetic field or rotating magnetic field is provided to the electrical steel sheet through the excitation and measurement module 4. According to the experimental requirements, the current size and frequency of the excitation coil can be adjusted to generate magnetic fields of different intensities. Adjust the excitation coil and the winding skeleton to ensure that the electrical steel sheet can accurately respond to magnetic field excitation under different magnetic field strengths and magnetic flux densities. Start the signal measurement module of the excitation and measurement module 4, and simultaneously measure the changes in magnetic field strength and magnetic flux density generated by the electrical steel sheet in the magnetic field through the magnetic field strength coil and the magnetic flux density coil. The magnetic field strength coil is placed in the measurement space, while the magnetic flux density coil surrounds the periphery of the excitation winding skeleton 40, ensuring that the measurement data is synchronized and accurate when the magnetic field is applied.

[0106] Before describing the method for determining the hysteresis characteristics of an electrical steel sheet provided in this application, the relevant technologies are first introduced below.

[0107] The magnetic properties of electrical steel sheets, such as magnetization curves and loss characteristics, are primarily determined by their microstructure. In particular, due to the presence of anisotropy, the material's magnetic microstructure consists of magnetic domains that follow the easy axis of the anisotropy functional. The magnetization process can be described by the displacement of domain walls or the rotation of the magnetization vector within the domain. Existing hysteresis models, such as the Preisach model, the Jiles-Atherton model, the Enokizono and Soda (E&S) model, and the Stoner-Wohlfarth (SW) model, primarily describe magnetization behavior under a single excitation condition. However, in practical applications, the magnetic field often exhibits a vector distribution, making it difficult for traditional scalar models to accurately simulate this magnetic field distribution and the resulting core losses, resulting in significant errors in the calculated results. Therefore, accurately describing the hysteresis characteristics of electrical steel sheets under different excitation conditions is key to solving these problems. Consequently, the method for determining the hysteresis characteristics of electrical steel sheets provided in this application has emerged.

[0108] In an exemplary embodiment, a method for determining the hysteresis characteristics of an electrical steel sheet is provided, such as Figure 12 As shown, the method includes the following steps:

[0109] Step S1201: Obtain the temperature, external stress, and magnetic field strength of the environment in which the electrical steel sheet is located.

[0110] The temperature, applied stress, and magnetic field strength parameters obtained in the method for determining the hysteresis characteristics of the electrical steel sheet can be obtained and verified by the hysteresis characteristics detection device for the electrical steel sheet according to the above embodiment.

[0111] For example, the temperature is controlled by the ceramic heating plate in the hysteresis characteristics of the steel sheet, and the temperature sensor monitors the temperature of the sample; the external stress is applied by an electric push rod, and the stress magnitude is fed back in real time through the stress sensor, and the magnetic field strength is measured by the magnetic field strength coil to ensure accurate recording of the magnetic field strength.

[0112] Step S1202 , determining the relationship between the magnetic field intensity and the magnetization intensity of the electrical steel sheet when the magnetic structure of the electrical steel sheet is stable under temperature and applied stress; the magnetic structure stability is characterized by minimization of the hysteresis operator free energy in the electrical steel sheet.

[0113] For example, the magnetic structure of an electrical steel sheet is determined by multiple factors, including demagnetization energy, magnetic anisotropy, exchange energy, and applied magnetic field energy (Zeeman energy). In the SW model, the magnetization process is assumed to be an energy-minimizing process. To describe the stable state of magnetic domains in a magnetic material, the total free energy consists of two components: the anisotropy energy and the Zeeman energy. The anisotropy of a magnetic material makes it easier for magnetic domains to align in a specific direction, resulting in a stable state with minimal energy. The Zeeman energy represents the effect of an applied magnetic field on the magnetization direction of a material. An applied magnetic field forces the magnetization direction toward the direction of the magnetic field, minimizing the Zeeman energy. Therefore, minimizing the total free energy can determine whether the electrical steel sheet is currently magnetically stable. Furthermore, a quantitative relationship between magnetic field strength and magnetization intensity is derived under the current temperature and applied stress. According to the SW model, the relationship between magnetization intensity and applied magnetic field is not directly linear but is influenced by the internal magnetic domain structure of the material. Therefore, factors influencing magnetic structural stability must be considered. Specifically, the relationship between magnetic field strength and magnetization intensity is determined based on the relationship between different magnetic field strengths, temperatures, and stresses.

[0114] Step S1203 , determining the hysteresis angle of the magnetization intensity relative to the magnetic field intensity in each hysteresis operator according to the relationship between the magnetic field intensity and the magnetization intensity; the hysteresis angle has different values ​​at different temperatures and applied stresses.

[0115] The hysteresis operator describes the behavior of individual magnetic domains in a material and is closely related to the relative change in the applied magnetic field. The hysteresis angle describes the deviation between the magnetization intensity and the direction of the applied magnetic field, revealing the hysteresis effect in the magnetization process. Each hysteresis operator has a specific hysteresis angle, which represents the deviation of the magnetization direction relative to the direction of the applied magnetic field.

[0116] For example, under different operating conditions, the hysteresis angle changes dynamically with changes in the external magnetic field and environmental conditions. Based on the relationship between magnetization intensity and magnetic field intensity, the hysteresis angle between the magnetization intensity and the external magnetic field is calculated according to different environmental conditions, and the changes in the hysteresis angle are tracked in real time.

[0117] Step S1204: Accumulate the polarization effect of the hysteresis operator on the magnetic field strength according to the hysteresis angle to obtain the relationship between the magnetic flux density and the magnetic field strength in the electrical steel sheet, and determine the hysteresis characteristics of the electrical steel sheet according to the relationship between the magnetic flux density and the magnetic field strength.

[0118] For example, the polarization effect of a hysteresis operator represents how microscopic magnetic domains within a material respond to an applied magnetic field. The change in magnetization intensity is described by each hysteresis operator using a hysteresis angle. The polarization effect of each hysteresis operator on the magnetic field is accumulated to produce the overall magnetization intensity. Based on the overall magnetization intensity, the relationship between the magnetic flux density and magnetic field intensity in the electrical steel sheet is further determined based on the hysteresis angle.

[0119] In this embodiment, by integrating the multi-physics coupling effects of temperature, stress, and magnetic field, and based on the principle of energy minimization to determine the stability of the magnetic structure, the polarization characteristics of the microscopic hysteresis operator are accumulated to obtain macroscopic polarization characteristics, which are used to further determine the hysteresis characteristics of the electrical steel sheet. This overcomes the shortcomings of traditional models that cannot accurately describe the stability of magnetic structures in complex environments, improves the accuracy of magnetic flux density calculations, ensures that the relationship between magnetic field strength and magnetization intensity is accurately described under various environmental conditions, and enables more accurate simulation and prediction of the magnetic properties of electrical steel sheets and other soft magnetic materials (such as amorphous alloys and nanocrystalline materials) under multi-physics coupling.

[0120] In an exemplary embodiment, Figure 13 As shown, the method for determining the hysteresis characteristics of electrical steel sheets can be combined with the Preisach model and the SW model to determine the hysteresis characteristics of electrical steel sheets. For example, the SW model is used to calculate the magnetization direction of the operator inside the magnetic domain, taking into account the anisotropy and vector characteristics of the material. The Preisach distribution function can be used to calculate the magnitude of the magnetization intensity, taking into account the mutual influence between the operators, determining the two-dimensional Preisach double Gaussian distribution function, and analyzing the influence of the anisotropy coefficient and the interaction field on the operators in the model. The SW operator is replaced by the Preisach operator and the Preisach distribution is constructed, the local polarization is converted into global polarization, and the Preisach / SW hybrid hysteresis model is modeled. From the local to the whole, the overall magnetic properties of the material are obtained.

[0121] Determine the basic parameters of the calculation, magnetic field strength H, saturation magnetization , direction of external magnetic field and anisotropy coefficient α.

[0122] The magnetization state of the material is calculated according to the strength of the external magnetic field. The Stoner-Wohlfarth (SW) model is used to describe the behavior of the magnetic domains, and the relationship between the magnetization strength and the magnetic field strength of a single hysteresis operator is calculated.

[0123] Specifically, the total free energy E can be expressed by formula (1):

[0124]

[0125] Where, is the anisotropic energy, For Zeeman energy, is the vacuum permeability, a physical constant, and its value is ; H is the magnetic field strength; is the saturation magnetization, is the angle between the external magnetic field and the easy magnetization axis, and θ is the angle between the magnetization intensity M and the easy magnetization axis. In this formula, θ is the state variable to be determined, and H are known control variables.

[0126] Solving the minimum value of the energy equation can yield the energy extreme interface. The condition for the energy equation to obtain the minimum value is shown in formula (2):

[0127]

[0128] Assume the operator switching field is , Formula (2) is obtained by using the product and difference formula of trigonometric functions based on Formula (1):

[0129]

[0130] Assume that the components of the external magnetic field along the x-axis and y-axis are as shown in formula (4):

[0131]

[0132] Substituting formula (4) into formula (3) and simplifying it, we get formula (5):

[0133]

[0134] Using trigonometric identities Simplifying formula (5) and squaring it yields the equation shown in formula (6).

[0135]

[0136] Divide both sides of formula (5) by Combined with formula (2), we can obtain the equation that satisfies the energy extreme value:

[0137]

[0138] Combining formula (7) with formula (5) yields the following analytical solution:

[0139]

[0140] The direction of the magnetization intensity M as a function of the magnetic field intensity H can be determined by the graphical construction of formula (8).

[0141] The equilibrium angle (i.e., hysteresis angle) is derived using the interaction between the applied magnetic field and the magnetic domains of the material, and the magnetization angle when the magnetic domains are stable is calculated based on the model.

[0142] In the two-dimensional magnetic field plane, the angle between the magnetization intensity and the easy magnetization axis in the above derivation is It is a function of the external magnetic field. The final stable magnetization direction can be determined by tracing the tangent trajectory of the star line at the end of the magnetic field intensity, and the law of magnetization direction change can be obtained.

[0143] The magnetization equilibrium position of the material is determined based on the magnetization angle at stability.

[0144] The Preisach model is used to establish the spatial distribution of the hysteresis operator to describe the hysteresis phenomenon. The distribution function can take many forms, one of which is to assume a probability density distribution function as the Preisach distribution function. In this application, a double Gaussian distribution function is selected. The Gaussian-Gaussian distribution has a wide range of adaptability and is closer to the idealized distribution in soft magnetic materials.

[0145] Specifically, the anisotropy coefficient K and the interaction field As two key factors that can effectively describe the magnetic properties of the vector hysteresis operator, the expression of the distribution function is derived

[0146]

[0147] Where, Preisach function is the product of two distributions assumed to be independent, i.e. the interaction field distribution and anisotropic distribution ;Parameter N is the normalization factor of the function; and Anisotropy coefficients and interaction fields The standard deviation determines the magnitude of the distribution function and is consistent with the unit of measurement of the original data; is the expected value of the anisotropy coefficient K.

[0148] When the SW model and Preisach model are determined, the temperature and applied stress in the current environment are further determined.

[0149] The behavior of each hysteresis operator is calculated using the Preisach distribution function. The effects of all hysteresis operators are accumulated to calculate the hysteresis characteristics of the electrical steel sheet.

[0150] Specifically, the SW model is embedded in the Preisach model, the two models are coupled together, and the overall magnetic properties of the magnetic material are derived using the distribution function relationship obtained by formula (9) and the functional relationship between the magnetization angle and energy of the single-domain uniaxial operator:

[0151]

[0152] In the formula, the variable is the hysteresis angle function representing the vector hysteresis operator considering temperature and stress; is a two-dimensional double Gaussian distribution function; and are the interaction field parameters and anisotropy parameters.

[0153] Using magnetic flux density , magnetic field strength and magnetization The relationship between the three transforms the data of formula (10), and the relationship between the three is:

[0154]

[0155] Finally, the relationship between the magnetic flux density and magnetic field strength of the electrical steel sheet is obtained to represent the hysteresis behavior of the electrical steel sheet.

[0156] In this example, by combining the Stoner-Wohlfarth model with the Preisach model, a model was successfully established that can accurately simulate and predict the hysteresis behavior of soft magnetic materials, such as electrical steel sheets, in complex environments. By considering the coupled effects of multiple physical fields, including temperature, stress, and magnetic fields, this method significantly improves the accuracy of magnetic property measurements and expands the application range of soft magnetic materials.

[0157] In an exemplary embodiment, the elliptical rotation magnetization condition is defined by three parameters, namely, the maximum magnetic flux density , magnetization angle and axle ratio , magnetization angle Defined as the rolling direction (easy magnetization axis) and the maximum magnetic flux density vector The angle between the directions. Is the ratio of the minimum magnetic flux density to the maximum magnetic flux density, the elliptical rotation magnetization is as follows Figure 14 As shown in a. When the axis ratio When it is 0, it is alternating magnetization, such as Figure 14 As shown in b. When the axis ratio When it is 1, it is circular rotation magnetization, such as Figure 14 As shown in c.

[0158] In an exemplary embodiment, by Figure 15 In the process shown, alternating magnetization and circular rotating magnetization are performed on the electrical steel sheet so that the electrical steel sheet is in an alternating magnetic field and a rotating magnetic field, and the hysteresis characteristics are determined.

[0159] In one embodiment, in the alternating magnetic field under the same environment (external stress, temperature), at different magnetization angles =30°, the relationship between the magnetic flux density and magnetic field strength of the electrical steel sheet is obtained by the hysteresis characteristic determination method of the above embodiment, and the magnetic flux density and magnetic field strength are measured by the hysteresis characteristic measurement device of the above embodiment, and the relationship obtained by the determination method is verified, and the following is obtained: Figure 16 Results shown.

[0160] Alternatively, in the same environment (external stress, temperature) in an alternating magnetic field, at different magnetization angles =90°, the relationship between the magnetic flux density and magnetic field strength of the electrical steel sheet is obtained by the hysteresis characteristic determination method of the above embodiment, and the magnetic flux density and magnetic field strength are measured by the hysteresis characteristic measurement device of the above embodiment, and the relationship obtained by the determination method is verified, and the following is obtained: Figure 17 Results shown.

[0161] Comparing the results of the two images shows that the model fit is relatively accurate when close to the rolling direction. This is because the material's grain orientation is more ordered and the magnetic domains are more regularly arranged. When deviating from the rolling direction, the grain orientation and magnetic domain structure may become more complex, causing the shape of the hysteresis loop to deviate from the measured result.

[0162] In one embodiment, in a rotating magnetic field under the same environment (external stress, temperature), the relationship between the magnetic flux density and magnetic field strength of the electrical steel sheet is obtained by the hysteresis characteristic determination method of the above embodiment, and the measurement results under rotating magnetization excitation are simulated to verify the relationship obtained by the determination method, and the following is obtained: Figure 18 Results shown.

[0163] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, database or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory, ROM, tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory, ReRAM, magnetic random access memory, MRAM, ferroelectric random access memory, FRAM, phase change memory, PCM, graphene memory, etc. Volatile memory can include random access memory, RAM or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processor involved in the various embodiments provided herein may be a general-purpose processor, a central processing unit (CPU), a graphics processor (GPU), a digital signal processor (DSP), a programmable logic device (PLD), a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to these.

[0164] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0165] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A device for measuring the hysteresis characteristics of electrical steel sheets, characterized in that: The device includes an excitation module, a signal measurement module, a temperature control module, and a stress application module; The excitation module includes an excitation coil and an excitation winding frame; the excitation coil is surrounded by the periphery of the excitation winding frame and is used to provide an excitation magnetic field for the electrical steel sheet when the electrical steel sheet is located in the measurement space formed by the excitation winding frame; The temperature control module includes a heating plate; the heating plate is located in the measurement space and is used to provide heat to the electrical steel sheet while the excitation magnetic field acts on the electrical steel sheet; The stress applying module includes a stress push rod; the stress push rod is configured to use a reserved application channel of the measurement space formed by the excitation winding skeleton to apply stress to the electrical steel sheet located in the measurement space, so as to perform a hysteresis characteristic measurement of the electrical steel sheet in the measurement space with the physical characteristics of the excitation magnetic field, heat loading, and stress application coupled when the excitation magnetic field and heat loading are simultaneously applied to the electrical steel sheet; The signal measurement module includes a magnetic field strength coil and a magnetic flux density coil; the magnetic flux density coil surrounds the periphery of the excitation winding skeleton; the magnetic field strength coil is located in the measurement space and is configured to obtain the magnetic field strength in a non-exposed manner, and the coil specifications of the magnetic field strength coil match the specifications of the electrical steel sheet; the signal measurement module is linked with the excitation module, the temperature control module and the stress application module, and is used to measure the magnetic flux density and the magnetic field strength of the electrical steel sheet under different conditions of the heat and the stress when the electrical steel sheet is in the excitation magnetic field.

2. The device according to claim 1, characterized in that The magnetic field strength coil is placed in the measurement space through a coil sealing box; the coil sealing box includes a magnetic field strength coil positioning plate; The magnetic field strength coil includes a first magnetic field strength coil and a second magnetic field strength coil; The magnetic field strength coil positioning plate includes a plurality of positioning side surfaces; the first magnetic field strength coil and the second magnetic field strength coil are fixed on different positioning side surfaces.

3. The device according to claim 1, characterized in that The heating plate is placed in the measuring space through a heating plate fixing box; A plurality of heating plates are evenly arranged above the heating plate fixing box, receiving electric energy transmitted by the wiring in the heating plate fixing box and converting the electric energy into heat energy to complete the heat loading of the electrical steel sheet.

4. The device according to claim 3, characterized in that A temperature measuring wire groove is provided in the heating plate fixing box for carrying a temperature measuring wire to control the temperature of the heating plate.

5. The device according to claim 1, characterized in that The device includes an electrical steel sheet clamping module; the electrical steel sheet clamping module includes a clamping unit, and the clamping unit includes a push-pull clamp, a first clamping body, a second clamping body, a third clamping body, and a fourth clamping body; The push-pull clamp is used to fix the electrical steel sheet in a space formed by the first clamp body, the second clamp body, the third clamp body and the fourth clamp body, and the space is aligned with the position of the electrical steel sheet on the excitation winding skeleton.

6. The device according to claim 5, characterized in that The electrical steel sheet clamping module includes a sliding unit, which includes a slider, a slider guide and a sliding platform; the sliding unit is connected to the clamping unit through the sliding platform, so that the slider drives the clamping unit to slide on the slider guide.

7. The device according to claim 6, characterized in that The stress applying module is connected to the sliding unit of the electrical steel sheet clamping module to apply stress to the electrical steel sheet; The stress applying module further comprises a stress sensor and a push rod fixing box composed of a stress fixing plate; The stress push rod is connected to the stress sensor and fixed in the push rod fixing box to obtain stress data of the electrical steel sheet.

8. The device according to claim 7, characterized in that The push rod fixing box is composed of a plurality of push rod fixing plates, and the push rod fixing plates include heat dissipation holes.

9. The device according to any one of claims 1 to 8, characterized in that The device includes a magnetic conductive module; the magnetic conductive module includes a plurality of symmetrical iron yokes, so as to form a magnetic field introduction path for the electrical steel sheet when the excitation coil generates a magnetic field excitation.

10. A method for determining the hysteresis characteristics of an electrical steel sheet, characterized in that: The method comprises: Obtaining the temperature, external stress, and magnetic field strength of the environment in which the electrical steel sheet is located; the temperature, the external stress, and the magnetic field strength are detected by the electrical steel sheet hysteresis characteristic measuring device according to any one of claims 1 to 9; determining a relationship between a magnetic field intensity and a magnetization intensity of a hysteresis operator in the electrical steel sheet when the magnetic structure of the electrical steel sheet is stable under the temperature and applied stress; wherein the magnetic structure stability is characterized by minimization of a free energy of a hysteresis operator in the electrical steel sheet; Determining a hysteresis angle of the magnetization intensity relative to the magnetic field intensity in each hysteresis operator based on the relationship between the magnetic field intensity and the magnetization intensity; the hysteresis angle has different values ​​in different environments and external stresses; According to the hysteresis angle, the polarization influence of the hysteresis operator on the magnetic field of the magnetic field strength is accumulated to obtain the relationship between the magnetic flux density in the electrical steel sheet and the magnetic field strength, and the hysteresis characteristics of the electrical steel sheet are determined according to the relationship between the magnetic flux density and the magnetic field strength.

Images