Method and device for testing magnetic performance of soft magnetic material

Abstract

The invention discloses a method and device for testing the magnetic performance of a soft magnetic material, and the method comprises the steps: making a to-be-tested soft magnetic material into a closed-circuit shape to obtain a tested sample, winding a secondary induction winding on the tested sample, and taking a double-layer excitation coil which is wound through a double-ring equidistant winding method as a primary excitation winding; in response to a test signal, an arbitrary waveform generator and a power amplifier are synchronously triggered through a clock generator to output an arbitrary waveform excitation signal to be applied to a primary excitation winding, a signal on a secondary induction winding is synchronously collected, and then magnetic performance data are calculated according to the excitation signal, an induction signal and sample parameters; and the surface temperature of the sample is monitored, regulated and controlled in real time through the thermocouple in the test. The primary excitation winding is wound through a double-circle equidistant winding method, so that the magnetization uniformity of the winding is improved, the skin effect and the proximity effect are reduced, and the accuracy and the reliability of a test result are improved; the surface temperature of the sample is monitored and regulated in real time, and adverse effects caused by temperature changes are reduced.

Description

Technical Field

[0001] This invention relates to the field of materials testing technology, and in particular to a method and apparatus for testing the magnetic properties of soft magnetic materials. Background Technology

[0002] Soft magnetic materials refer to materials where magnetization occurs at a value of Hc not exceeding 1000 A / m. They possess low coercivity and high permeability, and are widely used in electrical and electronic equipment. They also hold a place in power electronics, energy industries, and scientific research fields such as electromagnetic signal detection, inductive components, energy conversion, and filtering.

[0003] Currently, the AC magnetic properties testing of soft magnetic materials (oriented silicon steel, amorphous alloys) is mostly based on Ampere's law, using direct measurement methods (measuring magnetic induction intensity B) or indirect measurement methods (measuring magnetic field strength). However, conventional AC magnetic properties testing systems typically use sine or triangular waveforms for the excitation current, making it impossible to test AC magnetic properties under arbitrary waveform excitation. Furthermore, the testing frequency range for oriented silicon steel is 50Hz to 1kHz, while for amorphous alloys it is 50Hz to 20kHz. Therefore, a single testing system cannot meet the wideband testing requirements (50Hz to 100kHz). Moreover, conventional AC magnetic properties testing systems cannot suppress stray parameters such as high-frequency leakage current and coupling capacitance of the excitation coil under high-frequency testing conditions, easily leading to distortion of the high-frequency test waveform results and adversely affecting the test results. Summary of the Invention

[0004] This invention provides a method and apparatus for testing the magnetic properties of soft magnetic materials, enabling the testing of the magnetic properties of soft magnetic materials under arbitrary waveform and frequency band conditions, while also improving the accuracy and reliability of the test results.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a method for testing the magnetic properties of soft magnetic materials, comprising the following steps:

[0006] The soft magnetic material to be tested is made into a closed-circuit shape to obtain a test sample. A secondary induction winding is wound on the test sample, and a double-layer excitation coil is wound as a primary excitation winding by winding two turns at equal intervals.

[0007] In response to the test start signal, the arbitrary waveform generator and power amplifier are synchronously triggered by the clock generator to output and amplify the arbitrary waveform excitation signal in sequence and apply it to the primary excitation winding. At the same time, the signal on the secondary induction winding is collected, and then the magnetic performance data of the soft magnetic material under test is calculated and output according to the arbitrary waveform excitation signal, the induction signal and the parameters of the test sample.

[0008] During the test, temperature data of the thermocouple placed on the surface of the test sample is collected in real time, and the surface temperature of the test sample is then adjusted based on the temperature data.

[0009] The magnetic performance testing method provided by this invention first prepares the soft magnetic material to be tested into a closed-circuit shape to obtain the corresponding test sample. By forming a closed path with the soft magnetic material to create a magnetic closed circuit, the magnetic reluctance of the test sample is reduced, while its magnetic induction intensity and magnetic field strength are enhanced. Furthermore, by winding a double-layer excitation coil on the test sample using a double-turn, equidistant winding method as the primary excitation winding, the turn spacing of the primary excitation winding is made the same. This not only meets the magnetic performance testing requirements of soft magnetic materials under high-frequency conditions but also reduces the interference of the skin effect and proximity effect of the excitation coil in the high-frequency material on the test results, improving the accuracy and reliability of the test results. Simultaneously, the method of uniformly winding the double coil along the test sample also improves the magnetization uniformity of the winding and reduces the impact of stray parameters such as high-frequency leakage current and coupling capacitance, as well as high-frequency stray parameter interference, on the test results.

[0010] Upon responding to the test start signal, the system synchronously triggers the arbitrary waveform generator and power amplifier via the clock generator to generate and amplify the arbitrary waveform excitation signal. This enables the testing of the magnetic properties of soft magnetic materials under arbitrary waveform conditions. Furthermore, since the arbitrary waveform generator and power amplifier are triggered synchronously, the phase difference between the magnetic induction intensity and magnetic field intensity of the arbitrary waveform excitation signal and the induced signal in the primary and secondary windings caused by asynchronous triggering times under high-frequency testing conditions is reduced, thereby improving the accuracy of the test results.

[0011] Meanwhile, during magnetic performance testing, the system will also collect temperature data from the thermocouples placed on the surface of the test sample in real time, thereby achieving real-time monitoring of the surface temperature of the test sample. This avoids the adverse effects of the temperature rise of the test sample under high-frequency testing conditions on the test results. Adjusting the surface temperature of the test sample based on the collected temperature data can further reduce the adverse effects caused by the temperature rise of the test sample and excitation coil under high-frequency testing conditions.

[0012] As a preferred example, the step of responding to a test start signal by synchronously triggering an arbitrary waveform generator and a power amplifier via a clock generator to sequentially output and amplify an arbitrary waveform excitation signal and apply it to the primary excitation winding specifically includes:

[0013] In response to the test start signal triggered by the user, the clock generator is controlled to synchronously output corresponding clock signals to the power amplifier, the arbitrary waveform generator, and the integrated processing unit, so that the integrated processing unit sends a control signal to the arbitrary waveform generator and adjusts the arbitrary waveform generator and the power amplifier to the on state;

[0014] The arbitrary waveform generator is controlled to determine a corresponding first test frequency according to the control signal, and generates and outputs the arbitrary waveform excitation signal to the power amplifier according to the first test frequency, so that the power amplifier applies the amplified arbitrary waveform excitation signal to the primary excitation winding.

[0015] To further reduce measurement errors caused by different trigger times, the magnetic performance testing method provided by this invention, after responding to the test start signal, first controls the clock generator to synchronously output clock signals to the integrated processing unit and the arbitrary waveform generator, and synchronously triggers the arbitrary waveform generator, power amplifier and integrated processing unit, adjusting the trigger times of the above three to be synchronized, thereby ensuring a high degree of synchronization of time signals and avoiding measurement errors caused by the time asynchrony between input and output signals under high-frequency testing conditions.

[0016] The frequency of the arbitrary waveform excitation signal output by the arbitrary waveform generator can be adjusted by sending control signals through the integrated processing unit. This allows users to adjust the test frequency band of the soft magnetic material under test by adjusting the control signals, thus improving the flexibility and adaptability of test frequency band adjustment.

[0017] As a preferred example, the real-time acquisition of temperature data from the thermocouple placed on the surface of the test sample, and the subsequent adjustment of the surface temperature of the test sample based on the temperature data, specifically includes:

[0018] The temperature data of several thermocouples placed on the surface of the test sample are collected in real time, and the temperature data is compared with the preset temperature threshold data. Based on the calculation result, it is determined whether the surface temperature of the test sample needs to be adjusted.

[0019] If the calculation result shows that the difference between the temperature data and the temperature threshold data is greater than the preset temperature limit, then it is determined that the surface temperature needs to be adjusted, and the surface temperature is adjusted according to the temperature threshold data.

[0020] If the calculation result shows that the difference between the temperature data and the temperature threshold data is less than or equal to the temperature limit, then it is determined that no adjustment to the surface temperature is required.

[0021] To further mitigate the adverse effects of elevated test sample temperature on test results, the magnetic performance testing method provided by this invention synchronously collects surface temperature data of the test sample using several thermocouples placed on the test sample during performance testing. This data is then compared with preset temperature threshold data to determine whether the surface temperature change of the test sample exceeds the system's allowable range based on the comparison calculation results.

[0022] If the difference between the current temperature data of the test sample and the set temperature threshold data exceeds the preset range, it means that the temperature variation range of the test sample surface has exceeded the temperature fluctuation range allowed by the system. The system needs to intervene and implement corresponding temperature adjustment measures to keep the temperature variation range of the test sample within the system's allowed fluctuation range, thereby reducing the impact of temperature changes on the test results.

[0023] If the difference between the current temperature data of the test sample and the temperature threshold data is not greater than the preset range, it means that the surface temperature change range of the test sample is still within the temperature fluctuation range allowed by the system. This means that the impact of the temperature change on the test results will be regarded as a normal error that the system will produce.

[0024] As a preferred example, adjusting the surface temperature based on the temperature threshold data specifically includes:

[0025] Trigger and adjust the parameters of the corresponding temperature adjustment device according to the activation signal of the temperature adjustment device;

[0026] If the temperature adjustment device is a constant temperature control box, then the constant temperature parameters of the constant temperature control box are adjusted according to the temperature threshold data, and the adjusted constant temperature control box is turned on.

[0027] If the temperature adjustment device is a circulating liquid cooling device, the liquid cooling parameters of the circulating liquid cooling device are adjusted according to the temperature threshold data, and the adjusted circulating liquid cooling device is turned on.

[0028] By adjusting the surface temperature of the test sample using the two different temperature adjustment devices described above, the surface temperature change of the test sample can be controlled, reducing its potential impact on the test results.

[0029] Accordingly, this invention also provides a magnetic property testing device for soft magnetic materials, the magnetic property testing device comprising: an arbitrary waveform generator, a power amplifier, a signal acquisition unit, a comprehensive processing unit, a clock generator, and a thermocouple;

[0030] The arbitrary waveform generator is used to generate a corresponding arbitrary waveform excitation signal, and the arbitrary waveform excitation signal is applied to the test sample made of the soft magnetic material to be tested through the power amplifier. The test sample is wound with a secondary induction winding and a double-layer excitation coil wound in a double-turn equidistant winding manner as a primary excitation winding.

[0031] The power amplifier is used to amplify the arbitrary waveform excitation signal output by the arbitrary waveform generator and apply the amplified arbitrary waveform excitation signal to the test sample.

[0032] The signal acquisition device is used to acquire the induced signal on the secondary induction winding;

[0033] The integrated processing unit is used to calculate and output the magnetic property data of the soft magnetic material under test based on the arbitrary waveform excitation signal, the induction signal and the parameters of the test sample, and to adjust the surface temperature of the test sample based on the temperature data received from the thermocouple.

[0034] The clock generator is used to synchronously trigger the arbitrary waveform generator and the power amplifier to output and amplify the arbitrary waveform excitation signal in sequence and apply it to the primary excitation winding.

[0035] The thermocouple is used to collect the surface temperature of the test sample in real time and transmit the temperature data to the integrated processing unit.

[0036] As a preferred example, the signal acquisition device includes an integrating amplifier circuit and an analog-to-digital converter;

[0037] The integrating amplifier circuit is used to integrate and amplify the induced signal and transmit the amplified signal to the analog-to-digital converter.

[0038] The analog-to-digital converter is used to acquire the amplified inductive signal, convert the signal type of the inductive signal into a digital signal form, and transmit the processed signal to the integrated processing unit.

[0039] As a preferred example, the magnetic property testing device further includes a digital storage oscilloscope;

[0040] The digital storage oscilloscope is used to store and display the magnetic property data of the soft magnetic material under test, and the digital storage oscilloscope is electrically connected to the integrated processing unit.

[0041] With the digital storage oscilloscope, users can more intuitively determine the test results output by the system. At the same time, multiple test data stored in the oscilloscope can also be integrated and displayed to the user, so that the user can more clearly determine whether the magnetic properties of the test sample change with the change of frequency band and waveform, and the trend of the change.

[0042] As a preferred example, the soft magnetic material to be tested can be an amorphous alloy strip, a permalloy, or a magnetic powder core.

[0043] The magnetic property testing method provided by this invention can test and identify many different types of soft magnetic materials, thus expanding the range of soft magnetic materials to be tested.

[0044] As a preferred example, the primary excitation winding is made of multi-stranded wires, and the material of the primary excitation winding can be oxygen-free copper, pure silver, or copper-graphene composite material.

[0045] The primary excitation winding made of multi-stranded wires reduces the skin effect and proximity effect caused by excitation coils made of high-frequency materials under high-frequency test conditions. Furthermore, the effects of the skin effect and proximity effect can be further reduced by using materials with high conductivity, such as oxygen-free copper, pure silver, or copper-graphene composite materials, to make the excitation winding.

[0046] As a preferred example, the test sample can be made into a closed-loop ring shape, which can be achieved by strip winding or multi-layer stamping. Attached Figure Description

[0047] Figure 1 : A flowchart of an embodiment of the magnetic property testing method for soft magnetic materials provided by the present invention;

[0048] Figure 2 : A structural diagram of an embodiment of the magnetic property testing device for soft magnetic materials provided by the present invention;

[0049] Figure 3 : This is a structural diagram of the magnetic property testing system for broadband soft magnetic materials provided by the present invention;

[0050] Figure 4 : A schematic diagram of the cross-section of the multi-conductor stranded wire used for the high-frequency test excitation coil provided by the present invention. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] Example 1

[0053] Please refer to Figure 1 The flowchart below shows an embodiment of the magnetic property testing method for soft magnetic materials provided by the present invention, including steps 101 to 103, each step of which is as follows:

[0054] Step 101: The soft magnetic material to be tested is made into a closed-circuit shape to obtain the test sample, and a secondary induction winding is wound on the test sample, and a double-layer excitation coil is wound as the primary excitation winding by means of double-turn equal-distance winding.

[0055] The magnetic performance testing method provided in this invention first prepares the soft magnetic material to be tested into a closed-circuit shape to obtain the corresponding test sample. By forming a closed path with the soft magnetic material to create a magnetic closed circuit, the magnetic reluctance of the test sample is reduced, while its magnetic induction intensity and magnetic field strength are enhanced. Furthermore, by winding a double-layer excitation coil on the test sample using a double-turn, equidistant winding method as the primary excitation winding, the turn spacing of the primary excitation winding is made the same. This not only meets the magnetic performance testing requirements of soft magnetic materials under high-frequency conditions but also reduces the interference of the skin effect and proximity effect of the excitation coil in the high-frequency material on the test results under high-frequency testing conditions, improving the accuracy and reliability of the test results. Simultaneously, the method of uniformly winding the double coil along the test sample also improves the magnetization uniformity of the winding and reduces the impact of stray parameters such as high-frequency leakage current and coupling capacitance, as well as high-frequency stray parameter interference, on the test results.

[0056] In this embodiment, the soft magnetic material to be tested is preferably made into a closed-circuit shape by preparing it into a magnetic ring. That is, the test sample is preferably a ring-shaped specimen, and the magnetic ring shape is also a common type of magnetically closed-circuit specimen. After preparing the soft magnetic material to be tested into a magnetic ring-shaped test sample, no insulating layer is coated on its surface, which facilitates the subsequent winding of the primary excitation winding and the secondary induction winding onto the test sample. The test sample can be made into a ring-shaped closed-circuit shape by strip winding or multi-layer stamping.

[0057] Furthermore, the soft magnetic material to be tested in the embodiments of the present invention can be an amorphous alloy strip, permalloy, or magnetic powder core. The magnetic property testing method provided by the embodiments of the present invention can test and identify many different types of soft magnetic materials, thus expanding the range of soft magnetic materials to be tested.

[0058] The excitation coil provided in this embodiment is made using a double-coil method. After fabrication, it is wound uniformly along the axial direction of the magnetic ring. In order to reduce the high-frequency skin effect and proximity effect that will occur under high-frequency testing conditions, it is necessary to strictly ensure that the inter-turn distance of the excitation coil is the same. Therefore, in this embodiment, it is preferable to wind the double-layer excitation coil on the surface of the test sample by winding two coils at equal distances as the primary excitation winding, while the secondary induction winding will also be wound along the axial direction of the test sample.

[0059] The primary excitation winding is made of multi-stranded wires, such as... Figure 4 As shown, Figure 4 This is a schematic diagram of the cross-section of a multi-conductor stranded wire used in the high-frequency test excitation coil provided by the present invention. Furthermore, the primary excitation winding can be made of oxygen-free copper, pure silver, or a copper-graphene composite material.

[0060] The primary excitation winding made of multi-stranded wires reduces the skin effect and proximity effect caused by excitation coils made of high-frequency materials under high-frequency test conditions. Furthermore, the effects of the skin effect and proximity effect can be further reduced by using materials with high conductivity, such as oxygen-free copper, pure silver, or copper-graphene composite materials, to make the excitation winding.

[0061] Step 102: In response to the test start signal, the arbitrary waveform generator and power amplifier are synchronously triggered by the clock generator to output and amplify the arbitrary waveform excitation signal in sequence and apply it to the primary excitation winding. At the same time, the signal on the secondary induction winding is collected, and then the magnetic performance data of the soft magnetic material under test is calculated and output according to the arbitrary waveform excitation signal, the induction signal and the parameters of the test sample.

[0062] Upon responding to the test start signal, the system synchronously triggers the arbitrary waveform generator and power amplifier via the clock generator to generate and amplify the arbitrary waveform excitation signal. This enables the testing of the magnetic properties of soft magnetic materials under arbitrary waveform conditions. Furthermore, since the arbitrary waveform generator and power amplifier are triggered synchronously, the phase difference between the magnetic induction intensity and magnetic field intensity of the arbitrary waveform excitation signal and the induced signal in the primary and secondary windings caused by asynchronous triggering times under high-frequency testing conditions is reduced, thereby improving the accuracy of the test results.

[0063] Specifically, in this embodiment, in response to the test start signal, an arbitrary waveform generator and a power amplifier are synchronously triggered by a clock generator to sequentially output and amplify an arbitrary waveform excitation signal, which is then applied to the primary excitation winding. This specifically includes:

[0064] In response to the test start signal triggered by the user, the clock generator is controlled to synchronously output corresponding clock signals to the power amplifier, the arbitrary waveform generator, and the integrated processing unit, so that the integrated processing unit sends a control signal to the arbitrary waveform generator and adjusts the arbitrary waveform generator and the power amplifier to the on state;

[0065] The arbitrary waveform generator is controlled to determine a corresponding first test frequency according to the control signal, and generates and outputs the arbitrary waveform excitation signal to the power amplifier according to the first test frequency, so that the power amplifier applies the amplified arbitrary waveform excitation signal to the primary excitation winding.

[0066] To further reduce measurement errors caused by different trigger times, the magnetic performance testing method provided in this embodiment of the invention, after responding to the test start signal, first controls the clock generator to synchronously output clock signals to the integrated processing unit and the arbitrary waveform generator, and synchronously triggers the arbitrary waveform generator, power amplifier and integrated processing unit, adjusting the trigger times of the above three to be synchronized, thereby ensuring a high degree of synchronization of the time signals and avoiding measurement errors caused by the time asynchrony between the input signal and the output signal under high-frequency test conditions.

[0067] The frequency of the arbitrary waveform excitation signal output by the arbitrary waveform generator can be adjusted by sending control signals through the integrated processing unit. This allows users to adjust the test frequency band of the soft magnetic material under test by adjusting the control signals, thus improving the flexibility and adaptability of test frequency band adjustment.

[0068] In this embodiment, the user can continuously adjust the control signal output by the integrated processing unit to adjust the arbitrary waveform excitation signal output by the arbitrary waveform generator, including adjusting its frequency, so as to obtain the magnetizing magnetic field and corresponding magnetic flux density generated by the primary excitation coil at different frequencies, and further obtain the relationship curve between the two, and obtain magnetic performance indicators such as coercivity and saturation magnetic induction intensity from the relationship curve as reference data for judging the magnetic performance of the soft magnetic material under test.

[0069] Step 103: During the test, the temperature data of the thermocouple placed on the surface of the test sample is collected in real time, and then the surface temperature of the test sample is adjusted according to the temperature data.

[0070] Meanwhile, during magnetic performance testing, the system will also collect temperature data from the thermocouples placed on the surface of the test sample in real time, thereby achieving real-time monitoring of the surface temperature of the test sample. This avoids the adverse effects of the temperature rise of the test sample under high-frequency testing conditions on the test results. Adjusting the surface temperature of the test sample based on the collected temperature data can further reduce the adverse effects caused by the temperature rise of the test sample and excitation coil under high-frequency testing conditions.

[0071] Specifically, the real-time acquisition of temperature data from thermocouples placed on the surface of the test sample, as described in this embodiment, and the subsequent adjustment of the surface temperature of the test sample based on the temperature data, specifically includes:

[0072] The temperature data of several thermocouples placed on the surface of the test sample are collected in real time, and the temperature data is compared with the preset temperature threshold data. Based on the calculation result, it is determined whether the surface temperature of the test sample needs to be adjusted.

[0073] If the calculation result shows that the difference between the temperature data and the temperature threshold data is greater than the preset temperature limit, then it is determined that the surface temperature needs to be adjusted, and the surface temperature is adjusted according to the temperature threshold data.

[0074] If the calculation result shows that the difference between the temperature data and the temperature threshold data is less than or equal to the temperature limit, then it is determined that no adjustment to the surface temperature is required.

[0075] To further mitigate the adverse effects of elevated test sample temperature on test results, the magnetic performance testing method provided by this invention synchronously collects surface temperature data of the test sample using several thermocouples placed on the test sample during performance testing. This data is then compared with preset temperature threshold data to determine whether the surface temperature change of the test sample exceeds the system's allowable range based on the comparison calculation results.

[0076] If the difference between the current temperature data of the test sample and the set temperature threshold data exceeds the preset range, it means that the temperature variation range of the test sample surface has exceeded the temperature fluctuation range allowed by the system. The system needs to intervene and implement corresponding temperature adjustment measures to keep the temperature variation range of the test sample within the system's allowed fluctuation range, thereby reducing the impact of temperature changes on the test results.

[0077] If the difference between the current temperature data of the test sample and the temperature threshold data is not greater than the preset range, it means that the surface temperature change range of the test sample is still within the temperature fluctuation range allowed by the system. This means that the temperature change at this time may affect the test results and will be regarded as a normal error that the system will produce. This normal error will not affect the user's judgment of the magnetic properties of the soft magnetic material under test.

[0078] Furthermore, the adjustment of the surface temperature based on the temperature threshold data described in this embodiment specifically includes:

[0079] Trigger and adjust the parameters of the corresponding temperature adjustment device according to the activation signal of the temperature adjustment device;

[0080] If the temperature adjustment device is a constant temperature control box, then the constant temperature parameters of the constant temperature control box are adjusted according to the temperature threshold data, and the adjusted constant temperature control box is turned on.

[0081] If the temperature adjustment device is a circulating liquid cooling device, the liquid cooling parameters of the circulating liquid cooling device are adjusted according to the temperature threshold data, and the adjusted circulating liquid cooling device is turned on.

[0082] By adjusting the surface temperature of the test sample using the two different temperature adjustment devices described above, the surface temperature change of the test sample can be controlled, reducing its potential impact on the test results.

[0083] Example 2

[0084] Please see Figure 3 , Figure 3 This is a structural diagram of the magnetic property testing system for broadband soft magnetic materials provided by the present invention. This system is used to perform another method for testing the magnetic properties of soft magnetic materials provided in Embodiment 2.

[0085] like Figure 3 As shown, the magnetic property testing system for the broadband soft magnetic material includes an arbitrary waveform generator, a power amplifier, a feedback resistor, a magnetic ring, a thermocouple, an integrator, a clock generator, an analog-to-digital converter, a processing unit, and a digital storage oscilloscope. Compared to Embodiment 1, the magnetic property testing system provided in Embodiment 2 also incorporates a feedback resistor and a coaxial cable.

[0086] Depend on Figure 3Thus, the output terminal of the arbitrary waveform generator is electrically connected to the input terminal of the power amplifier, and the output terminal of the power amplifier is electrically connected to the feedback resistors R1 and R2 through a coaxial cable. The other ends of the feedback resistors R1 and R2 are both electrically connected to the primary excitation winding. The shielding layer of the coaxial cable is grounded, and the other end of the feedback resistor R2 is also electrically connected to the positive input terminal of the integrator through a coaxial cable.

[0087] Thermocouple and the test sample Figure 3 The magnetic ring shown is mechanically connected and attached to the surface of the test sample. To ensure uniform temperature distribution across the test sample surface, this embodiment employs a multi-point temperature measurement method, deploying multiple thermocouples at various points on the test sample surface and electrically connecting these thermocouples to the integrated processing unit. Figure 3 The FPGA shown has a comprehensive processing unit that reads and processes the temperature data collected by the thermocouple, i.e., the temperature measurement results.

[0088] The test samples include Figure 3 The magnetic ring shown includes a primary excitation winding (primary winding) and a secondary induction winding (secondary winding) wound around its surface. The primary excitation winding is made of a double-layer excitation coil. One coil of the double-layer excitation coil is connected to a feedback resistor R1, and the other coil is connected to a feedback resistor R2.

[0089] The secondary induction winding in the test sample is also connected to an integrator via a coaxial cable, the integrator being as follows: Figure 3 The diagram shows an AC integrating amplifier circuit consisting of resistor R3, capacitor C, and amplifier. This integrator can integrate and amplify the voltage signal output from the secondary induction winding. One end of resistor R3 in the integrator is electrically connected to the secondary winding, and the other end is connected to the negative input terminal of the amplifier. The positive input terminal of the amplifier is electrically connected to the feedback resistor R2 via a coaxial cable.

[0090] Analog-to-digital converter (ADC) Figure 3 The ADC shown converts the analog signal output from an AC integrator amplifier into a digital signal. One end of the ADC is electrically connected to the output of the amplifier, and the other end is connected to the integrated processing unit. Figure 3 The FPGA is electrically connected as shown. The ADC also embeds a sampling clock and a digital filter. The sampling clock is electrically connected to a clock generator and receives the clock signal output by the clock generator, while the digital filter is used to filter the signal output by the AC integrator amplifier.

[0091] Integrated processing unit (IPU) Figure 3 One end of the FPGA shown is electrically connected to an analog-to-digital converter (ADC) to receive the filtered signal output by the ADC, while the other end is electrically connected to a digital storage oscilloscope to transmit the synthesized digital signal to the oscilloscope for storage and display. Figure 3As shown, the integrated processing unit can be Figure 3 The field-programmable device (FPGA) shown can also be a microcontroller (MCU) or other device with digital signal processing and logic operation functions.

[0092] In summary, this embodiment is based on Figure 3 The illustrated broadband soft magnetic material magnetic property testing system also provides a corresponding method for testing the magnetic properties of broadband soft magnetic materials, the specific steps of which are as follows:

[0093] The first step is to prepare the test sample and fabricate it into a closed-loop shape, preferably a ring-shaped test sample. This can be achieved by winding a strip into a ring or by multi-layer stamping into a ring. The test sample can be a soft magnetic material suitable for broadband magnetic field conditions, such as amorphous alloy strip, permalloy, or magnetic powder core. The preferred dimensions of the magnetic ring are an inner diameter of 35±2mm and an outer diameter to inner diameter ratio of less than 1.25.

[0094] The second step is to uniformly wind a double-layer excitation coil along the axial direction of the sample being tested. This excitation coil will serve as the primary excitation winding. Figure 3 The primary winding is shown, and a second winding is wound along the axial direction of the test sample to serve as the secondary induction winding. The excitation coil should be made of Litz wire prepared from multiple strands of fine wire. To reduce the skin effect and proximity effect in the excitation coil under high-frequency excitation, the excitation coil material can be oxygen-free copper, pure silver, copper-graphene composite materials, etc., with high conductivity.

[0095] The third step is to use a clock generator to send a clock signal to trigger the arbitrary waveform generator and analog-to-digital converter to start the test.

[0096] The fourth step is to control the integrated processing unit to communicate with the arbitrary waveform generator. The integrated processing unit sends a control signal to control the arbitrary waveform generator to output an AC excitation voltage waveform with a fixed frequency f. This excitation waveform is amplified by the power amplifier and applied to the excitation coil, i.e., the primary winding, thereby generating a magnetizing magnetic field H(f).

[0097] In the fifth step, the magnetizing magnetic field H(f) in the excitation coil generates a signal in the secondary winding. The signal is integrated and amplified by the integrating amplifier circuit, and the analog-to-digital converter collects the amplified signal and transmits it to the integrated processing unit. The integrated processing unit calculates the magnetic flux density B in the test sample based on the signal in the secondary winding. The magnetic flux density is affected by the frequency and is expressed as B(f).

[0098] The sixth step involves the integrated processing unit monitoring the surface temperature of the test sample via thermocouples during testing to prevent temperature rise from affecting the test results. The surface temperature variation of the sample at different frequencies is controlled within ±1℃. If the temperature variation is large, a constant temperature control chamber or a circulating liquid cooling device is installed on the surface of the test sample to control the surface temperature of the sample.

[0099] Step 7: Continuously adjust the frequency of the excitation voltage waveform and repeat steps 3 to 5, gradually increasing the frequency to obtain the relationship curves of B(f) and H(f) at different frequencies. Based on the measured B(f) and H(f) data points, plot the BH relationship curves at different frequencies, and obtain magnetic performance indicators such as coercivity and saturation magnetic induction intensity from the BH curves.

[0100] To better illustrate the working principle and steps of the magnetic property testing method and apparatus for soft magnetic materials of the present invention, please refer to the relevant description above, but not limited to.

[0101] Accordingly, see Figure 2 , Figure 2 This is a structural diagram of one embodiment of the magnetic property testing device for soft magnetic materials provided by the present invention. Figure 2 As shown, the magnetic performance testing device includes: an arbitrary waveform generator, a power amplifier, a signal acquisition unit, a comprehensive processing unit, a clock generator, a thermocouple, and a digital storage oscilloscope.

[0102] The arbitrary waveform generator is used to generate a corresponding arbitrary waveform excitation signal, and the arbitrary waveform excitation signal is applied to the test sample made of the soft magnetic material to be tested through the power amplifier. The test sample is wound with a secondary induction winding and a double-layer excitation coil wound in a double-turn equidistant winding manner as a primary excitation winding.

[0103] The power amplifier is used to amplify the arbitrary waveform excitation signal output by the arbitrary waveform generator and apply the amplified arbitrary waveform excitation signal to the test sample.

[0104] The signal acquisition device is used to acquire the induced signal on the secondary induction winding. The signal acquisition device also includes an integrating amplifier circuit and an analog-to-digital converter. The integrating amplifier circuit is used to perform integrated amplification processing on the induced signal and transmit the amplified signal to the analog-to-digital converter. The analog-to-digital converter is used to acquire the amplified induced signal, convert the signal type of the induced signal into a digital signal form, and transmit the processed signal to the integrated processing unit.

[0105] The integrated processing unit is used to calculate and output the magnetic property data of the soft magnetic material under test based on the arbitrary waveform excitation signal, the induction signal and the parameters of the test sample, and to adjust the surface temperature of the test sample based on the temperature data received from the thermocouple.

[0106] The clock generator is used to synchronously trigger the arbitrary waveform generator and the power amplifier to output and amplify the arbitrary waveform excitation signal in sequence and apply it to the primary excitation winding.

[0107] The thermocouple is used to collect the surface temperature of the test sample in real time and transmit the temperature data to the integrated processing unit.

[0108] The digital storage oscilloscope is used to store and display the magnetic property data of the soft magnetic material under test, and the digital storage oscilloscope is electrically connected to the integrated processing unit.

[0109] With the digital storage oscilloscope, users can more intuitively determine the test results output by the system. At the same time, multiple test data stored in the oscilloscope can also be integrated and displayed to the user, so that the user can more clearly determine whether the magnetic properties of the test sample change with the change of frequency band and waveform, and the trend of the change.

[0110] In summary, this invention provides a method and apparatus for testing the magnetic properties of soft magnetic materials. The soft magnetic material to be tested is formed into a closed-circuit shape to obtain a test sample. A secondary induction winding and a double-layer excitation coil wound using a double-turn equidistant winding method are wound on the sample as the primary excitation winding. In response to a test signal, an arbitrary waveform generator and a power amplifier are synchronously triggered by a clock generator to output an arbitrary waveform excitation signal applied to the primary excitation winding. Signals on the secondary induction winding are simultaneously acquired. Magnetic property data are then calculated based on the excitation signal, the induction signal, and the sample parameters. During the test, the sample surface temperature is monitored and controlled in real time using a thermocouple. The double-turn equidistant winding method for the primary excitation winding improves the magnetization uniformity of the winding, reduces the skin effect and proximity effect, and improves the accuracy and reliability of the test results. Real-time monitoring and control of the sample surface temperature reduces the adverse effects caused by temperature changes.

[0111] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A method for testing the magnetic properties of soft magnetic materials, characterized in that, Includes the following steps: The soft magnetic material to be tested is made into a closed-circuit shape to obtain a test sample. A secondary induction winding is wound on the test sample, and a double-layer excitation coil is wound as a primary excitation winding by winding two turns at equal intervals. In response to the test start signal, the arbitrary waveform generator and power amplifier are synchronously triggered by the clock generator to output and amplify the arbitrary waveform excitation signal in sequence and apply it to the primary excitation winding. At the same time, the signal on the secondary induction winding is collected, and then the magnetic performance data of the soft magnetic material under test is calculated and output according to the arbitrary waveform excitation signal, the induction signal and the parameters of the test sample. During the test, temperature data of the thermocouple placed on the surface of the test sample is collected in real time, and the surface temperature of the test sample is then adjusted based on the temperature data.

2. The method for testing the magnetic properties of soft magnetic materials as described in claim 1, characterized in that, In response to the test start signal, the arbitrary waveform generator and power amplifier are synchronously triggered by the clock generator to sequentially output and amplify the arbitrary waveform excitation signal and apply it to the primary excitation winding. Specifically, this includes: In response to the test start signal triggered by the user, the clock generator is controlled to synchronously output corresponding clock signals to the power amplifier, the arbitrary waveform generator, and the integrated processing unit, so that the integrated processing unit sends a control signal to the arbitrary waveform generator and adjusts the arbitrary waveform generator and the power amplifier to the on state; The arbitrary waveform generator is controlled to determine a corresponding first test frequency according to the control signal, and generates and outputs the arbitrary waveform excitation signal to the power amplifier according to the first test frequency, so that the power amplifier applies the amplified arbitrary waveform excitation signal to the primary excitation winding.

3. The method for testing the magnetic properties of a soft magnetic material as described in claim 1, characterized in that, The real-time acquisition of temperature data from thermocouples placed on the surface of the test sample, and the subsequent adjustment of the surface temperature of the test sample based on the temperature data, specifically includes: The temperature data of several thermocouples placed on the surface of the test sample are collected in real time, and the temperature data is compared with the preset temperature threshold data. Based on the calculation result, it is determined whether the surface temperature of the test sample needs to be adjusted. If the calculation result shows that the difference between the temperature data and the temperature threshold data is greater than the preset temperature limit, then it is determined that the surface temperature needs to be adjusted, and the surface temperature is adjusted according to the temperature threshold data. If the calculation result shows that the difference between the temperature data and the temperature threshold data is less than or equal to the temperature limit, then it is determined that no adjustment to the surface temperature is required.

4. The method for testing the magnetic properties of soft magnetic materials as described in claim 3, characterized in that, The adjustment of the surface temperature based on the temperature threshold data specifically includes: Trigger and adjust the parameters of the corresponding temperature adjustment device according to the activation signal of the temperature adjustment device; If the temperature adjustment device is a constant temperature control box, then the constant temperature parameters of the constant temperature control box are adjusted according to the temperature threshold data, and the adjusted constant temperature control box is turned on. If the temperature adjustment device is a circulating liquid cooling device, the liquid cooling parameters of the circulating liquid cooling device are adjusted according to the temperature threshold data, and the adjusted circulating liquid cooling device is turned on.

5. A magnetic property testing device for soft magnetic materials, characterized in that, The magnetic performance testing device includes: an arbitrary waveform generator, a power amplifier, a signal acquisition unit, a comprehensive processing unit, a clock generator, and a thermocouple; The arbitrary waveform generator is used to generate a corresponding arbitrary waveform excitation signal, and the arbitrary waveform excitation signal is applied to the test sample made of the soft magnetic material to be tested through the power amplifier. The test sample is wound with a secondary induction winding and a double-layer excitation coil wound in a double-turn equidistant winding manner as a primary excitation winding. The power amplifier is used to amplify the arbitrary waveform excitation signal output by the arbitrary waveform generator and apply the amplified arbitrary waveform excitation signal to the test sample. The signal acquisition device is used to acquire the induced signal on the secondary induction winding; The integrated processing unit is used to calculate and output the magnetic property data of the soft magnetic material under test based on the arbitrary waveform excitation signal, the induction signal and the parameters of the test sample, and to adjust the surface temperature of the test sample based on the temperature data received from the thermocouple. The clock generator is used to synchronously trigger the arbitrary waveform generator and the power amplifier to output and amplify the arbitrary waveform excitation signal in sequence and apply it to the primary excitation winding. The thermocouple is used to collect the surface temperature of the test sample in real time and transmit the temperature data to the integrated processing unit.

6. The magnetic property testing device for soft magnetic materials as described in claim 5, characterized in that, The signal acquisition device includes an integrating amplifier circuit and an analog-to-digital converter; The integrating amplifier circuit is used to integrate and amplify the induced signal and transmit the amplified signal to the analog-to-digital converter. The analog-to-digital converter is used to acquire the amplified inductive signal, convert the signal type of the inductive signal into a digital signal form, and transmit the processed signal to the integrated processing unit.

7. The magnetic property testing device for soft magnetic materials as described in claim 5, characterized in that, The magnetic property testing device also includes a digital storage oscilloscope; The digital storage oscilloscope is used to store and display the magnetic property data of the soft magnetic material under test, and the digital storage oscilloscope is electrically connected to the integrated processing unit.

8. The magnetic property testing device for soft magnetic materials as described in claim 5, characterized in that, The soft magnetic material to be tested can be an amorphous alloy strip, permalloy, or magnetic powder core.

9. The magnetic property testing device for soft magnetic materials as described in claim 5, characterized in that, The primary excitation winding is made of multi-stranded wires, and the material of the primary excitation winding can be oxygen-free copper, pure silver, or copper-graphene composite material.

10. The magnetic property testing device for soft magnetic materials as described in claim 5, characterized in that, The test sample can be made into a closed-loop ring shape, which can be achieved by strip winding or multi-layer stamping.

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