Time domain BH magnetic characteristic test method

Abstract

The invention discloses a time domain BH magnetic characteristic testing method, and belongs to the field of magnetic material testing. The problems that transient information cannot be captured, the test time is long, the test precision is poor and the repeatability is poor due to the fact that an integral mode is adopted in an existing BH test are solved, pulse voltage excitation based on an H bridge is adopted, transient voltage and current information on a magnetic core is synchronously collected through a high-speed signal processing circuit, and the test accuracy is improved. The transient magnetic field intensity is calculated based on the current information, the magnetic field change condition of the magnetic core under pulse excitation can be accurately reflected, the magnetic induction intensity is calculated based on the voltage information and in combination with a local integration algorithm, and the test efficiency is improved. Errors possibly brought by a traditional integration method can be overcome, a time domain BH curve can be generated finally according to the magnetic field intensity and the magnetic induction intensity obtained through calculation, and the dynamic magnetic characteristics of the magnetic core under pulse excitation can be comprehensively reflected.

Description

Technical Field

[0001] This invention relates to the field of magnetic material testing technology, specifically a time-domain BH magnetic property testing method. Background Technology

[0002] The BH curve test for magnetic materials is the cornerstone for characterizing the core performance of magnetic materials and connecting their intrinsic properties with engineering applications. This closed loop is like the material's "magnetic fingerprint." Its shape, area, and key coordinate points (such as saturation magnetic induction s, coercivity Hc, and remanence Br) directly define the material's soft magnetic or permanent magnetic properties and determine its applicability and efficiency in specific electromagnetic devices. By analyzing the BH curve, the material's magnetization, energy product, losses (hysteresis loss is proportional to the loop area), and stability can be accurately evaluated, thus providing indispensable key data for the optimized design, material selection, and quality control of various electromagnetic components such as motors, transformers, inductors, and magnetic storage devices. Currently, BH testing methods are mainly divided into the following two categories: DC BH test: The DC detection method is to apply a quasi-static DC magnetic field and measure the process of the magnetization intensity changing slowly with the magnetic field, that is, to detect the induced voltage by applying an excitation current.

[0003] Alternating magnetic field (BH) test: By applying an alternating magnetic field and measuring the dynamic magnetization response, the hysteresis loop and loss can be obtained.

[0004] However, the existing BH testing methods still have the following problems: 1. Both of the above test methods test the BH curve of magnetic materials by integration. Whether it is DC or AC, the integration method has its own advantages, but the biggest drawback is that the integration method masks a lot of transient information and cannot accurately reflect transient information. As a result, the test results cannot meet the requirements of some application scenarios that require transient magnetic information. 2. The two testing methods mentioned above also have problems such as long testing time, poor testing accuracy, and poor repeatability. In addition, there is the problem of saturated waveform distortion when testing in AC scenarios, which requires very complex signal processing and compensation to reduce the impact.

[0005] Therefore, since it does not meet the existing requirements, we propose a time-domain BH magnetic property testing method. Summary of the Invention

[0006] The purpose of this invention is to provide a time-domain BH magnetic characteristic testing method. By employing pulse voltage excitation based on H-bridge and high-speed synchronous sampling technology, it is possible to achieve high-precision, real-time capture of the dynamic magnetization process of the magnetic core in the time domain, thereby obtaining transient voltage and current information, and then calculating the transient magnetic field strength and magnetic induction intensity, ultimately generating a time-domain BH hysteresis loop. This achieves high-precision and high-efficiency testing of the dynamic magnetic characteristics of the magnetic core, solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a time-domain BH magnetic property testing method, comprising the following steps: A pulse voltage is applied to the excitation coil of the magnetic core under test to activate the working state of the magnetic core under test; The transient voltage and current information on the magnetic core are acquired synchronously using a high-speed signal processing circuit. The transient magnetic field strength is calculated based on the current information according to the preset structural parameters of the magnetic core under test. Simultaneously, based on the preset structural parameters of the magnetic core under test and using local integration, the approximate transient magnetic induction intensity is calculated based on the voltage information. The time-domain BH curve is generated based on the values ​​of magnetic field strength and magnetic induction intensity at the same moment.

[0008] Furthermore, the pulse voltage excitation applies a pulse voltage excitation signal of specified amplitude and duration to the magnetic core under test by controlling the on / off state of the DC voltage source and the switching transistor in the H-bridge circuit.

[0009] Furthermore, based on the preset structural parameters of the magnetic core under test, the transient magnetic field strength is calculated using current information, as shown in the following formula: ; in, This represents the magnetic field strength, measured in A / m. The number of coil turns indicates the number of conductor coils wound around the magnetic core under test. This represents the current flowing through the coil wound on the magnetic core, measured in amperes (A). This indicates the average length of the circuit formed by the magnetic core under test.

[0010] Furthermore, based on the preset structural parameters of the magnetic core under test and using a local integration method, the approximate transient magnetic flux density is calculated based on the voltage information, as shown in the following formula: ; in, This represents magnetic flux density, measured in tons (T). The number of coil turns indicates the number of conductor coils wound on the magnetic core under test. This represents the effective cross-sectional area of ​​the magnetic core, in meters (m²).2 This refers to the area of ​​the cross-section of the magnetic core; This represents the instantaneous induced voltage across the coil, measured in volts (V). Indicates time, in seconds; This indicates that the induced voltage is integrated over time.

[0011] Furthermore, before applying the excitation, the magnetic core to be tested is placed in the demagnetizing device to demagnetize it. During the demagnetizing process, the magnetic induction intensity of the magnetic core is monitored in real time to ensure that the magnetic induction intensity gradually decreases to zero. When the magnetic induction intensity stabilizes near zero, the demagnetizing process is completed. At this time, the operation of the demagnetizing device is stopped, and the demagnetized magnetic core to be tested is inspected to confirm that the initial magnetic induction intensity of the magnetic core to be tested is zero.

[0012] Furthermore, the preset structural parameters of the magnetic core under test include, but are not limited to, the core shape, magnetic circuit length, effective cross-sectional area, and demagnetization coefficient.

[0013] Furthermore, a high-speed signal processing circuit is used to synchronously acquire transient voltage and current information. The voltage information on the magnetic core under test is directly sampled and read out, while the current signal is converted and read out by the sampling resistor on the left or right side of the magnetic core under test.

[0014] Furthermore, transient voltage and current information on the magnetic core are acquired synchronously, including: The voltage signals directly drawn from both ends of the magnetic core are connected to the positive and negative input terminals of a high-speed differential amplifier, while the voltage signals across the sampling resistor connected in series in the magnetic core circuit are connected to another identical differential amplifier. A single-chip ADC with multi-channel synchronous sampling function is used to ensure that voltage and current signals are sampled and held at the same instant. A single-chip ADC synchronously converts two analog signals into digital samples and writes the sample data into a dual-port RAM in real time via a parallel data bus. Paired voltage and current sample data blocks are read from the buffer via direct memory access and stamped with the same timestamp. By comparing the sampling time and numerical sequence of the two signals in real time, a digital delay compensation algorithm is used to fine-tune the time alignment, ensuring the synchronization of voltage and current data throughout the entire pulse excitation period.

[0015] Furthermore, the acquired transient voltage and current information is filtered, including: The digital filtering algorithm is determined based on the characteristics of the magnetic core under test and the noise frequency range in the test environment. The digital filtering algorithm includes low-pass filtering, high-pass filtering and band-pass filtering. Among them, low-pass filtering is used to remove high-frequency noise, high-pass filtering algorithm is used to remove DC bias or low-frequency interference, and band-pass filtering algorithm is used to retain only signals within a specific frequency range. The selected digital filtering algorithm is applied to the acquired voltage and current information, and each data point is filtered to obtain the filtered voltage and current information data. The filtered voltage and current information data are output for subsequent calculations of magnetic field strength and magnetic induction intensity, as well as the generation of time-domain BH curves.

[0016] Furthermore, based on the numerical values ​​of magnetic field strength and magnetic induction intensity at the same moment, a time-domain BH curve is generated, including: The transient magnetic field strength and transient magnetic induction intensity data points obtained from a series of discrete time points are paired to form coordinate pairs; In a two-dimensional rectangular coordinate system, the magnetic field strength is used as the horizontal axis and the magnetic induction intensity is used as the vertical axis to establish the BH plane; Following the chronological order of the time series, all data points obtained in each calculation cycle are plotted sequentially on the BH plane, and discrete points are connected by curve fitting to form a continuous, closed hysteresis loop trajectory. The generated time-domain BH curve is displayed on the user interface, while also providing local zoom and data export operations.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention employs H-bridge-based pulse voltage excitation and high-speed synchronous sampling technology to ensure that voltage and current signals are sampled and held simultaneously. This allows for accurate acquisition of the transient response of the magnetic core under pulse excitation, thereby collecting transient voltage and current information from the magnetic core. This provides a reliable data foundation for subsequent calculations of magnetic field strength and magnetic induction intensity. The transient magnetic field strength is calculated based on the current information, and the magnetic induction intensity is calculated based on the voltage information combined with a local integration algorithm. This effectively solves the problem of decreased measurement accuracy caused by phase delay and integration error in traditional AC testing methods under high-frequency conditions. Finally, a time-domain BH curve can be generated based on the calculated magnetic field strength and magnetic induction intensity, thus comprehensively reflecting the magnetic characteristics of the magnetic core. Attached Figure Description

[0018] Figure 1 This is a flowchart of the time-domain BH magnetic property testing method of the present invention; Figure 2 This is a schematic diagram of the H-bridge circuit of the present invention; Figure 3 This is a schematic diagram of the BH results of the first type of magnetic material tested according to the present invention; Figure 4This is a schematic diagram of the BH results of the second type of magnetic material tested according to the present invention. Detailed Implementation

[0019] 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.

[0020] To address the shortcomings of existing H-tests, which use integration and fail to capture transient information, while also suffering from long test times, poor accuracy, and poor repeatability, as well as saturation waveform distortion issues in AC scenarios, highly complex signal processing and compensation techniques are required to mitigate these problems. Please refer to [link to relevant documentation]. Figures 1-4 This embodiment provides the following technical solution: A time-domain BH magnetic property testing method includes the following steps: Apply a pulse voltage excitation to the excitation coil of the magnetic core under test to activate the working state of the magnetic core under test. It should be noted that the excitation method is not limited to pulse excitation, but can be sinusoidal excitation or other forms of voltage and current excitation. The transient voltage and current information on the magnetic core are synchronously acquired using a high-speed signal processing circuit. It should be noted that the circuit sampling method is not limited to the method described above, and can be used to measure voltage and current information in a way similar to sensor sampling. The transient magnetic field strength is calculated based on the current information according to the preset structural parameters of the magnetic core under test. Simultaneously, based on the preset structural parameters of the magnetic core under test and using local integration, the approximate transient magnetic induction intensity is calculated based on the voltage information. Among them, the preset structural parameters of the magnetic core under test include, but are not limited to, the core shape, magnetic circuit length, effective cross-sectional area, and demagnetization coefficient, which can provide the necessary basic data for accurately calculating the magnetic field strength and magnetic induction intensity; The time-domain BH curve is generated based on the values ​​of magnetic field strength and magnetic induction intensity at the same moment.

[0021] The technical effect of the above solution is as follows: by applying a pulse voltage excitation to the magnetic core under test to activate its working state, the transient voltage and current information are collected synchronously using a high-speed signal processing circuit, and then the transient magnetic field strength and the approximate transient magnetic induction intensity are calculated based on the preset structural parameters of the magnetic core, and finally the time-domain BH curve is generated. This method realizes efficient and accurate testing of the magnetic properties of the magnetic core, which helps to improve the accuracy and reliability of the performance evaluation of magnetic materials.

[0022] The pulse voltage excitation applies a pulse voltage excitation signal of specified amplitude and duration to the magnetic core under test by controlling the on / off state of the DC voltage source and the switching transistor in the H-bridge circuit. It should be noted that the implementation of the circuit is not limited to the form of H-bridge, and can be other methods of providing or controlling the application of pulse signals.

[0023] In this embodiment, by controlling the voltage source and the H-bridge, a pulse signal of specified amplitude and duration is applied to the magnetic core under test. The voltage information on the magnetic core under test can be directly sampled and read out, while the current signal is converted and read out by the sampling resistor on the left or right side of the magnetic core under test. Through high-precision and rapid sampling and precise control, transient voltage and current information is measured, and then the BH parameters are calculated. Figure 2 As shown, the representation of the magnetic core under test is simplified. The illustration uses a magnetic ring with a single copper wire through a central hole. The actual number of turns and the shape of the magnetic core may differ from the illustration. In addition, the control signals are not shown. The key control is divided into two parts: one part controls the pulse size and time according to the required magnetic field strength and magnetic induction intensity for the test, and the second part controls the on / off state of the H-bridge according to the test frequency.

[0024] The technical effect of the above solution is as follows: by controlling the on / off state of the DC voltage source and the switching transistor in the H-bridge circuit to apply a pulse voltage excitation signal of specified amplitude and duration, the working state of the magnetic core under test can be accurately activated, thereby ensuring the accuracy and effectiveness of the BH magnetic characteristic test in the entire time domain, and making the test results more scientific and reliable.

[0025] Based on the preset structural parameters of the magnetic core under test, the transient magnetic field strength is calculated based on the current information, as shown in the following formula: ; in, This represents the magnetic field strength, measured in A / m. The number of coil turns indicates the number of conductor coils wound around the magnetic core under test. This represents the current flowing through the coil wound on the magnetic core, measured in amperes (A). This indicates the average length of the circuit formed by the magnetic core under test.

[0026] The technical effect of the above solution is as follows: based on the preset structural parameters of the magnetic core under test and using current information to calculate the transient magnetic field strength, the transient change of magnetic field strength can be accurately obtained, which helps to analyze the magnetic properties of the magnetic core in depth, thereby providing key data support for generating accurate and reliable time-domain BH curves.

[0027] Based on the preset structural parameters of the magnetic core under test, and using a local integration method, the approximate transient magnetic flux density is calculated based on the voltage information, as shown in the following formula: ; in, This represents magnetic flux density, measured in tons (T). The number of coil turns indicates the number of conductor coils wound on the magnetic core under test. This represents the effective cross-sectional area of ​​the magnetic core, in meters (m²). 2 This refers to the area of ​​the cross-section of the magnetic core; This represents the instantaneous induced voltage across the coil, measured in volts (V). Indicates time, in seconds; This indicates that the induced voltage is integrated over time. It should be noted that, for different test scenarios, the magnetic induction intensity will be further modified by Maxwell's correction and frequency band relaxation correction.

[0028] The technical effect of the above solution is as follows: Based on voltage information, the approximate transient magnetic induction intensity is calculated by using a local integration method and combining it with the preset structural parameters of the magnetic core under test. Under complex and ever-changing transient conditions, the transient changes of magnetic induction intensity can be obtained quickly and relatively accurately. Combined with the calculation results of magnetic field intensity, it can provide complete and crucial data support for generating time-domain BH curves, thereby realizing the dynamic and accurate evaluation of the magnetic properties of the magnetic core in the time domain.

[0029] Before applying excitation, the magnetic core to be tested is placed in a demagnetizing device to demagnetize it. During the demagnetizing process, the magnetic induction intensity of the magnetic core is monitored in real time to ensure that the magnetic induction intensity gradually decreases to zero. When the magnetic induction intensity stabilizes near zero, the demagnetizing process is complete. At this time, the operation of the demagnetizing device is stopped, and the magnetic core to be tested after demagnetization is inspected to confirm that the initial magnetic induction intensity of the magnetic core to be tested is zero.

[0030] The technical effect of the above solution is as follows: by demagnetizing the magnetic core under test before applying excitation and monitoring the magnetic induction intensity in real time, the initial hysteresis effect of the magnetic core can be effectively eliminated, and the interference of the initial hysteresis on the test results can be avoided, thus providing an accurate initial state for subsequent accurate measurement of the time-domain BH magnetic properties.

[0031] Transient voltage and current information are acquired synchronously using a high-speed signal processing circuit. The voltage information on the magnetic core under test is directly sampled and read out, while the current signal is converted and read out by a sampling resistor on the left or right side of the magnetic core under test. Specifically, this includes: The voltage signals directly drawn from both ends of the magnetic core are connected to the positive and negative input terminals of a high-speed differential amplifier, while the voltage signals across the sampling resistor connected in series in the magnetic core circuit are connected to another identical differential amplifier. A single-chip ADC with multi-channel synchronous sampling function is used to ensure that voltage and current signals are sampled and held at the same instant. A single-chip ADC synchronously converts two analog signals into digital samples at a sampling rate of no less than 1 MS / s, and writes the sample data into a dual-port RAM in real time via a parallel data bus; Paired voltage and current sample data blocks are read from the buffer via direct memory access and stamped with the same timestamp. By comparing the sampling time and numerical sequence of the two signals in real time, a digital delay compensation algorithm is used to fine-tune the time alignment, ensuring the synchronization of voltage and current data throughout the entire pulse excitation period.

[0032] The technical effects of the above solution are as follows: By using a high-speed signal processing circuit to synchronously acquire transient voltage and current information, and through specific circuit design and data processing flow, high-precision and high-synchronization acquisition of voltage and current signals is achieved, providing a high-quality data foundation for subsequent accurate calculation of magnetic field strength and magnetic induction intensity and generation of time-domain BH curves, thereby improving the accuracy and efficiency of the entire time-domain BH magnetic characteristic test.

[0033] The acquired transient voltage and current information is filtered, including: The digital filtering algorithm is determined based on the characteristics of the magnetic core under test and the noise frequency range in the test environment. The digital filtering algorithm includes low-pass filtering, high-pass filtering and band-pass filtering. Among them, low-pass filtering is used to remove high-frequency noise, high-pass filtering algorithm is used to remove DC bias or low-frequency interference, and band-pass filtering algorithm is used to retain only signals within a specific frequency range. The selected digital filtering algorithm is applied to the acquired voltage and current information, and each data point is filtered to obtain the filtered voltage and current information data. The filtered voltage and current information data are output for subsequent calculations of magnetic field strength and magnetic induction intensity, as well as the generation of time-domain BH curves.

[0034] The technical effect of the above solution is as follows: by filtering the acquired transient voltage and current information, high-frequency noise, DC bias or low-frequency interference are removed, and only signals within a specific frequency range are retained, which effectively improves the purity and accuracy of the data, thereby improving the quality and reliability of the generated time-domain BH curve.

[0035] Based on the values ​​of magnetic field strength and magnetic induction intensity at the same moment, a time-domain BH curve is generated, including: The transient magnetic field strength and transient magnetic induction intensity data points at a series of discrete time points are collected and calculated, and then paired to form (H, B) coordinate pairs; In a two-dimensional rectangular coordinate system, the magnetic field strength is used as the horizontal axis and the magnetic induction intensity is used as the vertical axis to establish the BH plane; Following the chronological order of the time series, all (H, B) data points obtained in each calculation cycle are plotted sequentially on the BH plane, and the discrete points are connected by curve fitting to form a continuous, closed hysteresis loop trajectory. The generated time-domain BH curve is displayed on the user interface, while also providing local zoom and data export operations.

[0036] In this embodiment, such as Figure 3-4 As shown, the BH results for different magnetic materials are presented. In this example, the time-domain BH test not only accurately measures the BH parameters in the time domain, but also precisely measures the data of the negative permeability effect caused by magnetic aftereffect relaxation. This is of great significance for further analysis of magnetic material properties and design of magnetic products.

[0037] The technical effect of the above solution is as follows: Based on the numerical values ​​of magnetic field strength and magnetic induction intensity at the same moment, a time-domain BH curve is generated, which realizes an intuitive and accurate presentation of the dynamic change process of magnetic core magnetic properties, making it easier for staff to conduct in-depth analysis of key parameters such as magnetic hysteresis characteristics, coercivity, and remanence of the magnetic core.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A method for testing the time-domain BH magnetic properties, characterized in that, Includes the following steps: A pulse voltage is applied to the excitation coil of the magnetic core under test to activate the working state of the magnetic core under test; The transient voltage and current information on the magnetic core are acquired synchronously using a high-speed signal processing circuit. The transient magnetic field strength is calculated based on the current information according to the preset structural parameters of the magnetic core under test. Simultaneously, based on the preset structural parameters of the magnetic core under test and using local integration, the approximate transient magnetic induction intensity is calculated based on the voltage information. The time-domain BH curve is generated based on the values ​​of magnetic field strength and magnetic induction intensity at the same moment.

2. The time-domain BH magnetic property testing method according to claim 1, characterized in that, The pulse voltage excitation applies a pulse voltage excitation signal of specified amplitude and duration to the magnetic core under test by controlling the on / off state of the DC voltage source and the switching transistor in the H-bridge circuit.

3. The time-domain BH magnetic property testing method according to claim 1, characterized in that, Based on the preset structural parameters of the magnetic core under test, the transient magnetic field strength is calculated based on the current information, as shown in the following formula: in, This represents the magnetic field strength, measured in A / m. The number of coil turns indicates the number of conductor coils wound around the magnetic core under test. This represents the current flowing through the coil wound on the magnetic core, measured in amperes (A). This indicates the average length of the circuit formed by the magnetic core under test.

4. The time-domain BH magnetic property testing method according to claim 1, characterized in that, Based on the preset structural parameters of the magnetic core under test, and using a local integration method, the approximate transient magnetic flux density is calculated based on the voltage information, as shown in the following formula: in, This represents magnetic flux density, measured in tons (T). The number of coil turns indicates the number of conductor coils wound on the magnetic core under test. This represents the effective cross-sectional area of ​​the magnetic core, in meters (m²). 2 This refers to the area of ​​the cross-section of the magnetic core; This represents the instantaneous induced voltage across the coil, measured in volts (V). Indicates time, in seconds; This indicates that the induced voltage is integrated over time.

5. The time-domain BH magnetic property testing method according to claim 1, characterized in that, Before applying excitation, the magnetic core to be tested is placed in a demagnetizing device to demagnetize it. During the demagnetizing process, the magnetic induction intensity of the magnetic core is monitored in real time to ensure that the magnetic induction intensity gradually decreases to zero. When the magnetic induction intensity stabilizes near zero, the demagnetizing process is complete. At this time, the operation of the demagnetizing device is stopped, and the magnetic core to be tested after demagnetization is inspected to confirm that the initial magnetic induction intensity of the magnetic core to be tested is zero.

6. The time-domain BH magnetic property testing method according to claim 1, characterized in that, The preset structural parameters of the magnetic core under test include, but are not limited to, core shape, magnetic circuit length, effective cross-sectional area, and demagnetization coefficient.

7. The time-domain BH magnetic property testing method according to claim 1, characterized in that, Transient voltage and current information are acquired synchronously using a high-speed signal processing circuit. The voltage information on the magnetic core under test is directly sampled and read out, while the current signal is converted and read out by the sampling resistor on the left or right side of the magnetic core under test.

8. The time-domain BH magnetic property testing method according to claim 7, characterized in that, Synchronously acquire transient voltage and current information on the magnetic core, including: The voltage signals directly drawn from both ends of the magnetic core are connected to the positive and negative input terminals of a high-speed differential amplifier, while the voltage signals across the sampling resistor connected in series in the magnetic core circuit are connected to another identical differential amplifier. A single-chip ADC with multi-channel synchronous sampling function is used to ensure that voltage and current signals are sampled and held at the same instant. A single-chip ADC synchronously converts two analog signals into digital samples and writes the sample data into a dual-port RAM in real time via a parallel data bus. Paired voltage and current sample data blocks are read from the buffer via direct memory access and stamped with the same timestamp. By comparing the sampling time and numerical sequence of the two signals in real time, a digital delay compensation algorithm is used to fine-tune the time alignment, ensuring the synchronization of voltage and current data throughout the entire pulse excitation period.

9. The time-domain BH magnetic property testing method according to claim 1, characterized in that, The acquired transient voltage and current information is filtered, including: The digital filtering algorithm is determined based on the characteristics of the magnetic core under test and the noise frequency range in the test environment. The digital filtering algorithm includes low-pass filtering, high-pass filtering and band-pass filtering. Among them, low-pass filtering is used to remove high-frequency noise, high-pass filtering algorithm is used to remove DC bias or low-frequency interference, and band-pass filtering algorithm is used to retain only signals within a specific frequency range. The selected digital filtering algorithm is applied to the acquired voltage and current information, and each data point is filtered to obtain the filtered voltage and current information data. The filtered voltage and current information data are output for subsequent calculations of magnetic field strength and magnetic induction intensity, as well as the generation of time-domain BH curves.

10. The time-domain BH magnetic property testing method according to claim 1, characterized in that, Based on the values ​​of magnetic field strength and magnetic induction intensity at the same moment, a time-domain BH curve is generated, including: The transient magnetic field strength and transient magnetic induction intensity data points at a series of discrete time points are collected and calculated, and then paired to form coordinate pairs; In a two-dimensional rectangular coordinate system, the magnetic field strength is used as the horizontal axis and the magnetic induction intensity is used as the vertical axis to establish the BH plane; Following the chronological order of the time series, all data points obtained in each calculation cycle are plotted sequentially on the BH plane, and discrete points are connected by curve fitting to form a continuous, closed hysteresis loop trajectory. The generated time-domain BH curve is displayed on the user interface, while also providing local zoom and data export operations.

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