60results about "Permeability measurements" patented technology

The invention relates to the technical field of bearing detection, and discloses a bearing fault diagnosis method and system, and the system comprises the steps that an acquisition unit collects magnetic signals of a to-be-detected bearing in a non-contact manner in the operation process of the to-be-detected bearing, and the magnetic signals specifically comprise magnetic flux density and magnetic conductivity; the preprocessing unit is used for preprocessing the acquired magnetic signals to form signal fragments to be analyzed; the first processing unit judges whether an early fault exists or not according to the preprocessed magnetic conductivity; the second processing unit extracts a fault discrimination feature vector based on Hilbert transform and wavelet packet reconstruction, inputs the fault discrimination feature vector into a historical discrimination database or a health state baseline model, and outputs a judgment result of a fault degree; the early warning unit determines an alarm level according to the fault degree and an early fault. According to the method, continuous sensing of multi-stage fault states is realized, and the recognition capability of early micro-damage such as fatigue cracks and local stripping is effectively improved.

The invention relates to the technical field of low-temperature environment simulation and material characteristic test, in particular to a high-speed rail traction system fault diagnosis method based on electromagnetic parameter fusion, which is used for solving the problems of material electromagnetic characteristic test distortion and fault diagnosis algorithm verification deficiency in a high and cold environment. The method comprises the following steps: constructing a multi-physical field coupling test environment, simulating temperature cycle and humidity sudden change working conditions from-50 DEG C to + 80 DEG C, and synchronously acquiring dynamic parameters of resistivity, dielectric loss and magnetic conductivity; according to the method, the limitation of a traditional static test is broken through, the real representation of the material performance degradation rule is realized, a closed-loop verification system of laboratory and field data is constructed, and the performance of the material is verified. The accuracy and environmental adaptability of fault diagnosis in a high and cold environment are remarkably improved, and reliable guarantee is provided for safe operation of a traction system under an extreme working condition.

The application provides a kind of bar type magnetic core effective permeability low frequency distribution measurement method and device, it is related to low frequency fluctuation detection and application technical field.The method comprises: winding test coil on coil framework, the winding length of test coil is measured and the number of turns is recorded;Test magnetic core is inserted into different positions of test coil, and the inductance of test coil is measured when test magnetic core is in different positions;According to the relationship between permeability and inductance, the area average effective permeability of test magnetic core in different positions is calculated;Based on the preset algorithm, the effective permeability distribution function of test magnetic core is fitted;According to the effective permeability distribution function of test magnetic core, the effective permeability distribution function of the bar type iron-based nanocrystalline alloy magnetic core to be measured is obtained.The application can reduce the measurement error of magnetic core effective permeability, improve the modeling reliability, and obtain the effective permeability distribution function, so as to reduce repeated experiments and improve the modeling efficiency.

A sensor apparatus for determining and / or monitoring a process variable of a medium in a containment includes: a crystal body including at least one defect; a magnetic field system for producing a magnetic field in the region of the crystal body and in the region of the medium within the containment, wherein the crystal body and the magnetic field system are arrangeable from the outside at a wall of the containment; a detection unit for detecting a magnetic field-dependent, fluorescent signal from the crystal body, wherein the detection unit has an excitation unit for optical exciting of the defect and a detector for detecting the fluorescent signal; and an evaluation unit for ascertaining at least one piece of information concerning the process variable based on the fluorescent signal.

This invention provides a method for constructing a magnetic property measurement system for magnetic materials based on an LLC resonant circuit, belonging to the field of switching converter technology. The measurement system includes: a DC power supply. V in Square wave generator, resonant capacitor C r Resonant inductor L r Magnetic ring, primary winding of magnetic ring L p Secondary winding of magnetic ring L s rectifier and filter capacitor C 0. Load L o And a power analyzer; wherein, the magnetic ring is made based on the magnetic material to be tested; wherein, a DC power supply V in Square wave generator, resonant capacitor C r and resonant inductor L r Connect sequentially and connect to the primary winding of the magnetic ring. L p resonant capacitor C r Resonant inductor L r and the primary winding of the magnetic ring L p excitation inductor L m Forming a resonant circuit; the rectifier is connected to the secondary winding of the magnetic ring. L s A filter capacitor is connected in parallel across the rectifier. C 0 and load L o A power analyzer is used to collect the primary-side current and secondary-side voltage of a magnetic ring to determine the magnetic characteristic parameters of the magnetic material under test. This invention can reduce the error in the measurement results of the magnetic characteristics of magnetic materials.

The application discloses a kind of anti DC bias magnetic methods and current transformers based on magnetic permeability feedback compensation, comprising: the magnetic permeability of current transformer core is acquired in real time by magnetic permeability measuring unit;According to the relationship model of magnetic permeability and DC component established in advance, the DC component of invading current transformer is determined based on the magnetic permeability acquired;DC bias compensation unit generates reverse DC counter-biasing according to the DC component determined on compensation winding.The application realizes real-time monitoring and dynamic compensation adjustment to the magnetization state of transformer core by introducing magnetic permeability measuring unit and magnetic permeability feedback control, compared with traditional open-loop compensation or simple current feedback, can more accurately judge the saturation degree of magnetic core, adjusts compensation strategy in time according to the change of magnetic core state, effectively avoids compensation lag or overcompensation problem, improves the adaptability and measurement stability of transformer in complex current environment.

The invention relates to the field of composite material electromagnetic parameter testing, in particular to a composite material electromagnetic parameter automatic testing system based on vector network analysis. The data acquisition module is used for acquiring electromagnetic characteristic parameters through the vector network analyzer; acquiring an environment temperature; analyzing an electromagnetic characteristic characterization value according to the electromagnetic characteristic parameters through a data analysis module; evaluating whether the electromagnetic parameter automatic test system meets the standard or not through a standard evaluation module; determining, by the compensation control module, a cause of non-compliance with the criteria based on the ambient temperature; and determining to start a test area temperature compensation device or determine whether to start an electromagnetic shielding device based on the reason that the test area does not accord with the standard. By analyzing the reason that the automatic test system does not meet the standard, the environment temperature is adjusted or the electromagnetic interference is eliminated according to the reason, so that the precision of the automatic test system for the electromagnetic parameters of the composite material based on vector network analysis is remarkably improved.

This invention relates to a testing device for the magnetic properties of high-permeability materials under low-frequency weak magnetic environments, comprising: a coil assembly, a magnetic property tester, a magnetic shielding cylinder, and a host computer; the coil assembly is wound around the sample under test and connected to the magnetic property tester, and the sample under test with the coil assembly placed inside the magnetic shielding cylinder; the magnetic shielding cylinder provides a weak magnetic environment for the sample under test; the magnetic property tester is used to provide excitation current to the coil assembly and detect the induced voltage of the sample under test, and transmit the measured data to the host computer; the host computer is used to acquire the data measured by the magnetic property tester and plot the magnetization curve. The technical solution of this invention solves the problem that current magnetic property testing devices for magnetic materials cannot obtain the permeability of high-permeability materials under low-frequency weak magnetic environments, thereby improving the accuracy and precision of theoretical and simulation calculations of magnetic shielding devices and reducing the error between design and actual values.

The present invention relates to the field of data processing technology, and specifically to a method and system for online monitoring the inductance of an inductor device, comprising: determining the magnetic leakage ratio of the inductor device at the current moment based on the proportion of the core insertion length in the coil length at the current moment, combined with the minimum and maximum magnetic leakage ratios, then determining the effective change in the magnetic permeability of the core of the inductor device at the current moment, determining the effective total magnetic resistance of the electromagnetic device at the current moment based on the vacuum magnetic permeability, the coil length, the relative magnetic permeability and cross-sectional area of ​​the core, and the core insertion length at the current moment, combined with the effective change, and determining the true effective inductance of the inductor device at the current moment based on the effective total magnetic resistance and the number of coil turns, combined with the magnetic leakage ratio of the inductor device at the current moment. The present invention improves the accuracy of online monitoring of the inductance of the inductor device.

Provided herein is a magnetic permeability measuring method including measuring a measured permeability coefficient of the magnetic material using a measuring probe; setting an analysis model corresponding to a measurement condition, and calculating, using finite element analysis, a calculated permeability coefficient of the magnetic material in the analysis model and the magnetic permeability of the magnetic material corresponding to the calculated permeability coefficient; acquiring a first set including a plurality of pairs of real-parts and imaginary-parts of the magnetic permeability corresponding to a real-part of the calculated permeability coefficient that matches a real-part of the measured permeability coefficient; acquiring a second set including a plurality of pairs of real-parts and imaginary-parts of the magnetic permeability corresponding to an imaginary-part of the calculated permeability coefficient that matches an imaginary-part of the measured permeability coefficient; and determining the magnetic permeability whose real-part and imaginary-part match in the first and second sets.

The invention relates to a material magnetic permeability temperature stability testing device and method based on an atomic magnetometer, characterized in that the device comprises an atomic magnetometer, a magnetic material layer, a flexible heating coil, a temperature sensor, a simulated magnetic field coil, a magnetic shielding unit, a magnetic field control module, a temperature data acquisition module, a temperature control module, a magnetometer circuit acquisition control module, and a multifunctional host computer. The atomic magnetometer tests the magnetic shielding coefficient of the magnetic material layer. After the flexible heating coil heats the magnetic material layer to a specific temperature, the atomic magnetometer measures magnetic noise and incorporates the magnetic noise into the relationship between the shielding coefficient and the magnetic permeability to calculate the material magnetic permeability at different temperatures. The temperature stability of the material magnetic permeability is analyzed, which is conducive to in-situ measurement of the magnetic permeability temperature stability of the formed magnetic shielding barrel material. At the same time, the device can effectively avoid the problems of multiple measurements, the influence of the number of coil turns, and the inability to flexibly adjust the test voltage and frequency in traditional magnetic permeability testing methods.

The application provides a multi-coil incremental permeability dynamic detection probe and a yield strength detection method. The probe mode of the multi-coil is used to detect different positions of materials in different magnetization states at the same time. In the movement process, the mechanical properties of the materials can be quickly and efficiently predicted. Compared with the traditional static detection mode, the dynamic detection probe can be used for continuous detection, so as to improve the detection efficiency and realize the purpose of pipeline detection operation.

This application proposes a magnetic coupling coil optimization method. The method comprises: calculating an equivalent magnetic permeability of a magnetic coupling coil based on an air gap length of the magnetic coupling coil; calculating an effective cross-sectional area of the magnetic coupling coil based on the equivalent magnetic permeability and the power of the magnetic coupling coil; calculating a number of turns of the secondary winding of the magnetic coupling coil based on the effective cross-sectional area and the equivalent magnetic permeability; optimizing the magnetic coupling coil based on the number of turns of the secondary winding. The present application can reasonably configure the parameters of the magnetic coupling coil, effectively acquire energy from the power grid to provide stable power for detection or communication equipment in the power grid, and make the magnetic coupling coil more reliable while meeting the power demand.

The application discloses a current transformer measurement method, and particularly relates to the field of current transformer monitoring and measurement, which comprises the following steps: before the measurement of the current transformer starts, the nanocrystalline material made core of the current transformer is initially magnetized, and the core is brought to a saturation state through a magnetic field; a known alternating current signal is applied to the current transformer through a primary winding, the alternating current generates an alternating magnetic field in the core, and the magnetic flux in the core changes; after the current transformer senses the change of the current, an induced electromotive force is generated through a secondary winding, and a measurement value is represented; the induced current in the secondary winding and the induced current of the primary winding change in a fixed proportional relationship, and the induced current is transmitted to a measurement device for collection. Through real-time monitoring of the external mechanical stress density and the core magnetic permeability decline rate, the system can timely judge and respond to the high stress state, and ensure the working stability and measurement accuracy of the current transformer under the high stress condition.

The present invention relates to the field of grain detection technology and discloses a device and method for measuring grain electromagnetic parameters. This device aims to address the poor accuracy of existing electromagnetic parameter detection methods. The solution primarily comprises a temperature sensor, a coaxial transmission line structure, a vector network analyzer, and a control module. The coaxial transmission line structure includes a cylindrical inner conductor and an outer conductor, the inner conductor being located on the central axis of the outer conductor, with a hollow structure formed between the inner and outer conductors. The hollow structure is used to hold grain, the temperature sensor is used to detect the grain temperature, the vector network analyzer is used to calculate the grain's electromagnetic parameters based on the amplitude and phase of the output and input electromagnetic wave signals, and the control module is used to establish a mapping relationship between the grain temperature and the electromagnetic parameters, which is used to detect the grain pile temperature. The radii of the inner and outer conductors meet impedance matching conditions. The present invention improves the accuracy of grain electromagnetic parameter measurement and is applicable to various types of grain.

The present invention provides a system and method for measuring the electromagnetic parameters of materials in a strong microwave electric field environment based on parallel strips, belonging to the field of microwave testing technology. The present invention innovatively designs a double-sided parallel strip with a slotted structure, and constructs a measurement system under strong microwave electric field loading based on the double-sided parallel strip. The test sample is tested by separating the test frequency from the strong microwave electric field frequency, and the reflection coefficient and transmission coefficient of the test sample are obtained, thereby calculating the electromagnetic parameters of the material to be tested under the microwave strong field loading environment. The measurement system of the present invention realizes the decoupling of the test frequency and the strong microwave electric field frequency, that is, the test frequency is no longer determined by the setting of the microwave electric field frequency, thereby meeting the testing requirements at different frequencies.

The present invention relates to techniques for determining the electromagnetic response of an electrical component made of ferromagnetic material, wherein the magnetic permeability and the electric permittivity of the ferromagnetic material are derived from VNA measurements of the complex impedance and complex capacitance by means of the complex reflection coefficients- The magnetic permeability and the electric permittivity are then used in solving Maxwell's e guations using numerical simulation technigues.

The present invention relates to techniques for determining the electromagnetic response of an electrical component made of ferromagnetic material, wherein the magnetic permeability and the electric permittivity of the ferromagnetic material are derived from VNA measurements of the complex impedance and complex capacitance by means of the complex reflection coefficients- The magnetic permeability and the electric permittivity are then used in solving Maxwell's e guations using numerical simulation technigues.

Provided is a magnetic permeability measurement probe capable of accurately measuring the magnetic permeability, in particular the imaginary part of a complex permeability, of a magnetic material. The probe for measuring the magnetic permeability of a magnetic material comprises: a band-shaped strip conductor formed on the front surface of a dielectric substrate; a transmission line body having a grounding conductor formed on the front surface or the back surface of the dielectric substrate; a first connector that connects to one end of each of the strip conductor and the grounding conductor; and a second connector that connects to the other end of each of the strip conductor and the grounding conductor. The strip conductor is composed of a first length part including a portion that connects to the first connector at the one end side, a second length part including a portion that connects to the second connector at the other end, and a third length part that extends between the first length part and the second length part. The third length part has a current imbalance reducing means.

The present invention provides a device for testing the magnetic permeability of an absorbing material, comprising: a rotating portion comprising a first rotating member and a second rotating member, the first rotating member and the second rotating member rotating in conjunction with each other and driving the absorbing material; an inductance testing portion having an opening for accommodating the passage of the absorbing material, the testing coil being disposed on the opening; and a thickness measuring portion comprising a first thickness measuring member and a second thickness measuring member, the first and second thickness measuring members being disposed opposite each other, with a test area for the absorbing material to pass between the first and second thickness measuring members; wherein the inductance testing portion and the thickness measuring portion are disposed between the first and second rotating members. The device for testing the magnetic permeability of an absorbing material provided by the present invention can continuously test the magnetic permeability of the absorbing material without damaging the absorbing material, thereby achieving continuous testing of the magnetic properties of the absorbing material.

The invention provides a three-dimensional nonlinear magnetic material equivalent circuit model and a test method, and is applied to the technical field of power electronics. According to the model, a current source module applies bias current and excitation current to a nonlinear coupling packaging module; a plurality of node ports of the nonlinear coupling packaging module are connected with physical coupling nodes of a plurality of nonlinear coupling devices; the mapping sub-module maps the plurality of physical coupling nodes and the plurality of nonlinear coupling devices, constructs an analog nonlinear coupling circuit according to a connection coupling relation between the linear damping module and the plurality of nonlinear coupling devices, and responds to an applied bias current and an excitation current, so that the nonlinear coupling circuit is simulated. The analog nonlinear inductance unit is coupled to generate an analog induced voltage, and the analog induced voltage is applied to the linear damping module and other analog nonlinear devices through a plurality of node ports to reproduce a magnetic domain rotation coupling effect and an anisotropic hysteresis effect; the linear damping module responds to the analog induced voltage and reproduces a damping effect in combination with the analog nonlinear resistor unit.

The present invention relates to the field of bearing detection technology, and discloses a bearing fault diagnosis method and system, which includes: an acquisition unit that non-contactly acquires magnetic signals from a bearing to be detected during its operation, the magnetic signals specifically including magnetic flux density and magnetic permeability; a preprocessing unit that preprocesses the acquired magnetic signals to form signal segments to be analyzed; a first processing unit that determines whether an early-stage fault exists based on the preprocessed magnetic permeability; a second processing unit that extracts a fault discrimination feature vector based on Hilbert transform and wavelet packet reconstruction, inputs the fault discrimination feature vector into a historical discrimination database or a health status baseline model, and outputs a judgment result on the degree of the fault; and an early warning unit that determines an alarm level based on the degree of the fault and the early-stage fault. This application realizes continuous perception of multi-stage fault states, effectively improving the ability to identify early-stage micro-damages such as fatigue cracks and local debonding.

A method includes receiving, from a plurality of magnetic field receivers including magnetic sensors, data characterizing samples obtained by the plurality of magnetic field receivers, the samples of a combination of a first magnetic field and a second magnetic field resulting from interaction of the first magnetic field and an object; determining, using the received data, a polarizability index of the object, the polarizability index characterizing a magnetic polarizability property of the object; classifying, using the determined polarizability index, the object as threat or non-threat; and providing the classification. Related apparatus, systems, techniques, and articles are also described.

This invention provides a method for detecting and calculating the austenite content in steel based on a permeability meter, relating to the fields of steel and electromagnetics. Based on the theoretical differences in saturation magnetization of different phases in ferromagnetic materials, this invention establishes a theoretical calculation model and detection method for measuring austenite content using a permeability meter. A standard-prepared sample is placed in a magnetic pole shoe, and the magnetic field strength H corresponding to the maximum permeability of the ferromagnetic material is first measured. μ Then at ≥1.5H μ Under a magnetic field strength of J, the polarization intensity of the magnetic field strength at multiple points was measured at continuous intervals. m Then, based on the saturation magnetization approximation law and derivation law, the saturation magnetization Js is fitted and solved. Finally, the austenite content is determined according to the theoretical calculation model of austenite content. The method described in this invention solves the influence of the constantly changing effective magnetic path length of traditional magnetometers on the measurement results. The method for determining austenite content is simple, has a solid theoretical basis, high measurement accuracy, and strong data repeatability.

The invention relates to a transformer fault detection method and device based on a temperature-magnetic conductivity coupling effect. The method comprises the following steps: acquiring current leakage magnetic field measured data, current temperature data and current winding terminal voltage data of a transformer; calculating the time-varying phase permeability, the time-varying winding inductance and the time-varying winding resistance according to the current temperature data; inputting the time-varying winding inductance, the time-varying winding resistance and the current winding end voltage data into a winding current time-varying response model to calculate a time-varying winding current; determining current leakage magnetic field theoretical data in the transformer; the current leakage magnetic field theoretical data is obtained by synthesizing a steady-state leakage magnetic field and a fault disturbance field corresponding to each preset fault type; calculating a magnetic balance tensor and a deformation positioning tensor; and under the condition that the magnetic balance tensor or the deformation positioning tensor meets a preset fault criterion, executing fault alarm. By adopting the method, rapid and accurate detection of transformer winding deformation and turn-to-turn short circuit faults can be realized.

The present application relates to the field of composite material electromagnetic parameter test, especially to a kind of composite material electromagnetic parameter automation test system based on vector network analysis.The present application obtains electromagnetic characteristic parameter by vector network analyzer through data acquisition module;And obtain ambient temperature;According to the electromagnetic characteristic parameter analysis electromagnetic characteristic representation value by data analysis module;Whether the electromagnetic parameter automation test system meets the standard is evaluated by standard evaluation module;The reason of not meeting the standard is determined based on ambient temperature by compensation control module;And based on the reason of not meeting the standard, it is determined to open test area temperature compensation device, or, it is determined whether to open electromagnetic shielding device.The present application improves the accuracy of the composite material electromagnetic parameter automation test system based on vector network analysis by analyzing the reason of not meeting the standard of automatic test system, and adjusting ambient temperature or eliminating electromagnetic interference according to the reason.

The measurement device for measuring permeability and permittivity of an object, includes a probe in which a signal transmission line is formed and on which the object is capable of being disposed close to or in contact with the signal transmission line; a magnetic-field application unit configured to apply a magnetic-field to the object; a signal measurement instrument configured to measure a signal transmitted through the signal transmission line in each state in which the object is disposed and not disposed on the signal transmission line and in each state in which the magnetic-field is applied and not applied; a permeability processing unit configured to obtain the permeability of the object; and a permittivity processing unit configured to obtain the permittivity of the object, the both units obtaining based on the signal transmitted through the signal transmission line in each state in which the magnetic-field is applied and not applied.

A method includes receiving, from a plurality of magnetic field receivers including magnetic sensors, data characterizing samples obtained by the plurality of magnetic field receivers, the samples of a combination of a first magnetic field and a second magnetic field resulting from interaction of the first magnetic field and an object; determining, using the received data, a polarizability index of the object, the polarizability index characterizing a magnetic polarizability property of the object; classifying, using the determined polarizability index, the object as threat or non-threat; and providing the classification. Related apparatus, systems, techniques, and articles are also described.

The present invention discloses a method and system for measuring the magnetic permeability of a flat plate, comprising: placing a flat plate of soft magnetic material within a spatial range of a uniform magnetic field; measuring the magnetic field strength of the soft magnetic material flat plate before and after placement at a plurality of measurement points within the spatial range; establishing a magnetic field distribution model around the soft magnetic material flat plate to obtain the theoretical magnetic field strength of the plurality of measurement points; calculating the theoretical magnetic induction intensity and the actual magnetic induction intensity of the measurement points after the soft magnetic material flat plate is placed, and establishing a fitness function with the flat plate magnetic permeability as an unknown quantity; optimizing and solving the problem with the minimum fitness function as the goal to obtain the flat plate magnetic permeability. The present invention tests flat plate samples for actual installation of shielding bodies, and can directly obtain the magnetic permeability of the shielding layer structure, which can truly reflect the magnetic properties of the soft magnetic material flat plate; the process of measuring and obtaining the magnetic permeability is simple and fast, and the data can be read and detected after the plate to be tested is placed, resulting in high testing efficiency.

The invention discloses a magnetic conductivity detection device and method, and belongs to the technical field of soft magnetic material testing, the magnetic conductivity detection device comprises a control panel, a digital multimeter, a signal amplifier, a signal generator and a resistor unit, the control panel is provided with a first binding post group, a second binding post group, a third binding post group, a fourth binding post group and a voltage switch, the signal amplifier is configured to output a test signal to the excitation coil through the fourth binding post group, so that the excitation coil generates excitation voltage; the input end of the signal amplifier is electrically connected with the second binding post group, and the signal amplifier is configured to amplify the induction voltage of the induction coil; the voltage switch comprises a first connecting end, a second connecting end, a third connecting end and a first control end, and the first control end is configured to enable the voltage switch to output the excitation voltage or the amplified induced voltage to the digital multimeter. According to the magnetic conductivity detection device provided by the invention, the soft magnetic material can be detected under the condition of low frequency and low magnetic field.