3020 results about "Eddy current" patented technology

The invention provides a method for measuring the conductivity and the inner diameter of a pipeline based on sweep frequency eddy current. The method comprises the following steps: establishing an eddy current detection device, designing an absolute eddy current detection coil, placing the coil in a metal pipeline, arranging the coil and the pipeline coaxially, introducing alternating current to excite an alternating magnetic field, and inducing eddy current on the surface and the near surface of the pipeline; establishing a metal pipeline eddy current analysis theoretical model, setting coil geometric parameters, and calculating an analysis expression of coil impedance changing along with excitation frequency; calculating the peak frequency and the corresponding phase value of the impedance phase of the coil in a frequency sweep mode, respectively changing the conductivity and the inner diameter of the pipeline, extracting the corresponding peak frequency and phase value, and constructing an inner diameter relation model based on quadratic curve fitting and a conductivity relation model based on power function fitting; and inverting the inner diameter and the conductivity of the metal pipeline by combining a coil impedance sweep frequency phase measurement result. The method can be used for simultaneously measuring the conductivity and the inner diameter of the pipeline, and is suitable for nondestructive testing and performance evaluation of the metal pipeline.

The invention relates to the technical field of fault diagnosis of power electronic equipment, and particularly discloses a fault analysis and diagnosis method and system for a mining high-voltage frequency converter, and the method comprises the steps: collecting the skin effect depth and parasitic parameter drift distance in real time under a high-frequency working condition through a multi-physics field sensor array; constructing three-dimensional current density distribution of the conductor based on a non-Euclidean space mesh generation technology, and dynamically correcting the equivalent resistivity of the conductor in combination with a metamaterial database to calculate a dynamic eddy current loss characteristic value; optimizing and solving the parasitic parameter time-varying evolution equation by using a quantum annealing algorithm to obtain a voltage peak sensitivity characteristic value; inputting the characteristic value into a pre-trained deep residual shrinkage network diagnosis model for multi-modal fusion analysis, and outputting a fault risk assessment result; according to the method, the problem of parasitic parameter time-varying characteristic modeling in the vibration environment is innovatively solved, and early warning of hidden faults is achieved.

The invention relates to the technical field of electromagnetic relay control, in particular to an electromagnetic relay control system, which comprises a relay execution unit, a contact state monitoring unit and an intelligent viscosity elimination control unit, and is characterized in that the contact state monitoring unit acquires quantum tunneling effect impedance spectroscopy and acoustic emission energy entropy change signals in real time; the intelligent viscosity-eliminating control unit analyzes signals through a fusion welding risk multi-dimensional evaluator, triggers a three-stage control sequence, firstly starts a magnetostriction high-frequency oscillator to inject an inverted eddy current array, activates a hysteresis loop restorer to apply a gradient demagnetization potential field if the fusion welding risk multi-dimensional evaluator is not recovered, and finally, recovers the fusion welding risk multi-dimensional evaluator; when an acoustic emission signal is abnormal, a chaotic encryption message is generated through the fault feature topology generator and is linked with the magnetic solitary wave breaking device, ultrasonic frequency mechanical energy can be captured and converted into regenerative current, an adhesion evolution path is reconstructed after diagnosis, the problems of contact adhesion risk identification lagging and lack of multi-physics field cooperative control in the prior art are solved, and the reliability of the contact adhesion risk identification is improved. And the adhesion early warning success rate and the removal efficiency are improved.

The invention provides a body armor composite interlayer defect positioning method and system based on multi-modal nondestructive testing, electronic equipment and a storage medium, and relates to the technical field of nondestructive testing. Ultrasonic guided wave, pulsed eddy current and infrared thermal wave excitation signals are synchronously applied to a body armor composite interlayer, and multi-modal response signals of all positions are collected; and generating an original multi-modal response signal set. And inputting the signal into a pre-trained deep convolutional neural network, determining a target frequency band parameter and a target noise suppression parameter of each modal response signal, and outputting an adaptive modulation parameter group. Performing frequency domain filtering and noise suppression processing on an original signal set to generate an optimized signal set, inputting spatial frequency features into a cross-modal feature fusion model, adaptively associating defect sensitive features of different modals through an attention mechanism in the model, and generating a three-dimensional defect distribution diagram of the composite interlayer, thereby realizing millimeter-level precision defect positioning. The precision and efficiency of body armor composite interlayer defect positioning can be improved.

The invention provides an intelligent eddy current nondestructive testing method and system based on a flexible GMR sensor array, and relates to the technical field of nondestructive testing. According to the invention, a GMR sensor array and a micro excitation coil array are integrated on a flexible substrate, and synchronous acquisition under multi-frequency and multi-phase excitation is realized by establishing a probe-workpiece unified space coordinate system and a time synchronization reference; performing temperature drift compensation, attitude correction and gap normalization processing on the original response tensor to generate a corrected response tensor; the intelligent inversion model based on the prior constraint of the electromagnetic field jointly identifies the conductivity, the thickness and the crack parameters, and outputs a defect parameter map and a confidence map; and a detection report containing the position, the size, the depth and the confidence coefficient is generated through spatial clustering and connectivity analysis, so that high-sensitivity and high-reliability nondestructive detection under a complex curved surface structure is realized.

The embodiment of the invention discloses a transformer transient temperature rise prediction method and device and a storage medium, and the method comprises the steps: constructing a two-dimensional model, calculating the magnetic flux density distribution conditions of a transformer iron core and a winding under a first preset load rate condition, and further obtaining an iron core loss value and an eddy current loss value of the winding, the method is used as heat source excitation of a temperature-flow field of the transformer, a step type function is adopted for representation and is substituted into a heat flow field coupling calculation model, electromagnetism, fluid mechanics, heat transfer theory and a finite element method are involved, and the problem that transient temperature rise simulation calculation of the dry type transformer under different load rates is difficult to converge can be effectively and accurately solved.

The invention discloses a pulsed eddy current detection method and system for a thermal power pipeline with a coating layer, and relates to the technical field of pulsed eddy current nondestructive detection.The pulsed eddy current detection method comprises the steps that pulsed eddy current detection simulation and experiment are conducted under the condition of a three-dimensional simulation model and a test piece, and excitation current waveform, amplitude and frequency parameters are determined; an induced voltage signal is collected, peak values, time points and attenuation characteristics are extracted, the corresponding relation between the wall thickness, the coating layer thickness and the welding seam structure and detection signals is constructed, a parameterized database is constructed, and temperature correction is completed; and optimizing a sensor structure and a signal acquisition scheme according to a parameterized database, obtaining detection data in a pipeline operation state, completing two-dimensional imaging of wall thickness distribution and welding seam positioning, and forming detection information covering a straight pipe, an elbow and a welding seam area. According to the method, wall thickness detection and welding seam positioning of the thermal power pipeline under the conditions of a thick wall and a thick coating layer are achieved through the full-process design of test piece modeling, simulation experiment and imaging collection.

The invention discloses a tangential eddy current-based pipeline welding seam array type detection device and method. The device comprises a detection probe module, a signal excitation and acquisition module and a signal processing module, the detection probe module comprises a flexible probe unit, the flexible probe unit comprises a plurality of tangential eddy current probes, each tangential eddy current probe comprises an excitation coil and two detection coils, and the excitation coils and the detection coils are coaxially and orthogonally distributed; the axis of the tangential eddy current probe and the surface of the weld form an included angle of 0-20 degrees, the excitation magnetic field is tangentially distributed along the weld, and the eddy current field is perpendicular to the weld and penetrates through the inside. The method comprises the following steps: A, detecting by using the detection probe module; b, a signal excitation and acquisition module acquires and records original data in real time; and C, the signal processing module processes, analyzes, identifies and positions defects according to the original data. Through tangential eddy current excitation and multi-channel signal fusion, the method has the advantages that interference of weld reinforcement on detection signals is eliminated, and the defect recognition capability is improved.

The invention discloses a pulse eddy current signal late period slope feature extraction method and system based on segmentation fitting, and belongs to the technical field of nondestructive testing. The method comprises the following steps: performing logarithmic transformation and filtering processing on a to-be-detected eddy current signal; intercepting a characteristic signal segment based on the filtering signal; dividing the feature signal segment into a plurality of sub-segments, performing piecewise linear fitting, determining a linear segment, and extracting a slope as a feature value; repeating the steps to obtain characteristic values of the test pieces with different thicknesses, performing curve fitting according to the characteristic values of the test pieces with different thicknesses and the corresponding thicknesses, and calculating a fitting error; and finally, iteratively optimizing the division number of the sub-segments by taking the minimum fitting error as a target. Through adaptive filtering, segmentation fitting and an intelligent optimization algorithm, the anti-interference performance, the linearity and the measurement precision of pulse eddy current signal feature extraction are remarkably improved, and efficient and reliable thickness detection of the high-temperature and high-pressure industrial pipeline under the condition that a heat preservation layer does not need to be disassembled is achieved.

A double cold rolled non-oriented electrical steel sheet having a composition including: 0.0001%≤Carbon≤0.007%, 0.1%≤Manganese≤0.2%, 3.1%≤Silicon≤3.6%, 0.8%≤Aluminum≤1.1%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, and can contain various optional elements. The remainder composition being iron and unavoidable impurities caused by processing, the microstructure is made of ferrite and has in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, is from 35% to 45% when calculated in accordance of Bertotti method and simultaneously having a magnetic polarization at 5000 A / m (J50) from 1.64 T to 1.66 T.

A double cold rolled non-oriented electrical steel sheet having a composition including, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%, 0.15%≤Manganese≤0.3%, 3.2%≤Silicon≤3.8%, 0.8%≤Aluminum≤1.1%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, and can contain various optional elements. The remainder composition being iron and unavoidable impurities caused by processing, the microstructure is made of ferrite and has in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, less than 30% when calculated in accordance of Bertotti method and simultaneously having a magnetic polarization at 5000 A / m (J50) from 1.66 T to 1.69 T.

The embodiment of the invention provides a magnetic resonance eddy current prediction method, system and device. The method comprises the following steps: acquiring a gradient parameter of a gradient signal of a magnetic resonance system; the gradient parameters are processed through an eddy current prediction model, eddy current field components corresponding to gradient signals are determined, and the gradient signals comprise single gradient signals or gradient signal combinations.

A non-oriented electrical steel sheet having a composition including of the following elements, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%,, 0.15% ≤Manganese≤0.2%, 3%≤Silicon≤3.6%, 0.7%≤Aluminum≤1.3%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, with 3.85%≤Si+Al+Mn ≤5.5%, and can contain various optional elements, the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel sheet being made of ferrite and including in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, of 35 to 55% when calculated in accordance with Bertotti method and simultaneously having a magnetic polarization at 5000 A / m (J50) from 1.635T to 1.670T.

A double cold rolled non-oriented electrical steel sheet having a composition including of the following elements, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%, 0.1%≤Manganese≤0.3%, 3.1%≤Silicon≤3.8%, 0.6%≤Aluminum≤0.8%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, and can contain various optional elements. The remainder composition is iron and unavoidable impurities caused by processing. The microstructure ferrite and has in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, of 40 to 50% when calculated in accordance with Bertotti method and simultaneously having a magnetic polarization at 5000 A / m (J50) from 1.66T to 1.7T.

The invention discloses a fusion device high-temperature superconducting magnet quenching detection method based on deep learning, and the method comprises the steps: obtaining a magnet quenching voltage noise signal, a magnet current signal, a plasma current signal and an eddy current signal from the historical operation data of a fusion device, and taking the signals as a data set to train a deep learning model; a magnet current signal, a plasma current signal and an eddy current signal during operation of the device are continuously collected in real time, and a magnet quenching voltage noise signal is calculated in real time by using an offline trained deep learning model; and deducting the magnet quench voltage noise signal calculated in real time from the magnet quench voltage detection signal acquired in real time to obtain a real magnet quench voltage signal, thereby realizing accurate detection of the high-temperature superconducting magnet quench of the fusion device. According to the method, quench of the high-temperature superconducting magnet is detected timely and accurately by means of the strong learning ability of deep learning, and safe and stable operation of the high-temperature superconducting magnet in a fusion device is guaranteed.

The invention provides a method and a system for measuring plasma current in a quasi-ring symmetrical star simulator, and relates to the technical field of star simulators, and the method comprises the steps: determining a sensor design index according to a bootstrap current simulation calculation result, and converting the design index into an actual arrangement scheme according to an installation environment constraint; all the magnet coils are independently excited in a plasma-free state, wall eddy current interference signals generated by the magnet coils are calibrated, and thus wall eddy current calibration voltage signals are output; a sensor in an actual arrangement scheme is used for synchronously collecting a total original induced voltage signal including plasma current and wall eddy current; an integral voltage signal representing the total current is output; and compensating the integral voltage signal by using the wall eddy current calibration voltage signal, and inverting the final measurement value of the plasma current in the quasi-ring symmetric star simulator. The device and the method have the beneficial effects that the interference of a stray field on a measurement result is weakened, and a high-precision diagnostic tool is provided for the plasma physical research of the star simulator.

The invention relates to the technical field of copper rod detection, in particular to a copper rod grain size detection method and system based on double-frequency eddy current analysis, and the method comprises the steps: synchronously obtaining a high-frequency eddy current response signal and a low-frequency eddy current response signal of the surface of a moving copper rod according to an orthogonally arranged double-frequency eddy current probe, and collecting the moving speed of the copper rod in real time; performing phase demodulation on the high-frequency eddy current response signal and the low-frequency eddy current response signal to respectively obtain a first phase angle and a second phase angle; calculating an instantaneous difference value between the first phase angle and the second phase angle, and generating an original phase difference characteristic quantity; performing dynamic compensation on the original phase difference characteristic quantity based on the movement speed of the copper rod to generate a speed compensation phase difference characteristic quantity; and inputting the speed compensation phase difference characteristic quantity into a pre-calibrated grain size mapping relation model to obtain a real-time grain size grade value. According to the invention, eddy current response interference caused by speed change in the continuous movement process of the copper rod is effectively eliminated, and high-precision detection of the grain size grade is realized.

The invention discloses a preparation method of a slot wire for a superconducting wire. The preparation method comprises the following steps: manufacturing a copper bar into a copper flat wire through a drawing process; soaking the copper flat wire in a soldering flux, and then washing and air-drying the copper flat wire to obtain a prefabricated copper flat wire; combining the plurality of prefabricated copper flat wires according to the cross section structure of the superconducting wire; performing induction heating welding on the plurality of combined prefabricated copper flat wires through a welding mold to obtain a copper groove wire; performing water cooling, cleaning and drying on the copper slot wire to obtain a copper slot wire with a clean surface; and screening the copper slot line through a laser diameter measuring instrument and eddy current flaw detection equipment to obtain a copper slot line finished product. The copper slot wire with the groove in the surface is obtained by welding the copper flat wire, integrated forming of the structural slot wire is achieved, the production efficiency is improved, welding and finishing forming are carried out by designing dies of different structures, the surface quality of the copper slot wire is improved, the slot wire of a high-precision complex structure is obtained, the drawing speed is high, and the production cost is low. And large-scale production of the copper slot line is facilitated.

The invention discloses a metal flat plate thickness and conductivity eddy current measurement method and system. According to the method, an electromagnetic detection platform is built, and a coaxial excitation-receiving eddy current probe structure is designed. Establishing a coaxial eddy current detection analysis model, and deducing a dynamic calculation result of mutual inductance parameters of the sensor in a frequency sweeping mode; setting two PID (Proportion Integration Differentiation) controllers and initial control variables thereof, and inputting the control variables serving as a thickness value and a conductivity value into the analytical theoretical model to obtain a corresponding mutual inductance change result; calculating an instantaneous error term and an accumulative error term of the current iteration period in real time, and when the error exceeds a preset convergence threshold value, inputting the error into a PID controller and updating the two control quantities until the maximum iteration frequency is reached; otherwise, outputting a control variable value, wherein the two control variables output by the controller are the thickness and the conductivity of the metal plate respectively. According to the invention, the thickness and conductivity of the metal plate can be accurately and simultaneously measured.

A non-oriented electrical steel sheet having a composition including of the following elements, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%, 0.15%≤Manganese≤0.25%, 3.2%≤Silicon≤3.8%, 0.7%≤Aluminum≤1.3%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, and various optional elements. The remainder composition is iron and unavoidable impurities caused by processing. The microstructure is ferrite and has in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, less than 33% when calculated in accordance with Bertotti method and simultaneously having a magnetic polarization at 5000 A / m (J50) from 1.630T to 1.65T.

The embodiment of the invention provides an eddy current displacement sensor and a temperature drift compensation method. The eddy current displacement sensor comprises a probe, a cable and a front-end device, the probe comprises a metal probe protection cover, and a measuring coil, a metal partition plate, a compensating coil, a metal pressing sheet and a framework body which are arranged in the metal probe protection cover, and the measuring coil, the metal partition plate, the compensating coil and the metal pressing sheet are sequentially arranged on the framework body; the first end of the compensating coil and the first end of the measuring coil are both connected with the front-end device, and the front-end device is used for carrying out differential processing on a measuring signal sensed by the measuring coil and a compensating signal sensed by the compensating coil to obtain distance information. The sensor provided by the embodiment of the invention can provide high-precision displacement measurement in a complex environment, is suitable for various industrial application scenes, especially in an environment with high temperature or large temperature fluctuation, and ensures the reliability and accuracy of a measurement result.

According to the preparation method and application of the metal soft magnetic composite material, the surface of the metal soft magnetic powder is coated with the metal oxide insulating layer through the ALD technology, then the characteristics that the ferrite phase layer is high in resistivity, low in loss and good in high-frequency characteristic are utilized, insulating coating is conducted on the surface through the ALD technology, and the metal soft magnetic composite material is obtained. And a ferrite coating layer is formed on the surface of the metal soft magnetic powder during high-temperature annealing, so that electric contact among particles is blocked, the resistivity of the soft magnetic material is improved, and the eddy-current loss at high frequency is reduced, thereby improving the high-frequency performance.

The invention discloses a precise positioning method of an automatic transmission conductor breaking device, and relates to the technical field of line detection, and the method comprises the following steps: obtaining eddy current detection signal data of the surface of a transmission conductor; performing sliding window segmentation processing on the eddy current detection signal data, and extracting a transient impedance sequence; the transient impedance sequence is processed through a phase sensitive demodulation circuit, and impedance real part information and impedance imaginary part information are separated; impedance real part information features are extracted, impedance imaginary part information frequency domain energy is deconstructed, and an impedance track feature vector is generated; and carrying out space segmentation on the impedance track feature vector, and calculating defect position information and severity level based on the offset of the track center point. The problem that an existing wire detection technology is insufficient in automation level and difficult to meet the requirement for accurate defect positioning of an automatic wire breaking device is solved.

A non-oriented electrical steel sheet having a composition including of the following elements, expressed in percentage by weight: 0.0001%≤Carbon≤0.007%, 0.21%≤Manganese≤0.7%, 3%≤Silicon≤3.6%, 0.7%≤Aluminum≤1.3%, Phosphorus≤0.15%, Sulfur≤0.006%, Nitrogen≤0.09%, with 3.85%≤Si+Al+Mn≤5.5%, and can contain various optional elements. The remainder composition being composed of iron and unavoidable impurities. The microstructure is ferrite and has in area fraction, 80% to 100% recrystallized microstructure, 0% to 20% non-recrystallized microstructure wherein the average grain size of recrystallized microstructure is from 20 microns to 110 microns and having a percentage of eddy current losses in total iron losses, measured at 1 T and 400 Hz according to IEC 60404-2 standards, from 35% to 45% and simultaneously having a magnetic polarization at 5000 A / m (J50) from 1.63T to 1.66T.

A crack quantification method and apparatus based on orthogonal twinning and used for oil and gas pipelines, and a storage medium. The method comprises: acquiring a triaxial magnetic flux leakage measurement signal modulus value of an inner wall crack or an outer wall crack under a condition of a unidirectional direct-current excitation, and acquiring a dynamic magnetic signal or an eddy current signal under a condition of a dynamic magnetic field excitation that is orthogonal to the direct-current excitation; inputting the triaxial magnetic flux leakage measurement signal modulus value into a crack signal orthogonal twin model, so as to obtain a magnetic flux leakage enhancement estimation signal, wherein the magnetic flux leakage enhancement estimation signal is a function of an orthogonal twin triaxial magnetic flux leakage signal modulus value, the orthogonal twin triaxial magnetic flux leakage signal modulus value is a magnetic flux leakage response signal modulus value under a condition of a virtual orthogonal twin direct-current excitation, and the virtual orthogonal twin direct-current excitation and the unidirectional direct-current excitation are in the same plane and have equal magnitudes and perpendicular directions; and extracting feature vectors from the magnetic flux leakage enhancement estimation signal and the dynamic magnetic signal or the eddy current signal, and inputting the feature vectors into a crack scale estimation model, so as to obtain the size and inclination angle of a crack.

The invention belongs to the technical field of mechanical transmission, and discloses a conductor ring and magnetic resistance array composite permanent magnet thrust bearing and a damping force calculation method. The conductor ring and magnetic resistance array combined type permanent magnet thrust bearing realizes the bearing of non-contact magnetic thrust through the combination of the eddy current ring and the magnetic group array. When thrust from a propeller at the stern end of a propulsion shafting acts, the rotor magnetic group array axially moves, axial traction force is generated between the rotor magnetic group array and the stator magnetic resistance array to counteract the thrust action from the axial direction, meanwhile, the magnetic group array cuts the vortex ring, induction damping is generated on the surface of the vortex ring, damping force is formed, and the vortex ring is driven to rotate. And therefore, the longitudinal vibration during transmission of the propulsion shafting is reduced, and the propulsion shafting system is more silent and stable during operation. In addition, the damping force calculation method does not need complex three-dimensional structure modeling and grid division, is simple in solution, high in universality and short in calculation time consumption, and has high engineering application practical value.

The embodiment of the invention provides a coating layer wall thickness pulse eddy current detection method and system based on multiple eddy current rings, and the method comprises the steps: applying a square wave excitation signal to an excitation coil, and carrying out the induction in a structural member with a coating layer to generate eddy current; collecting a voltage signal generated by induction of an attenuation magnetic field generated by the eddy current by using a receiving coil, wherein the attenuation process of the voltage signal comprises three stages; identifying a power function interval of the second stage to determine the starting time of the third stage; taking the starting time of the third stage as a reference, and selecting a preset thickness quantitative time interval in the third stage; calculating a first-order derivative of the voltage signal to time under a single logarithmic coordinate system in the thickness quantitative time interval to obtain a slope; according to the quantitative relation between the slope and the wall thickness of the structural part with the coating layer, the wall thickness value of the structural part with the coating layer is obtained through calculation.

The invention discloses a magnetostrictive electromagnetic ultrasonic transducer for a pipeline and a detection device and method, and relates to the field of electromagnetic ultrasonic nondestructive detection, and the electromagnetic ultrasonic transducer comprises a magnetostrictive strip arranged on the outer surface of a to-be-detected pipeline, an eddy current coil and a plurality of excitation coil units; the eddy current coil is wound on the outer surface of the magnetostriction strip in the circumferential direction; the eddy current coil can be used as an excitation end and receiving end eddy current coil, an excitation end eddy current coil or a receiving end eddy current coil; the excitation coil units are distributed on the magnetostrictive strip at intervals; the magnet exciting coil of each magnet exciting coil unit is wound on the wall surface of the magnetostrictive strip along the axial direction; a magnet exciting coil of the magnet exciting coil unit provides a bias magnetic field for the magnetostrictive strip. The magnet exciting coil is adopted to replace a permanent magnet, so that the heat resistance of the electromagnetic ultrasonic transducer is improved; the sparse excitation coil increases the contact area between the magnetostriction strip and the pipeline to be detected, and the energy efficiency of the electromagnetic ultrasonic sensor is improved.

The invention relates to an eddy current heating device for a thermoluminescence element and a heating method. The device comprises a heating disc, a copper coil assembly, a supporting frame, a temperature measuring sensor assembly and a control circuit, the heating disc is in a disc shape, and the copper coil assembly is composed of four multi-layer closely-wound fan-shaped copper coils which are arranged in four quadrant areas of the heating disc respectively; the temperature measuring sensor assembly is provided with four temperature sensors which are embedded into the bottom of the heating disc through heat-conducting glue and connected with the control circuit. The control circuit adopts a PID (Proportion Integration Differentiation) algorithm to independently adjust the current of each sector according to feedback signals of each temperature sensor, realizes rapid temperature rise and accurate temperature control through frequency adjustment and power compensation, and has an over-temperature protection function. According to the device, the temperature of the heating disc can be raised to 300 DEG C within 3 seconds, and the temperature deviation is controlled within + / -0.5 DEG C. Compared with traditional resistance heating, the device has the advantages of being fast in temperature rise, low in energy consumption, high in temperature uniformity, convenient to maintain and the like, and meets the high-precision temperature control requirement of thermoluminescence measuring and reading equipment.

The invention discloses a weld defect identification method based on sweep frequency array eddy current, which relates to the technical field of nondestructive testing, and comprises the following steps: step A, adopting a sweep frequency signal as an input signal of an array eddy current excitation coil to excite and generate a multi-frequency eddy current field; step B, collecting full-waveform data of the output response signal as original data of defect identification; c, performing feature extraction on the full-waveform data of the output response signal by adopting wavelet transform to form a discrete wavelet transform coefficient map; d, training and classifying feature vectors of the defect signal coefficient atlas and the weld reinforcement signal coefficient atlas by adopting a support vector machine; and E, identifying the weld defect according to the difference of output response signals of the defect and weld reinforcement to the eddy current fields with different frequencies. Compared with the prior art, the problem that false detection or missing detection of existing nondestructive weld defect recognition detection is too high is solved.