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1023 results about "Excitation current" patented technology

A transformer exciting current is the current or amperes required to energize the core. Even with zero load, a transformer will draw a small amount of current due to internal loss. The excitation current is made up of two components.

Ultra-short beam homogenization transmission line system and method based on four-pole and eight-pole composite magnet

The invention provides an ultra-short beam homogenization transmission line system and method based on a four-eight-pole composite magnet. The system comprises the four-eight-pole composite magnet, a system, a linear beam homogenization structure, a bent beam homogenization structure and secondary iron used for a beam homogenization transmission line. The system further comprises an ultra-short linear beam homogenization transport line, an ultra-short bent beam homogenization transport line, an ultra-short linear bent composite beam homogenization transport line and an ultra-short symmetrical bent beam homogenization transport line based on the homogenization structure and / or the dipolar iron. The method comprises an exciting current debugging method based on the four-pole and eight-pole composite iron and a linear type and bending type beam debugging method. According to the invention, the problem that the maximum enveloping part on the transmission line is occupied and the effect of octopole iron cannot be fully exerted is solved; the problems that the beam envelope of the position where the octopole iron is located is small, and the requirement for the field intensity of the octopole magnet is high are solved. The problem that the civil engineering shielded around the transmission line is more expensive because the transmission line is too long is solved.
Owner:CHINA INSTITUTE OF ATOMIC ENERGY

Method and system for detecting pulsed eddy current of thermal power pipeline with coating layer

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.
Owner:GD POWER JIUQUAN GENERATION CO LTD

Lithium ion battery thermal runaway early warning method, equipment and medium

The invention relates to a lithium ion battery thermal runaway early warning method and device and a medium, and the method comprises the steps: setting an AC excitation power supply parameter, and outputting a sine excitation current with a preset frequency and amplitude; injecting the polymer into a single battery through a four-probe method; synchronously acquiring an injection current signal and a response voltage signal; through fast Fourier transform analysis, the amplitude and the phase of a signal fundamental frequency component are extracted; and calculating the electrochemical impedance under the frequency. And in combination with an electrochemical impedance-thermal runaway precursor mapping database established by a pre-experiment, converting the impedance value into a corresponding thermal runaway risk level, and outputting corresponding early warning information. According to the method, lithium dendrite growth and internal micro short circuit signs can be captured in advance, and the early warning time efficiency is remarkably improved compared with traditional voltage / temperature monitoring.
Owner:CRRC ZHUZHOU ELECTRIC LOCOMOTIVE RESEARCH INSTITUTE CO LTD

Phase modifier unit state monitoring and load control method and system for reactive power compensation of power grid

The invention discloses a phase modifier unit state monitoring and load control method and system for reactive power compensation of a power grid, belongs to the technical field of automatic control of power systems, and mainly solves the problem that service life loss is aggravated or a control target is single due to the fact that the health state of equipment is not fully considered when an existing phase modifier unit responds to reactive power requirements of the power grid. The method comprises the following steps of: calculating reactive vacancy and extracting vibration frequency band energy characteristics by acquiring voltage and frequency of a power grid as well as vibration, temperature and exciting current signals of a unit in real time, and constructing a health state index HSI in combination with self-adaptive wavelet basis selection; taking minimum equipment life loss and optimal power grid voltage stability as multiple objectives, dynamically generating a load control instruction by adopting a particle swarm algorithm, realizing weight adaptive adjustment based on HSI, and introducing an online life loss model as a constraint condition; finally, reactive power output is adjusted through an excitation system, and cooperative control of power grid stability and equipment life extension is achieved.
Owner:GUONENG LIAONING NEW ENERGY DEVELOPMENT CO LTD

Exciting current adjusting method for four / eight-pole composite iron

The invention discloses an exciting current adjusting method for four-pole / eight-pole composite iron. The exciting current adjusting method comprises the following steps: establishing a two-dimensional data comparison table of coil currents of four-pole iron and eight-pole iron; performing experimental measurement to obtain a quadrupole field magnetic field gradient three-dimensional curved surface sample database and an octupole field magnetic field gradient three-dimensional curved surface sample database; performing two-dimensional interpolation on the magnetic field gradient three-dimensional curved surface sample database by using a cubic spline function; a quadrupole field magnetic field gradient plane and an octupole field magnetic field gradient plane are selected and intersect with the quadrupole field magnetic field gradient three-dimensional curved surface sample database curved surface and the octupole field magnetic field gradient three-dimensional curved surface sample database curved surface respectively, and current curves meeting the quadrupole field gradient and the octupole field gradient are obtained; and obtaining an intersection point of the two curves, and using the intersection point as a solution of the compound iron exciting current. According to the invention, based on magnetic field measurement data under a few groups of excitation currents, a large amount of excitation current debugging time is saved, and accurate adjustment of the magnetic field gradient of the composite multi-pole magnet can be realized.
Owner:CHINA INSTITUTE OF ATOMIC ENERGY

Electrochemical impedance spectroscopy detection method and system and related equipment

The invention discloses an electrochemical impedance spectroscopy detection method and system and related equipment. The electrochemical impedance spectroscopy detection system comprises: a battery pack comprising a plurality of cells; the battery cell management module is connected with the plurality of battery cells and is used for acquiring response voltage of the battery pack and performing discrete Fourier transform on the excitation current and the response voltage to obtain an electrochemical impedance spectrum of the battery pack under the target excitation frequency; the battery management module is connected with the excitation source module and used for sending the target excitation frequency to the excitation source module; and the excitation source module is used for generating excitation current according to the target excitation frequency sent by the battery management module.
Owner:ZHEJIANG GEELY HLDG GRP CO LTD +1

Bidirectional power conversion topology for power battery test excitation power supply, method and system

The present invention provides a topology, method and system for bi-directional power conversion of excitation power supply for power battery testing, wherein the topology comprises a three-phase PWM (pulse width modulation) converter, a high-frequency isolation three-level LLC (logical link control) resonant converter and a DC-DC (direct current) converter forming a topology structure for a three-stage power conversion; an input end of the three-phase PWM converter is connected to a power grid side; the high-frequency isolation three-level LLC resonant converter is connected between the three-phase PWM converter and the DC-DC converter in series and is configured for realizing bi-directional DC voltage conversion and isolation, and to raise a busbar voltage between the high-frequency isolation three-level LLC resonant converter and the DC-DC converter; and, the DC-DC converter is configured to generate charging and discharging excitation currents for a power battery testing.
Owner:SHANDONG UNIV

Measurement switch fault identification and early warning system

The invention relates to the technical field of power system fault monitoring, and discloses a measurement switch fault identification and early warning system, which comprises a signal acquisition unit, a feature analysis unit, a fault judgment unit and an early warning trigger unit. The signal acquisition unit acquires a potential fluctuation sequence and an exciting current pulse sequence through a contact voltage sensor and a coil current transformer; the feature analysis unit extracts time-frequency domain and statistical domain feature groups by means of wavelet transform and moment function analysis; the fault judgment unit generates a fault judgment vector by adopting kernel principal component analysis fusion features; and the early warning triggering unit triggers four-level early warning by using dynamically updated grading threshold values (including historical reference values and online dynamic values). According to the system, through multi-modal feature fusion, dynamic threshold adjustment and a grading early warning strategy, accurate identification and grading early warning of measurement switch faults are achieved, the fault identification accuracy and early warning timeliness are improved, and the system is suitable for the field of electric power and industrial automation.
Owner:BEIJING ZHONGZHAO LOONGSON SOFTWARE TECH CO LTD

Synchronous generator excitation method based on mathematical modeling and gain scheduling

The invention discloses a synchronous generator excitation method based on mathematical modeling and gain scheduling, and relates to the technical field of synchronous generator control, and the method comprises the steps: building a synchronous generator global dynamic mathematical model comprising the electromagnetic dynamic characteristics of a stator winding, a rotor winding and a damping winding through a modeling module; a discretization simulation platform is constructed in a Matlab / Simulink environment by utilizing a simulation module, model parameters are corrected, dynamic adjustment is realized through a gain scheduling excitation controller, an automatic voltage regulator (AVR) adopts PID (Proportion Integration Differentiation) control and comprises a voltage deviation integral separation strategy, and a power system stabilizer (PSS) dynamically adjusts parameters of a lead-lag compensator based on active power. According to the method, the deviation between a model and an actual system can be reduced by more than 30%, the electromechanical oscillation damping ratio within the rated power range of 10%-150% is increased by 25%-40%, the harmonic content of exciting current is reduced to be lower than 5%, the stability of an electric power system and the electric energy quality are remarkably improved, the engineering practicability is high, and the method is easy to transform and upgrade on an existing synchronous generator.
Owner:CHINA YANGTZE POWER

Monitoring method, system and related device

The invention discloses a monitoring method and system and a related device, which are applied to first electronic equipment, the first electronic equipment is provided with a first circuit, and the first circuit comprises a first electrode, a second electrode, a third electrode, a fourth electrode, an excitation current generation unit and a voltage measurement unit; receiving and responding to a first instruction, and determining that the first electrode and the second electrode are in good contact with skin through a first circuit; first information is determined through the first circuit, the first electrode makes contact with a first position of the user skin, the second electrode makes contact with a second position of the user skin, and the first position and the second position are located at the two ends of the thoracic cavity tissue respectively; and outputting first information, wherein the first information comprises one or more of the following items: cardiac output, stroke output, heart rate, ejection fraction and cardiac function judgment result. Therefore, the heart function condition of the user can be monitored in real time, and the user can conveniently monitor anytime and anywhere.
Owner:HUAWEI TECH CO LTD

Magnetic adjustment water lubricated bearing and bearing support control method

The invention discloses a magnetic adjustment water lubricated bearing and a bearing support control method, which are applied to a large ship propulsion shaft system, and comprise a bearing shell, an electromagnetic excitation module, a batten, a sensor module, a power supply driving module and a control system, a plurality of mounting grooves are formed in the bearing shell; an electromagnetic excitation module is arranged in each mounting groove and generates a variable magnetic field with set intensity; a plurality of magnetically soft alloy segments are arranged on the batten, the magnetically soft alloy segments correspond to the electromagnetic excitation modules one to one, and a magnetic field acts on the magnetically soft alloy segments to generate electromagnetic attraction force; the control system independently controls the excitation current of each electromagnetic excitation module according to data of the sensor module, and generates magnetic fields with different intensities to act on soft magnetic alloy areas at corresponding positions, so that precise control of local supporting rigidity and lubricating gaps of the water-lubricated bearing is realized, unbalance loading and abnormal wear risks are effectively reduced, and the service life of the water-lubricated bearing is prolonged. And the adaptive capacity of the bearing under low-speed heavy load and dynamic disturbance is improved.
Owner:CHINA SHIP DEV & DESIGN CENT

Energy storage type phase modifier control method, recording medium and system

The invention belongs to the technical field of power system operation and motors, and particularly relates to an energy storage type phase modifier control method which comprises the steps that a rotating shaft of a double-fed motor is connected with a flywheel to serve as an energy storage type phase modifier; the rotor winding is connected to a power grid through an excitation system and a transformer in sequence, and the excitation system is electrically connected by a reactor, a back-to-back converter and a filter in sequence; the stator winding is directly connected to a power grid; the control system decouples reactive power and active power, vector control is carried out on exciting current to absorb or release power, and reactive power-voltage support and active power-frequency support of the power grid are completed. The method overcomes the defects that a traditional direct-current excitation phase modulation mode can only modulate phase and cannot modulate frequency, or is cumbersome and slow in response. The system can meet the requirement of wide-range variable-speed operation, quickly store / release a large amount of rotor kinetic energy, inhibit the voltage and frequency fluctuation of a power grid, and is especially suitable for stations with high new energy occupation ratio. The invention also provides a non-transitory readable recording medium storing the program of the method and a system comprising the medium, and the program can be called through a processing circuit to execute the method.
Owner:WUHAN UNIV OF TECH

Protection element and current-limiting resonance eliminator

The utility model relates to the field of resonance eliminators, and discloses a protection element and a current limiting type resonance eliminator, the protection element comprises at least two groups of protection units, the two adjacent groups of protection units are connected in series, and each protection unit comprises a protection module; the current-limiting resonance eliminator based on the current-sensitive resistor made of the current-sensitive material is connected in series between the PT neutral point and the ground. Under the normal operation condition, the current-limiting resonance eliminator is in a low-resistance state, and system parameters and PT performance are not affected; when excitation energy is generated due to a system fault, the current-limiting resonance eliminator suddenly changes into a high resistance state, quickly absorbs resonance energy, destroys resonance parameters, suppresses PT excitation current below 200mA, and ensures that a voltage transformer is unsaturated and a PT fuse is not fused; and a built-in current sensor is connected, so that the running state of the current-limiting resonance eliminator can be monitored in real time.
Owner:GUANGXI POWER GRID CORP

Electric drive system with static pulsed power transfer

An electric drive system includes an electric machine having a stator assembly and a rotor assembly. The stator assembly has a plurality of multi-phase stator windings, including a first stator winding and a second stator winding. A first inverter is adapted to feed the first stator winding. A second inverter is adapted to feed the second stator winding. The rotor assembly includes rotor windings having a single phase. A controller is configured to selectively command excitation of the rotor windings with a pulsed field current such that a direct-axis (d-axis) stator flux linkage is generated. A d-axis stator voltage is induced in the first stator winding and the second stator winding by the d-axis stator flux linkage. Pulsed power transfer is enabled through interaction of the d-axis stator voltage and respective d-axis winding currents in the first stator winding and the second stator winding.
Owner:GM GLOBAL TECHNOLOGY OPERATIONS LLC

Method for batch detection of pseudo soldering and unsoldering of chip packaging bonding based on ATE

The invention relates to a method. The invention discloses an ATE-based method for batch detection of pseudo soldering and sealing-off of chip packaging bonding, and belongs to the technical field of semiconductors. The method comprises the following steps: aiming at packaged and bonded chips, providing excitation current for each chip to be tested through an ATE test machine, and conducting an ESD (Electro-Static Discharge) diode connected with each pin of the chip; detecting the voltage drop between each pin and the pin GND; and calculating the equivalent resistance to determine whether pseudo soldering or unsoldering exists. The detection method has high practicability, is simple to operate, is very suitable for large-scale application and popularization, and has a certain promotion effect on improvement of a chip packaging test technology, improvement of chip performance reliability and chip packaging inspection.
Owner:NANJING MICRO ONE ELECTRONICS

Battery broadband electrochemical impedance spectroscopy time domain rapid detection method and system

The invention provides a battery broadband electrochemical impedance spectroscopy time domain rapid detection method and system, and the method comprises the steps: S1, dividing a target signal frequency band into a low frequency band, a middle frequency band and a high frequency band from low to high, and setting the parameters of an excitation signal DIBS of each frequency band; s2, enabling the discrete binary sequence to have spectrum distribution corresponding to the target signal through an optimization algorithm, and obtaining a DIBS signal containing all set frequency points; s3, performing current excitation on the battery by adopting DIBS excitation signals of different frequency bands to obtain excitation current and response voltage; and S4, respectively calculating the frequency spectrums of the excitation current and the response voltage under the three frequency bands, and obtaining the final impedance. A multi-band excitation mode is adopted, the sequence length of a single-segment signal is shortened, the clock period of the single-segment signal is prolonged, and the storage burden of excitation equipment and the data processing complexity of a time-frequency conversion algorithm are effectively prevented from being aggravated due to the long sequence period.
Owner:SHANGHAI JIAOTONG UNIV

Electromagnetic quasi-zero stiffness vibration isolator and control method

The invention provides an electromagnetic quasi-zero stiffness vibration isolator and a control method, and belongs to the technical field of vibration isolation. The vibration isolator comprises a base, a positive stiffness mechanism, a negative stiffness mechanism, a positive and negative stiffness connecting mechanism and a dynamic control module. The positive stiffness mechanism adopts a hydraulic spring to provide basic positive stiffness; the negative stiffness mechanism comprises a plurality of stator units distributed on the base in an annular array and a rotor suspended in the center of a magnetic field of the stator units, and is used for generating nonlinear negative stiffness; the top end of the hydraulic spring supports a load through the bearing table and keeps a preset gap with the inner wall of the rotor; the positive and negative stiffness connecting mechanism realizes displacement transmission and cooperative adjustment; the dynamic control module comprises a displacement sensor and a controller, the sensor collects displacement signals, and the controller adjusts excitation currents of the stator units according to the signals and dynamically adjusts electromagnetic force, so that the vibration isolator is kept in a quasi-zero stiffness state. The quasi-zero stiffness state can be still kept when the load changes, load self-adaption low-frequency vibration isolation is achieved, and the system stability and the vibration isolation performance are improved.
Owner:NAT ENG LAB FOR HIGH SPEED RAILWAY CONSTR +2

Automobile generator self-adaptive excitation control method based on load prediction

The invention discloses an automobile generator self-adaptive excitation control method based on load prediction, and relates to the technical field of automobile electrical control, and the method comprises the following steps: injecting a micro-amplitude identification pulse into a whole vehicle electrical system, capturing the dynamic response of an electrical load, building a load transition curvature map, marking a high-risk time window, and generating a buffer time slot; and in the buffer time slot, constructing a prediction model fusing time domain extrapolation calculation and frequency domain envelope regression, and outputting collaborative confidence with credibility. A load transition curvature map is constructed to identify a high-risk window, a time domain and a frequency domain are fused to predict output confidence, excitation current is guided to form an anti-shake track, and a dynamic adjustment path is generated by combining start-stop broadening of high-power equipment and voltage second-order derivative identification. And finally, a slew rate self-adaptive strategy is introduced at a chip end to reduce peak impact, power supply and chip cooperative protection is realized, and system robustness and intelligent driving electrical safety are improved.
Owner:湖北睿信汽车电器股份有限公司

Pull-type transient electromagnetic gradient detection device and method based on transmitting-receiving weak coupling structure

The invention belongs to the field of geophysical geological exploration equipment, and relates to a pull-type transient electromagnetic gradient detection device and method based on a transmitting-receiving weak coupling structure, and the device comprises a transmitting coil which is used for generating excitation current; the receiving coil is used for receiving a secondary field signal and comprises a first receiving coil, a second receiving coil and a third receiving coil, and the size parameters of the first receiving coil and the second receiving coil are the same and are different from those of the third receiving coil; the first receiving coil and the second receiving coil are located on the same plane, have the same height from the plane where the transmitting coil is located, are eccentrically arranged relative to the transmitting coil and are symmetrical about the central axis of the transmitting coil; and the second receiving coil and the third receiving coil are coaxially arranged in parallel. According to the invention, environmental noise interference can be effectively suppressed, and the data signal-to-noise ratio is improved; and the effective data length is increased, and the detection depth is increased, so that non-blind area detection of the deep and shallow whole space is realized.
Owner:JILIN UNIVERSITY

Downhole string detection method and system and medium

The invention provides an underground pipe column detection method and system and a medium, and the underground pipe column detection system comprises detection equipment, an excitation signal generator and an underground detection device; the detection equipment is in communication connection with the excitation signal generator and the underground detection device; the underground detection device comprises a transmitting coil and a magnetic sensor array consisting of a plurality of receiving coils; the excitation signal generator is configured to apply transient excitation current to the transmitting coil; the transient excitation current enables the transmitting coil to generate an excitation magnetic field; the excitation magnetic field enables the sleeve layer to generate an induced magnetic field; the magnetic sensor array is configured to collect the magnetic field intensity of the induced magnetic field and generate a magnetic field intensity vector; the detection equipment is configured to perform sparse reconstruction solution on the target vector containing the wall thickness information of the casing layer according to the magnetic field intensity vector and the space observation matrix corresponding to the magnetic sensor array, and through the embodiment of the invention, the limitation of the number of array elements on the detection resolution can be broken through, and the detection precision of the wall thickness of the underground pipe column is improved.
Owner:XI'AN PETROLEUM UNIVERSITY

Control of an asymmetric half bridge converter

A control circuit is provided, for controlling switching elements of an asymmetric half bridge (AHB) converter. The AHB converter includes a first switching element, a second switching element, a capacitor, and a transformer having a primary side and a secondary side. The control circuit includes a first output, for controlling the first switching element; and a second output, for controlling the second switching element. The control circuit also includes control logic, configured to generate a first pulse width modulated, PWM, control signal at the first output and a second PWM control signal at the second output. The control logic may have a first operation mode in which it is configured to cause a magnetizing current of the transformer to remain greater than zero throughout a switching period of the first and second PWM control signals.
Owner:INFINEON TECH AUSTRIA AG

Grid-connected system and method based on parallel operation power equalization of synchronous motor units

The invention provides a grid-connected system and method based on parallel operation power equalization of synchronous motor units, and relates to the technical field of new energy and electric power engineering. The system comprises a new energy station power generation system and a parallel synchronous motor unit group, wherein the parallel synchronous motor unit group at least comprises two synchronous motor units which have the same electrical parameters and are connected in parallel; the first end of the parallel synchronous motor unit group is connected with the new energy station power generation system, and the second end is connected with the power grid. The method comprises the following steps: connecting one ends of all synchronous motor units to the same power supply bus, applying excitation current to the motor at the end, applying excitation current to the motor at the other end, then measuring the generator end voltage waveform, adjusting the relative mechanical angles of the synchronous motor units according to the measurement result, and ensuring that the relative mechanical angles of all the motor units are equal. And power equalization between parallel synchronous motor units is realized. The system structure can be simplified, the cost can be reduced, and the reliability and the flexibility of the new energy grid-connected system can be improved.
Owner:DONGFANG ELECTRIC MACHINERY

Soft start system based on excitation current reduction

The utility model discloses a soft start system based on excitation current reduction, which is characterized in that a time relay mainly controls the switching of a live wire between a power resistor and an alternating current contactor, the power resistor magnetizes a transformer at the moment of electrification, and the alternating current contactor is connected into a circuit by the time relay after the magnetization is completed; and after the power resistor is short-circuited, the circuit is cut out, so that the purpose of suppressing the excitation inrush current is finally achieved, the excitation effect caused by voltage abrupt change at the power-on moment of the isolation transformer can be avoided, and the excitation abrupt change of the isolation transformer during power-on is effectively reduced.
Owner:杭州邦杰星医疗科技有限公司

Electromagnetic noise suppression control method for multi-phase self-excitation synchronous motor

The invention discloses an electromagnetic noise suppression control method for a multi-phase self-excitation synchronous motor. A driving system of the synchronous motor comprises a double-closed-loop control system and an inverter. The specific method comprises the steps that the double-closed-loop control system outputs voltage reference signals of all coordinate axes, and all the coordinate axes are arranged in an electromechanical energy conversion plane and a non-electromechanical energy conversion plane respectively; injecting the square wave signal into a selected coordinate axis, and cooperatively adjusting excitation and noise values by using the positive correlation between excitation current and the amplitude of the square wave and the negative correlation between the excitation current and the frequency of the square wave; and then outputting the adjusted voltage reference signal, processing the adjusted voltage reference signal and other voltage reference signals, and outputting the processed voltage reference signal and other voltage reference signals to an inverter to generate a driving voltage. Therefore, the square wave amplitude is synchronously increased and the excitation current is kept stable when the noise reduction of the square wave frequency is improved by utilizing the quantitative relation that the excitation current is positively correlated with the square wave amplitude and negatively correlated with the square wave frequency, so that the load capacity of the synchronous motor is prevented from being reduced.
Owner:FUJIAN AGRI & FORESTRY UNIV

Electrical impedance imaging method and device based on hybrid excitation and program product

The invention relates to the field of intelligent medical treatment, in particular to an electrical impedance imaging method and device based on mixed excitation and a program product. Comprising the steps that an initial current vector and an initial boundary voltage vector of mixed excitation are obtained, the mixed excitation comprises L kinds of excitation, and L is a natural number larger than 1; performing weighted fusion on the L excitation initial current vectors to obtain a mixed excitation current vector, and performing weighted fusion on the L excitation initial boundary voltages to obtain a mixed excitation voltage; performing electrical impedance imaging optimization function calculation based on the mixed excitation current vector and the mixed excitation voltage to obtain conductivity change; the optimization function is used for carrying out regularization calculation on regional potential distribution and conductivity variation based on the mixed excitation current vector and the mixed excitation voltage; an electrical impedance distribution image is generated based on the conductivity change. According to the invention, the resolution of EIT imaging is improved, and the method has good clinical value.
Owner:FOURTH MILITARY MEDICAL UNIVERSITY

Battery self-heating control method, medium, controller, vehicle and program product

The invention relates to a battery self-heating control method, a medium, a controller, a vehicle and a program product, and the battery self-heating control method comprises the steps: determining the target equivalent impedance of a battery and the target current frequency corresponding to the target equivalent impedance according to the current temperature and the current state of charge of the battery; obtaining a target current amplitude according to the target equivalent impedance and the current excitation voltage of the battery; and obtaining a target excitation current signal according to the target current frequency and the target current amplitude, and carrying out self-heating on the battery through the target excitation current signal. The excitation current signal used for self-heating can be adjusted according to the state of the battery, frequency conversion and current conversion of the excitation current signal are achieved, and it is guaranteed that the battery can maintain a good self-heating effect.
Owner:BYD CO LTD

Argon arc welding tungsten electrode appearance defect detection method and system and storage medium

The invention provides an argon arc welding tungsten electrode appearance defect detection method and system and a storage medium, and relates to the technical field of tungsten electrode appearance detection.The method comprises the steps that firstly, a sample electrode with known defects is subjected to three-dimensional scanning and discretization into a plurality of space points, and each point is endowed with a defect existence mark; by applying a composite sine wave excitation current, an eddy current signal generated when a collector spirally passes through a detection coil at a constant speed is acquired, and laser ultrasonic scanning is synchronously utilized to acquire full-matrix data and reconstruct a three-dimensional gray model. And constructing a double-branch deep learning model, fusing the eddy current feature vector and the ultrasonic image block feature, and learning a mapping relationship between the eddy current feature vector and the defect mark. And performing the same detection on a to-be-detected electrode, outputting the defect confidence of each position by using the trained model, calculating a comprehensive quality index in combination with a preset defect severity weight and a spatial key region weight, and judging whether the electrode is qualified or not according to a qualified threshold value. According to the invention, high-precision, automatic and comprehensive detection of surface and internal defects is realized.
Owner:NORTH CHINA INST OF AEROSPACE ENG

Intelligent start-stop control method and system for magnetic suspension refrigeration compressor

The invention discloses an intelligent start-stop control method and system for a magnetic suspension refrigeration compressor, and the method comprises the steps: obtaining a position perception enhancement source through collecting and analyzing the current response data of a magnetic bearing coil, and extracting the current response change characteristics; rotor position estimation is carried out based on current response change characteristics, a positioning precision driving source is extracted from estimation deviation, and a non-impact starting excitation current instruction is generated; a multi-sensor fusion data network is established, configuration is reconstructed through an abnormal response activation signal, and a degradation operation fault-tolerant mode is formed; converting a response preparation gain according to the shutdown instruction signal, performing shutdown state evaluation in combination with signal reconstruction configuration, and generating an emergency shutdown trigger condition; and the power supply state of a bus capacitor is detected, gradient control potential is released, the active damping control opportunity is determined, a damping force control instruction is generated, finally intelligent start-stop control over the magnetic suspension refrigeration compressor is achieved, and safe and reliable operation of the system under various working conditions is ensured.
Owner:SHANGHAI ENVIRONMENT PROTECTION GROUP +1

Magnetic suspension fan motor winding temperature monitoring equipment and early warning method

The invention belongs to the technical field of magnetic suspension motors, and discloses magnetic suspension fan motor winding temperature monitoring equipment and an early warning method. The method comprises the following steps: laminating a preset temperature-sensitive ferromagnetic material and a magnetic suspension fan motor stator iron core according to a preset process to obtain a composite iron core; deploying a high-frequency excitation system on the composite iron core, adjusting the number of turns of a micro-coil of the high-frequency excitation system according to the target magnetic field intensity, collecting real-time excitation current, and analyzing to obtain magnetic induction intensity; analyzing the magnetic induction intensity through multi-physics field coupling iteration to obtain a winding three-dimensional temperature field; performing temperature gradient analysis on the three-dimensional temperature field, performing temperature early warning according to an analysis result, and dynamically adjusting motor operation parameters; according to the invention, the comprehensiveness of temperature monitoring of the magnetic suspension fan motor winding, the timeliness of early warning and the accuracy of cooling control are effectively improved, and safe and stable operation of the motor under complex working conditions is guaranteed.
Owner:SHANGHAI RONGENTROPY POWER TECH CO LTD

Battery SOC prediction method and system based on dynamic electrochemical impedance spectroscopy measurement

The invention discloses a battery SOC prediction method and system based on dynamic electrochemical impedance spectroscopy measurement in the technical field of lithium battery state prediction, and the method comprises the steps: superposing DIBS square wave signals as excitation current input on the basis of the main charging and discharging current of a battery, and collecting the voltage and current data of the battery in real time; according to the impedance spectrum, fitting a fractional order equivalent circuit model by adopting a nonlinear least square optimization method to obtain initial parameters of the fractional order equivalent circuit model; the initial parameters and voltage and current data collected in real time are input into a self-adaptive dual augmented extended Kalman filter, the main filter and the secondary filter operate cooperatively, state prediction and parameter prediction are executed alternately, and real-time synchronous prediction of SOC and fractional order equivalent circuit model parameters is achieved. The method is suitable for the SOC estimation requirement of the battery under the dynamic working condition, the working state of the battery does not need to be interrupted, and the method has good linearity, robustness and adaptivity.
Owner:NANJING INST OF TECH