1044 results about "Pulse current" patented technology

The invention provides a single-tube boost PFC circuit control method and system for single-cycle control, and relates to the technical field of data processing, and the method comprises the steps: generating a self-adaptive PWM control signal according to a duty ratio adjustment amount and a frequency compensation factor, and dynamically limiting the pulse current amplitude of a power switch tube through a peak current prediction algorithm, a load current change rate is generated based on the real-time relevance between the pulse current amplitude and the load current; setting a first monitoring point in a dynamic duty ratio change path of the PWM control signal, and extracting a duty ratio change rate and a switching frequency fluctuation parameter in real time; setting a second monitoring point in a feedback path of a load current change rate, and extracting a load current slope characteristic and a transient change amplitude in real time; and based on the parameters of the first monitoring point and the second monitoring point, generating a correction factor through a dynamic response correlation model. According to the invention, a high power factor can be realized under wide input voltage and load fluctuation.

A driving method of a transcranial magnetic stimulation 3D coil device is disclosed, which includes: determining first and second signal peaks corresponding to a specified rotating magnetic field direction, in which the first and second signal peaks respectively correspond to first and second coils in multiple coils; providing a first pulse current having the first signal peak to the first coil, in which the first pulse current signal stimulates the first coil to provide a first magnetic field; providing a second pulse current signal having a second signal peak to the second coil, in which the second pulse current signal stimulates the second coil to provide a second magnetic field, in which the first magnetic field and the second magnetic field form a rotating magnetic field having the specified rotating magnetic field direction.

The invention discloses a transformer partial discharge detection method and system based on multi-modal feature combination, and relates to the technical field of transformer detection, and the key points of the technical scheme are that the method comprises the steps: collecting an electromagnetic wave signal, a pulse current signal and a sound wave signal of a target transformer; respectively extracting an electromagnetic wave time-frequency matrix, a pulse current waveform parameter and a sound wave space coordinate; performing multi-modal feature fusion on the electromagnetic wave time-frequency matrix, the pulse current waveform parameters and the sound wave space coordinates based on a dynamic weighting strategy to generate a joint feature tensor; and inputting the joint feature tensor into a pre-constructed neural network model, identifying a discharge type and optimizing a positioning coordinate. According to the method, multi-modal features are subjected to tensor fusion, cross-modal correlation learning is realized through the neural network model, information islands can be eliminated, and the misjudgment rate is effectively reduced; and electromagnetic wave-current-sound wave signal adaptive fusion is realized through a dynamic weight coefficient, and the signal-to-noise ratio is obviously improved through characteristic complementation in an oil paper insulation discharge scene.

The present invention relates to the field of defect detection technology, and in particular to an OLED screen defect detection method based on optical-magnetic multimodal fusion, comprising the following steps: S1: synchronous excitation and data acquisition based on pulsed current drive; S2: cross-modal spatial calibration and noise suppression; S3: polarization-magnetic field coupling feature extraction; S4: dynamic correlation decision-making and closed-loop feedback, including realizing defect classification determination through correlation analysis of multimodal data, and verifying the authenticity of defects through current overload testing. This method effectively solves the problems of ambient light interference, missed detection, high cost, low resolution, etc. existing in the prior art, has significant beneficial effects, can improve detection accuracy, efficiency and reliability, meet the needs of large-scale production lines, and can efficiently locate and reduce errors and redundant steps in the detection process.

The invention relates to the technical field of integrated circuit manufacturing, in particular to a precise electroplating control system and method for an electroplated layer of a double-layer circuit board, and the method comprises the steps: building a multi-physical field coupling simulation model, and simulating the internal current density and ion concentration distribution of a via hole; constructing a mapping relation between the current density and the side wall electroplating thickness based on a simulation result, and predicting the electroplating thickness; through thickness prediction feedback, a time sequence adjustable pulse current control strategy is designed, the pulse amplitude, the duty ratio and the on-off period are dynamically adjusted, and current distribution optimization is guided; the state of the electroplating process is sensed in combination with real-time monitoring and analysis of multi-source parameters of electrode potential, conductivity and fluid velocity; and based on the prediction model and the real-time parameters, adjusting the pulse waveform and the time sequence through closed-loop compensation. According to the method, the uniformity and controllability of the thickness of the electroplated layer on the side wall of the via hole can be remarkably improved.

The invention discloses a high-voltage level conversion circuit with a symmetric pulse current structure, which belongs to the technical field of integrated circuits and comprises a level conversion module, a symmetric pulse current auxiliary module and a latch output module. According to the level conversion module, the defect that in the prior art, when the voltage of a power supply jumps rapidly, a circuit may be triggered by mistake is overcome, and the immunity of the circuit is improved. According to the symmetrical pulse current auxiliary module, the defect that transmission delays at the rising edge and the falling edge of an input signal are asymmetric in the prior art is overcome, so that the symmetrical pulse current auxiliary module keeps high transmission delay symmetry while ensuring a high transmission speed; and the problem of possible distortion of digital signal input and output in a high-speed circuit is effectively suppressed.

The invention discloses a power supply rapid charging pulse current regulation and control system and method based on current monitoring, and particularly relates to the technical field of power supply management. The method comprises the following steps: acquiring a pulse current signal in a battery charging process, performing nonlinear decoupling analysis, and decomposing the pulse current signal into a first characteristic sub-vector representing a real charging state of the battery and a second characteristic sub-vector representing a high-frequency harmonic interference state; predicting the change trend of the electrochemical impedance of the battery based on the first feature sub-vector to form an instant charging acceptance evaluation index, and evaluating the harmonic interference degree based on the second feature sub-vector to form a charging state misjudgment risk level index; based on the battery instant charging acceptance assessment index and the battery charging state misjudgment risk grade index, the optimal pulse current regulation and control strategy is determined, the power output parameters are adjusted in real time, the state misjudgment problem caused by high-frequency harmonic interference and electrochemical impedance coupling is effectively solved, and the battery charging performance and the long-term reliability are improved.

The invention provides a blade lightning protection channel online test method and system based on a pulse current method, and belongs to the technical field of blade lightning protection detection.The method comprises the steps that a pulse waveform is generated through a pulse current generator to simulate lightning impulse, and the lightning impulse is injected into the surface of a lightning arrester of a blade lightning protection system; measuring channel currents at different positions of the surface of the lightning arrester in the length direction by using a distributed sensor; a high-voltage differential probe is used for collecting and measuring the waveform of an incident wave and the waveform of a reflected wave of an injection point; detecting blade surface potential distribution by using a capacitive coupling sensor; comparing the waveform of the incident wave, the waveform of the reflected wave and the theoretical waveform, determining a time domain reflection coefficient and a frequency domain impedance spectrum, and determining a fault type; after the fault type is determined, the fault point is positioned based on the channel current and the blade surface potential distribution, the lightning impulse is simulated through the pulse waveform, the lightning protection channel is further tested, shutdown is not needed, the testing efficiency of the blade lightning protection channel is effectively improved, and the power generation efficiency is ensured.

The invention discloses an extra-high voltage DC bushing insulation state monitoring system and method, and belongs to the technical field of bushing monitoring, and the system comprises a monitoring platform, a bushing partial discharge monitoring device, and a bushing dielectric loss, capacitance and leakage current monitoring device. The bushing partial discharge monitoring device comprises a high-frequency partial discharge acquisition module and a high-frequency pulse current sensor, and the high-frequency pulse current sensor, the high-frequency partial discharge acquisition module and the monitoring platform are in signal connection in sequence; the bushing dielectric loss, capacitance and leakage current monitoring device comprises a dielectric loss acquisition module, a leakage current sensor and a signal sampling unit, the leakage current sensor and the signal sampling unit are both in signal connection with the dielectric loss acquisition module, and the dielectric loss acquisition module is in signal connection with the monitoring platform. According to the invention, through integration of the monitoring platform and the monitoring equipment, comprehensive real-time monitoring of the running state of the sleeve is realized.

The invention discloses an insulation resistance and capacitance measuring circuit and method based on monopulse double-edge analysis, and relates to the related field of the electrical insulation online monitoring technology, and the circuit comprises a detected object and an insulation detection circuit. The insulation detection circuit comprises a controlled pulse voltage source, a coupling resistance network, a current sensor, a switch control module, a signal modulation circuit and a processor. The measurement method implemented based on the circuit comprises the following steps: injecting a common-mode voltage pulse into a transmission line of the power transmission system by adopting a pulse transmitter; pulse current response is collected in real time, a current oscillogram is drawn, and a three-point sampling method is introduced to record a current value for insulation impedance parameter calculation; according to a load condition, a double-edge verification method is applied based on a pulse current attenuation characteristic, and insulation impedance parameters including a resistive component and a capacitive component are independently calculated by analyzing a pulse current rising edge and a pulse current falling edge. According to the invention, non-intrusive synchronous monitoring of resistive and capacitive components of line-to-ground impedance is realized, and the detection precision is improved.

The present invention discloses an auxiliary pet training apparatus, where pet bark is received by a microphone, amplified through an amplification circuit, subjected to signal filtering, and transmitted to a micro-processing module; the micro-processing module receives a corresponding electrical signal, and transmits a control signal to a pulse generating device and a vibration module; a pulse module outputs a pulse current to be transmitted to a conductive sleeve via a vibration head sleeve; and a vibration motor in the vibration module is started to transmit vibration to the vibration head sleeve. The present invention provides an auxiliary pet training apparatus providing stimulation for pets using low-voltage pulse current in combination with mechanical vibration, thereby achieving training for the pets, avoiding occurrence of electric arcs to damage fur of the pets, and preventing injury to a user due to touch by mistake.

The invention relates to a direct current GIL / GIS surface charge and surface discharge on-line monitoring method, which is used for a direct current GIL / GIS, and comprises the following steps: S1, carrying out the corresponding division of the surface area of an insulator based on a number; s2, establishing a GIL / GIS model, and performing corresponding numbering and division; s3, the simulated induced voltage is calculated, and a contribution coefficient matrix is calculated based on the simulated induced voltage; s4, on the basis of the induction current, actual induction voltage is obtained through calculation in combination with the measurement resistance, and actual surface charge density is obtained through calculation; and S5, judging the position area of the creeping discharge point according to the amplitude of the pulse current on each segmented electrode. Compared with the prior art, the direct-current GIL / GIS basin-type insulator surface charge online measurement device has the advantages of realizing online measurement of the direct-current GIL / GIS basin-type insulator surface charge and the

According to the cable multi-parameter fusion sensor and method, in the cable multi-parameter fusion sensor, a shielding shell is of an open-close type metal annular structure; the zero-flux sensor module is arranged on the inner layer of the shielding shell so as to detect a cable sheath ring current signal; the pulse current sensor module is arranged on the outer side of the zero-flux sensor module so as to detect a cable partial discharge pulse current signal and an overvoltage impact current signal; the magnetic shielding layer is arranged between the zero-flux sensor module and the pulse current sensor module to shield low-frequency magnetic field interference; the zero magnetic flux sensor module and the pulse current sensor module share the shielding shell to form an electromagnetic shielding structure.

The invention discloses an electro-optical-acoustic cooperative partial discharge detection device and method, and belongs to the field of equipment discharge fault detection. The device integrates a high-frequency current detection module, a photoelectric coupling detection module and an acoustic emission detection module; a high-frequency pulse current signal of a cable grounding loop, a pulse electric field of an insulating surface and an ultrasonic signal in a solid medium can be collected at the same time; all the collected signals are sent to the signal integrated processing module for alignment, noise reduction and multi-signal homologous conformity test; after detection, the signal integration processing module extracts combined feature vectors from the signals and inputs the combined feature vectors to the classification discriminator; finally, the discriminator outputs the probability of partial discharge, and if the probability exceeds a preset threshold value, it is judged that partial discharge exists in the cable. Therefore, by implementing the method and the device, the problems that single-mode detection in the prior art is poor in anti-interference capability in a complex field environment, and false alarm or missing alarm is easy to occur can be solved.

The present invention discloses a pulse generator and a pulse rod, which relate to the field of pulse circuit technology. The pulse generator includes a frequency control unit, a dual closed-loop pulse amplification unit, a digital signal processing unit and an adaptive power management unit. The frequency control unit includes an environmental sensor and a microcontroller. The microcontroller can calculate a preset pulse frequency based on information transmitted by the environmental sensor. The input end of the dual closed-loop pulse amplification unit can receive a pulse signal transmitted by the microcontroller, amplify it to a preset pulse frequency, and provide a pulse current to an electrostatic elimination needle. The digital signal processing unit can digitize the pulse signal to enhance the anti-interference ability of the pulse signal. The adaptive power management unit includes a dynamic voltage regulation module electrically connected to an external power supply, and the dynamic voltage regulation module can dynamically adjust the output voltage. The technical solution provided by the present invention can provide a pulse generator with high stability, a wide adjustment range and strong anti-interference ability.

The invention discloses a discharge current pulse width inversion method based on an electromagnetic wave signal, and relates to the field of pulse current characteristic inversion, and the method comprises the steps: S1, building a simulation model of partial discharge in a gas insulated switchgear (GIS), carrying out the streamer simulation of the GIS, and obtaining a simulation model of partial discharge in the GIS; establishing a partial discharge excitation source model based on a signal obtained by streamer simulation; s2, an excitation source and four probes are arranged, timing is started when the excitation source radiates electromagnetic waves outwards, and voltage signal waveforms received by the probes are recorded; and S3, processing and analyzing the received signal to obtain the pulse width of the pulse current, and analyzing the inversion pulse current characteristics according to the pulse width of the pulse current. According to the measured pulse width, the definition and characteristics of the pulse current are combined, and key parameters such as the amplitude and the frequency are analyzed, so that the dynamic characteristics of the pulse current can be known.

The invention discloses a cable operation environment optimization method based on cable trench collection information, and relates to the technical field of intelligent operation and maintenance of a power system, and the method comprises the steps: collecting an original parameter data set in a cable trench; a pulse current signal is collected at a cable grounding wire connection point, and a standard pulse discharge capacity sequence is generated through band-pass filtering and amplitude integral conversion; based on the original relative humidity measurement value and the environment temperature value, calculating a compensated relative humidity value through a multi-scale heat conduction-diffusion coupling equation; calculating a cable insulation risk index through a quantum annealing algorithm by using the compensated relative humidity value and the standard pulse discharge capacity sequence; the dynamic measurement deviation of the temperature and humidity sensor is subjected to double compensation of thermal radiation and molecular adsorption by constructing a multi-scale heat conduction-diffusion coupling equation, so that the reliability of environmental state sensing is greatly improved, and the operation safety, stability and intelligent operation and maintenance level of a power cable system are effectively enhanced.

The invention discloses a pulse type electromagnetic thruster performance detection system and an analysis method. A direct-current power supply, an ignition trigger controller, a pulse current detector, a pulse high-voltage detector, a discharge waveform collector, a pulse type electromagnetic thruster, a polar plate inductance intensity measuring device, a thruster impulse measuring device and a plasma movement speed measuring device are adopted. The polar plate inductance intensity measuring device is used for measuring the inductance gradient of a polar plate discharge channel of the pulse type electromagnetic thruster under different polar plate configurations; the thruster impulse measuring device is positioned below the pulse type electromagnetic thruster and is used for acquiring an output impulse value of the thruster when the pulse type electromagnetic thruster discharges and works; the plasma motion speed measuring device is arranged at the front end of a nozzle of the pulse type electromagnetic thruster and used for measuring the motion speed of plasma plume jetted by the pulse type electromagnetic thruster. According to the invention, measurement of macroscopic performance parameters of the pulse type electromagnetic thruster is realized, and quantitative characterization of microscopic characteristics of the thruster can be realized at the same time.

The invention discloses an oil-immersed transformer active defense method and system based on pulse current characteristics. The acquisition device is used for acquiring output signals of high-frequency pulse current sensors mounted at a high-voltage bushing end screen grounding position, a high-voltage bushing position and an iron core grounding position to obtain digital pulse current signals; whether active defense is started or not is judged according to whether the instantaneous value of the pulse current signal at the iron core grounding position reaches a protection starting threshold or not; judging whether the current pulse cluster is a discharge pulse cluster with abnormal internal discharge or not based on the three groups of pulse current signal characteristics; and judging whether protection acts or not according to the number of abnormal discharge pulse clusters in a set period. According to the method, serious partial discharge in the large oil-immersed transformer can be identified, protection measures are actively taken, and the situation that serious discharge defects are further developed into arc breakdown faults is effectively avoided.

The invention relates to the technical field of battery energy storage system evaluation, and relates to the technical field of battery energy storage, in particular to a method for balancing the service life and performance of a fuel cell, which comprises the following steps of: 1, acquiring multi-source data of the fuel cell, and applying a series of preset pulse current load sequences to the fuel cell, measuring response parameters output by the fuel cell in real time; 2, Fourier transform processing is carried out on the response parameters, and frequency domain signals of the response parameters are obtained; the performance and service life balance model is constructed based on the fusion feature vector containing the dynamic performance, the service life characteristic and the operation state of the fuel cell, the load distribution weight can be dynamically adjusted, the performance and the service life of the single fuel cell are kept balanced, and therefore the overall service life of the fuel cell pack is prolonged, and the reliability of the fuel cell pack is improved. And the influence on the performance of the whole system due to overload or too fast loss of the single fuel cell is avoided.

The invention relates to the technical field of intelligent control, and discloses an ultra-low power consumption miniature LED visible light intensity self-adaptive regulation and control method and system, and the method comprises the steps: obtaining an analog light intensity signal, and carrying out the smoothing processing of the analog light intensity signal, and obtaining an environment light intensity value; calculating a light intensity change rate, and if the light intensity change rate exceeds a dynamic threshold value, marking an environment state and outputting a light intensity difference value; generating a preliminary adjustment instruction according to the state matching control parameter and the difference value quantization mapping, and calculating target light intensity in combination with the basic brightness; after executing the instruction, calculating actual and target deviation, and iteratively correcting to obtain a light intensity control signal; if the power consumption exceeds the limit, optimizing the signal amplitude; the input driving circuit analyzes the synthesized pulse current, excites pixels to emit light and gathers to obtain adjustment data; and if the visual contrast is lower than a threshold value, the change rate is adjusted again to realize closed-loop refining, and the light intensity adjustment accuracy is improved. The method can improve the real-time sensing capability of ambient light.

The invention is suitable for the technical field of grounding grid defect evaluation, and provides a transient electromagnetism-based grounding grid corrosion defect evaluation method and system, and the method comprises the steps: placing a sensor of a transient electromagnetic detection device above a to-be-detected region of a grounding grid, injecting a pulse current excitation signal into a conical focusing excitation coil, and carrying out the detection of the to-be-detected region of the grounding grid; acquiring an induced voltage time sequence signal through a receiving coil; extracting at least one characteristic parameter from the induced voltage time sequence signal, wherein the characteristic parameter comprises a signal peak value, peak value time, an attenuation rate or a signal integral quantity; inputting the characteristic parameters into a preset corrosion evaluation model, and performing inversion to obtain a residual thickness value or a corrosion depth value of the grounding grid in the to-be-detected area; generating and outputting a quantitative evaluation result containing the residual thickness value or the corrosion depth value; the method can be implemented in a non-stop state of the grounding grid, and an efficient and reliable decision basis is provided for safe operation and state maintenance of a power system.

The invention provides a wind power tower drum defect detection surface wave sensor and a detection method thereof. The sensor comprises a shell, a magnetic attraction part and a transmitting and receiving integrated signal part. The magnetic attraction component adopts a U-shaped structure and is formed by connecting two ends of a strip-shaped magnet with a magnetizer respectively; and the receiving and transmitting integrated signal component is positioned at the opening end of the U-shaped structure of the magnetic component. The sensor is adsorbed on the surface of the outer wall of a tower drum, meanwhile, a near surface layer of the outer wall of the tower drum presents a strong bias magnetic field, radio frequency pulse current is introduced into a transmitting and receiving integrated signal component, a high-frequency dynamic magnetic field is induced on the near surface, surface waves in any direction are excited and received under the action of the two fields, and echo signals of the surface waves are analyzed. And judging whether the outer wall of the tower drum has defects. The sensor disclosed by the invention is small in size and capable of meeting mobile scanning, the propagation distance of the excited surface wave is long, the recognition precision is high, the working difficulty of tower drum defect detection is reduced, circumferential and axial defect detection is realized, and the detection efficiency is improved.

The invention relates to the technical field of intelligent sensors, in particular to a method and system for measuring current through an electrometer of a radiation monitor, and the method comprises the steps: obtaining a pulse current signal of the electrometer in a radiation environment, and carrying out the pulse period division of a pulse current sequence, the overshoot reactivity in each pulse period is obtained according to the difference between the maximum value and the maximum value of the current in each pulse period and the change rate between the adjacent maximum value and minimum value in the current value of each pulse period; the ringing fluctuation deviation of each pulse period is obtained by combining the fluctuation degree of the current when ringing is generated in each pulse period, the distortion coefficient of each pulse period is obtained, the current change distribution condition of a plurality of sampling moments closest to the time interval of each sampling moment is analyzed, and then the self-adaptive search window of each sampling moment is obtained; and filtering the pulse current to obtain an electrometer current measurement result. According to the invention, accurate measurement of the electrometer current in the radiation environment can be realized.

The invention belongs to the technical field of equipment state monitoring and fault diagnosis, and relates to a pole-mounted switch damp defect diagnosis method and system based on multi-source information fusion, and the method comprises the steps: collecting a leakage current signal and a high-frequency pulse current signal flowing through a grounding wire in real time, and environment parameters around a target pole-mounted switch; preprocessing the leakage current signal and the high-frequency pulse current signal, and performing feature extraction based on the preprocessed leakage current signal, the preprocessed high-frequency pulse current signal and environmental parameters to obtain a leakage current feature quantity, a high-frequency discharge feature quantity and an environmental coupling factor; and based on the leakage current characteristic quantity, the high-frequency discharge characteristic quantity and the environment coupling factor, judging a damp fault of the target pole-mounted switch, and combining a D-S evidence theory and fusing multi-source information confidence to complete damp defect diagnosis of the target pole-mounted switch. According to the invention, complementarity between different information sources can be fully utilized, and the damp state of the pole-mounted switch can be accurately judged.

The invention discloses a laser radar transmitting circuit with pulse width compensation and a control method thereof. The circuit comprises an optical pulse transmitting circuit and a pulse width sampling control signal feedback circuit. The method comprises the following steps: generating a starting pulse signal and exciting an optical pulse transmitting circuit to output a laser pulse signal according to the starting pulse signal; comparing the laser pulse signal with a reference voltage, and outputting a square wave pulse signal; capturing the square wave pulse signal to obtain time interval data; carrying out calculation according to the time interval data to obtain the pulse width of the laser pulse current and carrying out output voltage regulation processing to obtain a signal feedback quantity; and performing feedback regulation on the output voltage of the optical pulse transmitting circuit according to the signal feedback quantity. According to the embodiment of the invention, pulse width acquisition and adjustment of the optical pulse current can be realized, so that the pulse width stability of the optical pulse current is improved. The laser radar transmitting circuit can be widely applied to the technical field of laser radar transmitting circuits.

The embodiment of the invention provides a method and a system for simulating a neural synaptic characteristic behavior by a spin-orbit moment device, and belongs to the field of neural computation. The spin-orbit torque device is of a multi-end Hall rod structure and comprises an input end and a plurality of output ends, and the method comprises the steps that continuously-changing pulse current is applied between counter electrodes of the input end of the spin-orbit torque device; under the condition of no external magnetic field, the continuously changing pulse current is used as an input signal of the simulated nerve synapse, and the Hall resistor is used as an output of the simulated nerve synapse; wherein the emission threshold value of the neural synapse is adjusted through the position of the output end and voltage regulation and control. Neural synapses with different thresholds are simulated by utilizing a spin-orbit torque device which comprises an input end and a plurality of output ends and is of a multi-end Hall rod structure and adjusting the distance between the spin-orbit torque device and the input end and the distance between the spin-orbit torque device and the output end; and voltage can be applied to the device, so that the neural synaptic threshold value can be dynamically adjusted. Through different modes and principles, various neural synapses with different thresholds are simulated.

The invention discloses a light-sensing external trigger signal output device for laser far-field parameter analysis, comprising: a light signal detector, used for collecting laser signals irradiated on a target plate and outputting a pulse current signal; a signal primary amplification module, used for converting the pulse current signal into a pulse voltage signal and amplifying the pulse voltage signal; a signal superposition amplification module, used for amplifying the pulse voltage amplification signal output by the signal primary amplification module again; a laser pulse signal judgment module, comprising a comparator, used for setting a signal judgment threshold value, the comparator being connected to a monostable trigger, and the monostable trigger sending a trigger signal when the pulse signal is greater than the signal judgment threshold value set by the comparator; an MCU main control module, used for interrupt processing, trigger signal delay and output frequency setting, trigger signal output and transmitting a timing control signal to an imaging camera; a power management module, connected to an external power supply and supplying power to the remaining modules.

The invention discloses a self-adaptive cable grounding resistance detector and a self-checking method, the self-adaptive cable grounding resistance detector comprises a shell, the shell is provided with an indicating lamp, a charging socket, a power switch and a single-ended grounding and cross-connected wiring socket, the shell is internally provided with a main control unit, and the algorithm of the main control unit has functions of function calibration, compensation calibration, power supply self-checking and the like. The main control unit is integrated on a circuit board, and can adapt to various grounding detections without replacing hardware by controlling automatic switching of a relay, so that the universality and the economical efficiency are improved. The device is controlled by an integrated circuit chip, has high precision and high environmental adaptability, and is suitable for single-end grounding and cross interconnection grounding resistance detection of a high-voltage cable. According to the invention, the self-checking process is completed before starting up, and through pulse current and standard resistance simulation detection, the measurement accuracy is improved, and personal errors are reduced.

The invention discloses a low-frequency and differential-phase pulse combined electromagnetic continuous casting method, which belongs to the field of metal material preparation and processing, in the processes of semi-continuous casting, horizontal continuous casting and vertical continuous casting, A + 2B excitation coils are placed in a crystallizer jacket in the direction parallel to the central axis of a cast ingot, and A and B are integers greater than or equal to 1; the 2B excitation coils are divided into a group B1 and a group B2; a coils form a group; a power supply control system with a plurality of sets of built-in control circuits is utilized to respectively output two different currents and voltages which are applied to three groups of magnet exciting coils; one set of circuit system outputs low-frequency alternating-current voltage and sinusoidal current and generates a low-frequency alternating-current electromagnetic signal; the other set of circuit system outputs two groups of square-wave pulse voltage and zigzag pulse current; and a low-frequency electromagnetic field and a differential-phase pulsed magnetic field are applied to melt combinations with different heights in the crystallization sleeve, so that the electromagnetic utilization rate is increased, grains are refined, and the ingot casting quality is improved.