474results about "Measuring interference from external sources" patented technology

The invention belongs to the technical field of geophysical monitoring, and relates to an electromagnetic interference detection method for earthquake monitoring, which comprises the following steps: deploying a multi-dimensional electromagnetic field sensing unit and an earthquake signal acquisition unit and realizing high-precision synchronization; synchronously acquiring multi-dimensional electromagnetic field and seismic physical signal data; performing multi-feature and noise feature extraction on the two; inputting the features into a pre-trained machine learning / deep learning model for identification, and outputting information such as interference type, intensity and azimuth angle; and carrying out influence evaluation and quality marking on the seismic data according to the output, and selectively inhibiting or compensating. Through the above scheme, multi-dimensional perception and characterization, high-precision synchronization and correlation analysis, intelligent identification and spatial positioning are realized, and the reliability and accuracy of earthquake monitoring data are significantly improved.

The invention discloses a driver controller detection system, which comprises an acquisition module, an acquisition module, a processing module, an identification module, a judgment module, an analysis module and a generation module, the acquisition module captures contact information and electromagnetic interference data of contacts in real time by means of a high-dynamic voltage sensor and a broadband EMC probe; the acquisition module is triggered by a locomotive signal and records dynamic working condition data; the processing module aligns the data, performs denoising and extracts fault parameters; the identification module scans the voltage waveform and judges the transient contact failure; the judgment module monitors EMC data and compares an instruction position, and judges misoperation; the analysis module analyzes fault association, judges a composite type and triggers an alarm; the generation module generates a detection report and a log. According to the system, a multi-dimensional monitoring network is constructed under a dynamic working condition, data reliability is guaranteed, faults are accurately identified, a compound fault source is positioned, and the safety and stability of locomotive operation are improved through risk grading early warning and automatic reporting.

The invention relates to the technical field of radio orientation, in particular to an unmanned aerial vehicle flight state detection method based on a frequency spectrum detection technology, which comprises the following steps: acquiring an initial time domain signal of an initial frequency spectrum signal of an unmanned aerial vehicle in a monitoring period in a flight process; segmenting the initial time domain signal according to the flight state so as to screen out each complex change time period; performing signal decomposition on the time domain sub-signals in each complex change time period to obtain a plurality of components; and determining an interference frequency tendency index of each component, determining an interference characteristic comprehensive index of each component according to the interference frequency tendency index of each component, the oscillation intensity characteristic value and the correlation coefficient, and reconstructing the frequency spectrum sub-signal corresponding to the time domain sub-signal to obtain a target frequency spectrum signal. According to the method, the data reference value of the target spectrum signal obtained through adaptive filtering is larger, and the accuracy of detection of the flight state of the unmanned aerial vehicle is improved.

The invention discloses a ship power grid transient electromagnetic interference grading evaluation method and system, relates to the technical field of ship power grid safety evaluation, realizes scientific grading evaluation of ship power grid transient peak interference, and provides a reliable basis for stable operation and equipment protection of a ship power grid. Comprising the following steps: measuring a transient peak sensitive threshold value of equipment by adopting a peak signal transduction sensitivity test; performing classification and importance coefficient assignment on the equipment according to the importance degree of the equipment; and calculating a weighted average sensitive threshold value of load equipment at the rear end of the distribution box by adopting a weighted average method. At the output end of a power distribution box of a ship power grid cabin, a transient peak conducted emission detection device is used for monitoring and collecting power grid transient peak conducted emission data in real time, and a power grid transient peak interference measured value is recognized from the power grid transient peak conducted emission data. Comparing the power grid transient peak interference measured value with the weighted average sensitive threshold value, and calculating a difference value between the two values; and according to a difference value result, carrying out ship power grid transient peak interference grading evaluation.

The invention discloses an integrated cabinet testing device and a detection method thereof, particularly relates to the technical field of integrated cabinet state detection, and is used for solving the problem that in the prior art, gradual drift of a signal monitoring unit under transient electromagnetic interference cannot be quantized, and consequently equipment degradation characteristics and measurement errors are difficult to decouple. A high-strength transient electromagnetic interference environment conforming to switch operation physical characteristics is simulated in a cabinet; the acquisition end of the signal monitoring unit is connected with a high-precision reference sensor in parallel to realize millisecond-level synchronous acquisition of double-track signals; generating a difference sequence representing drift; self-adaptive fault excitation is dynamically generated based on the interference characteristic frequency band of the difference value sequence; performing covariance matrix orthogonal decomposition on the mixed signal, separating a drift feature vector and a fault feature vector, and calculating a projection scalar value; and finally, the historical reference output drift interference coefficient and the three-level fault confidence report are combined, so that the credibility of predictive maintenance of the intelligent power distribution system is remarkably improved.

The invention belongs to the field of flexible direct-current transmission power module tests, and discloses a multi-dimensional electromagnetic compatibility test system and method for a flexible direct-current transmission power module, and the method is characterized in that a dynamic power grid simulation unit simulates the electrical stress of the power module under a complex working condition by reproducing power grid limit faults such as direct-current short circuit and alternating-current harmonic waves; the broadband interference injection unit is used for superposing multi-band electromagnetic interference to simulate a composite interference scene according to the noise characteristics of the IGBT / IGCT switching process; the multi-physical field monitoring unit synchronously acquires key parameters such as electromagnetic field intensity, signal transmission, temperature rise and vibration, and analyzes module response under the action of multiple stress coupling in real time. According to the system, cooperative loading of power grid faults and noise is realized, limitation of a single interference source and a simple scene in a traditional test is broken through based on multi-physics field data fusion analysis, and the comprehensive evaluation precision of the anti-interference capability, the operation reliability and the safety of the power module in an extreme electromagnetic environment is improved.

The invention relates to the technical field of electrical variable measurement, in particular to a power distribution overhead line fault traveling wave positioning anti-electromagnetic interference method and system and a medium. According to the method, a broadband equivalent circuit model of a power distribution overhead line is constructed based on a vector matching method and is used for simulating transmission characteristics of fault traveling waves and switching operation overvoltage; performing multi-scale decomposition on the acquired signals by adopting a wavelet transform algorithm, extracting disturbance signal parameters, and calculating traveling wave propagation characteristics according to different fault types and switch working conditions; constructing an electromagnetic disturbance propagation coupling model, and performing time-frequency domain analysis by taking the traveling wave propagation characteristics, the disturbance signal parameters and the line environment parameters as input to obtain coupling characteristics of electromagnetic disturbance; carrying out numerical simulation by utilizing electromagnetic field simulation software, analyzing the influence of line environment parameters on coupling characteristics, and optimizing model parameters; and finally, analyzing the coupling characteristics of electromagnetic disturbance, eliminating the influence of electromagnetic interference on the traveling wave signal through a reverse decoupling algorithm, and achieving the accurate fault positioning of the power distribution overhead line.

The invention discloses an electromagnetic compatibility fault prediction method for a pulse withstand voltage generator, and relates to the technical field of electromagnetic compatibility evaluation, and the method comprises the steps: collecting original signals of different circuit states of the pulse withstand voltage generator, extracting voltage ripple, current phase and magnetic field radiation frequency spectrum, and generating a time sequence monitoring data set; based on the time sequence monitoring data set, electromagnetic disturbance characteristics are extracted through deep analysis, a rule engine is built, and a fault probability and a fault type are output; triggering a plurality of suppression rules based on different fault types; after any suppression rule is executed, collecting the original signal again, and inputting the original signal into a pre-constructed risk assessment model to generate an interference suppression efficiency index; comparing the interference suppression efficiency index with a preset efficiency threshold value; if the interference suppression efficiency index is lower than the efficiency threshold value, generating a strategy compensation instruction and feeding the strategy compensation instruction back to the corresponding suppression step to iterate and adjust parameters; the electromagnetic interference suppression effect is improved.

This invention discloses an electromagnetic interference prediction method based on statistical analysis of electromagnetic environment monitoring data, belonging to the field of equipment electronics technology. The method collects spectral data from various monitoring points in the electromagnetic environment; the spectrum, time, and operating condition information form a spectral sample. Through spectral stability calculation, the monitoring point X with the lowest stability is determined. Based on the spectral sample, statistics reflecting electromagnetic environment fluctuations are calculated from data at different times and the same frequency, generating a fluctuation characteristic spectrum of the statistics as a function of frequency. Based on the correlation between the fluctuation characteristic spectra of monitoring point X and other monitoring points, and combined with the type of equipment at monitoring point X, potential interference source equipment is identified. This invention can predict electromagnetic interference based on statistical analysis of spectral data.

The invention relates to an electromagnetic compatibility and radio frequency coexistence framework, and belongs to the technical field of vehicle-mounted display and electromagnetic compatibility. The device comprises a display module and a control system which are arranged outside a vehicle body, the control system is provided with a cooperative control unit, an electromagnetic interference suppression module and a running state monitoring and adjusting module to form a closed-loop framework, and the closed-loop framework is used for dynamically managing display signals, power and a time sequence in the running process of the vehicle, suppressing conduction and radiation interference and controlling the running state of the vehicle. And the coexistence performance of the external display and the vehicle-mounted radio frequency system is ensured, and the electromagnetic compatibility regulations are met. Further, the system comprises an integrated topology unit, a coexistence monitoring unit and a strategy execution unit, driving time sequence shaping, backflow path constraint and power supply ripple shaping are achieved, and when interference exceeds a threshold value, the system is switched to a controlled display state. A shielding-grounding-filtering three-in-one layout and a driving time sequence shaping unit can be adopted. According to the invention, the safety and reliability of external display in the aspects of electromagnetic compatibility, radio frequency coexistence and service life management are ensured.

The invention relates to a near-field scanning method and device, computer equipment, a storage medium and a program product. The method comprises the following steps: grouping scanning points in a to-be-scanned area of to-be-tested equipment to obtain a plurality of to-be-scanned point groups; according to the group identifier of the currently scanned to-be-scanned point group, determining a target to-be-scanned point group from each to-be-scanned point group; for each scanning point in the target to-be-scanned point group, determining a first parameter according to the electromagnetic field intensity of the scanned point in the neighborhood of the scanning point; and scanning the scanning points under the condition that the first parameter is greater than the preset threshold value, thereby screening the scanning points in the to-be-scanned area of the to-be-detected equipment, reducing the number of the scanning points needing to be scanned in the near-field scanning process on the premise of keeping certain detection quality, and improving the detection efficiency. And the detection efficiency of the electronic equipment is improved by improving the near-field scanning speed.

The invention discloses an intelligent distinguishing system and method for surface defects of a non-welding bottle type container, and particularly relates to the technical field of magnetic powder detection. Electromagnetic interference in an industrial field is simulated by arranging different types of electromagnetic interference sources, and reference measurement and comprehensive analysis are performed on surface magnetic field distribution of a non-welding bottle type container and defect signal intensity change of magnetic powder detection equipment under a step-by-step interference condition, so that the anti-interference capability of the equipment is evaluated. The accuracy of a detection result is divided into different grades, repeated detection and abnormal degree evaluation are performed on an area with an incomplete accuracy result, and if the abnormal degree is high, the area is marked as a pseudo signal area and fed back to a machine learning model to gradually update the model discrimination capability, so that the problem of false defect misjudgment under electromagnetic interference is effectively reduced, and the accuracy of the detection result is improved. And the accuracy and reliability of the detection system in a complex interference environment are improved.

The invention discloses an electromagnetic compatibility detection method and device of a rail transit signal system and electronic equipment, and relates to the technical field of electromagnetic safety. Determining an actual electromagnetic compatibility area corresponding to the equipment according to the actual distance between the actual installation positions of the multiple pieces of equipment of the rail transit signal system and a target reference line on a rail; and determining the electromagnetic interference risk condition between the relation pairs based on the electromagnetic interference information of the actual electromagnetic compatibility area corresponding to the equipment. According to the method, the electromagnetic interference scene of the actual rail transit signal system is analyzed to cover the random and coexisting electromagnetic interference combination of the field, so that the confidence coefficient of the risk assessment result in the complex electromagnetic environment of the field is improved, and the analysis is ensured to cover the random and composite scene which cannot be reproduced by the standard test; moreover, the electromagnetic interference risk condition between a relation pair formed by a plurality of devices in the rail transit signal system is determined, that is, systematic evaluation of complex electromagnetic interaction is realized through system-level analysis.

The invention discloses an electromagnetic field near-field visualization method and device fusing machine vision and electromagnetic measurement, and relates to the technical field of electromagnetic compatibility test and electromagnetic environment perception. The method comprises the following steps: firstly, acquiring an image of the surface of a measured object, identifying and positioning a probe by using a model, and performing grid division on a view field area; meanwhile, electromagnetic field intensity data are obtained, and a representative typical field intensity value is extracted. When the probe is identified to be located in a certain grid unit, if the grid enters for the first time, creating the grid and writing the typical value of the current area; if yes, the typical value of the grid is updated on the existing basis, and two-dimensional and three-dimensional electromagnetic field patterns which are continuously distributed are formed. And carrying out fusion rendering on an electromagnetic field interpolation result and a video image to realize visual output of electromagnetic field distribution in a real scene. According to the method, the electromagnetic field distribution, the equipment three-dimensional structure and the actual environment can be visually presented while the measurement precision is ensured.

The invention provides a method and system for detecting electromagnetic compatibility efficiency of a wave-absorbing material and a storage medium, and relates to the technical field of electromagnetic compatibility efficiency detection. The method comprises the following steps: firstly, carrying out first electromagnetic measurement on a target area of the electronic equipment when a wave-absorbing material is not laid to obtain a first near-field scattering parameter set; and carrying out local minimum detection and amplitude and space distribution threshold presetting on the parameter set to screen out problem resonance frequency points. And laying the to-be-measured wave-absorbing material in the target area, and carrying out second electromagnetic measurement according to the same measurement condition to obtain a second near-field scattering parameter set. And comparing the two measurement data, calculating the local variable quantity, the space average suppression degree and the peak suppression ratio of each problem resonance frequency point, and constructing a comprehensive efficiency index on the basis of the local variable quantity, the space average suppression degree and the peak suppression ratio, thereby realizing quantitative evaluation on the overall efficiency and the local hot spot suppression capability of the wave-absorbing material. And finally, judging whether the electromagnetic compatibility efficiency of the material reaches the standard or not according to the space average suppression degree and the comprehensive efficiency index. Accurate evaluation of the electromagnetic compatibility efficiency of the wave-absorbing material is realized.

The invention relates to the technical field of PLC detection, in particular to a PLC main control module testing method, device and equipment, a medium and a product, and the method comprises the steps: recording normal working data of a to-be-tested PLC main control module as reference data in an electromagnetic interference-free environment; starting an electromagnetic interference generator, testing key electromagnetic interference modes in the single electromagnetic interference modes in sequence, and recording the performance conditions of the to-be-tested PLC main control module under different interference intensities; constructing a complex electromagnetic interference simulation environment, starting an electromagnetic interference generator, and recording operation conditions of the to-be-tested PLC main control module under different interference combination modes and different interference intensities; and acquiring operation parameters of the to-be-tested PLC main control module in the testing process, and performing data analysis and result judgment based on the operation parameters, the performance condition and the operation condition. Therefore, the problems that evaluation is not comprehensive, and the performance of the PLC main control module under composite interference cannot be reflected are solved.

The invention belongs to the technical field of electrical equipment magnetic monitoring, and discloses an electrical equipment magnetic field interference intelligent monitoring and early warning sensing system, which establishes a magnetic field, working condition, environment and space four-dimensional data sensing system and matches a bimodal separation technology. Pure magnetic field interference, working condition correlation interference, environment induced interference and space correlation interference components can be effectively separated; the generated three-dimensional traceability map can visually present the position of an interference source, a propagation path and the priority of affected equipment, and then the accuracy of interference type identification and source positioning is greatly improved in combination with a feature library covering a large amount of historical normal operation data, so that fault pre-judgment is changed from passively coping with an existing fault into actively preventing and controlling risks in advance; a dual-path active suppression mechanism is formed by combining a software compensation mode of dynamically generating a magnetic field compensation current through a PID control algorithm with a tunable magnetic shielding device hardware adjustment means configured for high-priority equipment.

The invention relates to the technical field of industrial automation electronic testing, in particular to an industrial control mainboard anti-interference performance evaluation system and method for a complex disturbance scene, and the system comprises a clock disturbance scene generation module, a dynamic clock interference injection module, a clock bus deterioration collection module and an anti-interference level output module. Wherein the clock disturbance scene generation module is used for generating a clock disturbance spectrum; the dynamic clock interference injection module is used for converting the clock disturbance spectrum into a frequency-phase dual-modulation signal and injecting the frequency-phase dual-modulation signal into the tested industrial control mainboard; the clock bus deterioration acquisition module is used for acquiring bus error code characteristics caused by clock disturbance in real time; and the anti-interference level output module is used for generating a four-level clock anti-interference level. According to the invention, by constructing a closed-loop system of disturbance injection-feature acquisition-grade evaluation, quantitative evaluation and stability determination of the anti-interference capability of the industrial control mainboard in a complex disturbance scene are realized.

Systems, methods, and other embodiments associated with a specialized antenna expansion card for EMI fingerprint characterization of target computing systems are described. In one embodiment, a method for EMI scanning using a broadband antenna expansion card installed within a target computer includes causing the target computer to execute a test pattern of computer operations. The method includes taking readings of radiofrequency EMI generated by execution of the test pattern through the broadband antenna card that is installed within a chassis of the target computer. The method includes detecting that hardware of the target computer system is behaving anomalously based on a dissimilarity between the readings of radiofrequency EMI and machine learning estimates of radiofrequency EMI for nominal operation of a reference computer system. And, the method includes generating an electronic alert that the hardware of the target computer system is behaving anomalously.

The invention discloses a fault diagnosis method and device for electrical equipment, electronic equipment and a storage medium. According to an electromagnetic interference index, the data acquisition frequency and range are dynamically adjusted, high-frequency acquisition is pertinently started for state abnormal equipment so as to accurately capture abnormal signals, and multi-source data such as partial discharge pulses are fused. An equipment state feature sequence is constructed in combination with historical operation data, and high-correlation sensitive features are screened, so that the limitation of a single parameter is avoided; meanwhile, early faults are recognized and early warning is output through a pre-trained long-short-term memory neural network, a protection constant value is rechecked in cooperation with a rule engine and a convolutional neural network, a standby loop is automatically switched or the constant value is adjusted when abnormity occurs, and a complete monitoring-early warning-response closed loop is formed; the technical effects of improving the equipment state evaluation comprehensiveness, enhancing the early fault recognition capability, improving the early warning accuracy, increasing the response speed of the protection system and guaranteeing the operation safety and reliability of the electrical equipment and the power grid of the power plant are achieved.

The present disclosure provides an electromagnetic interference testing system and method for an electric automobile under dynamic working conditions. The method includes the steps of: estimating electromagnetic interference presence state information about each of all wiring harnesses connected to a motor driving device based on operation state data, and identifying an abnormal wiring harness in which a signal conduction interference event occurs; tracking and identifying an electromagnetic interference signal of the abnormal wiring harness to obtain propagation path information, and determining, based on this, an electronic device which may be affected by the electromagnetic interference signal inside the electric automobile; and determining whether an operation disorder event occurs in the electronic device, and determining an electromagnetic interference concentrated circuit interval inside the electronic device, which is convenient for subsequent electromagnetic interference shielding processing for corresponding circuit intervals.

The invention discloses an electromagnetic interference detection method and device and a nonvolatile storage medium. The method comprises the following steps: acquiring an initial voltage signal; fourier transform is carried out on the initial voltage signal, and a target spectral line corresponding to the initial voltage signal is determined; the target spectral line is input into a preset phase-locked loop detector, a target signal component is obtained based on a transmission mode in the phase-locked loop detector, and the target signal component comprises amplitude and frequency; demodulating and filtering the target signal component in sequence to obtain a target filtering signal; processing the target filtering signal by adopting a preset quasi-peak value detector to obtain a target voltage quasi-peak value; based on the target voltage quasi-peak value, an interference detection result of the initial voltage signal is determined, and the interference detection result comprises existence of electromagnetic interference or absence of electromagnetic interference. According to the invention, the technical problems of inaccurate measurement result, complex measurement process and high cost of the existing detection technology are solved.

The invention provides a frequency converter electromagnetic interference spectrum real-time monitoring and tracing method and device, and relates to the technical field of frequency converters, and the method comprises the steps: building a mapping relation between frequency converter operation state parameters and magnetic leakage point electromagnetic interference data; taking the operation state parameters of the frequency converter as excitation sources to be injected into an electromagnetic simulation space, and generating predicted interference spectrum and electromagnetic field distribution information in real time; according to the mapping relation, matching and comparing the predicted interference spectrum and electromagnetic field distribution information with the electromagnetic interference data, and comparing with a preset interference fingerprint database; and positioning field intensity space coordinates by combining the space magnetic field distribution of the electromagnetic interference data according to the interference spectrum characteristics, and generating an interference spectrum traceability result based on the interference spectrum characteristics, the field intensity space coordinates and predicted interference spectrum and electromagnetic field distribution information. According to the invention, the technical problem of low electromagnetic interference identification precision of the frequency converter in the prior art can be solved, and the technical effect of improving the electromagnetic interference identification precision is achieved.

The invention discloses an evaluation method for anti-electromagnetic interference performance of an unmanned aerial vehicle, a storage medium and electronic equipment, and the method comprises the steps: building a controllable electromagnetic interference simulation system which is used for simulating an electromagnetic interference environment where the unmanned aerial vehicle is actually located, and installing a monitoring device which is used for monitoring experimental environment parameters and the flight attitude of the unmanned aerial vehicle in real time on the unmanned aerial vehicle, controlling the unmanned aerial vehicle to take off, setting a hovering state, adjusting parameters of an electromagnetic interference simulation system, observing and collecting data of the unmanned aerial vehicle under different electromagnetic interferences, processing the collected data, extracting characteristic parameters, and carrying out quantitative evaluation on the electromagnetic anti-interference capability of the unmanned aerial vehicle according to the characteristic parameters. The problem that performance evaluation of the unmanned aerial vehicle in the electromagnetic environment is inconvenient is solved, and the anti-magnetic interference performance of the unmanned aerial vehicle in the complex electromagnetic environment can be comprehensively and accurately evaluated.

The invention discloses a chip radiation emission test method, device and equipment and a storage medium, and relates to the technical field of chip electromagnetic compatibility design and simulation, and the method comprises the steps: constructing a target packaging body model corresponding to a to-be-tested chip; constructing a target test circuit board model corresponding to the to-be-tested chip; determining a target scattering parameter corresponding to the target to-be-measured electromagnetic structure; based on the target scattering parameters, the target to-be-tested electromagnetic structure is connected to the first simulation model, the second simulation model and a voltage source model and a current source model matched with the target to-be-tested electromagnetic structure, and a test link of the target to-be-tested electromagnetic structure is constructed; performing frequency response analysis on the test link, and determining radiation emission energy data of an output port of the transverse electromagnetic wave cell model; and generating a corresponding amplitude-frequency characteristic curve based on the radiation emission energy data. According to the method, the early simulation test of the radiation emission characteristic of the chip can be realized, and the research and development efficiency of the chip is remarkably improved.

The invention discloses an EMC interference source rapid positioning method, system and device, and relates to the technical field of electrical measurement, and the method comprises the steps: laying a monitoring sensor network based on an electromagnetic interference signal conduction path and a radiation path of a tested device; connecting a monitoring sensing network, and acquiring interference signal data of the tested equipment in real time; performing spectrum analysis and interference type judgment on the acquired interference signal data; and taking the data acquisition flag bit as a positioning engine, and respectively carrying out adaptive interference tracking analysis according to the interference type based on judgment to obtain an interference source positioning result. The technical problems that an existing electromagnetic interference source positioning method cannot position the interference source in real time when the equipment operates normally, the positioning efficiency is low, and the accuracy is poor are solved, and the technical effect that efficient and accurate interference source positioning is achieved in the normal operation state of the equipment by collecting interference signal data in real time to conduct self-adaptive tracking analysis is achieved.

The application discloses a kind of warship power grid transient electromagnetic interference grading evaluation method and system, it is related to warship power grid safety evaluation technical field, realize the scientific grading evaluation of warship power grid transient peak interference, provide reliable basis for the stable operation and equipment protection of warship power grid.It includes the following steps: using peak signal conduction sensitivity test, determine equipment transient peak sensitive threshold value.According to the importance of equipment, the importance coefficient of equipment is valued;Weighted average method is used to calculate the weighted average sensitive threshold value of the load equipment at the back end of distribution box.In the output end of the cabin distribution box of warship power grid, the transient peak conduction emission detection device is used to monitor and collect power grid transient peak conduction emission data in real time, and the power grid transient peak interference measurement value is identified from the data.The difference between the power grid transient peak interference measurement value and the weighted average sensitive threshold value is calculated;According to the difference result, the grading evaluation of warship power grid transient peak interference is carried out.

The invention relates to a multi-frequency sensitivity test evaluation method and system, the evaluation method is realized based on a multi-frequency sensitivity test device, and the device comprises a signal generator, an attenuator, a power amplifier, a directional coupler, a power meter, a frequency spectrograph and an interference applying module. According to the evaluation method, the sensitivity of the electronic product to single-frequency interference and multi-frequency interference in different frequency bands can be determined, modes such as frequency band sub-band division and reverse frequency spectrum monitoring are designed, the influence of multi-frequency-point signal intermodulation interference on a test result can be reduced, and the test accuracy is improved. The problem that the accuracy of a multi-frequency-point sensitivity test result is affected due to the fact that a traditional multi-frequency-point test method generates extra interference risks on the tested electronic product is solved. Meanwhile, under the condition that the multi-frequency sensitivity indication parameter provided by the invention meets a certain condition, a continuous wave sensitivity test method can be adopted to replace a multi-frequency point sensitivity test method, so that the test cost is reduced.

The application relates to a method for locating and identifying an electromagnetic interference source in a shielding box, which comprises the following steps: acquiring tangential magnetic field information of a sampling plane outside the shielding box, constructing an equivalent source model based on the tangential magnetic field information, acquiring dipole moment information of an initial equivalent electric dipole, and realizing first source reconstruction; acquiring a contribution degree evaluation index of each electric dipole based on the dipole moment information of the initial equivalent electric dipole, removing electric dipoles with low contribution degrees based on the contribution degree evaluation index, updating the equivalent source model, acquiring dipole moment information of an updated equivalent dipole, and realizing second source reconstruction; and realizing location and identification of the electromagnetic interference source in the shielding box based on the dipole moment information of the updated equivalent dipole. Compared with the prior art, the application has the advantages of improving equivalent source accuracy, being capable of accurately locating and identifying the electromagnetic interference source in the shielding box, and the like.

The invention discloses an active noise reduction method and device for an automobile electromagnetic compatibility test. The method comprises the following steps: acquiring an original interference noise signal through a pre-arranged reference sensor array; processing the original interference noise signal through a pre-constructed intelligent noise reduction model to obtain a noise reduction control signal; a noise reduction signal is emitted according to the noise reduction control signal, and an electromagnetic field counteracting the original interference noise signal is formed; detecting the offset resultant field intensity signal in real time through a pre-arranged error sensor; and performing parameter optimization on the intelligent noise reduction model according to the synthesized field intensity signal. According to the method, the problem that the test accuracy is seriously influenced by environmental background noise and electromagnetic interference generated by test equipment in an automobile electromagnetic compatibility test can be solved.