84results about "Frequency measurement arrangement" patented technology

The application discloses a lightning impulse grounding grid frequency characteristic analysis method, system, device and medium, including: obtaining initial sample data; using the sample and a preset test frequency set to construct at least two different structure rational function interpolation models, and calculating the output residual thereof in the test frequency band; determining the target frequency point with the maximum modeling uncertainty according to the residual, calling the moment method to supplement high-precision response samples at the point; based on the updated sample set, constructing a diagonal or near-diagonal form rational interpolation model, and judging whether the prediction error of the model at the target frequency point is lower than a preset convergence threshold; if the convergence condition is not met, returning to the multiple model construction step, reiterating using the current sample set until the error meets the standard, and finally outputting the grounding grid frequency response characteristics covering the lightning impulse frequency band. The application realizes efficient analysis of the grounding grid frequency characteristics under lightning impulse, and effectively reduces the time used for analyzing the grounding grid frequency characteristics under lightning impulse.

The application provides a power distribution line multi-pseudo fault point checking method based on a multi-frequency signal, the checking method comprises a single-ended traveling wave positioning method, a traveling wave positioning terminal for traveling wave positioning is installed at a first end of a line feeder of a transformer substation, current signals collected by power distribution terminals at power distribution lines are collected, and pseudo fault points are excluded according to current frequency information of the current signals and position information of the traveling wave positioning, so that a real fault point is determined; the power distribution terminal comprises a pole-mounted switch and a fault indicator; the application has high economy, can accurately identify the real fault position from multiple pseudo fault points, and can solve the problems of serious pseudo point interference and difficult discrimination of the real fault point in the single-ended method.

A method and electronic device for determining the resistance of a battery cell are disclosed. The method includes the steps of: performing an EIS analysis of the battery cell based on a plurality of temperatures including a first temperature and a second temperature to obtain a graph relating the impedance of the battery cell to a frequency variation; extracting a first inductance of the battery cell at the first temperature based on a first graph relating the impedance of the battery cell at the first temperature; and determining the resistance of the battery cell at a second temperature based on the first inductance, wherein the second temperature is higher than the first temperature.

The chamber cleaning process monitoring method of the present application provides: a high-frequency power supply step, in response to starting the seasoning process after the cleaning process in the chamber is completed, a high-frequency power supply is supplied to the inside of the chamber; an impedance matching step, the frequency of the high-frequency power supply is adjusted to achieve impedance matching in the inside of the chamber; a chamber abnormality judgment step, whether the adjusted frequency deviates from the first frequency band is judged to judge whether an abnormality occurs in the inside of the chamber; and a warning output step, a warning reminder caused by the abnormality in the inside of the chamber is output, thereby unnecessary reprocessing can be reduced, process time can be predicted, and production planning can be effectively established.

This invention relates to the field of microwave detection technology, specifically to a broadband microwave rapid detection method based on atomic level electric field tuning, which mainly solves the problem of detection limitations in traditional Rydberg atom-based microwave information detection. The broadband microwave rapid detection method based on atomic level electric field tuning includes the following steps: 1) First, a probe light and a coupling light are applied sequentially to a Rydberg atom gas cell, and then the microwave to be measured is applied to the Rydberg atom gas cell; 2) A spatial gradient radio frequency electric field is applied within the Rydberg atom gas cell; 3) The spot of the probe light is projected into an optical camera to form an image set, the pixel signals within the image set are merged, and the splitting response of the EIT-AT spectrum is observed. The electric field strength and frequency of the microwave to be measured are calculated. This invention's detection method achieves the requirement for rapid detection of random microwave signals over a wide frequency range.

A test and measurement probe device is disclosed. In some implementations, the device may include one or more sensors. In addition, the device may include a plurality of analog signal paths, each analog signal path connected to one of the one or more sensors. The device may include an adjustable gain element within each analog signal path. Moreover, the device may include a combiner to combine the output of each adjustable gain element together to produce a probe output signal. Also, the device may include a digital path including a processor, where the processor is configured to compute a gain value for at least one adjustable gain element.

To identify one period of signal data even when periodicity of the signal data is temporarily lost.SOLUTION: A computer system has one or more processors and one or more memory resources. The one or more processors each acquire partial data of a predetermined period from signal data, divide the partial data into a plurality of pieces of division data for each of a plurality of time zones, identify a peak time of a cross-correlation function between the partial data and the signal data for every division data, calculate an evaluation value for evaluating if a temporal first order of the plurality of time zones is the same as a second order of the plurality of peak times for the plurality of pieces of division data belonging respectively to the plurality of time zones, identify the period of the signal data on the basis of the evaluation value, and acquire reference data of the identified period from the signal data.SELECTED DRAWING: Figure 1

The present invention is directed at a method for evaluating the degradation level of capacitors of a power filter connected to an adjustable speed drive (ASD) or a power converter. The invention is also directed at an adjustable speed drive and a power converter provided for performing the method.

A circuit apparatus includes an oscillation control circuit configured to control oscillation of a resonator, a measurement unit configured to measure information corresponding to a frequency of an oscillation signal output from the oscillation control circuit, and an interface, and is configured such that, when a first signal that determines a measurement period received from outside, the measurement unit measures the information corresponding to the frequency of the oscillation signal output during the measurement period, and the interface outputs a measurement result of the information corresponding to the frequency.

The application discloses a kind of microcavity optical frequency comb ultra-high repetition frequency precision measurement system and method, solve the existing microcavity optical frequency comb repetition frequency measurement system because of facing electronic device frequency bandwidth bottleneck lead to the problem that measurable range is seriously limited, including optical rough measurement unit, comb tooth processing unit, modulation frequency shift unit, reference equalization unit, beam combination beat frequency unit and microwave precision measurement unit;Optical rough measurement unit is used to measure the repetition frequency of the light beam to be measured, and is divided into measurement beam and reference beam;Comb tooth processing unit is used to filter out target comb from measurement beam;Modulation frequency shift unit is used for electro-optic modulation to target comb;Reference equalization unit is used to control the reference comb power of reference beam to obtain better beat frequency detection effect;Beam combination beat frequency unit is used for optical beam combination beat frequency between target comb and reference comb and is divided into two beams;Microwave precision measurement unit is used to detect the beat frequency signal between target comb and reference comb, to realize the precision measurement of repetition frequency.

This application discloses a high-precision microwave frequency measurement method and system based on continuous-time crystal phase transitions, belonging to the field of quantum sensing technology. This method utilizes the characteristic of the Rydberg atom system at the critical point of a continuous-time crystal phase transition where the response slope of the detected light transmission signal to the microwave frequency is significantly enhanced, breaking through the resolution limit of traditional linear responses. The system includes a quantum sensing unit, an optical excitation and detection module, a microwave modulation and scanning module, an auxiliary radio frequency field module, and a signal processing and control center. By precisely adjusting the parameters, the system is driven to the vicinity of the critical point, the critical frequency is identified, and its high response slope is used to achieve precise frequency measurement. This invention employs a two-stage measurement process, balancing wide dynamic range and high precision, and can be flexibly tuned to adapt to different frequency bands, possessing broad application prospects, especially in microwave communication, frequency metrology, and other fields with significant technical value.

The application relates to the technical field of discharge signal collection, in particular to a high-voltage cable partial discharge signal synchronous collection method and system, which comprises the following steps: based on a multi-channel high-speed double-ADC architecture, synchronously collecting ground loop current signals and high-frequency current signals in the operation process of a high-voltage cable; calculating pulse frequency spectrum consistency and mutation phase fluctuation to obtain a discharge loop current abnormality; determining the pulse periodicity of the high-frequency current signals; extracting harmonic frequency parameters and energy attenuation parameters of the high-frequency current signals, calculating a harmonic abnormality, combining the pulse periodicity to obtain a pulse harmonic abnormality factor; performing weighted summation on the discharge loop current abnormality and the pulse harmonic abnormality factor to evaluate the reliability of the synchronously collected signals, and outputting a synchronous collection result of the high-voltage cable partial discharge. Therefore, the accuracy of the synchronous collection of the partial discharge signals is improved.

The invention relates to a test needle for measuring electrically conductive layers in holes of printed circuit boards, as well as to a test probe equipped with such a test needle and to a flying probe tester for testing printed circuit boards equipped with such a test needle or such a test probe.The test needle has a capacitive measuring body, which is connected via a cable to a capacitive measuring device. The cable is shielded so that only the capacitive measuring body can form a capacitive coupling with other electrically conductive bodies. This makes it possible to determine this capacitive coupling with a high local resolution.

The application discloses a kind of multi-channel adaptive real-time signal processing methods, comprising the following steps: to multiple analog input signals are synchronously sampled, obtain multi-channel digital signal;The multi-channel digital signal is adaptively filtered and processed, and low-pass filtering and median filtering are executed in parallel for the digital signal of the same channel;Signal zero-crossing point is identified based on zero-crossing detection principle, and multi-cycle synchronous measurement strategy is used, and the frequency value of each channel signal is calculated according to the frequency range of multi-channel digital signal;To the filtered multi-channel digital signal, square sum is accumulated to sampling value using time sliding window, and the effective value of each channel signal is calculated by hardware accelerated square root algorithm;The frequency value and effective value calculated by each channel are output through the preset communication interface or analog output channel.

The application provides a visual control-based test method and system for a non-stop spare power automatic switching device, which proposes a visual control-based test method for a non-stop spare power automatic switching device, connects a voltage collection end of a test device to a power supply side voltage transformer secondary output terminal of the spare power automatic switching device, simultaneously acquires a current transformer secondary current signal and inputs the current transformer secondary current signal to the test device, and pre-connects a current output end to a protection side current input terminal. During the test process, actual voltage and current are monitored in real time through a graphical user interface, and the test device synchronously outputs simulated voltage and current. After being started, the test device automatically applies test working conditions to the spare power automatic switching device according to parameters, synchronously collects test data, and finally calculates performance indexes based on the test data and generates a test report. The method realizes comprehensive, accurate and safe testing of the spare power automatic switching device without interrupting power supply.

Disclosed are a method and an electronic device for determining a resistance of a battery cell, the method comprising the steps of: performing EIS analysis of the battery cell according to a plurality of temperatures including a first temperature and a second temperature so as to obtain a chart relating to the impedance of the battery cell according to a change in frequency; extracting a first inductance of the battery cell at the first temperature on the basis of a first graph relating to the impedance of the battery cell at the first temperature; and determining the resistance of the battery cell at the second temperature on the basis of the first inductance, wherein the second temperature is higher than the first temperature.

This application relates to an intelligent ultra-high voltage series resonant withstand voltage test method and test platform. The method includes: analyzing the amplitude deviation between the current frequency point and its neighboring frequency points during frequency sweeping to obtain the amplitude mutation rate of the current frequency point; if the amplitude mutation rate of the current frequency point is not less than a trigger threshold and the amplitude mutation rate of the current frequency point is less than the amplitude mutation rate of neighboring frequency points, determining the backoff distance and target step size based on the current sweep step size and reference bandwidth, backing off from the current frequency point by the backoff distance, and continuing the frequency sweep with the target step size; determining multiple candidate peaks based on the extreme points in the local curvature of multiple frequency points; performing fine sweeping on at least some of the candidate peaks to obtain the resonant frequency of each finely swept candidate peak, and determining the resonant frequency corresponding to the candidate peak with the largest current value as the main resonant frequency, which is the resonant frequency for the withstand voltage test. This application can improve the safety of withstand voltage tests on ultra-high voltage equipment.

The application relates to a detection and communication integrated identification method for instantaneous permanent fault of a power collection line by means of IIDG active energy injection, and belongs to the technical field of power system relay protection and automation. The method comprises the following steps: after a fault occurs in a power collection line, starting an IIDG with network construction capability, realizing zero starting voltage rise through VF control, establishing a characteristic voltage, judging whether a composite voltage criterion is met, if yes, the fault is permanent, and the injection source exits after maintaining a constant frequency transmission; if not, the fault is instantaneous, and the injection source sends a frequency shift information after a time delay. Voltage is continuously monitored during the injection, and whether a complete frequency shift signal is received is determined through a frequency variance criterion and data segment correlation. If the voltage does not meet the composite voltage criterion during the detection process and the complete frequency shift signal is received, reclosing is allowed after power loss again, otherwise, reclosing is locked. The method aims to solve the technical problem that the fault nature of the power collection line under a voltage loss condition is difficult to identify in the prior art.

The application discloses a high-precision frequency estimation method for real sine signals based on window sampling, and relates to the technical field of signal processing. The method can perform real-time and high-precision estimation on the frequency of dynamic sine signals, and can dynamically identify subtle changes in frequency information. The method comprises the following steps: performing window sampling on a to-be-measured real sine signal to obtain a discrete sequence of the real sine signal in the window; performing spectrum transformation on the discrete sequence of the real sine signal to obtain an amplitude spectrum and a phase spectrum after spectrum transformation; extracting an initial estimation frequency of the peak position of the amplitude spectrum, and calculating a phase corresponding to the initial estimation frequency; calculating the full-phase order frequency of the discrete sequence of the real sine signal in the window by using the initial estimation frequency and the phase corresponding to the initial estimation frequency; and jointly estimating the corrected frequency of the to-be-measured real sine signal by using the full-phase order frequency, the truncated signal phase and the initial phase of the un-truncated signal.

Embodiments that translate a sensor measurement to a frequency characteristic are disclosed. The frequency characteristic can be wirelessly detected by a reader device. The detected frequency characteristic can be used to determine the corresponding sensor measurement. Devices utilizing this approach can be characterized or calibrated to increase accuracy. Systems and methods utilizing the approaches are also described.

The utility model discloses a kind of test circuit of general MOS tube and IGBT, comprising: positive and negative double electric power supply, FPGA control board, MOS / IGBT drive circuit and oscilloscope.The utility model is generated accurate PWM drive signal by design FPGA control board, so that MOS / IGBT drive circuit drives MOS / IGBT to be measured according to the duty ratio control signal and frequency control signal of outside;So as to utilize oscilloscope to complete the test of the frequency of MOS / IGBT to be measured.Compared with the complex measuring instrument in prior art, the utility model realizes the test of the frequency of MOS / IGBT to be measured using only a small amount of measuring instrument, greatly saves test cost, provides a lower cost measurement mode for user only needing to test frequency.

This invention discloses a method for accurately measuring inter-node frequency deviation based on power measurement, comprising the following steps: after a disturbance occurs in the power system, acquiring parameter data of the line transmission nodes, verifying the validity of the data, and eliminating outliers; using the arcsine function direct calculation method to solve for the inter-node phase difference, thus avoiding the problem of large inter-node phase difference errors caused by linearization; calculating the line transmission power based on the traditional power measurement method; and calculating the inter-node frequency deviation values ​​between different nodes. This invention introduces a virtual coordinate transformation of the active and reactive power of the line to eliminate the influence of the line resistance component on the measurement accuracy of inter-node frequency deviation in low-voltage power grids; the introduction of the arcsine function direct calculation method eliminates the problem of increased inter-node frequency deviation measurement errors caused by large inter-node phase differences due to linearization; for directly interconnected or indirectly interconnected nodes, this influence can be eliminated by introducing virtual coordinate transformation and virtual impedance, thereby improving measurement accuracy.

The application discloses a crystal oscillator detection jig and relates to the technical field of detection jigs. The crystal oscillator detection jig comprises a base, a motor is arranged on the surface of the base through a fixing frame, a lead screw is arranged at one end of the output shaft of the motor, a driving cylinder is arranged on the surface of the lead screw through a movable element, a transfer mechanism is arranged on the output end of the driving cylinder through a connecting frame, the transfer mechanism is used for transferring a crystal oscillator, and a buffer device is arranged on the surface of the base through a detection table. The transfer mechanism is arranged, so that the crystal oscillator can be automatically fed and discharged when the crystal oscillator is detected, the feeding and discharging speed is improved, the detection efficiency is improved, time and labor are saved, the problem that a crystal oscillator needs to be manually replaced after detection and then detected again is solved, the crystal oscillator cannot be automatically fed and discharged, operation is relatively complicated, and manual feeding and discharging is time-consuming and labor-consuming.

The application provides a modular multilevel converter parallel capacitor monitoring method and system, and relates to the field of modular multilevel converters.The method comprises the following steps: obtaining an oscillation current signal excited between two parallel capacitors in a sub-module when a power device of the modular multilevel converter sub-module is switched; extracting an inherent frequency from the oscillation current signal, and analyzing a series equivalent capacitance value of the capacitor based on the inherent frequency; solving the series equivalent capacitance value in combination with a parallel total capacitance value of the parallel capacitors to obtain a numerical solution; and identifying a physical corresponding relationship between the numerical solution and the two parallel capacitors as a monitoring result.The application realizes accurate calculation of an independent capacitance value of each parallel capacitor without needing to separately configure a current sensor for each parallel capacitor, has higher robustness and real-time performance, and effectively reduces system complexity and hardware cost.

The application discloses a non-ideal power grid impedance detection method based on an extended state observer, which comprises the following steps: 1, collecting three-phase voltage signals of a grid-connected point, and observing grid-connected point currents on line based on an extended state observer; 2, extracting power grid fundamental wave components through an improved phase-locked loop structure of a double second-order generalized integrator, and realizing adaptive tracking of a power grid frequency; 3, performing differential processing on the power grid original signals and the extracted fundamental wave components, and extracting target harmonic components in the residual signals through a double second-order generalized integrator; and 4, calculating the power grid impedance based on the voltage and current harmonic information. The application can realize accurate identification of the power grid impedance under the conditions of power grid frequency fluctuation and existence of background harmonics while reducing current sensors.

A battery management apparatus, a battery management method, and a program capable of detecting an abnormality in a circuit that monitors the battery voltage of a lithium-ion secondary battery are provided. A battery management apparatus includes a first measurement circuit configured to measure a battery voltage of a lithium-ion secondary battery, a second measurement circuit configured to apply a high-frequency signal of 0.1 MHz or higher to the lithium-ion secondary battery and measure an amplitude of a resonating electric signal, and an abnormality detection unit configured to calculate the battery voltage of the lithium-ion secondary battery from the amplitude of the electric signal and detect an abnormality in the first measurement circuit based on the calculated battery voltage.

The present disclosure relates to a method and system for estimating a grid frequency or grid phase angle of an electrical power distribution system in which instantaneous voltages output by the electrical power distribution system are sampled at a plurality of discrete sample times to generate a plurality of samples; α and β values are derived from the plurality of samples using a Clarke transformation; a complex variable is generated from the derived α and β values and is applied to a generating function; the generating function is integrated for the plurality of samples; and an estimate of the grid frequency or grid phase angle is generated based on the result of the integration of the generator function.