172results about "Frequency analysis" patented technology

The invention belongs to the technical field of power equipment state monitoring, and discloses a cable branch box operation state intelligent evaluation system based on multi-sensor fusion, which comprises a state acquisition module used for acquiring a partial discharge signal, a voltage fluctuation signal, a terminal temperature signal and a terminal contact resistance signal of a cable branch box in an operation process, constructing a multi-source operation state parameter set of the cable branch box through time synchronization and physical quantity normalization processing; the mutual coupling analysis module is used for performing transient correlation deduction on the partial discharge signal and the corresponding voltage fluctuation signal based on the multi-source operation state parameter set to obtain a partial discharge-voltage coupling amount; when the partial discharge-voltage coupling amount exceeds a preset partial discharge-voltage coupling amount threshold value, determining that partial discharge abnormity caused by insulation degradation exists in the cable branch box; comprehensive and accurate evaluation of the operation state of the cable branch box is realized, and reliable support is provided for safe operation and maintenance of equipment.

The invention relates to the technical field of power distribution network fault detection, and discloses a power distribution network high-resistance grounding fault intelligent detection method, system and device and a medium, and the method comprises the steps: collecting a power distribution network line transient signal which comprises a transient zero-sequence voltage signal and a transient zero-sequence current signal; preprocessing the transient signal and extracting a multi-dimensional feature set for representing high-resistance grounding fault characteristics, wherein the multi-dimensional feature set comprises a transient energy feature, a wavelet entropy feature and a harmonic component feature; and inputting the extracted multi-dimensional feature set into a pre-trained machine learning model, and simultaneously outputting a judgment result of the high-resistance grounding fault and an estimated value of the grounding resistance through the machine learning model. According to the method, the transient energy, the multi-scale wavelet entropy, the odd harmonic amplitude and the phase, which are derived from different analysis domains and have complementary physical meanings, are deeply fused, so that the problem that a single feature is weak in characterization capability and easy to fail under the conditions of high noise and high resistance is effectively solved.

The invention discloses a GIS ultrahigh frequency sensor ultrasonic cooperative detection system based on piezoelectric energization, and relates to the field of electric power detection, and the system comprises an excitation module which is used for transmitting a piezoelectric excitation signal with a specific frequency to a preset detection region in GIS equipment, so as to trigger the potential partial discharge acoustoelectric signal radiation of the region; the sensing module is used for receiving ultrahigh-frequency electromagnetic signals and ultrasonic vibration signals radiated by partial discharge in the GIS equipment; the excitation frequency, the filtering bandwidth and the sampling rate are dynamically optimized according to the detection result, the detection accuracy and efficiency are continuously improved, and reliable and effective guarantee is provided for safe operation and defect early warning of GIS equipment.

The invention belongs to the technical field of gap measurement, and particularly relates to a high-temperature-resistant transparent shell type eddy current tip gap measuring device and method, and the device comprises a sensor probe module, a signal conditioning module, a data collection module and a data processing module. The sensor probe module is mounted on the outer wall of the casing; the sensor probe module comprises a permanent magnet excitation source, a soft magnet magnetic core and a receiving coil; the signal conditioning module is electrically connected with the receiving coil and is used for amplifying, filtering and integrating the weak induction signal; the data acquisition module is electrically connected with the signal conditioning module and converts an analog signal into a digital signal; the data processing module is used for processing the acquired digital signals and extracting blade tip clearance information.

Provided are a method and apparatus for detecting a failure of a solar module. The method includes obtaining real-time power generation data of each of a plurality of solar modules included in at least one solar array, setting a reference value using at least one of past power generation data of the plurality of solar modules and specifications of the plurality of solar modules, determining each of the plurality of solar modules to be either a normal solar module or an abnormal solar module by comparing the reference value with a power generation amount of each of the plurality of solar modules, which is calculated using the real-time power generation data, and providing an interface displaying a solar module determined to be the abnormal solar module.

The invention discloses a transformer substation AC power supply residual current detection method and device, and the method comprises the steps: carrying out the vector synthesis of three-phase current data and zero line current data, forming a current difference sequence, exporting a residual current reference curve, and carrying out the fluctuation analysis of the residual current reference curve, and judging the leakage characteristics. After effective leakage features are formed through harmonic elimination, dominant frequency components are locked through frequency spectrum decomposition; calibrating a leakage type identifier according to the dominant frequency component and forming segmented leakage distribution; a deviation degree is formed by means of segmented leakage distribution and residual current reference curve deviation analysis, a correction deviation value is formed through load fluctuation compensation, and a standard exceeding coefficient is formed according to threshold value comparison to detect abnormal nodes to form hidden danger data; establishing a judgment rule based on the hidden danger data and the leakage type identifier to form a detection evaluation index; and executing path tracking on the detection evaluation indexes to form leakage position information, forming a disposal priority through intensity analysis to generate a residual current detection report, and realizing leakage current classification identification and self-adaptive evaluation.

The invention discloses a power distribution network reliability intelligent analysis method and analysis system, particularly relates to the technical field of power system fault detection, and is used for solving the problems of misjudgment and missed judgment caused by fault feature weakening and harmonic interference in a bidirectional power flow scene in an existing method. The method comprises the following steps: firstly, synchronously collecting fundamental wave and harmonic components of nodes of a power distribution network, extracting a current amplitude change rate and a phase offset by adopting time-frequency domain conjoint analysis, and generating dynamic distribution characteristics by combining harmonic energy clustering; identifying high-frequency interference components in a bidirectional power flow mode by quantizing a phase deviation direction and harmonic energy aggregation characteristics; based on a harmonic frequency band coupling effect and a current dynamic association relationship, an adaptive detection threshold function is constructed, and accurate separation of fault features is realized; and finally, combining a real-time fault judgment result with historical repair data to generate a reliability evaluation parameter. And the sensitivity of fault detection and the rationality of reliability evaluation in a complex operation environment are remarkably improved.

The invention relates to the technical field of power system monitoring, discloses an anti-harmonic PT current monitoring system and method, and aims to solve the problem of secondary side current signal distortion of a voltage transformer caused by power grid harmonic pollution in the prior art. The method comprises the steps of electrifying and initializing a system, starting a high-speed analog-to-digital converter to acquire a voltage signal, executing fast Fourier transform to identify dominant harmonic waves, calculating and configuring a capacitance value of a tunable LC trap unit to suppress specific harmonic waves, and finally outputting a high-fidelity analog voltage signal in direct proportion to fundamental current. The system comprises a current-voltage conversion module, a tunable LC notch filter array, a high-speed analog-to-digital converter, a digital signal processing unit and a microcontroller. According to the technical scheme, dynamic self-adaptive suppression and precise selective harmonic wave blocking of power grid harmonic waves can be realized, low delay and high fidelity characteristics are guaranteed, and the engineering practicability and reliability of the system are improved.

The invention belongs to the technical field of electronic information, and relates to an online low-voltage load monitoring and abnormal tripping positioning method and a related device. According to the method, electrical parameters of all monitoring points are collected in real time, key parameters are calculated after analog-to-digital conversion and filtering denoising, and the key parameters are compared with a set threshold value to judge whether the monitoring points are in an abnormal state or not; once an abnormal state is found, an early warning is generated and uploaded to a remote platform; and continuously monitoring the state of the main switch or the total current at the same time, and when tripping occurs, backtracking an abnormal record within a preset time period before tripping, and positioning the last or the most serious abnormal monitoring point as an abnormal source. The system comprises a data acquisition module, an analog-to-digital conversion module, a preprocessing module, a calculation module, a judgment module, an early warning module, a trip monitoring module and a positioning module. According to the invention, early warning before a fault and rapid positioning after tripping are realized, and the intelligent level, the operation and maintenance efficiency and the power supply reliability of the power distribution network are improved.

The invention discloses a wireless high-voltage current measurement method with a filtering anti-interference function, and belongs to the technical field of robot coordination control. The method comprises the following steps: obtaining an original discrete voltage signal sequence; calculating a discrete voltage signal sequence transient strength index; performing variational mode decomposition on the original discrete voltage signal sequence by using a mode number and a penalty parameter to obtain a group of intrinsic mode functions; respectively synthesizing the classified modes into corresponding interference reference signals; respectively inputting the orthogonal interference reference signals into a filter channel to estimate various interference components and carrying out dynamic adjustment; and a pure high-voltage wire current time domain signal is restored. According to the method, signal characteristics are sensed in real time by adopting the VMD, subsequent key parameters are dynamically adjusted, and the denoising performance is improved; a multi-feature modal intelligent classification method is adopted, mathematical modals with unknown physical meanings are mapped to four physical sets of useful signals, power frequency, high frequency and transient states, and decoupling of signals and noise in a time-frequency domain is achieved.

The present disclosure provides a battery. The battery includes a case formed of a conductive material, a sensing member attached to one surface of the case and including a conductor formed of a conductive material and a dielectric having at least a part thereof disposed between the case and the conductor, and a monitoring circuit electrically connected to the conductor and the case, wherein the monitoring circuit may monitor whether the battery is deformed based on an amount of change in a capacitance formed between the conductor and the one surface of the case.

This invention discloses a system for measuring the local spectrum of 4.6 GHz low-clutter waves in plasma, used to measure the local low-clutter power and spectral broadening information in a scraped layer. A 30 GHz microwave source generates a backscattered signal at a specific location in the scraped layer. This backscattered signal is transmitted into the tokamak plasma via a horn antenna in ordinary mode. The new microwave signal, with a frequency of 34.6 GHz, is generated by backscattering at a second horn antenna. This 34.6 GHz microwave signal is then frequency-differentiated by a mixer to 3.5 GHz, and further frequency-differiated by a second 4.6 GHz local oscillator signal to 1.1 GHz. The signal is finally fed into a spectrum analyzer. Unlike conventional copper loop antenna measurements, this system can reflect the local low-clutter power and spectral information, thus enabling more accurate analysis of the parasitic effects of low-clutter waves in the scraped layer.

A system and a method of calculating the current consumption of components in a vehicle are disclosed. The system may include a controller and a memory stored thereon instructions for executing the method. The method comprising: receiving from at least one magnetic flux sensor located at a known location in the vehicle, a magnetic flux pattern at various frequencies, indicative of the magnetic field at the location; identifying at least one first magnetic flux maximum at a first frequency corresponding to a first component of the vehicle; and calculating a first current consumption of the first component based on the at least one first magnetic flux maximum.

A method and system for testing the conversion losses of terahertz mixers capable of eliminating the influence of radio frequency sources includes grouping a mixer to be tested and at least two reference mixers in pairs; in each group, inputting a signal of a preset frequency and a preset power at an intermediate frequency port of a first mixer, and after up-conversion, outputting same to a second mixer to be down-converted, so as to obtain an output power with the frequency same as the preset frequency, and obtain the relationship between a first output power and a first preset power and the losses of two mixers; according to the relationship between the loss of the mixer in each group and the power, obtaining the loss of the mixer to be tested.

A printed circuit board (PCB) test system and method including temperature chamber including at least one slot to accommodate at least one PCB test coupon, input bus connected to inputs of the at least one slot, and output bus connected to outputs of the at least one slot, wherein temperature chamber is configured to apply a temperature to the at least one PCB test coupon; signal generator including output bus connected to the input bus of the at least one slot, frequency meter comprising an input bus connected to the output bus of the at least one slot and an output bus, and a comparator connected to the output bus of the signal generator and the output bus of the frequency meter for comparing corresponding outputs of the signal generator and the frequency meter.

Systems and methods for data transmission are disclosed. The system can include a phase test circuit including a difference detection circuit, a low pass filter circuit, and a reference comparison circuit. The difference detection circuit can be configured to produce an output signal having a duty cycle corresponding to a phase difference between a first input signal and a second input signal. The low pass filter circuit can be connected to an output of the difference detection circuit, and the reference comparison circuit can be configured to compare an output signal of the low pass filter circuit to a threshold.

The invention relates to the technical field of data acquisition, in particular to a data acquisition method and system for a high-low voltage transformer substation. The method comprises the following steps: acquiring an original electrical signal sequence, calculating an initial integer sampling point number based on a zero crossing point interval, determining a fundamental wave period by carrying out autocorrelation operation on the original electrical signal sequence in a preset window taking the fundamental wave period as a center, and obtaining a signal after primary filtering by adopting first comb filtering taking the fundamental wave period as a delay parameter; and performing short-time Fourier transform on the signal after primary filtering, forming a non-integer harmonic frequency point set in a preset non-harmonic frequency band, constructing a second filtering link according to the non-integer harmonic frequency point set, and filtering non-integer harmonics in the signal after primary filtering to obtain collected data. According to the scheme, the fundamental wave period can be accurately determined to deeply suppress the integer harmonics, the non-integer harmonics can be recognized and filtered out in the environment with the low signal-to-noise ratio, and meanwhile original signal damage is avoided.

The disclosure relates to an arc fault circuit interrupt capable of detecting an arc fault and a method of controlling the device. The arc fault circuit interrupt according to the disclosure is shipped in a factory reset state in which all functions are initialized after a test to check for functional abnormalities, and when receiving an update instruction from an authorized administrator after being installed in the field, receives an update file from a management device such as an energy management system to proceed with a firmware update and activates an arc fault detection function, thereby having the effect of preemptively preventing unauthorized copying of the arc fault circuit interrupt.

The invention relates to a satellite-borne fluorescence hyper-spectral detector electronics system with high integration level and high signal-to-noise ratio. A signal processing module is used for controlling the working mode of a detector; receiving a second pulse signal of a satellite GPS subsystem to generate a time count of a frame synchronization signal; carrying out extremely low noise quantization on an analog signal transmitted by the focal plane driving unit; the image data and the auxiliary data are coded and integrated and then sent to a satellite data transmission subsystem; a global clock and a global reset signal are generated and sent to the sequential control unit; the time sequence control unit generates a frame synchronization signal and a clock synchronization signal, and generates a driving time sequence signal of a CCD in the focal plane driving unit; the focal plane driving unit generates various bias voltages required by the work of the CCD; receiving a driving time sequence signal to generate various high-voltage driving signals required by the work of a CCD (Charge Coupled Device); and the CCD output analog signal is output to the signal processing unit after being subjected to power amplification and impedance matching. The signal-to-noise ratio of the system is improved, and the size, weight and power consumption of imaging electronics of the detector are reduced.

The invention relates to a method for partial discharge identification in high voltage applications and a high voltage unit using the method, the method comprising the steps of: detecting a signal; transforming the signal from time domain to frequency domain; cutting off frequencies above a defined threshold; and retransforming the cut-off signal from frequency domain to time domain. The information content of the detected signal and the information content of the cut-off signal are determined and compared.

The invention discloses a partial discharge monitoring method for a crosslinked polyethylene cable joint and a terminal. The method comprises the following steps: acquiring a front-end cable operation state signal and a rear-end cable operation state signal of the crosslinked polyethylene cable joint; judging whether the front-end cable operation state signal and the rear-end cable operation state signal are abnormal or not; when the front-end cable operation state signal and the rear-end cable operation state signal are abnormal, recording the abnormal time of the front-end cable operation state signal and the abnormal time of the rear-end cable operation state signal, and extracting the characteristics of the abnormal front-end cable operation state signal; determining an abnormal signal source according to the abnormal time of the front-end cable operation state signal and the abnormal time of the rear-end cable operation state signal; and when the source of the abnormal signal is the crosslinked polyethylene cable joint, judging whether the crosslinked polyethylene cable joint is subjected to partial discharge according to the signal characteristics of the running state of the front-end cable. The online accurate monitoring of the partial discharge of the cross-linked polyethylene cable joint is realized.

A system for measuring characteristics of a current transformer according to an embodiment of the present invention comprises: a power source having a constant voltage; a current transformer to be tested to measure characteristics; a first current transformer including a core on which a primary winding and a secondary winding are wound, respectively; a voltage regulator which varies the voltage applied from the power source and applies the varied voltage to the primary winding; a power cable which is formed to pass through the core of the current transformer to be tested and through which a current corresponding to the voltage of the secondary winding induced according to the voltage applied to the primary winding flows; a shunt resistor which connects both ends of the power cable to form a circuit composed of the power cable; a detection unit for detecting the voltage of the shunt resistor and the output current of the current transformer to be tested; and a measurement unit which receives the voltage value of the shunt resistor and the output current value of the current transformer to be tested from the detection unit and compares the current value calculated from the voltage value of the shunt resistor with the output current value of the current transformer to be tested so as to measure the characteristics of the current transformer to be tested.

The application discloses a spectrum analyzer-based amplitude compensation method and device. The method comprises the following steps: before frequency sweeping starts, determining the starting frequency, stopping frequency and calibration frequency step of the current scanning frequency range, and determining the corresponding shift bit number according to the calibration frequency step, wherein the calibration frequency step is a power of 2; generating calibration data of a plurality of calibration points according to the starting frequency, stopping frequency and calibration frequency step, and storing the calibration data in a storage space accessible by an FPGA in the order of corresponding frequencies; obtaining the frequency value corresponding to the current data during frequency sweeping, and determining the calibration data index according to the frequency value corresponding to the current data and the calibration frequency step according to the upward rounding rule; reading the corresponding calibration data according to the calibration data index; and performing amplitude compensation on the current data by using the calibration data after digital down-conversion and before decimation filtering. The method can reduce the calibration data storage amount and FPGA operation resource consumption, and improve the real-time amplitude compensation accuracy during frequency sweeping of the spectrum analyzer.

A method for measuring a resonance frequency response of passive microwave devices PMD 316 e.g. dielectric resonator includes transmitting RF signals through the passive microwave device, and measuring the resonance frequency response. One or more dielectric lossless mediums are placed within a distance of the passive microwave device. The distance may be adjusted, or the thickness of the dielectric lossless medium, or the effective permittivity of the dielectric lossless medium may be altered by subjecting it to an electric field. This modifies the effective permittivity of the PMD without directly modifying the PMD itself, which produces a frequency shift the PMD. Measuring the responses before and after this modification enables the resonance frequency response to be determined. An apparatus 300 includes a housing 302 for the PMD 316 and dielectric lossless media 308. A positioning mechanism 310 alters the distance between them. The thickness can be varied by dielectric stacking (611,612,613 Figure 6B). A digital signal processing unit 318 determines the resonance frequency response.

This invention discloses a high-resistivity fault location method for distribution networks based on virtual capacitor polarity and FIR filtering. First, the zero-sequence voltage of the bus and the zero-sequence current of the feeder are acquired. Then, a differential filter is used to process the zero-sequence voltage, removing the unbalanced component. Simultaneously, a sliding accumulation filter is used to process the zero-sequence current, removing the unbalanced component and suppressing measurement noise. The waveforms of the processed zero-sequence voltage and the processed zero-sequence current are multiplied to obtain a fault feature fusion waveform. A sliding accumulation filter is then used to process the fault feature fusion waveform, suppressing noise interference from the zero-sequence voltage and enhancing fault characteristics. A synchronous attenuation integral is used to generate a fault metric. Finally, the fault location is determined based on the negative polarity of the metric. This invention can adapt to high-interference environments under high-resistivity fault conditions, accurately extracting fault features for fault location, and has good applicability and engineering application value.

A processor of an electric meter receives a measurement signal corresponding to an input electricity, initiates a first counter at a first edge of a first pulse-per-second (PPS) signal of an RF communications system, and stops the first counter at a first edge of the measurement signal. The processor determines a first counter value from the first counter and initiates a second counter at a first edge of a second PPS signal of the RF communications system. The processor stops the second counter at a second edge of the measurement signal. The processor also determines a second counter value from the second counter, determines an actual sampling frequency of the measurement signal, and compares the actual sampling frequency of the measurement signal to a predetermined sampling frequency. The controller also performs a mitigation action in response to determining that the actual sampling frequency differs from the predetermined sampling frequency.

This disclosure relates to a direct conversion (zero-IF) architecture receive chain for use in a spectrum analyzer, where a local oscillator produces a local oscillator signal that has signal components at a clock frequency and at odd harmonics at odd multiples of the clock frequency. The local oscillator signal, including the signal components at a clock frequency and at its odd harmonics is fed into a mixer together with a radio frequency input signal for analog multiplication. The RF path may include a bandpass filter that filters the radio frequency input signal prior to its input to the mixer. The bandpass filter removes frequency components that are outside frequency span of the bandpass filter, where the frequency span of the bandpass filter is selected to match with a desired one of the frequency components of the local oscillator signal. The bandpass filter may be further configured to reject frequencies of the other, non-selected harmonic frequencies.

This invention relates to the field of power supply system technology, specifically a multi-level redundant power supply system for high-voltage frequency converter control power supply. The system includes a reference processing module, a health assessment module, an instruction determination module, a signal switching module, a bumpless switching module, and a stable output module. The system acquires real-time load demand signals and performs smoothing and filtering on these signals to obtain a load demand reference signal. It then assesses the health status of the power supply blocks in the high-voltage frequency converter to obtain health assessment coefficients; identifies faulty power supply blocks within the power supply blocks to determine the redundancy switching trigger instruction; performs energy efficiency collaborative optimization on the target power supply blocks within the power supply blocks to generate a power supply switching control signal; performs online bumpless switching of the high-voltage frequency converter, connecting the target power supply block to the power supply circuit and isolating the faulty power supply block from the power supply circuit; and determines output stability. This invention can improve the efficiency of multi-level redundant power supply for high-voltage frequency converter control power supply.

The present application relates to a kind of current voltage acquisition circuits of common mode interference inhibition, current amplification module, current transformer, high pass filter, interference acquisition module, interference analysis module and inhibition execution module;By such design, the inhibition effect of common mode interference is more optimal compared to traditional sampling circuit, the error caused by the deviation of sampling signal due to interference is avoided to the greatest extent, especially applicable to the occasion of interference scene or interference source change, the changing interference source can be calculated by sampling statistics, so as to adjust the inhibition ratio of common mode inhibition, accurately sampling effect is obtained by tracking environmental conditions dynamically.

The invention discloses a multi-domain parameter adaptive adjustment method for a digital oscilloscope matched with signal frequency characteristics, and the method comprises the steps: firstly sampling an unknown input signal through a high-speed data collection system, obtaining a digital parallel sampling signal, and transmitting the digital parallel sampling signal to a multi-information-domain data processing module in an FPGA (Field Programmable Gate Array); in the multi-information-domain data processing module, time-frequency graph data acquisition of unknown signals is completed based on accurate control, fast Fourier transform and data delay feedback of time-domain data required by each frame of frequency spectrum, and the time-frequency graph data is transmitted to an industrial personal computer through a high-speed interface after being acquired. The method comprises the following steps: performing data analysis, obtaining a maximum value of spectrum energy and calculating an effective frequency index value to obtain a maximum effective frequency index value and a minimum effective frequency index value, then obtaining a multi-domain analysis parameter center frequency and an analysis bandwidth through calculation, and setting, feeding back and adjusting a multi-domain analysis processing module on a user interface of a digital oscilloscope.