36results about "Form factor measurements" patented technology

Provided are methods and apparatus for characterizing a power waveform. Some such methods include sampling the power waveform to generate a plurality of samples and, for each of the samples, recursively processing the sample to generate an aggregate signal energy value, processing the sample to generate a harmonic component signal energy value associated with at least one target harmonic frequency, and accumulating the aggregate signal energy value and the component signal energy value with previously generated aggregate signal energy values and component signal energy values to generate an accumulated aggregate signal energy value and an accumulated harmonic component signal energy value. Methods also include characterizing the power waveform responsive to the accumulated aggregate signal energy value and the accumulated harmonic component signal energy value.

The invention relates to a lightning stroke fault recognition method for an EHV (extra-high voltage) DC transmission line based energy spectrum similarity, and belongs to the technical field of power system relay protection. The method comprises the steps: extracting the ratio of a positive time domain waveform to an area formed by the enclosing of the zero axis of the positive time domain waveform and the ratio of a positive time domain waveform of any fault type to the area formed by the enclosing of the zero axis of the positive time domain waveform during stable operation when the voltage of the EHV DC transmission line fluctuates, and recognizing the fault and lightning stroke interference according to the ratios; switching to fault classification recognition if the interference is a fault, carrying out the wavelet decomposition recognition of an additional component through wavelet, and judging whether the fault is a grounding fault or a lightning stroke fault; and switching to a shielding failure and back flashover fault recognition if the fault is the lightning stroke fault. The method achieves the time frequency analysis of the simulation data, achieves the extraction of data in a short time period, and integrates area ratios, energy spectrum similarity and modular maximum value. The method achieves the extraction of a set of criteria for thunder interference, grounding faults, back flashover faults and shielding failures, and can achieve the accurate, quick and effective recognition of various types of conditions.

The invention relates to a lightning stroke fault determination method based on a waveform difference degree and a lightning stroke fault sample database. According to the method, when a fault occurs at a power transmission line, a travelling-wave fault range finding apparatus records a fault waveform; calculation is carried out by using a cubic b-spline wavelet to obtain an initial traveling wave arrival time of the fault; data 5ms after the initial traveling wave arrival time are selected to carry out normalization processing; the fault waveform after normalization processing is compared with all waveforms in the lightning stroke fault sample database and waveform difference degrees are calculated; and if a minimum value of difference degrees of the fault waveform and all waveforms in the lightning stroke fault sample database is less than a set threshold value, the fault type is determined to be a lightning stroke fault type; and otherwise, the fault type is determined to a non-lightning stroke fault type. According to the invention, compared with the existing lightning stroke fault identification method, the provided determination method has the following beneficial effects: confirmation of fault points by field line patrol workers is not required; the accuracy is high; and the method is simple and effective.

The invention relates to a full lightning cloud cloud-to-ground lightning recognition method. The method can be used for recognizing different lightning types, includes intracloud discharging and cloud-to-ground discharging recognition and recognition of a special cloud lightning event (NBE) and can be used for conventional cloud-to-ground lightning and position cloud lightning. A specific waveform parameter extraction method is adopted to extract collected lightning field waveform parameters, the extracted lightning waveform parameters are utilized for comprehensive judgment, and lightning discharging types are given according to judgment results.

The invention belongs to the field of testing devices and discloses a periodic signal waveform testing device. The periodic signal waveform testing device is featured by comprising a signal input unit, a keyboard unit, a PLC unit, a signal collecting and processing unit, a programmable controller and a display unit. The programmable controller controls the PLC unit according to a received signal input channel message, and inputs a corresponding to-be-tested periodic signal wave into the signal collecting and processing unit through the PLC unit. The signal collecting and processing unit comprises a first functional circuit and a second functional circuit. The invention controls the testing process by the programmable controller. The overall testing process can be automatically conducted, the testing time is short, and the accuracy is high.

Provided is a method for detecting the saturation of a current transformer (CT) on the basis of a third-order central moment. The method comprises: sampling current at the secondary side of the CT; acquiring a current waveform from a position near the peak value of a waveform by using a data window in order to obtain a waveform symmetric about the peak value and with less sampling points; computing a dispersion coefficient by using the third-order central moment after the acquired waveform is subjected to waveform mirror image transformation; and outputting a detected result. In the method, a dispersion coefficient after a standard sinusoidal current waveform is subjected to mirror image transformation. By means of analysis and computation, the dispersion coefficient can be considered as a fixed value so as to be used as a comparison basis. The method mainly solves problems of low detection rate and low detection precision when the CT saturation occurs, may fast and accurately detect the generation of the CT saturation just by using sampled data in half cycle so as to improve relay protection reliability to a certain extent and have certain practical significance in the aspect of guaranteeing the accurate and reliable operation of the CT.

The invention discloses an identification method for excitation surge current of a transformer based on kurtosis and skewness. The identification method comprises the following steps: initially setting a first setting value, a second setting value and a third setting value, performing uniform continuous sampling on differential current of the transformer by adopting an assigned sampling frequency to obtain a sampling value sequence; if a current effective value of the differential current is smaller than the first setting value, exiting the procedure, and otherwise, aiming at the current sampling value sequence, calculating the kurtosis and the skewness of the differential current of the latest power frequency cycle; if the kurtosis is greater than the second setting value and the skewness is greater than the third setting value, judging that the transformer is in an operation state of the excitation surge current, and locking differential protection of the transformer, otherwise, judging that the transformer is in other non-excitation surge current operation states; returning to continuously process the current effective value of the differential current. The identification method disclosed by the invention has the advantages of obvious criterion distinguishing degree, high correctness of identification result, low requirement on hardware realization, short judgment time, good real-time property and low requirement on hardware of an implementation device.

The invention relates to a method for determining a correlated waveform on a real time oscilloscope. A method for determining a correlated waveform, includes acquiring a generalized waveform record with a repeating pattern, determining a possibly corrected recovered clock signal for the generalized waveform record, selecting a new sample rate that is higher than the clock rate by N time, where N is an integer greater than 1, resampling the generalized waveform so that the new samples fall precisely on two clocks instants of the recovered clock signal that define each unit interval, and on N-1 additional instants equally spaced between the two clock instants of each unit interval to create a resampled waveform, and forming the correlated waveform by taking the mean values of all samples from the resampled waveform having the same offset into a pattern repeat in unit intervals or fractions thereof.

The invention discloses a method for recognizing magnetizing rush current of a transformer based on dynamic quadrangle shape analysis. The method specifically comprises the steps of acquiring differential current waveforms of current mutual inductors at two differential protection sides of the transformer, and sampling; dividing the current waveforms into two parts according to the equal area condition; gradually moving the sampling points in the two waveform parts and forming a quadrangle set; determining the shape of each quadrangle; counting the proportion of parallelogram in the quadrangle set; determining whether the type of the current waveform is the type of magnetizing rush current or internal fault current according to the proportion. With the adoption of the method for recognizing magnetizing rush current of the transformer based on dynamic quadrangle shape analysis, the magnetizing rush current of the transformer can be effectively and reliably recognized, and thus the influence of local deformation of the sampled waveforms on the determining result can be effectively avoided.

A vehicle, system and method for monitoring an occurrence of thermal runaway in a battery pack of the vehicle. The system includes a plurality of voltage sensors and a processor. The plurality of voltage sensors obtains a plurality of voltage measurements at each of a plurality of battery cells of the battery pack. The processor is configured to determine a mean value based on the plurality of voltage measurements, compare a voltage measurement obtained from a selected battery cell to the mean value, and generate a notification signal when a difference between the voltage measurement from the selected battery cell and the mean value is greater than or equal to a prognostic threshold.

A method and an input signal level detection apparatus that correctly detect a level of an input signal while consuming low power apparatus including: a full-wave rectifier outputting a full-wave rectified waveform by performing a full-wave rectification on a first signal corresponding to an input signal, and on a second signal having a phase difference of 180 degrees from the first signal; a common voltage detector detecting a common voltage of the first signal and the second signal; and a level detection unit detecting a level of the input signal, based on a subtraction result obtained by subtracting the common voltage from the full-wave rectified waveform.

The present invention relates to a method for detecting oscillations of signals, including evaluating signals to be analyzed concerning to occurrence of maximum or minimum values, by considering determined number of values in an evaluation section of the signals. The maximum or minimum values are filtered by low pass transfer functions with time constants, and the maximum or minimum values are reprocessed by differentiation of amplitude value, where the amplitude value is evaluated for analyzing oscillations of the signals. Furthermore, the invention also relates to a diagnosing device for detecting oscillations of signals, having a first evaluating unit to select maximum or minimum values from the signal section, the maximum or minimum values is filtered by a low pass filter unit respectively, and the filtered values are input to a difference calculating unit as input paremeters. The amplitude value can be processed as an output parameter of the difference calculating unit and is filtered by a following low pass filter unit, and / or the amplitude value is compared with a prescribed value by another processing unit.

The invention discloses a DC bias calibration apparatus and method of a zero-intermediate-frequency waveform generation system, and relates to the technical field of signal processing. The device comprises a measurement module, a feedback module, a processing module and a compensation module. The measurement module is used for measuring waveform signals output by a zero intermediate frequency waveform generation system; the feedback module is connected with the measurement module and used for feeding back a measurement result to a data processing unit of the zero intermediate frequency waveform generation system; the processing module is connected with the feedback module, is deployed in a data processing unit of the zero intermediate frequency waveform generation system and is used for processing the measurement data so as to obtain a DC bias compensation amount; and the compensation module is connected with the feedback module, is deployed in a data processing unit of the zero intermediate frequency waveform generation system, and is used for calibrating an output waveform signal according to the DC bias compensation amount. According to the invention, the measurement of the amplitude is converted into the measurement of the time delay, and then the calibration of the DC bias is completed.

Embodiments of the present invention provide systems, devices and methods for efficiently calculating a true RMS values (either voltage or current) of an AC signal. The RMS value is generated from both high and low frequency components of the AC signal without a high speed ADC being integrated within the system. The high frequency component is processed by calculating an average current waveform of the high frequency component and approximating a corresponding RMS value using a waveform factor. The waveform factor is effectively a scalar that relates the average current waveform of the high frequency component to an appropriate RMS value.

Embodiments of the present invention provide systems, devices and methods for efficiently calculating a true RMS values (either voltage or current) of an AC signal. The RMS value is generated from both high and low frequency components of the AC signal without a high speed ADC being integrated within the system. The high frequency component is processed by calculating an average current waveform of the high frequency component and approximating a corresponding RMS value using a waveform factor. The waveform factor is effectively a scalar that relates the average current waveform of the high frequency component to an appropriate RMS value.

The invention discloses an electric vehicle with a safe circuit structure. Compared with the prior art, by arranging a security module in a vehicle circuit, detection is conducted through the security module; when something dangerous happens, the security module sends a signal to an alarm module which gives an alarm, and a driver knows danger in time and disposes the dangerous situation in time.

The invention provides a distribution line early fault severity evaluation method based on waveform characteristics, and the method comprises the steps: monitoring an early fault of a kth distributionline, and obtaining an original voltage waveform of the distribution line; according to the original voltage waveform of the distribution line, respectively calculating to obtain a voltage determination coefficient and a voltage approximate entropy; calculating to obtain a comprehensive evaluation index of the early fault degree of the distribution line according to the voltage determination coefficient and the voltage approximate entropy; and determining the severity of the kth early fault according to the interval range to which the comprehensive evaluation index of the early fault degree of the distribution line belongs. Through the design, the function of predicting and early warning the distribution network line is realized, so that the overhaul and maintenance of the distribution line is guided, permanent faults are avoided, and the power supply reliability is improved.

The invention discloses a pulse detection circuit and a pulse detection method, which can measure a higher-speed input pulse while reducing the power consumption of a microcontroller. The pulse detection circuit comprises an input module, an automatic trigger detection module and a data latching module. The input end of the input module receives an external input pulse, a pulse signal is transmitted to the clock pulse end of the automatic trigger detection module and the input end of the data latching module through the output end of the input module, and when the pulse signal is changed from a first level to a second level, the automatic trigger detection module is enabled, and the output end of the automatic trigger detection module sends a latch signal to the enabling end of the data latching module, so that the data latching module latches the pulse signal according to the latch signal.

The invention discloses an SF6 spark discharge energy analysis method. The method comprises the following steps: rectifying a high-voltage alternating-current power supply through a high-voltage silicon stack to obtain a required direct-current power supply; adopting a direct-current power supply to charge the charging capacitor, and enabling the charging capacitor to store energy of different voltage levels; storing energy charging capacitors with different voltage levels to respectively discharge the defects of the spark discharge simulation tank body and generate sparks; and measuring the voltage and the current of the spark discharge gap at the spark moment to calculate the SF6 spark discharge energy. According to the method, quantitative discharge can be carried out on the defects ofthe spark discharge simulation tank body, and regular sparks are generated, so that subsequent research on SF6 spark discharge can be carried out under a quantitative condition.

The invention provides a switching transient current waveform and parameter measuring device of a terahertz transit time device, including a single-chip microcomputer, a display unit, a high-frequency pulse current source circuit, a blocking pulse voltage source circuit, a switching transient current waveform detection circuit and a switch Transient current signal processing circuit. When the single-chip microcomputer sends the first pulse signal to the high-frequency pulse current source circuit and the first detection instruction to the switch transient current waveform detection circuit, it receives the instantaneous When the transient current signal is turned on, or when the second pulse signal is issued to the blocking pulse voltage source circuit and the second detection instruction is issued to the switch transient current waveform detection circuit, the signal processing circuit receiving the switch transient current signal is to be tested. Transient current signals instantaneously blocked by terahertz transit-time devices. By implementing the invention, the transient current waveforms and parameters of the forward conducting and reverse blocking of the device are obtained, the measurement reliability is improved, and the operation difficulty is reduced.

The embodiment of the invention provides an arc fault detection method, device and equipment, and a storage medium. The method comprises the steps of obtaining a current waveform of a current signal of a current period and a current waveform of a current signal of a previous period; determining current waveform deviation characteristics of the current waveform of the current period current signal and the current waveform of the previous period current signal; and determining whether an arc fault occurs in the circuit according to the current waveform deviation characteristic and the first zeroing zone duration of the current waveform of the current period current signal. In the prior art, a large number of samples are needed to train an intelligent algorithm or a neural network model for arc fault detection. A large number of samples are not needed, and the early-stage investment of arc fault detection is reduced; sample limitation is eliminated, the method is suitable for most arc fault detection scenes, and the universality and accuracy of the detection method are improved; and an intelligent algorithm and a neural network model do not need to be set and operated in the detection equipment, so that the performance requirements of memory and the like of the detection equipment are reduced.

The invention discloses an identification method for excitation surge current of a transformer based on kurtosis and skewness. The identification method comprises the following steps: initially setting a first setting value, a second setting value and a third setting value, performing uniform continuous sampling on differential current of the transformer by adopting an assigned sampling frequency to obtain a sampling value sequence; if a current effective value of the differential current is smaller than the first setting value, exiting the procedure, and otherwise, aiming at the current sampling value sequence, calculating the kurtosis and the skewness of the differential current of the latest power frequency cycle; if the kurtosis is greater than the second setting value and the skewness is greater than the third setting value, judging that the transformer is in an operation state of the excitation surge current, and locking differential protection of the transformer, otherwise, judging that the transformer is in other non-excitation surge current operation states; returning to continuously process the current effective value of the differential current. The identification method disclosed by the invention has the advantages of obvious criterion distinguishing degree, high correctness of identification result, low requirement on hardware realization, short judgment time, good real-time property and low requirement on hardware of an implementation device.

The invention relates to a lightning stroke fault recognition method for an EHV (extra-high voltage) DC transmission line based energy spectrum similarity, and belongs to the technical field of power system relay protection. The method comprises the steps: extracting the ratio of a positive time domain waveform to an area formed by the enclosing of the zero axis of the positive time domain waveform and the ratio of a positive time domain waveform of any fault type to the area formed by the enclosing of the zero axis of the positive time domain waveform during stable operation when the voltage of the EHV DC transmission line fluctuates, and recognizing the fault and lightning stroke interference according to the ratios; switching to fault classification recognition if the interference is a fault, carrying out the wavelet decomposition recognition of an additional component through wavelet, and judging whether the fault is a grounding fault or a lightning stroke fault; and switching to a shielding failure and back flashover fault recognition if the fault is the lightning stroke fault. The method achieves the time frequency analysis of the simulation data, achieves the extraction of data in a short time period, and integrates area ratios, energy spectrum similarity and modular maximum value. The method achieves the extraction of a set of criteria for thunder interference, grounding faults, back flashover faults and shielding failures, and can achieve the accurate, quick and effective recognition of various types of conditions.

The invention discloses a waveform data processing device, and the device comprises: a host end which is used for storing target waveform data in a first storage unit, and transmitting a synchronous starting signal to a waveform data generation module and a waveform data measurement module at the same time; a waveform data generation module which is used for carrying out DA waveform output according to the target waveform data in the first memory after receiving the synchronous starting signal; a waveform data measurement module which is used for performing AD waveform measurement to obtain measurement data after receiving the synchronous starting signal, and storing the measurement data into a second memory, wherein the waveform data generation module and the waveform data measurement module are modules in a target FPGA board card. According to the invention, generation and measurement of waveform data can be synchronously achieved. The invention further discloses a waveform data processing method, a storage medium and electronic equipment, which have the above beneficial effects.

There is provided a delay amount measuring method of measuring a delay amount in an electronic device that outputs an output signal according to an input signal. The method includes a conversion step of converting the input signal and the output signal into digital data, a shift step of sequentially shifting the digital data of either of the input signal or the output signal in a time direction, an error computing step of computing a squared error of the digital data of the input signal and the digital data of the output signal with respect to each shift amount in the shift step, and a delay amount computing step of computing the shift amount when the squared error is a minimum value by means of a nonlinear least squares method and using the computed shift amount as the delay amount in the electronic device.

A method and an input signal level detection apparatus that correctly detect a level of an input signal while consuming low power apparatus including: a full-wave rectifier outputting a full-wave rectified waveform by performing a full-wave rectification on a first signal corresponding to an input signal, and on a second signal having a phase difference of 180 degrees from the first signal; a common voltage detector detecting a common voltage of the first signal and the second signal; and a level detection unit detecting a level of the input signal, based on a subtraction result obtained by subtracting the common voltage from the full-wave rectified waveform.

The invention provides a test board structure for IGBT device current waveform detection. The invention aims to effectively capture a discharge current waveform consistent with a typical waveform in internationally accepted test specifications. The structure includes a pogo probe for directly contacting a discharge device, a filter for filtering out high-frequency interference, an attenuator for reducing current peaks to facilitate testing, a test resistor for converting current signals, and a grounding plate for connecting all the parts, wherein the filter and the attenuator are located on the grounding plate, and the grounding plate is connected with a metal socket so as to connect an oscilloscope, and the grounding plate contains a structure which enables a fixing effect and is used forconnecting the other parts of the test system.