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127 results about "Peak value" patented technology

Peak value. [′pēk ′val·yü] (electricity) The maximum instantaneous value of a varying current, voltage, or power during the time interval under consideration. Also known as crest value.

Distribution box remote diagnosis and maintenance system

The invention relates to the technical field of equipment maintenance, in particular to a distribution box remote diagnosis and maintenance system which comprises a voltage deviation detection module, a node hot stacking identification module, a channel stability classification module, a contact aging trend evaluation module and a period adjustment trigger module. According to the method, peak value change of effective voltage in each channel period in the distribution box is collected and compared with a preset criterion so as to accurately identify an abnormal discharge unit and accurately position a potential risk channel, and the change rate of equivalent series capacitance, contact conductance and contact resistance of a node is continuously sampled in a non-power-on state so as to accurately identify the potential risk channel. According to the method, multi-parameter same-trend change characteristics are determined, the contact aging process is accurately evaluated by integrating the parameter trend, the node trend and the maintenance plan period remaining time are subjected to cross comparison, the maintenance task advance opportunity is automatically judged, the maintenance plan is actively adjusted, the node fault missing detection risk is effectively reduced, and the maintenance timeliness and accuracy are remarkably improved.
Owner:SHENZHEN SANJIANG ELECTRIC

High-precision transformer fault detection method and system

The invention discloses a high-precision transformer fault detection method and system, relates to the technical field of transformer detection, is used for solving the problems of insensitive fault characterization and delayed diagnosis under a light load condition, and judges whether to enter a load judgment mechanism or not by acquiring input side access voltage information and counting low-load accumulated duration. When entering a load discrimination mechanism, detecting the start-stop behavior of a load branch and the temperature rise trend of a winding, calculating a light load index, identifying a light load state, carrying out region division on an iron core, collecting magnetic flux density data, and calculating iron loss balance characteristics aiming at iron loss deviation which is easy to occur under a light load condition; the insulation degradation coefficient is calculated by fusing the oil temperature peak value and the dielectric loss factor, and the abnormal index is generated with the iron loss balance characteristic, so that the early warning of the early hidden fault of the transformer can be realized in a light load scene in which the traditional temperature rise and current indexes are insensitive, and the operation reliability and maintenance efficiency of the transformer in a power distribution system are improved.
Owner:GUILIN UNIV OF ELECTRONIC TECH +1

Transient electromagnetism-based grounding grid corrosion defect evaluation method and system

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

Converter fault ride-through method and system based on dynamic virtual impedance parameters

The embodiment of the invention discloses a converter fault ride-through method and system based on a dynamic virtual impedance parameter, and relates to the technical field of power electronics, and the method comprises the steps: latching the virtual internal potential amplitude of a converter and the angular velocity of a system before a fault when the voltage amplitude of a grid-connected point is detected to be lower than a preset voltage threshold value; calculating d-axis and q-axis fault current components which are expected to flow through the converter by using latch data, a current grid-connected point voltage amplitude, a virtual impedance initial value before a fault and controller output delay, calculating to obtain a three-phase fault current maximum peak value, comparing the three-phase fault current maximum peak value with a maximum current which can be borne by the converter, and determining the current value of the converter. And according to a comparison result, an adjustment coefficient and an impedance proportionality coefficient, a virtual resistor and a virtual inductor are dynamically calculated and updated, new d-axis and q-axis current reference values are calculated together with a latched virtual internal potential amplitude and d-axis and q-axis voltages of the current grid-connected point, and the new d-axis and q-axis current reference values are input into a current inner loop controller to control the output of the converter.
Owner:YUNNAN POWER GRID CO LTD ELECTRIC POWER RES INST +1

Three-phase adaptive reclosing method and system for wind power transmission line

The invention relates to the technical field of relay protection, in particular to a three-phase self-adaptive reclosing method and system for a wind power transmission line. The method comprises the following steps: when a fault is detected, collecting a secondary side voltage signal of a target fault phase of the wind power system; determining a fault phase voltage envelope value according to the peak value of the secondary side voltage signal; calculating energy in a plurality of time windows according to the fault phase voltage envelope value; sequentially calculating the energy ratio between the energy of the jth (j = 2, 3, 4,...) time window and the energy of the first time window; if the value of the energy ratio of at least three continuous time windows in the maximum discrimination time limit is greater than 1, determining a reclosing moment so as to output a circuit breaker closing signal after the reclosing moment is reached; otherwise, judging that the fault type is a permanent fault, and not outputting the circuit breaker closing signal. The objective of the invention is to solve the problem of how to identify the fault type of a wind power system before reclosing of a circuit breaker.
Owner:KUNMING UNIV OF SCI & TECH

Power supply test method and system

The invention relates to the technical field of power supply testing, in particular to a power supply testing system and method. Comprising the following steps: performing power supply demand simulation based on a load transition mechanism: performing deep analysis on a correlation relationship among components of a load by using demand analysis, and performing power supply demand simulation according to a deep analysis result; and constructing a power supply response state set based on the power supply demand simulation result and in combination with the load response characteristics, and carrying out the adaptability test of the power supply behavior through a power supply adaptability clustering algorithm according to the distribution characteristics of the load states under different configurations. According to the method, the instantaneous peak value, the stable power consumption and the load transition characteristics are extracted, the power supply response model is constructed in combination with the load state, and the fitting degree of the real power supply demand of each component is improved; and through a multi-round clustering center iteration verification and adjustment mechanism, it is ensured that the test covers the power supply threshold of all components, and the comprehensiveness and reliability of the power supply test are improved.
Owner:ENNOCONN SUZHOU TECH CO LTD

Multi-parameter collaborative optimization design method for modular multilevel converter

The invention discloses a multi-parameter collaborative optimization design method for a modular multilevel converter, and belongs to the technical field of modular multilevel converter design. In order to solve the problem of reasonable design of main parameters of the modular multilevel converter, a mathematical model of the modular multilevel converter is constructed; designing a capacitor voltage fluctuation model, a sub-module capacitor capacitance value model and a fluctuation quantity model, and analyzing the relationship between the capacitor voltage fluctuation and the operation condition and the relationship between the sub-module capacitor capacitance value and the operation condition; determining an upper limit value of the bridge arm inductance based on consideration of a system power operation range, determining a design initial value of the bridge arm inductance based on consideration of ring current suppression, determining a lower limit value of the bridge arm inductance based on consideration of resonance avoidance and fault current rise rate limitation, and obtaining a design range of the bridge arm inductance; adjusting the bridge arm inductance to obtain a design value of the designed bridge arm inductance; and according to the capacitance value of the sub-module capacitor and the design value of the designed bridge arm inductor, analyzing the peak voltage and the peak current of the power device IGBT to determine the parameter selection of the power device.
Owner:HARBIN INST OF TECH

Fault detection method and system for filter

The invention relates to the technical field of electrical variable measurement, in particular to a filter fault detection method and system, and the method comprises the following steps: synchronously collecting an input current signal flowing through a filter and voltage time domain waveforms at the two ends of the filter based on a sine input voltage signal applied to the filter; the ratio of the peak voltage to the peak current in the initial stage is calculated, and the waveform transient amplitude ratio is obtained; and based on the waveform transient amplitude comparison, segmenting and sorting continuously acquired time domain waveforms according to a preset time window to generate an instantaneous electrical parameter sequence. An input current signal and voltage waveforms at the two ends are synchronously collected on the basis of application of a sine input voltage signal, the ratio of peak voltage to peak current is extracted to obtain waveform transient amplitude comparison, the sensitivity of waveform characteristics is improved, continuously collected time domain waveforms are divided through the waveform transient amplitude comparison, an instantaneous electrical parameter sequence is formed, and the accuracy of the waveform characteristics is improved. And the signal segmentation is more reliable.
Owner:QUZHOU TALENT FILTER CO LTD

Driving control method of interleaved parallel flyback micro inverter

The invention discloses a driving control method of an interleaving parallel flyback micro inverter. The driving control method comprises the following steps: comparing the total output power of the interleaved parallel flyback micro inverter with the maximum output power of a single branch; when the total output power of the interleaved parallel flyback micro inverter is smaller than the maximum output power of a single branch, determining a time point corresponding to the maximum value according to the peak current reference value, and controlling the first transformer and the second transformer to work alternately based on the time point; and when the total output power of the interleaving flyback micro inverter is greater than or equal to the maximum output power of the single branch, determining a time interval corresponding to the condition that the total output power is greater than or equal to the maximum output power of the single branch, and controlling the first transformer and the second transformer to work at the same time in the time interval, and alternately working outside the time interval. According to the technical scheme, the aging difference of branch devices can be effectively reduced, and the situation that branch heat accumulation is serious is avoided.
Owner:ZHEJIANG JIAMING TIANHEYUAN PHOTOVOLTAIC TECH

Pulse arc welding control method

A method for controlling pulse arc welding involving feeding a welding wire and applying a welding current by repeating a pulse cycle including: a peak rising period of applying a peak rising current increasing from a base current to a peak current; a peak period of applying the peak current; a peak falling period of applying a peak falling current decreasing from the peak current to the base current; and a base period of applying the base current. The feed speed of the welding wire is changed such that it beings to change from a reverse-feeding peak value toward a forward-feeding peak value at a point earlier by a first preceding period than the start of the peak rising period. Then, the feed speed reaches the forward-feeding peak value at a point earlier than an end of the peak rising period, and beings to change from the forward-feeding peak value toward the reverse-feeding peak value at a point earlier by a second preceding period than the start of the peak falling period, and reaches the reverse-feeding peak value at a point earlier than an end of the peak falling period.
Owner:DAIHEN CORP

Parallel energy storage array battery cluster adaptive parallel operation prediction method and system

The invention discloses a parallel energy storage array battery cluster adaptive parallel operation prediction method and system, and the method comprises the steps: estimating the total current of each battery cluster during parallel operation based on a parallel operation equivalent circuit model, and determining the estimated value of the total parallel operation current during each parallel operation according to a parallel operation sequence; based on the equivalent circuit model and the parallel operation equivalent circuit model, predicting the total voltage of the direct current bus during each parallel operation; based on a parallel operation peak current model, determining p and p + 1 times of parallel operation peak current; when the p parallel operation peak current is not greater than the closed peak current tolerance value of the parallel operation contactor, but the p + 1 parallel operation peak current is greater than the closed peak current tolerance value of the parallel operation contactor, calculating the voltage difference between the total voltage measured value and the direct current bus total voltage predicted value at the starting time and the ending time of the p and p + 1 parallel operation interval time; if the pressure difference at the starting moment is not greater than the pressure difference at the ending moment, judging that the (p + 1) th parallel operation cannot be executed; on the contrary, the p-th parallel operation interval period and the p + 1-th parallel operation interval period are prolonged, and battery cluster parallel operation prediction is achieved.
Owner:BEIJING SIFANG JIBAO ENG TECH +1

Scintillation pulse peak voltage sampling method and device and computer storage medium

The invention discloses a scintillation pulse peak voltage sampling method and device and a computer storage medium, and the method comprises the steps: carrying out the peak holding processing of a scintillation pulse, and obtaining a peak holding signal, the size of the peak holding signal and the peak value of the scintillation pulse meeting a first pre-calibrated mapping relation; generating a reference signal, wherein the reference signal conforms to the prior model; comparing the reference signal with the peak holding signal to obtain time difference information when the reference signal crosses the peak holding signal, the time difference information and the peak holding signal conforming to a second pre-calibrated mapping relation, and the second pre-calibrated mapping relation being associated with the prior model; and according to the time difference information, the first pre-calibrated mapping relation and the second pre-calibrated mapping relation, reversely obtaining the peak voltage of the scintillation pulse. On one hand, the problems existing in existing PP-MVT can be solved, on the other hand, the method can be highly compatible with an existing framework of an MVT method, and sampling and restoring of flash pulse key information are completed.
Owner:RAYCAN TECH CO LTD SU ZHOU

Method for Generating Short-Circuit Breaking Voltage and Current Waveforms of Circuit Breaker and Obtaining Parameters

The present invention discloses a method for generating the short - circuit breaking voltage and current waveforms of a circuit breaker and obtaining parameters, which is characterized in that by obtaining the positive - sequence reactance X1, positive - sequence resistance R1, and zero - sequence reactance X0 of the node where the circuit breaker is located, the total current, alternating - current component current, direct - current component current, and power - frequency recovery voltage during the short - circuit breaking process of the circuit breaker are calculated by applying a three - phase equivalent circuit model. Further, the parameters of the last half - wave of the short - circuit breaking current are obtained: the duration ΔT, the peak value I peak , the direct - current component p at the current zero - crossing point, and from p, the di / dt at the current zero - crossing point and the TRV parameters under the condition of modified asymmetrical short - circuit breaking can be calculated. The short - circuit breaking voltage and current parameters of the high - voltage alternating - current circuit breaker obtained by the method of the present invention can provide reference and basis for the evaluation of the breaking capacity of the circuit breaker and phase - selective breaking.
Owner:SHENYANG INST OF ENG

Reducing Transformer Inrush Current

A start-up method for reducing inrush current to a transformer when closing a switching device. The method includes monitoring a voltage in one of the phases. The method also includes, for each of a sequence of iterations: at a same opening angle relative to a reference angle of the monitored voltage, opening the switching device; at a closing angle relative to the reference angle, which is shifted in relation to the closing angle of all other iterations in the sequence, closing the switching device; and obtaining a peak value of the overall inrush current resulting from the closing. The method also includes selecting for future use with said same opening angle, the closing angle of one of the iterations in which the overall inrush current is relatively low when compared with the other iterations of the sequence.
Owner:ABB (SCHWEIZ) AG

Transient stability improvement method for virtual synchronous generator based on power outer loop collaborative optimization

The invention relates to a power outer loop collaborative optimization virtual synchronous generator transient stability improvement method, and belongs to the technical field of virtual synchronous generator transient stability, and the method comprises the following steps: S1, building a virtual synchronous generator small signal power angle model; s2, performing active transient compensation and capacity constraint of power angle-frequency difference cooperative state feedback; s3, voltage deviation driven adaptive reactive power coefficient and active-reactive power combined current limiting are carried out; and S4, fault current impact suppression of the current-driven virtual impedance. The method can effectively reduce peak values and oscillation time of a power angle and a frequency difference, limit a fault current not to exceed a set upper limit, consider voltage support and active support capabilities, has good stability and robustness, and is suitable for controlling the grid-connected virtual synchronous generator under different short-circuit ratios and various fault working conditions.
Owner:CHONGQING UNIV OF POSTS & TELECOMM

Output voltage ripple control method and related device of dual active bridge

The present application proposes a method for controlling the output voltage ripple of a dual active bridge and a related device, the method comprising: a controller obtaining a plurality of first circuit parameters and the n-1th ripple voltage peak-to-peak value under the current working condition, the plurality of first circuit parameters including a plurality of frequency-jittering-related frequency values ​​and a first phase shift angle; determining a phase shift angle control variable based on the n-1th ripple voltage peak-to-peak value; determining a second phase shift angle based on the phase shift angle control variable, the n-1th ripple voltage peak-to-peak value, the nth ripple voltage peak-to-peak value and the first phase shift angle; determining a target phase shift angle based on the second phase shift angle and a plurality of frequency-jittering-related frequency values; and performing a phase shift angle compensation operation based on the target phase shift angle when the frequency-jittering cycle reaches the n+1th frequency-jittering cycle. In this way, when a phase shift angle reverse compensation operation is performed based on the ripple voltage peak-to-peak value to offset the power transmission error caused by the frequency offset, the output power imbalance problem at the moment of frequency change is greatly alleviated, and the degree of deterioration of the output voltage ripple is reduced.
Owner:SHENZHEN WINLINE TECH

Systems and methods for monitoring a through fault current

The present application provides a method for monitoring a through fault current. The method may involve: detecting a through fault; calculating an electrical stress, peak current, and duration of the through fault; determining two sets of percentage state changes associated with the through fault; assigning a respective set of weights and criticalities to each set of percentage state changes; calculating a mechanical state change based on the first set of percentage state changes and the first set of weights and criticalities; calculating a thermal state change based on the second set of percentage state changes and the second set of weights and criticalities; calculating a cumulative state change based on the mechanical and thermal state changes; and training a machine learning model using the electrical stress, peak current, duration, two sets of percentage state changes, and mechanical, thermal, and cumulative state changes.
Owner:GE VERNOVA INFRASTRUCTURE TECHNOLOGY LLC

Relay branch state detection method, device, medium and electric meter of three-phase electric meter

ActiveCN121164892BTimestampPeak value
The application discloses a kind of relay branch state detection method, device, medium and electric meter of three-phase electric meter, including obtaining the voltage digital signal after superposition of each phase branch of three-phase electric meter relay;According to the voltage digital signal after superposition, the voltage peak value of each phase branch and the timestamp corresponding to the voltage peak value are obtained;According to the voltage peak value and the timestamp and the preset state determination condition, the state result of the three-phase electric meter relay branch is obtained.The application solves the problem that the prior art can only judge the overall on-off state of three-phase power supply, resulting in a single state recognition function.
Owner:SHENZHEN STAR INSTR

Linear control method and system for energy storage system

The invention provides a linearization control method and system for an energy storage system, and mainly provides a single-phase-shift frequency conversion modulation method applied to the linearization control method and system, the single-phase-shift frequency conversion modulation method is applied to a single-stage DAB type AC-DC converter, and the alternating current input voltage vac, the alternating current input current iac and the direct current output voltage Vdc of the single-stage DAB type AC-DC converter are sampled; based on the sampled alternating current input voltage vac, the alternating current input current iac and the direct current output voltage Vdc, a control variable theta is obtained through calculation; on the basis of the obtained control variable theta, at the moment when the leakage inductance peak current iLk has the maximum value, a mapping coefficient c of the leakage inductance peak current at the moment is obtained through a differential extreme value method; based on the obtained control variable theta and the mapping coefficient c, calculating to obtain a phase shift ratio D and a switching frequency fs; d = 1-c theta; fs = fa (c-c2theta); and based on the obtained phase shift ratio D and the switching frequency fs, a driving signal for single phase shift frequency conversion modulation is given.
Owner:ZHENGZHOU UNIV

Method, device and system for safety energization test of power distribution cabinet

The application relates to the technical field of electric variable monitoring, in particular to a safe power-on test method, device and system for a power distribution cabinet, which comprises the following steps: acquiring three-phase voltage signals of the power distribution cabinet in a safe power-on test process; analyzing the similarity between the three-phase voltage signals of the power distribution cabinet and the fluctuation degree of each-phase voltage of the power distribution cabinet, obtaining three-phase fluctuation characteristic values of the three-phase voltage signals, constructing a peak value difference rate between any two-phase voltage signals according to the peak value difference degree between the three-phase voltage signals, and then acquiring an electromagnetic interference factor of the three-phase voltage signals; and constructing an each-phase voltage abnormality judgment value according to the electromagnetic interference factor and the deviation degree of each-phase voltage, so as to judge the abnormal operation condition of the power distribution cabinet. The application can improve the safe power-on test precision of the power distribution cabinet.
Owner:洛阳市飞科机电设备有限公司

Three-phase voltage state estimation method and system based on virtual coordinates

The invention relates to the technical field of three-phase systems, and provides a three-phase voltage state estimation method and system based on virtual coordinates, and the method comprises the steps: calculating the voltage peak value of each phase for three-phase voltages, and determining that a phase is open if the peak voltage of a certain phase is lower than a threshold value in the three peak voltages; for three-phase voltage, virtual beta-axis voltage is generated through an all-pass filter, actual beta-axis voltage is obtained through Clark transformation, the product of the virtual beta-axis voltage and the actual beta-axis voltage serves as an evaluation function, and a positive sequence and a negative sequence are distinguished according to the positive and negative of the evaluation function. The system state can be accurately and effectively judged under the conditions of three-phase imbalance and voltage distortion, the anti-noise capability and the anti-harmonic interference capability are high, and safe and stable operation of equipment under the abnormal condition is ensured.
Owner:RODLESS PUMPS INC +2

Data-driven single three-phase meter automatic verification system and verification method

The invention relates to the technical field of electric energy meter quality detection, in particular to a data-driven single three-phase meter automatic verification system and method, and the method comprises the steps: obtaining a current sequence, a voltage sequence and an electromagnetic sequence of a single three-phase meter; acquiring peak values in all sequences; recording the current sequence and the voltage sequence as electric power sequences; obtaining an abnormal peak value in the power sequence; obtaining an abnormal factor of the power sequence according to whether the data dispersion degree in each peak neighborhood window in the power sequence is equal or not; according to the position and the fluctuation characteristic of each abnormal peak value in the power sequence, the total number of the abnormal peak values and the abnormal factors, obtaining a waveform deviation coefficient of the power sequence; obtaining the verification abnormity degree of the single-three-phase meter by combining the difference coefficient of each phase in the single-three-phase meter; and whether the single three-phase meter has a quality problem or not is judged. By analyzing the data characteristics of the single-three-phase meter, whether the single-three-phase meter has a quality problem can be accurately judged, so that the automatic verification precision is improved.
Owner:国网新疆电力有限公司营销服务中心

Impedance model construction method and system for new energy flexible low-frequency transmission system

The invention relates to the technical field of electric signal processing, in particular to an impedance model construction method and system of a new energy flexible low-frequency sending-out system. The method comprises the following steps: recording real-time timing sequences of voltage and current of a converter bridge arm under different working conditions; extracting a time interval between the voltage peak value and the current peak value, a voltage waveform slope change rate and a current waveform oscillation period, and labeling corresponding working condition labels to form a bridge arm dynamic feature library; and identifying the voltage waveform and the current waveform of the converter bridge arm, and synchronously recording the line resistance and the line reactance between the converter stations. According to the invention, through integration of the bridge arm dynamic features, construction of the bridge arm dynamic feature library and high-frequency correction cooperation, adaptive optimization of bridge arm parameters and construction of the impedance model of high and low frequency bands are realized, so that the matching efficiency of the impedance model is improved.
Owner:STATE GRID JIBEI ELECTRIC POWER COMPANY +2

SiC DSRD structure for optimizing pulse output characteristics and preparation method

PendingCN120769511APulse frontCharge carrier mobility
The invention relates to a SiC DSRD structure for optimizing pulse output characteristics and a preparation method, the structure comprises a cathode, an N + substrate, an N-base region, a P-base region, a P + region and an anode from bottom to top, and the main body structure material is a 4H-SiC material; one side, close to the N + substrate, in the N-base region is provided with at least one minority carrier lifetime attenuation suspension island layer, the top of the uppermost minority carrier lifetime attenuation suspension island layer does not exceed the transverse center line position of the N-base region, the minority carrier lifetime attenuation suspension island layers are arranged at intervals, one layer comprises at least one minority carrier lifetime attenuation suspension island, and the minority carrier lifetime attenuation suspension islands are distributed at equal thickness at intervals; the minority carrier lifetime attenuation suspension island is formed by injecting heavy metal ions into the N-base region; the problem of carrier distribution is solved from the source, the turn-off process of the SiC DSRD is quicker, the output voltage peak value is higher, the pulse leading edge is quicker, the carrier mobility is met, and meanwhile it is guaranteed that breakdown voltage is not degraded.
Owner:XIDIAN UNIV

Pulse arc welding control method

A method for controlling pulse arc welding involving feeding a welding wire (1) and applying a welding current (Iw) by repeating a pulse cycle including: a peak rising period (Tu) of applying a peak rising current (Iu) increasing from a base current (Ib) to a peak current (Ip); a peak period (Tp) of applying the peak current (Ip); a peak falling period (Tk) of applying a peak falling current (Ik) decreasing from the peak current (Ip) to the base current (Ib); and a base period (Tb) of applying the base current (Ib). The feed speed (Fw) of the welding wire (1) is changed such that it beings to change from a reverse-feeding peak value (Wr) toward a forward-feeding peak value (Ws) at a point earlier by a first preceding period (Ta1r) than the start of the peak rising period (Tu). Then, the feed speed (Fw) reaches the forward-feeding peak value (Ws) at a point earlier than an end of the peak rising period (Tu), and beings to change from the forward-feeding peak value (Ws) toward the reverse-feeding peak value (Wr) at a point earlier by a second preceding period (Ta2r) than the start of the peak falling period (Tk), and reaches the reverse-feeding peak value (Wr) at a point earlier than an end of the peak falling period (Tk).
Owner:DAIHEN CORP

Calibration method for conversion relation between particle number and mass concentration

The invention discloses a method for calibrating the conversion relation between the particle number and the mass concentration, and the method comprises the following steps: for aspheric particles, introducing a voltage correction coefficient through employing the concept of equivalent diameter, and obtaining a calculation formula of the mass concentration of the aspheric particles; in a test environment, the number of voltage pulses of the particulate matter sensor within a period of time is collected, the average value of peak voltage of each pulse is solved, and meanwhile, the PM2.5 mass concentration is collected by using a standard instrument; after the calibration coefficient and the proportionality coefficient are calculated and obtained by combining the mass concentration measured by the standard instrument and the quantity concentration detected by the particulate matter sensor, the calibration coefficient and the proportionality coefficient are substituted into a formula to calculate the mass concentration corresponding to the quantity concentration detected by the particulate matter sensor, and meanwhile, the measurement precision of the particulate matter sensor is guaranteed when the particulate matter concentration changes suddenly.
Owner:JIANGSU XINHONG TECHNOLOGY CO LTD

Low-voltage series arc fault identification method based on multi-frequency electrical quantity amplitude-phase combination

The present application belongs to the technical field of fault identification, and particularly relates to a low-voltage series arc fault identification method based on multi-frequency electrical quantity amplitude-phase combination. The steps include: each downstream monitoring point real-time monitors the voltage waveform distortion rate of adjacent cycles, and judges whether it is greater than or equal to the set distortion rate threshold; if yes, the fault detection algorithm is started; the voltage data of the downstream monitoring point and the corresponding upstream monitoring point are aligned asynchronously and in phase, differentiated to obtain the differential voltage, low-pass filtered, and the voltage characteristic energy is calculated; the minimum point of the voltage characteristic energy is obtained, the voltage energy peak values in the left and right windows are obtained and the corresponding phases are calculated; the peak threshold and the fault sensitive domain are determined, and the counting accumulation is performed; if the counting accumulation exceeds the counting threshold, it is determined as a fault. The present application can improve the sensitivity, accuracy and anti-interference ability of the power grid side fault detection.
Owner:SHANDONG UNIV OF TECH

Sign detection method, sign detection device, and computer program

The present invention acquires measurement values of the charge capacity and voltage of a power storage element when the power storage element has been charged from the discharge end state, derives, when the rate at which the voltage changes in accordance with changes in the charge capacity is defined as dV / dQ, the charge capacity dependency of dV / dQ on the basis of the acquired measurement values, identifies, on the basis of the derivation result, the peak position of a peak appearing on a characteristic curve indicating the charge capacity dependence of dV / dQ, and detects, on the basis of the identified peak position, a sign of sudden deterioration of the power storage element.
Owner:GS YUASA INT LTD

Ground fault detection method and device and medium

The invention discloses a ground fault detection method and device and a medium. Relates to the technical field of power system power distribution network detection, and solves the common problem of inaccurate ground fault detection of a power distribution network. According to the invention, the transient abrupt change characteristic of the fault moment is amplified through the zero-current transient increment and the zero-voltage transient increment, and even if the transient signal is weak during high-resistance grounding, the transient signal can be separated through increment operation; the transient change rate of the zero-voltage increment differential data is further amplified through an adjacent point difference value, and the voltage abrupt change characteristic under the high-resistance fault is strengthened; the first characteristic signal and the second characteristic signal convert transient relevance into energy quantification characteristics through product operation of current and voltage transient parameters, and the significance of the high-resistance fault signal is further improved. Whether effective mutation exists or not is judged by combining the zero-current transient increment peak-to-peak value, the zero-voltage increment differential data peak-to-peak value, the first characteristic signal and the second characteristic signal, misjudgment caused by single signal fluctuation is avoided, and the grounding fault detection performance is remarkably improved.
Owner:HANGZHOU HOUYU TECH CO LTD