74 results about "Current amplitude" patented technology

The application provides a primary and secondary fusion ring network box protection setting value adjustment method, which comprises the following steps: obtaining zero sequence current amplitude data from a zero sequence acquisition unit, obtaining sheath potential data from a sheath potential acquisition unit, obtaining bus voltage data from a bus voltage acquisition module, and collecting the data into an initial input set; dynamically adjusting a grounding protection discrimination criterion according to an adjustment direction, taking the adjustment direction and the bus voltage data as inputs, adopting a threshold comparison mechanism to form an updated grounding protection discrimination criterion, and using the updated grounding protection discrimination criterion to locate a real grounding branch; and matching the updated grounding protection discrimination criterion with the zero sequence current amplitude data, generating a protection setting value adjustment instruction after the protection setting value adjustment condition is established, updating the ring network box protection setting value, and completing the identification and setting value adjustment of the real grounding branch.

This application proposes a method and apparatus for detecting phase loss in a power plant starting transformer, relating to the field of power fault detection technology. The method includes: acquiring the signal energy distribution of the starting transformer; constructing an energy feature vector reflecting the relative energy relationship between the three-phase current signals and inputting it into a phase loss identification model to obtain the initial probability of phase loss faults in each phase; performing state inversion calculations by combining real-time calculated zero-sequence and negative-sequence current amplitudes to infer the changes in the equivalent circuit parameters of the transformer's internal windings and leads before and after the fault, thereby correcting the initial probability to obtain a confidence level, and finally generating a phase loss detection report including the fault phase and fault severity. This application comprehensively characterizes the energy correlation characteristics of the three-phase currents through energy feature vectors and corrects the initial probability of the model using changes in equivalent circuit parameters, eliminating random biases in the output of a single model, achieving accurate matching between the fault determination result and the actual fault state of the transformer, and improving the accuracy of fault phase identification.

The detection system of individual transcranial alternating current stimulation current amplitude threshold and frequency band range relates to the technical field of data identification, recording and processing in medical instrument and meter technology. It comprises: an upper computer which sends stimulation parameters to a stimulator, receives and stores detection information sent by the stimulator; a control keyboard which obtains stimulation sensitivity of an individual under current stimulation and transmits to the stimulator; and the stimulator which adjusts alternating stimulation current parameters, obtains a frequency band range supplement interval in a frequency adjustment stage, adjusts stimulation current amplitude value based on a fuzzy control algorithm according to a frequency band range proportion and stimulation sensitivity in an amplitude adjustment stage, and repeatedly and alternately carries out the frequency adjustment stage and the amplitude adjustment stage until the current amplitude threshold of the individual is detected or the upper limit of test time is reached. The present application is suitable for threshold detection under different frequency bands, and the current amplitude change is improved in two aspects of direction and size, which will improve the practicability and accuracy of the detection system.

This invention discloses a method and system for early warning of grounding wire breakage in armored shielded DC cables. The method includes: measuring the grounding current of the shielding layer and the grounding current of the armoring layer at both ends of the armored shielded DC cable; calculating the waveform similarity between the grounding current of the armoring layer and the grounding current of the shielding layer at each end; comprehensively judging whether a grounding wire breakage has occurred at each end based on the current amplitude, waveform similarity, cable operating status, and grounding grid health status; and issuing a corresponding breakage warning signal when a grounding wire breakage occurs. This invention can effectively improve the operation and maintenance level of substation secondary circuits.

A kind of DAS signal adaptive demodulation method and system based on FPGA, wherein, the method comprises: obtaining the in-phase component signal and quadrature component signal of DAS signal;When the address of write pointer occurs incremental change, the historical in-phase component signal and historical quadrature component signal in the preset history sampling window are read;The instantaneous amplitude energy of each time stamp is calculated, and the instantaneous amplitude energy sequence is obtained;The amplitude energy mean and variance eigenvalue of DAS signal are calculated;Adaptive gain factor is generated;The in-phase component signal and quadrature component signal are compensated and iteratively demodulated by adaptive gain, and the phase output value and demodulation module length value are obtained;The module length deviation amount of demodulation module length value and preset standard module length is calculated, and when the cumulative value is greater than preset locking threshold, the correction coefficient is calculated according to the current amplitude energy mean and module length deviation amount;The storage value of index address is updated based on correction coefficient.The application can improve the reliability of DAS system.

This invention proposes a method for detecting the failure of a PV common-mode inductor in an energy storage inverter, a storage medium, and an energy storage inverter. The method includes: acquiring the on / off state of the electronic switches of each PV input branch; determining whether the on / off state of the electronic switches of each PV input branch meets a preset trigger condition, wherein the trigger condition is: only one PV branch in the PV branch group corresponding to the common-mode inductor to be detected is in the active state, and each PV branch corresponding to each non-detected common-mode inductor is in the open state; when the trigger condition is met, detecting the current in any PV branch that is in the open state corresponding to any non-detected common-mode inductor, and calculating the current amplitude; if the current amplitude is greater than a preset threshold, it is determined that the common-mode inductor to be detected has a failure risk. This invention detects cross-branch current crosstalk caused by inductor failure in a multi-PV shared common-mode inductor structure online by detecting the current amplitude, and determines whether the inductor has failed.

This invention describes techniques for a medical device that delivers electrical stimulation using a current or voltage regulator with an adjustable principal amplitude. An exemplary method includes: receiving user input indicating a desired current amplitude via a programmer for an electrical stimulator; and selecting a first fractional adjustment or a second fractional adjustment as a target adjustment for achieving the desired current amplitude. A neural modulation system includes: a first electrode; a second electrode; a stimulation generator configured to deliver a first stimulation pulse to the first electrode and a second stimulation pulse to the second electrode, wherein a first current amplitude of the first stimulation pulse is a first fraction of the principal amplitude and a second current amplitude of the second stimulation pulse is a second fraction of the principal amplitude; and a processor configured to: generate initial instructions for the stimulation generator to perform: (i) deliver the first analog pulse based on the first fraction of the principal amplitude, and (ii) deliver the second stimulation pulse based on the second fraction of the principal amplitude, receiving user input including the desired current amplitude. The processor determines, based on the desired current amplitude, the adjustment of the first current amplitude of the first stimulation pulse to be required, and determines a target adjustment based at least in part on a comparison of the desired current amplitude with the main amplitude, wherein the processor is further configured to: (A) determine an adjustment to at least the first fraction as the target adjustment, or (B) determine the following as the target adjustment: (i) an adjustment to the main amplitude, and (ii) an adjustment to at least the second fraction relative to the main amplitude adjustment, and, based at least in part on the target adjustment, generate adjustment instructions for the stimulation generator to deliver the first stimulation pulse with the desired current amplitude and the second stimulation pulse with approximately the same second current amplitude.

The application relates to the technical field of relay protection, in particular to a large-scale wind farm sending-out transformer excitation inrush current identification method based on high-frequency components and application thereof. When detecting a differential current amplitude greater than a preset threshold, a Park transformation is used to transform a three-phase circuit into a rotating coordinate system, filter out a power frequency part in a steady-state waveform before a fault, make only a harmonic generated by an inrush current contained in a differential current waveform, and take the high-frequency component as a criterion. When the maximum value of the high-frequency component is zero, it is judged that the excitation inrush current occurs. The application aims to solve the problem of how to identify the excitation inrush current phenomenon of the sending-out transformer of the large-scale wind farm.

The application discloses a current fixed value setting method and device and electronic equipment. The method comprises the following steps: determining a set of operation scenarios of a power distribution network, and determining a set of system gears of a flexible interconnected device in the power distribution network; determining the fault current amplitude of a directional overcurrent protection device in the power distribution network under different fault categories according to the set of operation scenarios and the set of system gears; determining the fault current boundary of the directional overcurrent protection device under different fault categories according to the fault current amplitude; and determining the current fixed value corresponding to the directional overcurrent protection device according to the fault current boundary and a preset safety factor. The application solves the technical problem of low reliability of current fixed value setting due to the fact that the directional overcurrent protection setting method in the related art usually determines the fault current boundary based on a single working condition or an experience margin, and does not consider the operation uncertainty of the power distribution network and the flexible interconnected regulation capacity.

This application provides a VSG fault current limiting control strategy based on reactive power deviation integral feedback, including: constructing a reactive power deviation integral feedback control branch between the reactive power droop control output and the voltage command generation in the VSG reactive power loop; determining an integral feedback compensation value based on reactive power deviation control based on the reactive power deviation integral feedback control branch; and limiting the short-circuit current amplitude based on the integral feedback compensation value. The strategy proposed in this application, by introducing reactive power deviation integral feedback compensation control during fault periods, can equivalently adjust the reactive power droop coefficient and voltage command value, effectively reducing the fault current amplitude during fault periods and providing reactive power support for the system.

The present application relates to a kind of low-frequency magnetic field generator for rat electromagnetic experiment and its uniform area measuring method, the method includes the following steps: S1, analysis display terminal calculates the magnetic induction intensity distribution of Helmholtz coil under given condition, and according to the change of magnetic induction intensity relative error determines the uniform area of magnetic field distribution, is recorded as reference area, corresponding boundary is reference boundary;S2, using magnetic field probe coil measures the magnetic induction intensity on reference boundary;S3, least square method is applied to obtain the measured boundary of magnetic field distribution uniform area;S4, according to the average absolute percentage error of magnetic induction intensity at measured boundary and reference boundary determines its actual uniform boundary;S5, analysis display terminal displays the actual uniform area of Helmholtz coil magnetic field distribution under given current amplitude and frequency, for rat electromagnetic experiment.Compared with prior art, the present application has the advantages of obtaining accurate magnetic field uniform area, reducing test workload and the like.

This invention proposes a method and system for diagnosing open-circuit faults in three-phase inverter IGBTs, relating to the technical field of power electronic device fault diagnosis. The method involves lightweight processing of acquired historical data to obtain feature vectors; training a pre-defined three-phase inverter IGBT open-circuit fault diagnosis model based on these feature vectors; real-time acquisition of three-phase current data to be processed, followed by bounded normalization to obtain normalized current amplitudes; and generating IGBT open-circuit fault judgment results based on these normalized current amplitudes. Real-time data related to the three-phase inverter IGBT open-circuit fault is collected based on the IGBT open-circuit fault judgment results, and this real-time data is input into the trained three-phase inverter IGBT open-circuit fault diagnosis model to output the three-phase inverter IGBT open-circuit fault diagnosis results. This invention effectively achieves lightweight, efficient, and accurate diagnosis of three-phase inverter IGBT open-circuit faults.

The application discloses a network-constructing type VSC transient stability analysis method and system considering internal ring dynamic influence, and comprises the following steps: determining the control system of GFM-VSC, determining active power and virtual power angle based on virtual synchronous power outer ring control; determining port node voltage phase and internal potential amplitude based on the active power and virtual power angle; determining the output current amplitude of GFM-VSC based on the internal potential amplitude and virtual power angle; determining whether the saturation link of GFM-VSC is triggered based on the internal potential amplitude and output current amplitude, and determining the saturation link type when it is determined that the saturation link is triggered; and analyzing the transient stability according to the saturation link type.

This invention relates to the field of arc fault detection technology, specifically to an intelligent arc fault detection method and device. The method includes: acquiring electrical data from monitoring points; filtering current and voltage surge peaks based on the amplitude distribution of electrical data in the current and historical periods; constructing a bipartite graph with the current and voltage surge peaks as vertices; using the time interval between the current and voltage surge peaks as a matching weight to match the current and voltage surge peaks, obtaining matching pairs; obtaining the relative standard deviation of the ratio based on the overall distribution characteristics of the voltage amplitude to current amplitude ratio in the matching pairs; obtaining the proportion of isolated current surges based on the proportion of unmatched current surge peaks; and determining the current arc state by combining the relative standard deviation and the proportion of isolated current surges. This invention improves the accuracy of arc fault detection results.

A solenoid system and method can include providing an energizing voltage to a coil of a solenoid, providing an AC signal superimposed on the energizing voltage, detecting a current through the coil that includes an AC current magnitude caused by the AC signal and that includes a DC offset current magnitude, determining, with the control logic, that the AC current magnitude is a low AC current magnitude based on an armature within the solenoid being in a retracted position or that the AC current magnitude is a high AC current magnitude based on the armature being in an extended position, and wherein the AC signal is used for synchronous demodulation to determine the AC current magnitude, and determining a temperature fault based on the DC offset current magnitude falling below a DC offset current magnitude threshold.

A method of estimating a patient's cardiac preload in a patient having an implantable blood pump. The method includes generating a current waveform from operation of the implanted blood pump. A beat-to-beat pump filling index (PFI) is calculated, the PFI is calculated by dividing a current amplitude component by a time component, the amplitude component being calculated by subtracting a trough of the current waveform from an inflection point divided by an amplitude difference of peak to trough of the waveform, the time component being calculated by dividing a time between the trough and the inflection point by a time between the peak and the trough. An alert is generated if the PFI deviates from predetermined thresholds.

This application discloses a fully digital magnetic field measurement device and method, relating to the field of magnetic field measurement technology. The device generates a constant AC-DC superimposed current signal with adjustable frequency and amplitude, and outputs it to a Hall sensor placed in the magnetic field to be measured. It acquires the Hall voltage generated by the Hall sensor and performs analog-to-digital conversion to obtain a digital Hall signal. The digital Hall signal is quadrature demodulated to extract the in-phase and quadrature components. The magnetic field strength amplitude and phase are calculated based on the in-phase and quadrature components. The current is sampled in real time, and a closed-loop control signal is generated based on the deviation between a preset target current value and the actual sampled value to adjust the AC-DC superimposed current amplitude. Through a fully digital signal processing architecture and closed-loop control and output, high-precision, high-speed, and low-noise measurement of magnetic field strength and direction is achieved.

This invention relates to an online detection method and apparatus for stator short-circuit faults in motors under transient operating conditions. The method includes: performing Clark transform on the three-phase currents to obtain α and β two-phase currents; calculating the current amplitude, estimating the fundamental frequency, and determining the target frequency band based on the two-phase currents; constructing two-phase current signals by combining historical data; obtaining new two-phase current signals through fast Fourier transform, Hilbert filtering, bandpass filtering, and inverse fast Fourier transform; extracting the new two-phase currents; calculating the negative sequence current, current amplitude, and short-circuit fault index based on the new two-phase currents; and performing fault early warning processing based on the short-circuit fault index and fault index threshold. This invention can improve the detection sensitivity and reliability of short-circuit fault detection under transient operating conditions.

The application discloses a full-order terminal sliding mode control method for a brushless doubly-fed motor independent power generation system, and belongs to the field of motor control. The application solves the problem that the traditional full-order terminal sliding mode control algorithm does not simultaneously consider the matching and non-matching uncertainty caused by motor parameter perturbation in the motor model, resulting in low system output voltage precision, poor system anti-interference ability and control effect. According to the brushless doubly-fed motor mathematical model, the application considers the matching and non-matching uncertainty caused by brushless doubly-fed motor parameter perturbation, determines the voltage loop state equation of the non-matching power winding outer ring voltage subsystem and the current loop state equation of the matching control winding inner ring current subsystem, and designs corresponding inner and outer loop full-order terminal sliding mode controllers for the subsystems to compensate the uncertainty, so that the tracking error of the power winding voltage amplitude converges to zero, and the tracking error of the control winding current amplitude converges to zero. The application is mainly suitable for independent power generation control when the brushless doubly-fed motor is connected to a balanced load.

This invention provides a method and system for rapid short-circuit current identification and alarm for feeder terminals, relating to the field of cable line monitoring technology. The method includes: real-time acquisition of instantaneous sampled data of the feeder current, calculation of the current amplitude change rate, phasor extraction, calculation of the current phase value, construction of a phase transient characteristic quantity using the phase difference of continuous time sampling points, coupling analysis of the first-order amplitude change quantity and the phase transient characteristic quantity to construct a short-circuit characteristic coupling indicator, triggering an abnormal reporting command for a short-circuit event when the short-circuit characteristic coupling indicator exceeds a preset coupling threshold, determining the rapid alarm level of the short-circuit event based on the trigger time and the duration of the phase transient characteristic quantity, and issuing alarm information to the main station. This solves the technical problem of low accuracy and reliability in short-circuit current identification of feeder terminals in existing technologies. It achieves rapid identification and alarm of short-circuit current events in feeder terminals while improving the accuracy and reliability of the identification.

The application discloses an automatic door opening and closing control method of a household appliance. The automatic door opening and closing control method of the household appliance comprises the following steps: S10, obtaining a user instruction, wherein the user instruction comprises adjusting an opening amplitude of a door body to a target amplitude R0; S30, obtaining a current amplitude R of the door body; S50, comparing the current amplitude R with the target amplitude R0; when the comparison result is that the current amplitude R does not reach the target amplitude R0, controlling a moving part to move for a first set time, and then returning to step S30; when the comparison result is that the current amplitude R reaches the target amplitude R0, turning to step S70; and S70, after determining that an opening and closing device is in a corresponding state, adjusting is ended. The automatic door opening and closing control method of the household appliance can automatically control the door body to reach a required opening amplitude.

This invention relates to the field of power grid topology identification technology, and proposes an automatic topology identification method and system for low-voltage distribution networks. The method includes: injecting three characteristic currents of preset current amplitudes into the low-voltage distribution network at preset injection intervals; collecting power data of nodes during the injection process; calculating the second correlation, fidelity stability, and noise stability of the nodes; establishing potential parent-child node pairs; calculating the probability of actual node pairs for each potential parent-child node pair; screening actual parent-child node pairs; and combining the power data of the two nodes in each actual parent-child node pair to identify the topological relationship of the low-voltage distribution network. This invention can accurately identify the topological relationship of low-voltage distribution networks.

This application discloses a method, apparatus, equipment, and medium for testing the polarity of differential protection current transformers (CTs) in transformers, relating to the field of power system relay protection. The method includes: electrically connecting the high-voltage side and low-voltage side of the transformer under test to a cooperating transformer; fixing the tap position of one of the two transformers and adjusting the on-load tap changer of the other transformer to create a turns ratio difference between the two transformers; using the reactive power circulating current formed within the two transformers by the turns ratio difference as the test current, controlling the secondary current amplitude of the current transformers on each side of the transformer under test to meet the set current range required for the test; and performing a differential protection current transformer (CT) polarity test on the transformer under test based on the secondary current amplitude that meets the test requirements. This method can efficiently complete the polarity verification of the differential protection current transformers of newly commissioned transformers without interrupting the operation of other equipment in the substation, significantly improving the accuracy of the test.

The application discloses a kind of transformer fault ride-through control method, system, equipment and medium, belong to the technical field of fault ride-through control, method includes: obtaining grid-connected voltage constructs observation model and solves stable phase;Multi-dimensional constraint model is constructed, locks amplitude when overcurrent and anchors phase, simultaneously triggers integral freezing mechanism.System includes state observation module, phase solving module, constraint model configuration module, instruction generation module, collaborative control module.The application constructs virtual magnetic flux observation model, uses integral filtering characteristic to filter out noise and analyzes high robustness synchronous phase;Combined with multi-dimensional constraint control model, lock current amplitude under current limiting condition and force anchor phase, simultaneously trigger integral freezing mechanism to block error accumulation.Thereby effectively solve the problem of transient synchronization instability, inhibit the control signal dithering, and eliminate the oscillation phenomenon in fault recovery period.

The application relates to an optical path difference calculation method and device of a convolution acceleration system, equipment and a storage medium, comprising the following steps: acquiring a first current amplitude output by a real convolution acceleration system in a state where the optical path difference of two light paths is not 0, the real convolution acceleration system realizing convolution acceleration through an IQ modulator, a frequency mixer and a balanced detector; acquiring a theoretical current amplitude output by a simulation convolution acceleration system with the same structure as the real convolution acceleration system in a state where the optical path difference of two light paths is 0; based on the corresponding waveform similar state between the first current amplitude and the theoretical current amplitude, adjusting the optical path in the simulation convolution acceleration system to different degrees to update the theoretical current amplitude until a second current amplitude with a minimum difference value is obtained; and taking the optical path difference corresponding to the second current amplitude as the actual optical path difference existing in the real convolution acceleration system, so that the real convolution acceleration system can accurately complete convolution calculation.

The application discloses an AC solid-state circuit breaker adaptive turn-off method and system, the core of the method is to construct a two-dimensional phase space geometric evolution manifold according to the current amplitude sequence of the fault current and the hardware differential rate signal, realize geometric extrapolation of the short-circuit current peak value containing the non-periodic component through the trajectory curvature characteristics; combined with the cumulative equivalent operation times, the radiator temperature and the standing time and other physical state parameters, input them into the endogenous physical information neural network model, define the safe operation interval with physical certainty by using the hard-coded embedded Cauer thermal network operator; and in the interval, an analytical projection algorithm based on stress cost manifold is adopted to execute constant level optimization of the optimal turn-off time by using the control barrier function. The application can effectively solve the distortion problem of the traditional model under the magnetic saturation working condition and the uncertainty of the soft constraint prediction, while ensuring the breaking reliability, significantly reducing the online calculation complexity.

The application provides a DC micro-grid source-side converter control parameter design method and device considering current amplitude limiting. The method comprises the following steps: obtaining circuit parameters of a DC micro-grid, sudden power of a constant power load and current amplitude limiting threshold of a source-side converter; establishing a bus voltage transient response model under load sudden change considering current saturation nonlinear characteristics; based on the model and second-order system equivalence, deducing an analytical relationship between bus voltage transient drop amplitude and source-side converter voltage outer loop control bandwidth and bus capacitance; taking that bus voltage does not collapse as a constraint condition, combining the analytical relationship with the current amplitude limiting threshold, calculating a feasible region of control parameters and circuit parameters meeting system large signal stability; and performing quantitative parameter design or checking on the source-side converter according to the parameter feasible region. The application provides a design-oriented analytical criterion, effectively avoids bus voltage collapse caused by current amplitude limiting, and improves operation stability of the DC micro-grid under large disturbance working conditions.

This application discloses a battery heating method, apparatus, and storage medium. When battery heating is required and the motor is stationary, this application enables the application of a current in a specific direction through the two windings of the motor. This cancels out the torques generated by the two windings, keeping the motor stationary, and simultaneously cancels out the magnetic fields generated by the two windings. This allows for an increase in the current amplitude of the two windings without being limited by torque or demagnetization, utilizing the heat loss generated by the increased current to heat the battery. Therefore, this application solves the problem of permanent magnet demagnetization caused by the reverse magnetic field generated by a large current along the d-axis in related technologies, achieving a safe and efficient battery heating effect.

The application provides a distributed power balancing and voltage regulating method for a current control type converter cluster. The method belongs to the field of micro-grid control, and is based on reactive voltage droop and voltage amplitude control to generate a reference current amplitude of the parallel converter, so that each parallel converter outputs the same current amplitude; meanwhile, the phase of the current vector is determined by four-quadrant power factor control, so as to ensure that the output currents among the parallel converters are in the same phase state, and the load side currents are effectively superimposed and the maximum load current is obtained. In view of the harmonic problem caused by the access of a nonlinear load, the application further adopts harmonic virtual impedance control at a fundamental frequency and selected harmonic frequencies, and combines with the multi-resonance controller adjustment of the current loop to effectively reduce the amplitude of the equivalent harmonic impedance of the DG unit, so that the harmonic circulating current among the DGs is minimized, and the power quality at the point of common coupling (PCC) is improved.

This invention discloses a method for identifying abnormal sampled value data in bus current differential protection, belonging to the field of current abnormal sampled value data identification. It includes three symmetrical component scoring systems (positive-sequence, negative-sequence, and zero-sequence components) and one abnormal sampled data analysis system. The symmetrical component scoring system scores the sampled current amplitude of the bus branch based on its transient and steady-state characteristics and outputs corresponding feature values. The abnormal sampled data analysis system makes a final judgment on whether the sampled current value of the bus differential protection is normal or not based on the output of the symmetrical component scoring system. This invention utilizes the symmetrical component characteristics of the bus branch current to identify abnormal sampled data, and has the advantages of simple implementation, fast identification speed, and high reliability.