108 results about "Total impedance" patented technology

The invention belongs to the technical field of energy storage system state monitoring, and provides a lithium ion energy storage system abnormal state identification method and system based on impedance spectrum analysis, and the method comprises the steps: carrying out the decoupling of voltage response data and current response data through employing an excitation-response decoupling algorithm under a dynamic working condition, and obtaining an impedance spectrum; obtaining a voltage response component and a current response component; obtaining the total impedance spectrum of the lithium ion energy storage system under the current working condition; constructing a system-level impedance cloud picture; calculating a difference value between the current impedance spectrum and the weighted moving average baseline spectrum based on the system-level impedance cloud atlas to obtain an enhanced difference cloud atlas; and performing non-uniform segmentation and feature extraction on the enhanced difference cloud picture by using a visual Transform model oriented to electrochemical prior to obtain a multi-dimensional abnormal probability vector, and obtaining an abnormal state type of the lithium ion energy storage system based on the multi-dimensional abnormal probability vector. According to the technical scheme, the accuracy, timeliness and reliability of abnormal state recognition of the energy storage system are remarkably improved.

The invention discloses a high-voltage direct-current cable electromagnetic transient frequency domain modeling and time domain solving method, system, medium and equipment, and the method comprises the steps: obtaining an initialization parameter of a high-voltage direct-current cable, calculating an internal impedance matrix [Zi] of a multi-layer cross-section cable body during frequency calculation, and calculating an admittance coefficient matrix of the multi-layer cross-section cable body during frequency calculation; calculating ground loop impedance [] and potential coefficient [] of the air laying cable or the direct burial laying cable, and obtaining a total impedance matrix [] and a total admittance matrix [] of the cable at the time of frequency: importing obtained multi-frequency [] and [] calculation results into a PSCAD TLine module, and realizing time domain solution of frequency domain calculation by using a vector fitting model.

The invention discloses a resonance suppression method of a centralized new energy grid-connected system, solves the problem of resonance instability of the centralized new energy grid-connected system, and belongs to the technical field of new energy power generation and power grids. According to the method, the power grid impedance and the total output impedance of the new energy grid-connected converter are identified on line, the system resonant frequency and the grid-connected point voltage resonant component are extracted through the impedance identification result, the virtual impedance needing to be compensated is dynamically adjusted based on the adaptive virtual impedance algorithm, and the calculation result is sent to a control loop of the new energy grid-connected converter. A resonance suppression method based on virtual impedance compensation is utilized to remodel output impedance of a grid-connected converter at a resonance frequency band so as to suppress a resonance phenomenon, normal power output of a new energy grid-connected system is ensured, meanwhile, a wide-frequency-domain resonance suppression function is achieved, and an economical and feasible control scheme is provided for safe and stable grid connection of centralized new energy.

The invention relates to the technical field of battery self-discharge testing, in particular to a zero-impedance-based battery self-discharge testing device and a zero-impedance-based battery self-discharge testing method. The battery self-discharge testing device comprises a connector module; the current detection unit comprises a sampling resistor Rsense and a differential amplification circuit, and the sampling resistor Rsense is connected in series in a current input loop; the differential amplification circuit is in bridge connection with the two ends of the Rsense of the sampling resistor and outputs a voltage signal proportional to the self-discharge current Idischarge current; the input end of the voltage detection unit is connected with the four-wire system voltage test terminal, and the open-circuit voltage VOCV of the battery to be tested is sampled in real time; the controllable voltage source module is used for outputting a dynamic compensation voltage Vapplied which is equal to the sum of VOCV and Idischarg * Rcircit, wherein the Vapplied is equal to VOCV + Idischarg * Rcircit; the controller module is used for calculating the real-time voltage drop of the total impedance Rcircuit of the circuit based on the VOCV and the Idischarge, and dynamically adjusting the output of the controllable voltage source, so that the terminal voltage of the battery to be detected is locked as the VOCV; and when the terminal voltage of the to-be-detected battery is stabilized within the range of VOCV + / -0.0001%, determining that the to-be-detected battery enters a constant potential mode, and continuously recording the current value until the current value is stable.

The invention provides a logic control-based self-adaptive optocoupler compensation circuit and a switching power supply. The logic control-based self-adaptive optocoupler compensation circuit comprises a first operational amplifier circuit, a second operational amplifier circuit, a third operational amplifier circuit and a fourth operational amplifier circuit, the switching tube circuit is used for switching on or switching off a corresponding switching tube according to the level signal to match impedance access of a corresponding size; the output end of the impedance matching circuit is connected with the first input end of the photoelectric coupler, the second input end of the photoelectric coupler is connected with the output end of the feedback compensation circuit, and the current of the input end of the photoelectric coupler and the total impedance of the self-adaptive feedback compensation loop are adjusted by automatically matching different impedances. Therefore, automatic switching of different gain and bandwidth working modes of the photoelectric coupler under wide-range output is realized. According to the invention, the working current of the optocoupler is adaptively switched through the logic control circuit, and the compensation parameter of the feedback loop is dynamically optimized, so that the switching power supply can achieve the effect of high stability under the working condition of full-range output adjustment.

The invention discloses a resistor matching structure, a chip, an optical device and an optical module, and belongs to the technical field of electronics. The resistor matching structure comprises a plurality of strip-shaped resistors and a conductive structure, wherein the ends, close to the conductive structure, of the strip-shaped resistors are connected with the conductive structure, the ends, away from the conductive structure, of the strip-shaped resistors are used for being connected with the strip-shaped conductors, and the multiple strip-shaped resistors are jointly used for being connected with the multiple strip-shaped conductors; at least one resistor pair exists in the plurality of strip-shaped resistors, each resistor pair comprises two adjacent strip-shaped resistors which can be mutually inducted, and strip-shaped conductors connected with the two strip-shaped resistors have different potentials. In order to realize resistance matching, the total impedance of the plurality of strip-shaped resistors is equal to the total characteristic impedance of the plurality of strip-shaped conductors. According to the modulator, the problem that the modulated optical signal is affected by the reflected electric signal in the modulator, and the optical signal is degraded can be solved. The application is used for resistance matching.

The invention relates to the field of battery performance monitoring and early warning, in particular to a solid-state battery interface impedance monitoring and life early warning system which comprises a signal acquisition module, an impedance analysis module, a life prediction module and an early warning module. The signal acquisition module acquires interface impedance, temperature, pressure and electrochemical data of the solid-state battery in real time; the impedance analysis module analyzes, decouples and quantifies contribution values of the positive electrode interface, the negative electrode interface and the electrolyte body to the total impedance through relaxation time distribution (DRT); the life prediction module carries out parameter identification by adopting an improved adaptive genetic algorithm based on a contribution value and a multi-parameter collaborative optimization model of temperature, pressure, charge-discharge rate and the like, and predicts the residual life; and the early warning module generates an early warning signal when the residual life is lower than the threshold value or the contribution value is abnormal. Decoupling of the interface impedance and prediction of the service life are achieved, and the reliability and safety of solid-state battery management are effectively improved.

The invention relates to a design method of a zero sequence current transformer, and belongs to the technical field of transformers. According to the technical scheme, the method comprises the steps that the number of turns N2 of a secondary winding, load impedance Z2n, the total impedance Z2 of a secondary loop, a power factor angle phi 2 of the secondary loop, excitation impedance Z0 and an iron core loss angle theta are calculated, then known primary current I1 and the number of turns N1 of the primary winding are substituted into a formula, the secondary output voltage U2 can be calculated, and if U2 is not within the error range of the rated secondary output voltage U2n, the load impedance Z2n and the total impedance Z2 of the secondary loop are calculated. And all parameters need to be adjusted for recalculation, so that the error requirements are finally met. According to the design method, design errors possibly occurring in conventional current transformer error calculation are avoided. The cost can be reduced, and the performance requirement can be met when the structure is limited.

This invention belongs to the field of inverter control technology and provides a method for adaptive virtual impedance adjustment of parallel inverters with droop control. The method comprises: each parallel inverter increases its virtual impedance value at the same time and with the same adjustment step size by receiving a synchronous trigger signal instruction; then, the virtual impedance adjustment direction is determined based on the reactive power variation trend, and the virtual impedance value is adjusted accordingly, so that the reactive power distribution of each inverter tends to be equal as the total impedance approaches. Compared with existing adjustment methods for line impedance mismatch, the proposed solution does not require PCC point voltage measurement and has lower communication bandwidth requirements for the parallel system.

The present disclosure is directed to charging a battery pack by measuring an electrical impedance value of a battery pack by applying a sinusoidal AC excitation signal to a plurality of battery cells of the battery pack, measuring a total impedance value of the battery pack, obtaining a chemical impedance value of the battery pack based on the electrical impedance value and the total impedance value, and adjusting a charge current applied to the battery pack based on the chemical impedance value of the battery pack.

A connector structure for improving crosstalk is disclosed. The connector structure has a base, a first ground connecting sheet, and a second ground connecting sheet. The base includes a first terminal group and a second terminal group. The first ground connecting sheet is disposed within the base and connected to first ground terminals of the first terminal group. The second ground connecting sheet is disposed within the base and connected to second ground terminals of the second terminal group. A gap is disposed between the first ground connecting sheet and the second ground connecting sheet so as to prevent them from conducting with each other. Thus, the first terminal group and the first ground connecting sheet form an independent conducting route while the second terminal group and the second ground connecting sheet form another independent conducting route. Consequently, the overall impedance path of the connector structure can be reduced such that signal decay and crosstalk could be effectively improved during high frequency transmissions.

The invention belongs to the technical field of power system calculation, and discloses a distribution network short-circuit distance calculation system based on a mobile terminal, which is based on uniapp cross-terminal development framework construction, and integrates three core function modules of transformer substation bus impedance management, wire parameter management and short-circuit distance formula calculation. According to the method, basic parameters such as transformer substation bus voltage, maximum / minimum mode total impedance and the like and impedance data of wires of different models are stored in a structured mode, and a preset short-circuit distance calculation formula is combined, so that rapid calculation of the short-circuit distance and the number of corresponding towers is automatically completed after the basic parameters are input. The invention further discloses a calculation method. The problems that a traditional distribution network short-circuit distance calculation process is tedious, errors are prone to occurring, and data management is scattered are solved, the method has the advantages of being convenient and fast to operate, efficient in calculation, capable of achieving data localization storage and flexible expansion, and the method is suitable for electric power operation and maintenance personnel to rapidly carry out short-circuit distance calculation work on site.

The invention relates to a wireless power supply system mutual inductance and load identification method based on direct current information detection, and the method comprises the steps: constructing a series circuit model based on energy negative feedback WPT, and extracting the primary side data of the series circuit model; according to the primary side data, obtaining the total impedance of a real part and the total impedance of an imaginary part; and obtaining a mutual inductance value and a load resistance value based on the real part total impedance and the imaginary part total impedance. The coupling coefficient and the load can be estimated in real time by measuring the direct current component of the input current and the values of the input square wave voltage and the detuning correction voltage.

The utility model discloses a biasing circuit, a biasing chip and a biasing device, which relate to the technical field of integrated circuits and comprise a first capacitor, a second capacitor, an inductor and a resistor, the first end of the first capacitor is connected with the first end of the inductor and serves as the input end of the biasing circuit, and the second end of the first capacitor serves as the output end of the biasing circuit; the first end of the resistor is connected with the first end of the inductor, the second end of the resistor is connected with the first end of the second capacitor and serves as the input end of the direct current bias power supply, and the second end of the second capacitor is grounded. According to the bias circuit, the resistor is additionally arranged and connected with the inductor in series, namely, under the condition that the small inductor is used, the total impedance of the direct current branch is increased, the insertion loss is reduced, and the requirements of small size, high bandwidth and small insertion loss of a bias chip are met. And a second capacitor is led out from the direct current branch to lead out a leaked alternating current signal, so that the alternating current signal is better prevented from being leaked to the direct current bias power supply.

The application provides a parallel cavity shared radio frequency power supply system and a radio frequency adjusting method for a plasma process, which comprises the following steps: collecting the ground potential of the cavity wall of each parallel process cavity in real time through a detection and adjusting module, dynamically adjusting the ground impedance of each radio frequency coil, and balancing the total ground impedance of each branch; then, completing independent dynamic impedance matching of each branch by a matching module, eliminating the power distribution imbalance problem caused by the inconsistent impedance of each radio frequency coil, keeping the plasma discharge state of the multiple cavities consistent, improving the process uniformity of each cavity, and greatly reducing the equipment cost by using only one radio frequency power supply.

A stability evaluation method based on a common-bus DC interconnection system belongs to the technical field of DC interconnection system stability determination, and comprises the following steps: step 1, constructing an input impedance model and a transmission line impedance model of a voltage and current double-loop constant power regulation module; step 2, establishing a common bus direct current network impedance comprehensive model containing a load line; and 3, analyzing the mutual relation between the output impedance ZLRC (s) of the multi-machine DC voltage regulation module and the load input total impedance ZPOL (s) to judge the stable state of the system. The method is suitable for the direct current interconnection system, and can effectively prevent the stability problem possibly caused by the constant power module during the bus integration of the direct current system.

The invention relates to the technical field of new energy station control, in particular to a new energy station cluster broadband oscillation monitoring control method and device. The method comprises the following steps: synchronizing a clock signal in a new energy station cluster based on a satellite synchronous clock signal; a master-slave distributed architecture is constructed for each station, and each slave processes the acquired sampling data to acquire the oscillation power and frequency of the corresponding branch and sends the processed and acquired data to the corresponding host; processing the acquired data by each host, and judging whether the broadband oscillation power component of each slave reaches a corresponding preset threshold value or not; if so, measuring the impedance of a branch corresponding to the target slave under the broadband oscillation frequency in real time, and calculating the total impedance of a corresponding target system; and based on the total impedance of the target system, performing stable control on the corresponding branch through a hierarchical generator tripping control strategy. According to the invention, wide-area synchronous sampling is realized by relying on a Beidou satellite synchronous clock, and suppression of broadband oscillation of the new energy station cluster is realized by grading with the minimum removal amount.

The present invention discloses an electronic paper and its driving module, comprising: a main driving port for outputting a periodic voltage sequence; a parallel branch group comprising n branches, one end of each branch being connected to the main driving port and the other end being connected to the cholesteric liquid crystal layer of the electronic paper module via an AC common-level wiring; an adjustment resistor unit comprising m groups of adjustment resistors, one group of adjustment resistors being connected in series between any two of the n branches, where n ≥ 4 and m ≥ 2; and an impedance balancing logic unit for configuring the resistance values ​​of the m groups of adjustment resistors according to the wiring resistance values ​​of each branch, so that the total impedance of all branches is equal. The electronic paper driving module of the present application compensates for the uneven current distribution caused by the wiring resistance differences by connecting differentiated adjustment resistors in series in different branches, making the total impedance of all branches equal, thereby balancing the charge and discharge currents and avoiding the problem of device burning caused by local overcurrent in high-temperature environments.

The invention discloses a self-synchronizing voltage source control method based on damping and droop coefficient independent adjustment, and belongs to the field of new energy power generation. The control method comprises the steps that an active-frequency droop coefficient m and a virtual damping coefficient D are designed, so that the steady-state active power is only determined by m, and independent adjustment of m and D is achieved; and generating a terminal voltage amplitude instruction through the reactive power-voltage droop coefficient n, the reactive power deviation delta Q and the output voltage zero-sequence component u0 to realize reactive power-voltage droop control. And the reactive power-voltage droop coefficient n independently adjusts the dynamic response of the reactive power and the voltage amplitude, and does not influence the steady-state characteristic of active power-frequency droop control. Compared with the prior art, only the network side voltage needs to be sampled, the hardware cost is saved, and grid-connected pre-synchronization can be achieved without obtaining the total impedance on the line.

The invention discloses a converter station short-circuit current collaborative suppression method and system, terminal equipment and a storage medium. The method comprises the following steps: acquiring node short-circuit current of a to-be-tested flexible direct-current back-to-back converter station; constructing a short-circuit current loop model of the to-be-tested flexible direct current back-to-back converter station based on the electromagnetic transient simulation model and the node short-circuit current; selecting a target node from each converter station node based on the simulation configuration data, the fault working condition data and the short-circuit current loop model; performing impedance acquisition processing on the converter station nodes to obtain initial total impedance of the target nodes; performing impedance acquisition processing on the to-be-introduced node set and the converter station nodes to obtain a to-be-updated total impedance set of the target node; and selecting a target to-be-introduced node from the to-be-introduced node set based on the initial total impedance and the to-be-updated total impedance set, enabling the target to-be-introduced node to be connected with the target node, and carrying out short-circuit current suppression on the to-be-tested flexible direct current back-to-back converter station so as to suppress the excessive short-circuit current of the flexible direct current back-to-back converter station and improve the reliability.

This application proposes a method and system for determining overvoltage and overcurrent based on phase-to-phase grounding faults. The method includes: determining the maximum value of the negative-sequence fault current and the maximum value of the voltage of the non-faulty phase corresponding to the total impedance, positive-sequence voltage, and AC positive-sequence current of the system when a phase-to-phase grounding fault occurs; using the maximum value of the negative-sequence fault current as the negative-sequence overcurrent when a phase-to-phase grounding fault occurs, and using the maximum value of the voltage of the non-faulty phase as the overvoltage when a phase-to-phase grounding fault occurs in the wind power transmission system via flexible direct current transmission. The technical solution proposed in this application can accurately determine the negative-sequence overcurrent and overvoltage values ​​when a phase-to-phase grounding fault occurs in the wind power transmission system via flexible direct current transmission based on the total impedance, positive-sequence voltage, and AC positive-sequence current of the system, and control the stable operation of the wind power transmission system via flexible direct current transmission based on the determined negative-sequence overcurrent and overvoltage values.

The invention relates to the technical field of grid-connected inverters, in particular to a method for correcting positive virtual impedance of an LCL type inverter in a Nyquist frequency, which comprises the following steps of: accurately determining parameters of capacitor voltage feedback branches in an LCL filter, establishing an equivalent formula of virtual impedance, and adjusting parameters in primary differential feedback so as to correct the positive virtual impedance of the LCL type inverter in the Nyquist frequency. The method successfully widens the positive damping frequency range, optimizes the impedance characteristics of the inverter through the virtual impedance of the parallel proportional term, the primary differential term and the secondary differential term and the calculation of the total parallel impedance formula, and obtains the impedance characteristics of the inverter by drawing various impedance-frequency curves. Comprising a virtual impedance-frequency curve, a parallel impedance-frequency curve and a primary differential impedance-frequency curve, and an intuitive impedance characteristic analysis tool is provided for a system designer and an engineer; and finally, by drawing a total impedance-frequency curve and verifying whether the system maintains the positive resistance characteristic in the Nyquist frequency range, the stability of the system is ensured.

The present disclosure is directed to charging a battery pack by measuring an electrical impedance value of a battery pack by applying a sinusoidal AC excitation signal to a plurality of battery cells of the battery pack, measuring a total impedance value of the battery pack, obtaining a chemical impedance value of the battery pack based on the electrical impedance value and the total impedance value, and adjusting a charge current applied to the battery pack based on the chemical impedance value of the battery pack.

The subject matter of the invention is end-expiratory detection using impedance measurements. The present disclosure provides a method that includes measuring body impedance as a function of time using a plurality of electrodes attached to a patient. A total impedance value is calculated as a function of time from the measured impedance. A temporal minimum of the total impedance value is associated with a timing of end expiration of the patient.

The utility model belongs to the field of high-voltage switch temperature rise tests, and discloses a current regulating system for a high-voltage switch temperature rise test, a power supply device is sequentially connected with a voltage regulator, a reactance load unit and a current booster, the other end of the current booster is connected with a high-voltage switch to be tested, and two ends of the reactance load unit are connected with a short-circuit switch in parallel; due to the introduction of the reactance load unit, the total load of the system is increased when the load is small, the regulation of the voltage regulator is more stable, the output current of the large current generator is closer to the designed operation point, and the stability of the test current is obviously improved; when large current output is needed, the short circuit switch can bypass the reactance load unit to reduce the total impedance of the system, and the system can still keep efficient output. According to the system, through dynamic access or short circuit of the reactance load, the effective regulation range of the voltage regulator is expanded, the current regulation speed is reduced by utilizing the characteristics of the inductance load, stable current output is realized, the test precision is improved, good adaptability and controllability are achieved, and the temperature rise test requirements of switch equipment with different capacities are met.

The invention relates to a battery performance prediction method and system based on impedance spectroscopy analysis. The method comprises the steps of obtaining frequency, an impedance real part and an impedance imaginary part in impedance data of a to-be-detected battery to form an input array; defining element types and parameters in a battery circuit, generating possible impedance values of each element according to an input array, and storing the impedance values in a one-dimensional array Zp; traversing the value conditions of all possible impedances of each position element in the array Zp, comparing the calculated total impedance real part and imaginary part with the measured impedance data simulation value and sample value to obtain the corresponding error of the simulation value and the sample value, summing to obtain the total error, comparing the total error with the minimum error, and updating the total error to obtain the impedance data. Determining an element parameter combination configured by the current circuit, generating an array M containing a set number of elements by combining element types and parameter values, and generating an equivalent circuit diagram according to the element types and the parameter values in the array M; and performance prediction is realized by combining element types and parameter values in the array M with the trained computer model.

To provide a tuning-fork type crystal vibration piece and a resonator that avoid transmission of energy to a ceramic base and further evade too large total impedance of a device due to vibration leakage.SOLUTION: A turning-fork type crystal vibration piece that includes a crystal vibration piece body 1 and is provided with an energy shunt block 2 protruding outward in an energy transmission path of the crystal vibration piece body 1, is provided additionally with an energy shunt block 2 which protrudes outward at a turning fork fixed block, and when the crystal vibration piece is packaged and fixed to a ceramic base, the energy of the fork is not transmitted downward to a dispensing position of the fixed block, but effectively limited to the domain of the energy shunt block 2.SELECTED DRAWING: Figure 3

A parametric traveling wave amplifier (200) is disclosed in which the amplifiers include: a co-planar waveguide, in which the co-planar waveguide includes at least one Josephson junction (210) interrupting a center trace (204) of the co-planar waveguide; and at least one shunt capacitor coupled to the co-planar waveguide, in which each shunt capacitor of the at least one shunt capacitor includes a corresponding superconductor trace (214) extending over an upper surface of the center trace of the co-planar waveguide, and in which a gap separates the superconductor trace from the upper surface of the center trace, and in which the co-planar waveguide including the at least one Josephson junction and the shunt capacitor establish a predefined overall impedance for the traveling wave parametric amplifier.

The application provides a non-contact ECG signal collection foot ring sensor, which comprises a foot ring body and an ECG signal sensor arranged on the foot ring body, wherein the ECG signal sensor comprises an electrode composite layer, a first insulating layer, an electromagnetic shielding layer and a second insulating layer arranged in sequence, the electrode composite layer comprises a first electrode, a second electrode and a polarity layer arranged between the first electrode and the second electrode, the polarity layer comprises a polarity material of barium titanate and / or calcium titanate, the first electrode is used for being connected to an ECG collection circuit, the second electrode is arranged in suspension, and the electromagnetic shielding layer is grounded. The foot ring sensor of the application comprises the electrode composite layer, the electrode composite layer contains the polarity material of barium titanate and / or calcium titanate with high dielectric constant, and thus has high dielectric performance, can effectively improve the coupling capacitance between the skin and the electrode, and further reduce the capacitive reactance and total impedance, reduce the attenuation degree of the ECG signal in the coupling process, and improve the electric signal detection effect.

The invention discloses a wave trapper design method and system for partial discharge detection, and a medium. The method comprises the following steps: constructing a total impedance model for a wave trapper; determining the center frequency f0 of the blocking frequency band of the wave trapper according to the two boundary frequencies required to be blocked by the wave trapper, and constructing a function model of the blocking frequency band width of the wave trapper by combining the offset of the boundary frequencies; solving a function model of the blocking frequency band width of the wave trapper according to the total impedance model to obtain the blocking frequency band width of the wave trapper considering the offset; and calculating element parameters in the wave trapper according to the blocking frequency band width of the wave trapper considering the misalignment amount. According to the method, the detuning amount of the blocking boundary frequency required by the wave trapper is considered, the wave trapping effect of the designed wave trapper near the boundary frequency can meet the design expectation, and the method can be applied to a partial discharge detection scene with strict requirements on the wave trapping performance.