16 results about "Nyquist plot" patented technology

The invention relates to the technical field of power systems, and discloses a multi-level direct current sending end small disturbance stability assessment method, device and equipment and a medium. Carrying out frequency domain impedance modeling on the following network type new energy converter, the constructed network type energy storage converter, the following network type load converter and the modularized multi-level high-voltage direct current converter station, and constructing a frequency domain impedance network of the all-electric system based on an equivalent impedance model of each device; and performing small disturbance stability analysis on the frequency domain impedance network by using a generalized Nyquist stability criterion, and determining the small disturbance stability of the all-electric system in an alternating current and direct current hybrid scene through a Nyquist diagram of impedance ratios of two sides of a voltage source and a current source in the frequency domain impedance network. Therefore, an effective evaluation means is provided for stable operation of the alternating-current and direct-current series-parallel all-electric system.

The invention discloses a battery diagnosis method based on an electrochemical impedance spectroscopy, and the method comprises the following steps: 1, applying a disturbance current to a target battery, and collecting an AC voltage generated by the disturbance current; step 2, an impedance parameter is calculated based on a digital phase-locked amplification algorithm, and the calculation of the impedance parameter meets the following conditions: impedance, alternating voltage processed by a digital phase-locked amplifier and disturbance current; step 3, constructing an EIS fingerprint of the target battery, wherein the EIS fingerprint is generated based on the Nyquist diagram feature of the impedance parameter; and 4, evaluating the state of the target battery by using the EIS fingerprint, wherein the state comprises a state of charge, a state of health and a fault risk. The method evaluates the state of charge and the state of health of the battery based on the EIS fingerprint, and has the advantage of accurate evaluation result.

The purpose of the present invention is to provide a technique capable of accurately and quickly diagnosing the state of a battery without pre-storing measurement data. This battery diagnostic device determines a first frequency at which a component caused by diffusion resistance of an equivalent circuit of a battery begins to appear in a Nyquist map of the battery, and determines a second frequency at which a phase of the voltage and a phase of the current coincide with each other in phase frequency characteristics of the voltage and the current. The state of the battery is diagnosed using a real part of each of the first impedance of the battery at the first frequency and the second impedance of the battery at the second frequency (fig. 8).

To provide an electrochromic sheet, a laminate, a lens for spectacles, and spectacles capable of rapid color development. [Solution] An EC sheet comprising a first substrate, a second substrate, an EC element, and a sealing portion, wherein the EC element has a first transparent electrode, a second transparent electrode, and an EC layer, and the visible light transmittance of the EC sheet changes within a range including 30% upon application of a voltage, and the impedance of the EC sheet is measured under the following measurement conditions, and the internal resistance per unit area calculated from the obtained Nyquist diagram using the following formula (1) is 250 Ω / cm. 2 Below is the electrochromic sheet. Internal resistance = Resistor 1 + (Resistor 2 - Resistor 1) x 2…(1) (Resistance 1 is the value at the intersection of the horizontal axis of the Nyquist diagram and the graph of the Nyquist diagram. Resistor 2 is the real component of the point where the imaginary component of the graph is maximum in the low frequency region of the graph)

Providing electrochromic sheets, laminates, eyeglass lenses, and eyeglasses that enable rapid color development. [Solution] An EC sheet comprising a first substrate, a second substrate, an EC element, and a sealing portion, wherein the EC element has a first transparent electrode, a second transparent electrode, and an EC layer, and the visible light transmittance of the EC sheet changes within a range including 30% when a voltage is applied, and the impedance of the EC sheet is measured under the following measurement conditions, and the internal resistance per unit area obtained from the obtained Nyquist diagram using the following formula (1) is 250 Ω / cm². 2 The following is an electrochromic sheet. Internal resistance = Resistance 1 + (Resistance 2 - Resistance 1) × 2 ... (1) (Resistance 1 is the value at the intersection of the horizontal axis of the Nyquist plot and the graph of the Nyquist plot.) Resistor 2 is the real component of the point where the imaginary component of the graph is maximized in the low-frequency region of the graph.

The present invention uses the absolute value |Z| of impedance Z extracted at frequencies lower than or equal to the frequency at the apex of a semicircle (Nyquist plot) in the GEIS method or the PEIS method and evaluates the corrosion resistance of a constituent material of a working electrode of interest on the basis of the change over time in the absolute value |Z|.

The present application relates to the technical field of power system, discloses a kind of multi-level DC sending end small signal stability evaluation method, device, equipment and medium, the present application considers the coupling influence between different heterogeneous devices, to network type new energy converter, network type energy storage converter, network type load converter and modular multi-level high voltage direct current converter station are carried out frequency domain impedance modeling, and based on the equivalent impedance model of each device, the frequency domain impedance network of all-electric system is constructed, the small signal stability of frequency domain impedance network is analyzed using generalized Nyquist stability criterion, the Nyquist diagram of impedance ratio on the two sides of voltage source and current source in frequency domain impedance network is determined The small signal stability of all-electric system under AC / DC hybrid scene, so as to provide an effective evaluation means for the stable operation of AC / DC hybrid all-electric system.

This invention relates to the field of fuel cell technology and discloses a fuel cell impedance attribution method based on a physically interpretable impedance model. The method includes: performing impedance decomposition on the physically interpretable impedance model to obtain multiple sub-impedances of the fuel cell, including ohmic resistance, anode impedance, cathode activation impedance, cathode mass transfer diffusion impedance, and cathode mass transfer convection impedance; obtaining the frequency corresponding to the minimum value of the imaginary part of each sub-impedance, the inverse of the minimum value of the imaginary part, and the difference between the low-frequency real part value and the high-frequency real part value, as characteristic frequencies, imaginary peak values, and equivalent resistances; plotting the Nyquist plot, Bode plot, resistance ratio of the sub-impedance's equivalent resistance to the total equivalent resistance, and frequency-peak plot reflecting the relationship between the characteristic frequency and the imaginary peak value for each sub-impedance, to determine the contribution of each sub-impedance to the physically interpretable impedance model, thus realizing impedance attribution analysis under the physically interpretable impedance model.

The present invention relates to a method for the optimized simulation of a characteristic of a battery cell, containing a method for determining a varying internal resistance (RG) of a battery cell, in which method an electrochemical impedance spectroscopy is measured on the battery cell and an internal resistance (RG) of the battery cell is determined from a difference between a value of the locus curve with respect to a high-frequency measurement point (MPH) and a value of the locus curve with respect to a low-frequency measurement point (MPN) on the real-value axis (RE) of the Nyquist plot. In the further steps, a characteristic of the battery cell is simulated, comprising at least one output parameter from a simulated voltage (US), a simulated temperature (TS), a simulated state of charge (SOC) and a power limit, on the basis of a battery cell model (BM) according to input parameters comprising at least the previously measured current (I) and the previously measured temperature (TM). The simulated output parameter of the state of charge (SOC) is corrected on the basis of a predictive filter algorithm according to the measured voltage (UM) and the simulated voltage (US). Finally, to optimize the battery cell model (BM), a stored model parameter of the internal resistance (RG) is updated using a value which has been determined by the method for determining a varying internal resistance (RG) of a battery cell.

The application provides a thermal runaway early warning method and device for an energy storage battery, electronic equipment and a storage medium. The thermal runaway early warning method comprises the following steps: obtaining impedance spectrum data of a target energy storage battery at different temperatures and SOC; preprocessing the impedance spectrum data to obtain first data; determining a Nyquist diagram of the target energy storage battery according to the first data, fitting element parameter values of the target energy storage battery, and determining an equivalent impedance model; standardizing the element parameter values; analyzing the standardized element parameter values and operation data through a temperature relationship analysis model to predict the relationship between the standardized element parameter values and the internal temperature of the target energy storage battery, and then determining the predicted internal temperature; comparing the internal temperature with a preset thermal runaway condition, and early warning the thermal runaway of the target energy storage battery according to the comparison result. The application has the beneficial effect of improving the accuracy of battery thermal runaway early warning.

The present application belongs to the technical field of printed circuit board manufacturing, and relates to a PCB blind hole electroplating hole filling method, comprising the following steps: assembling a response signal stream to generate composite response current data; aggregating a two-dimensional Nyquist graph to generate a time-frequency domain electrochemical resonance vector; merging multi-dimensional digital parameters to establish a physical characteristic parameter vector; encapsulating target pulse waveform parameters according to a preset communication protocol to generate a pulse configuration vector; generating an in-situ peeling interface in combination with an electrostrictive stress; and generating a solid blind hole according to a directional cathode deposition waveform electroplating. The present application solves the problem that the existing blind hole electroplating process is difficult to perform in-situ diagnosis and self-adaptive differential repair on the microscopic pollution state of a single blind hole, thereby leading to the problem that the hole filling yield is not stable enough.

The present invention is intended to provide a technique capable of accurately and rapidly diagnosing a battery's condition without pre-accumulating measurement data. A battery diagnostic device according to the present invention specifies a first frequency at which a component caused by a diffusion resistance of an equivalent circuit of a battery begins to appear in a Nyquist diagram of the battery; specifies a second frequency at which a phase of the voltage and a phase of the current coincide in phase-frequency characteristics of the voltage and current; and diagnoses a battery's condition using the respective real parts of a first impedance of the battery at the first frequency and a second impedance of the battery at the second frequency.

Provided is a photoelectric conversion element having improved durability while achieving high initial photoelectric conversion efficiency. The photoelectric conversion element includes a first electrode, a second electrode, and a photoelectric conversion layer including a crystal of a perovskite structure, and is characterized in that: when the smaller one of an electrode area of the first electrode and an electrode area of the second electrode is S [cm2], S [cm2] is S [cm2] in a Nyquist map based on an impedance measurement result; the maximum value Rrecc [omega] among resistance values obtained by fitting an arc corresponding to a phase maximum value in a low-frequency range by a parallel circuit of the resistive element and the constant-phase element satisfies the following formula (E1): 1.0 * 104 lt; rrec* Slt; 1.0 * 107 (E1), and a maximum value Rct [Omega] and Rrecc [Omega] among resistance values obtained by fitting an arc corresponding to a phase maximum value in a high-frequency range by a parallel circuit of the resistive element and the constant-phase element satisfy the following equation (E2): Rrecc / Rct > = 25 (E2).

The present invention uses the absolute value |Z| of an impedance Z which has been extracted at a frequency equal to or lower than the frequency at the apex of a semicircle (Nyquist plot) in the GEIS method or the PEIS method to evaluate, from a change in the absolute value |Z| over time, the corrosion resistance of a constituent material of a working electrode to be evaluated.

The invention discloses a stability judgment method and device applied to a virtual inertia control system. The method comprises the following steps: constructing a state space model of the virtual inertia control system; converting the state space model into a multivariable system transfer function matrix G (s), wherein s is a Laplace operator; drawing a Nyquist diagram with a Gerer round belt of the system transfer function matrix G (s); and if the virtual inertia control system meets the use condition of the combined criterion based on the Gerer round belt, judging the stability of the virtual inertia control system by using the combined criterion. According to the method, the calculation complexity is remarkably reduced, a direct and visual reference is provided for optimal selection of key parameters such as a virtual inertia coefficient, and the applicability and efficiency in engineering practice are greatly improved.

This invention relates to a management device for detecting defects in the busbar fastening and cell-to-cell welding conditions of a battery pack using electrochemical impedance spectroscopy (EIS) technology. The device comprises: a current generation unit for applying a set alternating current to the battery pack; a voltage measurement unit for measuring the voltage generated at each battery cell or across the busbars by means of the current; an impedance calculation unit for calculating impedance using the measured current and voltage values; and a data output unit for generating a Nyquist plot or Bode plot based on the calculated impedance and outputting the impedance change.