6 results about "Transfer impedance" patented technology

The application provides a transient ground potential rise induced coupling determination method through cable shielding layer, and belongs to the technical field of cable shielding layer.The application establishes a distributed parameter partial element equivalent circuit model of a grounding network, solves transient ground potential distribution by using a finite difference time domain method, obtains equivalent transfer impedance frequency characteristics of a braided shielding layer by using a four-port S parameter vector network analysis method and a variational asymptotic homogenization multi-scale algorithm, solves core line common mode voltage and differential mode voltage by establishing a multi-conductor transmission line equation group, constructs an artificial intelligence prediction model based on a topology perception graph neural network, solves a large-scale sparse admittance matrix by using a multilevel fast multipole method to obtain full network induced voltage distribution, and establishes a quantitative relationship model between ground potential rise and core line induced voltage, so that the technical problems that cable core line induced voltage caused by transient ground potential rise is difficult to accurately predict and effectively suppress are solved.

The application discloses a kind of lithium battery charge-discharge intelligent early warning method and system, belong to computer technology field.The method includes: when battery charges and discharges, actively injects multiple-frequency ac disturbance signal;Response signal is collected and is parsed to obtain dynamic electrochemical impedance spectroscopy containing charge transfer impedance and low-frequency phase angle;Based on the preset multidimensional health impedance mapping table, the reference impedance and reference phase angle corresponding to the current temperature and state of charge are inquired;Impedance relative deviation and phase angle offset are calculated;At least based on the deviation and offset, the internal micro-short circuit of battery is identified and early warning operation is executed;Through multidimensional mapping table and dynamic threshold mechanism, effectively eliminate working condition and aging interference, with high sensitivity and low false alarm rate;And supplemented by hierarchical early warning, standing verification and multi-cell collaborative calibration, the safety and usability of battery system are significantly improved.

This invention discloses a simulation-based method and system for handling electromagnetic interference in motor controllers, belonging to the field of electromagnetic compatibility testing and simulation technology. By constructing a test environment structural model including a test bench, artificial power network, shielded cables, current probes, the motor controller body, and the motor load using an electromagnetic simulation platform, electromagnetic field simulation calculations are performed to extract structural parasitic parameters and convert them into an equivalent circuit model. The equivalent circuit model is integrated into the main circuit simulation model to form a field-circuit coupled simulation model, and preliminary conducted emission simulation results are obtained. A current probe model is established, and the transfer impedance calibration factor is calculated. The preliminary simulation results are coupled and calibrated to obtain high-precision conducted emission simulation results. Based on the calibrated simulation results, the suppression effects of different interference suppression schemes are configured and evaluated, and the optimal suppression scheme is selected. The proposed scheme significantly improves the simulation accuracy of the conducted emission current method.

The application provides a cost allocation method and device for an AC-DC hybrid power distribution network based on a distribution factor, which comprises the following steps: constructing an equivalent model of the AC-DC hybrid power distribution network; the equivalent model is used to calculate the transfer impedance of each node of the AC-DC hybrid power distribution network to a branch; based on the equivalent model, the transfer impedance of each node to the branch is calculated, and an augmented distribution factor matrix of the AC-DC hybrid power distribution network is determined; the augmented distribution factor matrix is used to calculate the usage degree of each node of the AC-DC hybrid power distribution network to a line; based on the augmented distribution factor matrix, a cost allocation principle is determined, the cost of the AC-DC hybrid power distribution network is allocated, and an initial cost allocation result is calculated; the cost comprises a fixed cost and a variable cost; based on a generator-load power distribution matrix, the initial cost allocation result is corrected to obtain a cost allocation result. The application can improve the rationality, fairness, applicability and stability of the cost allocation of the AC-DC hybrid power distribution network.

This invention discloses a charging method based on an adjustable charging curve for battery health status perception, comprising the following steps: synchronously acquiring voltage and current responses through a micro EIS measurement circuit and obtaining the real and imaginary parts of impedance at different frequencies using Fast Fourier Transform, thereby generating an electrochemical impedance spectrum of the battery during charging and discharging; segmenting and fitting the high-frequency, mid-frequency, and low-frequency regions, extracting characteristic values ​​of ohmic internal resistance, charge transfer impedance, and diffusion impedance respectively, and generating impedance spectrum characteristic parameters; inputting the impedance spectrum characteristic parameters to a control chip to fit and estimate the battery health status assessment value, and constructing a battery health status perception model to dynamically generate an adjustable charging curve; performing a charging operation on the battery according to the adjustable charging curve, and dynamically adjusting the parameters of the adjustable charging curve, thereby achieving closed-loop adaptive adjustment of the charging process. This invention can dynamically adjust the charging curve parameters to achieve closed-loop adaptive adjustment of the charging process.

This invention provides an in-situ non-destructive diagnostic method for sodium deposition during low-temperature charging of sodium-ion batteries, belonging to the field of battery diagnostic technology. In this invention, ultrasonic emission, reflection, and transmission receiving modules are arranged along the thickness direction of the battery under test, connected to an electrochemical workstation, constructing a dual-mode ultrasonic detection architecture of transmission and reflection to achieve in-situ non-destructive testing. The battery is adjusted to a fully discharged state, placed in a high-low temperature test chamber, and a room-temperature control group is set up. It is charged with a preset constant current, and AC disturbances are simultaneously applied to drive ultrasonic pulses. Cyclic testing is performed at set time intervals to achieve in-situ, continuous, and synchronous acquisition of electrochemical and ultrasonic data. Charge transfer impedance is extracted based on impedance spectroscopy, interface main echo and layered slice imaging are obtained based on ultrasonic reflection data, and a two-dimensional sound velocity distribution image is established based on ultrasonic transmission data. A multi-signal joint criterion is used to determine sodium deposition and distinguish between early and late stages, effectively improving the accuracy and flexibility of low-temperature sodium deposition diagnosis.