3385 results about "Equivalent circuit" patented technology

The invention provides a small multimode antenna capable of commonly using a single feeding point at a plurality of frequencies. The antenna includes a radiating conductor 1 disposed above a ground conductor 6 and distributed-constant circuits 2 and 3 coupled to the radiating conductor. Each of the distributed-constant circuits is constructed by a transmission line and has a branch. One end of the radiating conductor and one end of the distributed-constant circuit 2 are connected to each other to be a connection point and, further, the other end of the radiating conductor and one end of the distributed-constant circuit 3 are connected to each other. The connection point is a single feeding point 9 using the ground conductor as an earth. The distributed-constant circuits 2 and 3 are designed as an equivalent circuit in which different stubs are connected in parallel with a transmission line, and impedance matching at a plurality of frequencies is realized at the feeding point.

Systems and computer-implemented methods are used for analyzing battery information. The battery information may be acquired from both passive data acquisition and active data acquisition. Active data may be used for feature extraction and parameter identification responsive to the input data relative to an electrical equivalent circuit model to develop geometric-based parameters and optimization-based parameters. These parameters can be combined with a decision fusion algorithm to develop internal battery parameters. Analysis processes including particle filter analysis, neural network analysis, and auto regressive moving average analysis can be used to analyze the internal battery parameters and develop battery health metrics. Additional decision fusion algorithms can be used to combine the internal battery parameters and the battery health metrics to develop state-of-health estimations, state-of-charge estimations, remaining-useful-life predictions, and end-of-life predictions for the battery.

The invention provides a combined estimation method for lithium ion battery state of charge, state of health and state of function. The combined estimation method comprises the steps that the state of he---alth of a battery is estimated online: open circuit voltage and internal resistance are identified online by adopting a recursive least square method with a forgetting factor, the state of charge is indirectly acquired according to a pre-established OCV-SOC corresponding relation, and then the size of battery capacity is estimated according to cumulative charge and discharge electric charge between two SOC points; the state of charge of the battery is estimated online: the state of charge of the battery is estimated by adopting the Kalman filter algorithm based on a two-order RC equivalent circuit model, and the battery capacity parameter in the Kalman filter algorithm is updated according to the estimation result of battery capacity; and the state of function of the battery is estimated online: the maximum chargeable and dischargeable current is calculated based on the voltage limit and the current limit of the battery according to internal resistance obtained by online identification, and then the maximum chargeable and dischargeable function can be obtained through further calculation.

The present invention provides an algebraic approach to quantum circuit design based on using a GSVD (Generalized Singular Value Decomposition) to map a unitary matrix, representing a desired quantum computation, into a product of block diagonal unitary matrices, each of which can then be mapped into equivalent circuit fragments. The invention describes a number of rules allowing such circuits to be compactified.

DC inductive FSS technology is a printed slow wave structure usable for reduced size resonators in antenna and filter applications of wireless applications. It is a dispersive surface defined in terms of its parallel LC equivalent circuit that enhances the inductance and capacitance of the equivalent circuit to obtain a pole frequency as low as 300 MHz. The effective sheet impedance model has a resonant pole whose free-space wavelength can be greater than 10 times the FSS period. A conductor-backed DCL FSS can create a DC inductive artificial magnetic conductor (DCL AMC), high-impedance surface with resonant frequencies as low as 2 GHz. Lorentz poles introduced into the DCL FSS create multi-resonant DCL AMCs. Antennas fabricated from DCL FSS materials include single-band elements such as a bent-wire monopole on the DCL AMC and multi-band (dual and triple) shorted patches, similar to PIFAs with the patch/lid being a DCL FSS.

A switched-mode power amplifier is configured for performing power amplification of a plurality of signals input thereto and integrally summing (combining) those signals. Conceptually, this is achieved by replacing the input winding of the transformer component of a transformer-coupled voltage switching amplifier with separate input components, one for each input signal, in similar manner to the configuration of the input components of a three-port combiner (trifilar). In a first transformer-containing category of embodiments of the invention, the input winding of the amplifier's transformer is comprised of a plurality of series-coupled windings, one for each of the plurality of input components/signals such that the input components constitute a series connection of low output impedance sources applied to the amplifier's resonator and load. This, in turn, provides a high level of isolation between the amplifier input components and results in a low level of loss. In a second non-transformer-containing category of embodiments of the invention, the transformer component is replaced by a transmission line impedance transformer, or a lumped element equivalent circuit, which transforms the low output impedance sources to high output impedance sources and those sources are connected in parallel (rather than in series per the first category of embodiments).

A system and method for estimating internal parameters of a lithium-ion battery to provide a reliable battery state-of-charge estimate. The method uses a two RC-pair equivalent battery circuit model to estimate the battery parameters, including a battery open circuit voltage, an ohmic resistance, a double layer capacitance, a charge transfer resistance, a diffusion resistance and a diffusion capacitance. The method further uses the equivalent circuit model to provide a difference equation from which the battery parameters are adapted, and calculates the battery parameters from the difference equation.

Methods and apparatus for providing bioimpedance analysis are provided. In certain aspects, equivalent circuit frequency response models are provided which lead to improved correlations with MRI data. The frequency response models take account of body composition, including the fat component of a body segment. Data obtained by performing bioimpedance spectroscopy (BIS) and MRI on the calves of subjects illustrates the improved correlations achieved compared to single frequency analyses at 50 kilohertz and analyses performed using the conventional Cole-Cole model.

The invention discloses a method for estimating the charge state of a power cell, which comprises the following steps that: 1. a continuous state space model capable of expressing the relationship of each element in an expression circuit is obtained by an equivalent circuit model of a power cell; the relationship between the open-circuit voltage and the cell charge state is obtained through the standing experiment of the power cell, and the cell charge state is introduced into the continuous state space model of the power cell as a state variable; the power battery model under the noise environment is obtained by combining the noise information; and finally the continuous state space model is subjected to linearization and discretization so as to obtain a linear discrete state space model; 2. a relationship curve of the open-circuit voltage and the cell charge state is obtained through the standing experiment of the power cell, and a parameter k and a parameter d in the power cell model are obtained approximately; 3. parameters of the power cell model are obtained through the identification of current and voltage data collected by a data collecting system; and 4. the power cell charge state is estimated by utilizing a moving horizon estimation method based on the determined power cell model.

A detection circuit is provided with a differential capacitive sensor and with an interface circuit having a first sense input and a second sense input, electrically connected to the differential capacitive sensor. Provided in the interface circuit are: a sense amplifier connected at input to the first sense input and to the second sense input and supplying an output signal related to a capacitive unbalancing of the differential capacitive sensor; and a common-mode control circuit, connected to the first sense input and to the second sense input and configured to control a common-mode electrical quantity present on the first sense input and on the second sense input. The common-mode control circuit is of a totally passive type and is provided with a capacitive circuit, which is substantially identical to an equivalent electrical circuit of the differential capacitive sensor and is driven with a driving signal in phase opposition with respect to a read signal supplied to the differential capacitive sensor.

The present invention provides a designing method for a high-frequency transistor, which includes a transistor section, a drain region, and a gate electrode, a source wiring line, a drain wiring line, and a gate wiring line, for optimizing wiring lines and contacts from voltage supplying nodes to electrode lead nodes. The method includes the steps of measuring a sensitivity to a high-frequency characteristic of the high-frequency transistor regarding coupling capacities between the wiring lines and coupling capacities between the wiring lines and the semiconductor substrate from among equivalent circuit parameters which vary in response to a configuration of the wiring lines and the contacts; deciding layered levels individually of the gate wiring line, source wiring line, and drain wiring line based on the measured sensitivities; and designing patterns of the gate wiring line, source wiring line, and drain wiring line in the individually decided layered levels and the positions and the sizes of the wiring lines and the contacts for connecting the wiring lines and the transistor section to each other.

The present invention provides a method and a system for designing an integrated circuit comprising a plurality of elements. The method includes obtaining a lithography-simulated layout corresponding to at least one element. The lithography-simulated layout accounts for lithography effects on the element. The method further includes determination of an equivalent circuit representation that is compatible to a circuit analysis tool, corresponding to the lithography-simulated layout with respect to one or more performance characteristics and based on user preferences. The method also provides equivalent circuit representation to the circuit analysis tool that analyzes one or more performance characteristics of the elements.

The invention discloses a method for estimating the health state of a power battery. The method comprises steps of acquiring the constant-current charging voltage V, current I and time t of a batteryto obtain charging capacity Q, establishing a V-Q relationship curve, acquiring a capacity increment curve peak value and peak position information, establishing a RBF neural network, training a RBF neural network model by a particle swarm optimization algorithm, and estimating the health state of the battery by using the generated RBF neural network. The method establishes a mapping relationshipamong the constant-current charging capacity increment curve peak value, the peak position and the health state of the battery by means of a data driving mode without establishing an equivalent circuit of the electric vehicle power battery, thereby improving estimation accuracy and realizing online real-time estimation for the overall estimation of a battery pack.

The invention relates to the technical field of operation and control of an electric power system and discloses a method for detecting and identifying dynamic bad data of the electric power system. The method comprises the steps of A, reading a current network parameter and a network topology of the electric power system and forming a node admittance matrix and a branch circuit-node incidence matrix; B, establishing an equivalent circuit according to the network topology of the electric power system and configuring measurement functions and a power management unit (PMU) of the electric power system, wherein system measurement includes node voltage amplitude measurement, node current amplitude measurement, node power injection measurement and node trend measurement; C, detecting and identifying the dynamic bad data of the electric power system; D, judging the convergence condition. By means of the method, accidentally arisen bad data from a supervisory control and data acquisition (SCADA) system and in the PMU measurement can be found and eliminated, and accordingly an accurate operation state, voltage amplitude and phase angles of nodes of a power grid are obtained.

The invention discloses an online lithium ion battery SOC estimation method based on extended Kalman filter, belongs to the technical field of SOC prediction of a lithium ion battery, and aims to solve the problem that the reliability of the online estimation of a conventional lithium ion battery SOC is low due to influence of initial value selection. The method comprises the steps as follows: a voltage and current relation of a first-order RC (resistance/capacitance) equivalent circuit of a detected lithium ion battery and a voltage and current relation of a second-order RC equivalent circuit are established firstly; a charge-discharge experiment is performed on the detected lithium ion battery to establish a polynomial fitting function of a Kalman filter initial value SOC 0 of the detected lithium ion battery; a covariance P (0) of the Kalman filter initial value SOC 0 and a Kalman filter initial error of the detected lithium ion battery is obtained; and then, battery SOC estimation based on extended Kalman filter is performed, so that the online estimation of the lithium ion battery SOC is realized. The method is used for online estimation of the lithium ion battery SOC.

The invention brings forward a battery low-temperature preheating and charging method which comprises the following steps: an equivalent circuit model of a battery is obtained; multiple electrochemical impedance spectroscopy EIS data corresponding to multiple temperatures and multiple charged states are obtained, and corresponding parameters of the equivalent circuit model are obtained according to the multiple electrochemical impedance spectroscopy EIS data; current temperature and current charged state of the battery are obtained, and the working condition state of the battery, including low-temperature starting condition and low-temperature charging condition, is judged according to the current temperature and the current charged state; when the working condition state is the low-temperature starting condition, first frequency and a first amplitude of alternating current are selected according to parameter values of the equivalent circuit model corresponding to the current temperature and the current charged state; alternating current is applied on the battery according to the first frequency and the first amplitude for preheating until the temperature of the battery reaches a first preset temperature so as to make the battery to be normally used. By the method of the embodiment, lithium precipitation is avoided, and heat production rate inside the battery is raised.

A power conversion system comprises a power converter comprising a plurality of semiconductor power switches, an LC filter coupled between an output of the power converter and an electric grid, and a power conversion control system. The LC filter comprises an inductor coupled in series to the electric grid, and a capacitor. The LC filter and the grid result in an equivalent LC circuit comprising an impedance of the LC filter and an impedance of the electric grid. The power conversion control system comprises a damper and a converter controller. The damper receives an LC filter signal and an equivalent LC circuit impedance signal and generates a damping signal. The converter controller receives a current or voltage reference signal, a current or voltage command signal, and the damping signal to generate control signals for driving switching operations of the semiconductor power switches.

The invention discloses a lithium battery SOC estimation method of off-line data segmentation correction. The method is mainly applied to a battery management system of an electric vehicle and is used for correcting an actual capacity of a lithium battery and eliminating an accumulation error of a traditional ampere-hour integral method. The method comprises the following steps of establishing a battery equivalence circuit model; acquiring an OCV-SOC curve; using a terminal voltage response curve at the time that battery discharging is ended to carry out off-line parameter identification on the equivalence circuit model; calculating a battery health state SOH; using an ampere-hour integral method to calculate a current value of the SOC in real time; using the battery health state to correct a SOC value; using off-line data to carry out segmentation elimination on the accumulation error in the ampere-hour integral method. By using the method of the invention, the battery SOC can be accurately estimated and the accumulation error of battery SOC estimation performed through using the ampere-hour integral method is eliminated.

The invention discloses a power-cell SOC online closed-loop estimation method based on an N-2RC model. In the invention, an electrochemical model and an equivalent circuit model are combined and a novel power cell model is provided. The N-2RC model uses a Nernst electrochemical model to replace an electromotive force portion of a second-order RC equivalent circuit model so that one to one correspondence of a cell electromotive force and SOC can be accurately reflected. Based on the model, a recursive least-square method based on a forgetting factor is used to identify a model parameter, and then an expansion Kalman filtering algorithm is used to realize on-line closed loop estimation of the cell SOC. The electrochemical model can well describe a cell characteristic on an electrochemical aspect, but the structure is complex and the model is not suitable for individually individual usage. And the equivalent circuit model belongs to an external characteristic model and can well express a volt-ampere characteristic relationship of the cell, but can not reflect an internal characteristic of the cell. By using the method in the invention, the above problems are overcome.

The invention provides an antenna device, comprising: an antenna body including a conductor, an equivalent circuit of said conductor comprising an inductive component and a resistive component in a series connection, wherein a frequency adjusting circuit including at least a parallel circuit of a switching element and a passive element is connected to said conductor of said antenna body. The antenna body is connected in series with said frequency adjusting circuit. The invention enable to provide a compact antenna device for use in a mobile communication apparatus that performs transmission and reception on frequencies in a wide range.