Extraction of battery parameters using a multi-objective genetic algorithm with a non-linear circuit model

The current injected equivalent circuit approach (CIECA) to modeling switching converter power stages is extended to model the current programmed converter power stages operating in fixed frequency discontinuous inductor conduction mode. To demonstrate the method, the modeling is carried out for the buck, boost, and buckboost converters to obtain small signal linear equivalent circuit models that represent both input and output properties. The results of these analyses are presented in the form of linear equivalent circuit models as well as transfer functions.

Analysis of the terminal characteristics of the three-phase multi-winding insulated core transformer (ICT) requires a precise physical model. A linear equivalent electrical circuit model is proposed and constructed to facilitate the ICT design based on the principle of duality. It is composed by leakage inductances between adjacent windings, leakage inductances introduced mainly by the discrete insulation gaps, as well as ideal transformers. The value of each leakage inductance depends on the geometrical dimensions of the core, gaps or windings and the property of magnetic materials. Both short circuit simulations and self and mutual inductance matrix of transformer windings are employed to determine precisely each inductance. To validate the equivalent circuit, the magnetic flux leakage in a three-stage three-dimensional (3D) ICT is quantitatively analyzed.

Summary form only given, as follows. E to H mode transition is a typical nonlinear problem in an inductive Plasma sources. The mode transition has been explained in terms of power balance. In this presentation, the nonlinear equivalent circuit modeling has been studied. The linear transformer modeling has been used for inductive plasma source. However, linear transformer model can not explain the mode transition. The nonlinear circuit model based on the assumption that induction field is coupled nonlinearly to the plasma. When nonlinear coupling effects included in the linear transformer model, this nonlinear harmonic oscillation problem can be expressed by Duffing equation. The advantage of Duffing equation is hysteresis as well mode transition can be explained.

In this study, an equivalent linear and non‐linear circuit model of superconducting microstrip T‐junction (SMT) structures is proposed. Two types of SMT structures are analysed using suggested model and their scattering behaviour is compared using both the method of moment and the finite‐element method (FEM). The fundamental and third‐order harmonic outputs are obtained using harmonic balance method to observe the non‐linear behaviour in SMT structures. A linear and non‐linear model for enhanced SMT structures is also suggested and verified by S ‐parameters comparison between the model and FEM method. The non‐linearity in enhanced structures is modelled similarly and compared with results of normal structures.

In this article, a recurrent neural network (RNN) method is employed for dynamic time-domain modeling of both linear and nonlinear microwave circuits. An automated RNN modeling technique is proposed to efficiently determine the training waveform distribution and internal RNN structure during the offline training process. This technique extends a recent automatic model generation (AMG) algorithm from frequency-domain model generation to dynamic time-domain model generation. Two types of applications of the algorithm are presented, transient electromagnetic (EM) behavior modeling of microwave structures, and time-domain envelope modeling of power amplifiers (PA). For transient EM modeling, we consider EM structures with varying material and geometrical parameters. AMG automatically varies the EM structural parameters during training and drives time-domain EM simulators to generate necessary amount of data for RNN to learn. AMG aims to model the transient behavior with minimum RNN order while satisfying accuracy requirements. In modeling PA behavior, an envelope formulation is used to specifically learn the AM/AM and AM/PM distortions due to third-generation (3G) digital modulation input. The RNN PA model is able to model these time domain distortions after training and can accurately model the amplifier behavior in both time (AM/AM, AM/PM) and frequency (spectral re-growth). © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.

Ensuring the structural integrity of Steam Generator (SG) U-bend tube arrays during out-of-plane earthquakes is crucial. Rationalization of the design code is desired considering the increasing trend of design earthquake level. As a rationalization evaluation method, a primary stress criterion of tube arrays obtained from a limit analysis using a nonlinear model which can precisely consider the load sharing mechanism of the tubes by modeling all tubes and anti-vibration-bars (AVBs) is under consideration, and a response analysis is conducted using the equivalent linear model of the nonlinear model and response spectrum method. In this study, a response analysis method which can simultaneously evaluate the response displacement and bending strain distribution using an equivalent linear model and bending strain correction coefficient was proposed. The concept of the proposed method is that the macroscopic response (displacement and strain distributions) of the tube bundle is obtained by the response spectrum method using the equivalent linear model. The nonlinear behavior in which the strain per deformation just above the upper tube support plate (TSP) increases due to the change in the contact state between the tube and the TSP, which cannot be evaluated by the linear model directly, is corrected using the bending strain correction coefficient calculated based on the single tube analysis. The proposed method is validated by comparing the seismic test results obtained based on a full-scale mock-up consisting of square arrayed SG tubes. From the seismic test and pseudo static analysis using the nonlinear model, it was confirmed that near upper tube support plate (TSP) where high stress occurs as the out-of-plane response of the tube bundle increases, a change in contact occurs, resulting in the tube bundle only in contact with the upper surface of the TSP to also enter into contact with the lower surface of the TSP, and that the strain per deformation increases nonlinearly. In the linear model constructed in the previous study, the linear spring is defined at the contact point between the AVBs and the tube, whereas the non-contact point is free. In order to accurately predict stress, an evaluation method considering the contact state at the TSP is required. Therefore, a linear spring was defined only at the contact point at the moment of linearization at the top and bottom contact surfaces of the TSP, and the stiffness of the spring thereof was calculated as the equivalent stiffness from the contact force and gap displacement at the moment of linearization. This equivalent stiffness was also set for the AVB-tube contact point. Theoretically, responses such as deformed shape or strain distribution at the linearization moment, pseudo static analysis of the equivalent linear model and original nonlinear model are consistent. Furthermore, the bending strain correction coefficient, which can be calculated only by nonlinear analysis of a single tube, is set so that the response evaluation becomes conservative. The natural frequency of out-of-plane first mode obtained by the eigenvalue analysis of the equivalent linear model were well consistent with the seismic test. Bending strains of out-of-plane first mode obtained by the response spectrum method using the typical design damping ratio of 8% were larger than the test results. Furthermore, the response displacement was also well consistent with the measured values. Therefore, the proposed method can simultaneously evaluate the displacement response and the bending strain distribution by the response spectrum method. In addition, the natural frequencies of the out-of-plane second-mode were well consistent with the measured values in the linear model which is applied to the evaluation of the out-of-plane second or more higher mode. In conclusion, it was confirmed that the proposed method is applicable as a seismic response evaluation method that includes safety margins.

Large-signal modeling and simulation techniques for microwave and millimeter-wave transistors are described and reviewed. The relative merits of physical, physics-based and nonlinear equivalent circuit models are summarized. Several examples of MESFET, HBT, and HEMT simulation results are given. © 1996 John Wiley & Sons, Inc.

In this paper, a linear lumped-element equivalent circuit model (ECM) for ultrasonic laterally transduced electrostatic bulk-mode air-coupled resonant micro-electro-mechanical systems (MEMS) is described. A single-crystal silicon (SCS) square plate with T-shaped tethers is considered as the geometry of interest with a one-sided electrostatic actuation. This type of sensor can be used for sensitive mass sensing of airborne particles and possesses a large active surface with in-plane vibration modes in the ultrasonic frequency range. Firstly, the eigensolutions and eigenvectors of the problem are obtained using analytical equations and compared with finite-element modeling (FEM) solutions. Secondly, using modal analysis, the number of degrees of freedom is reduced and individual solutions are provided for each vibration mode, leading to various effective masses, stiffnesses and dampings. The first order Taylor expansion of both the electrical current equation and the electrostatic force applied on the resonator allows one to obtain expressions for the additional stiffness and the electro-mechanical transformation coefficient linked to the membrane actuation. Based on theses results, single-input single output (SISO) equivalent circuits are established using electro-mechanical and Butterworth-Van Dyke (BVD) approaches. Electrical admittance simulations resulting from different in-plane vibration modes are proven to be in excellent agreement with FEM simulations. Finally, a numerical mass sensing application is described to evaluate the relevance of both the model and the resonator design to act as a microbalance. The proposed model can be used to design, predict, analyze and optimize the behavior of highly sensitive air-coupled ultrasonic bulk-mode SCS MEMS for various physical applications.

Nonlinear current response of micro electroporation and resealing dynamics for human cancer cells

Pharmacokinetic-Pharmacodynamic Modeling and Simulation

Piezoelectric three-dimensional inkjet printing has been used to manufacture heterogeneous objects due to its high level of flexibility. The materials used are non-Newtonian inks with complex rheological properties, and their behavior in the context of inkjet printing has not been fully understood: for example, the fact that the shear-thinning viscosity affects the droplet generation. Therefore, a control strategy coping with shear-thinning behaviors is needed to ensure printing consistency. In this paper, a novel model-based approach is presented to describe the shear-thinning ink dynamics inside the piezoelectric inkjet printhead, which provides the basis to design the excitation parameters in a systematic way. The dynamic equation is simplified into a quasi-one-dimensional equation through the combination of the boundary layer theory and the constitutive equation of the power-law fluid, of which the viscosity is shear-thinning. Based on this, a nonlinear time-varying equivalent circuit model is presented to simulate the power-law fluid flow rate inside the tube. The feasibility and effectiveness of this model can be evaluated by comparing the results of computational fluid dynamics and the experimental results.

Coil currents of active magnetic bearing (AMB) change with the radial displacement of the rotor caused by rotor vibration, which affects the magnetic field distribution of the AMB. In order to analyze the influence of rotor radial vibration on the power loss of AMB, it is necessary to establish a relationship model between the magnetic field distribution characteristics and the rotor vibration. Considering the nonlinearity of the ferromagnetic material and the edge effect of the magnetic poles, the PID control method is used to control the currents of the stator coils in real time according to the vibration displacement of the rotor, and the nonlinear equivalent magnetic circuit model of the AMB considering the rotor and stator reluctance is established. The magnetic field distribution characteristics of AMB during rotor vibration are analyzed, and the magnetic density in air gap is obtained, and compared with the results given by the electromagnetic field finite element software. The error between the magnetic path method and the FEM analysis result is within 3%, Which has high accuracy. The model established in this paper provides a theoretical basis for the magnetic field analysis of the AMB during rotor vibration and the subsequent loss analysis.

Nonlinearity in superconducting metamaterial structures, including spirally coupled lines

This paper presents the calculated and the measured performance capability of a cage rotor induction machine used as a direct connected, crankshaft speed, combined starter-alternator for an automotive diesel engine in an experimental hybrid electric vehicle. The calculated results are based on a nonlinear equivalent circuit model of the machine which considers saturation in the stator and rotor magnetizing flux paths. The development details of this model are given as well as several sets of calculation results for the induction machine previously described. Finally, measured maximum performance results for the test machine are presented and compared with model based calculated results for the same operating conditions of speed, terminal voltage and current.

Estimation of high-spatial resolution clear-sky longwave downward and net radiation over land surfaces from MODIS data