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There are few of transient control models are adapted to asynchronous induction coil launcher (AICL) with air core coil. Thus, many papers about AICL were written with the goal of increasing muzzle velocity of projectile. This paper concentrate on how to control the projectile speed and thrust accurately by using improved current filament (CF) method and variable voltage variable frequency (VVVF) scheme. The improved CF method contains mathematical model of three-phase inverter based on switch function, including conventional two level converter and cascaded multilevel converter models. The whole launch process is programmed with MATLAB. Simulation results show that this scheme have a smoother thrust fluctuation on projectile than other driving models. The motor parameters are changing with the temperature and frequency in launching process. Hence, the constant voltage frequency ratio (V/f) in this paper is more simple and reliable than vector control. To verify the control model and simulation results, a nine stages coil launcher prototype is constructed. The measured force and muzzle velocity are basically consistent with simulation results. It is proved that the improved CF method and VVVF strategy is feasible, and it is characterized by its small calculating amount that make it a valuable tool for design of AICL. The simple and excellent control of the thrust during launch process avoids load peaks, which means that the payload is handled more carefully compared to the classical launchers. [ABSTRACT FROM PUBLISHER]

This paper presents an analysis based on recent Electric Power Research Institute research in which a comparison is made between the “loss factor” calculated directly from annual simulations and a loss factor estimated variously from established equations and published papers and articles. The analysis provides new insights into the use of loss factors in estimating feeder losses. Sources of possible errors are identified and quantified. [ABSTRACT FROM PUBLISHER]

In this paper, a new circuit model is proposed to simulate plasma-induced damage (PID). It includes the two sheaths of the plasma, the blocking capacitor, and the RF power source coupled with the victim device. As a result, this model accounts for both the ac behavior of the plasma and the local voltage imbalance induced by differences in shading factors. The advantage of this approach, compared with the previous works, is that it can yield the waveform impinged by the plasma on the transistor gate, which is known to influence the amount of reliability degradation experienced by the device. Finally, this model is also utilized to elucidate the impact of a parasitic capacitance connected to the transistor gate on the extent of the PID inflicted on the victim device. [ABSTRACT FROM AUTHOR]

This paper proposes a new dynamic behavior model for single-electron transistors (SETs). A comprehensive review of modeling techniques and previous models was carried out aiming to remark the originality of the new proposed technique. Once established that SET is a nonlinear system, five classes of nonlinear models were simulated and compared to each other. Characteristic SET curves obtained using Simulation of Nanostructures were used as benchmark. The mean squared error (mse) was used as metric, and the simulation time was computed for each model. Regarding these two criteria—least mse and least simulation time—the Hammerstein–Wiener model outperformed the others models. [ABSTRACT FROM AUTHOR]

The introduction of communication systems to power system controllers has brought in another layer of complexity in their design and operation. In this paper, a plug-in hybrid electric vehicle charging facility is studied. A linearized model of the facility is built, including both the dc/dc and dc/ac converters of the distributed energy resources. In addition, a control strategy that includes both local and networked loops is proposed to monitor and control the dc bus voltage of a local energy storage unit. This dc bus voltage is crucial to the self-sustaining capabilities of the system. A review of challenges and opportunities in networked control systems is presented, and the impacts of communication factors to the charging facility stability are analyzed. Finally, a real-time simulation platform which combines both electrical and communication networks is presented to validate the small-signal model, control strategy, and stability analysis including the communication effects. [ABSTRACT FROM PUBLISHER]

In this paper, a new continuous multilevel compact model for phase-change memory (PCM) is proposed. It is based on the modified rate equations with the introduction of a variable related to material melting. The model is evaluated using a large set of dynamic measurements and shows a good accuracy with a single model card. All fitting parameters are discussed, and their impacts are detailed. Full circuit simulation is performed. Good convergence and fast simulation time suggest that this new compact model can be exploited for PCM circuit design. [ABSTRACT FROM AUTHOR]

The proper modeling of the transient thermal behavior of mutual heating effects between underground power cables is very important for the rating of transmission and distribution cables. The IEC standards proposed an accurate model based on exponential integrals that it can be difficult to implement in basic electrical software. The model is not consistent with the layered modeling of the cable thermal resistances. In this paper, a simple and easy-to-use alternative model is presented. It consists of injecting the correct current at the right position of the RC circuit representing the soil. The new model can accurately reproduce the full physics of the transient phenomenon and is consistent with the modeling of the cable used in the IEC standards themselves. The new model is tested and validated against numerous finite-element simulations for realistic cable installations. [ABSTRACT FROM AUTHOR]

This paper proposes a dynamic model with iron saturation to obtain better dynamic performance and more accurately steady-state performance than the dynamic model without iron saturation for the dual-stator brushless doubly-fed induction generator. Based on the proposed dynamic model, the MATLAB/SIMULINK model is established. The key to the simulation model considering iron saturation is that the magnetizing inductance can be updated for each simulation cycle. The magnetizing inductance used in the simulation is experimentally measured to guarantee the simulation accuracy. Dynamic simulations including the current, voltage, flux linkage, active power, and torque are performed, showing that the dynamic model considering iron saturation contributes to the merits of reducing the setting time and the oscillation amplitudes of the torque and the power in starting stage. Experimental assessment is carried out to verify the effectiveness of the theoretical analysis. [ABSTRACT FROM AUTHOR]

This paper presents a quasi-static surface-based partial element equivalent circuit (PEEC) model for electromagnetic problems consisting of coupled conductors and heterogeneous dielectrics of finite size. The PEEC model is based on the surface equivalent principle. Unlike the traditional surface-based PEEC models, in which the integral equations are set up by enforcing the field continuity in the true field region, the homogeneous integral equations in this model are obtained by enforcing the tangential null field condition in the null field regions. Simplified integral equations are obtained under the quasi-static assumption, in which the circuit elements carrying electric currents and magnetic charges on the dielectric surfaces are vanished. Consequently, the size of the subcircuit describing dielectrics is reduced significantly compared to the full-wave surface-PEEC (S-PEEC) model. Since the quasi-static S-PEEC model only contains frequency-independent circuit elements, it can be conveniently used for time-domain simulation. Three numerical examples are presented to validate the new PEEC model for typical embedded RF passive components, packaging and interconnection problems in both the frequency domain and the time domain. Excellent agreement is observed between the results of the proposed PEEC model, S-PEEC model, and those of commercial software within the quasi-static frequency range. [ABSTRACT FROM AUTHOR]

A highly efficient wireless power transfer (WPT) system is required in many applications to replace the conventional wired system. The high temperature superconducting (HTS) wires are examined in a WPT system to increase the power-transfer efficiency (PTE) as compared with the conventional copper/Litz conductor. The HTS conductors are naturally can produce higher amount of magnetic field with high induced voltage to the receiving coil. Moreover, the WPT systems are prone to misalignment, which can cause sudden variation in the induced voltage and lead to rapid damage of the resonant capacitors connected in the circuit. Hence, the protection or elimination of resonant capacitor is required to increase the longevity of WPT system, but both the adoptions will operate the system in nonresonance mode. The absence of resonance phenomena in the WPT system will drastically reduce the PTE and correspondingly the future commercialization. This paper proposes an open bifilar spiral coils based self-resonant WPT method without using resonant capacitors at both the sides. The mathematical modeling and circuit simulation of the proposed system is performed by designing the transmitter coil using HTS wire and the receiver with copper coil. The three-dimensional modeling and finite element simulation of the proposed system is performed to analyze the current density at different coupling distances between the coil. Furthermore, the experimental results show the PTE of 49.8% under critical coupling with the resonant frequency of 25 kHz. [ABSTRACT FROM AUTHOR]

Applying the Jiles-Atherton (JA) model to simulate the dynamics of power electronics circuit is a challenge but very attractive since it is possible to carry out continuous simulation with only several input parameters. Although other methods such as the Preisach-model can result in approximate waveforms for such applications, it is still a far distance to reach exact ones to suit chaos and other high accuracy-requiring researches. In this paper, the JA model has been successfully applied to model the dynamics of resonant inverter for driving a nonlinear load: a fluorescent lamp. The circuit is driven by a high frequency square wave voltage source. A semi-theoretical fluorescent lamp model developed from HID lamp model is adopted in the modeling. The simulation waveforms of voltage across the lamp and current through it are close to those measured ones reported in the literature papers. [ABSTRACT FROM AUTHOR]

With the steady growth of chip complexity and shrinking feature size, multiple challenges are emerging for transistor level circuit simulation. Compact SPICE models are a fundamental part of circuit verification, serving as a bridge between the semiconductor design and foundry. It is also an integral part of SPICE simulators, which directly affects tool performance and therefore design schedule. While the advanced 3-D technology nodes deliver superior level of scalability, simulation cost is rapidly increasing due to the computational complexity introduced by device model equations and the number of iterations required for numerical methods. In this paper, an efficient solution is proposed to reduce the computational cost associated with UC Berkeley BSIM-CMG device model evaluation, by applying robust Verilog compiler and computer algebra techniques to the device model equations. As a result of this implementation, simulation time reduction is up to 72% for complex blocks of the latest generation processor design. [ABSTRACT FROM PUBLISHER]

This paper delivers a considerable improvement in the framework of the statistical simulation of highly nonlinear devices via polynomial chaos-based circuit equivalents. Specifically, a far more efficient and “black-box” approach is proposed that reduces the model complexity for nonlinear components. Based on recent literature, the “stochastic testing” method is used in place of a Galerkin approach to find the pertinent circuit equivalents. The technique is demonstrated via the statistical analysis of a low-noise power amplifier and its features in terms of accuracy and efficiency are highlighted. [ABSTRACT FROM AUTHOR]

This paper reports on a novel simulation method combining the speed of analytical evaluation with the accuracy of finite-element analysis (FEA). This method is known as the rapid analytical-FEA technique (RAFT). The ability of the RAFT to accurately predict frequency response orders of magnitude faster than conventional simulation methods while providing deeper insights into device design not possible with other types of analysis is detailed. Simulation results from the RAFT across wide bandwidths are compared to measured results of resonators fabricated with various materials, frequencies, and topologies with good agreement. These include resonators targeting beam extension, disk flexure, and Lamé beam modes. An example scaling analysis is presented and other applications enabled are discussed as well. The supplemental material includes example code for implementation in ANSYS, although any commonly employed FEA package may be used. [ABSTRACT FROM AUTHOR]

Near-threshold and sub-threshold voltage designs have been identified as possible solutions to overcome the limitations introduced by energy consumption in modern very large scale integration circuits. However, as we approach sub-10 nm transistor technology, aggressive voltage, and gate length scaling will reduce the reliability of logic circuits due to the increasing impact of noise and variability effects. Therefore, designers need new tools to simulate logic circuits in the presence of noise. Time-domain analysis helps understand how transient faults affect a circuit and can guide designers in producing noise-resistant circuitry. However, standard approaches to modeling intrinsic noise sources in the time domain are computationally expensive. Moreover, small noise-driven fluctuations in electron occupation of circuit nodes introduce time-varying biasing point fluctuations, increasing the modeling complexity. To address these challenges, this paper introduces a new approach to modeling thermal noise and random telegraph signal noise directly in the time domain by developing and solving a series of stochastic differential equations. In comparisons to traditional SPICE-based simulations, our approach can provide three orders of magnitude speedup in simulation time without sacrificing accuracy. Moreover, we introduce a novel, iterative threshold-crossing algorithm, aimed at the efficient sampling of rare noise transients. We show that Monte-Carlo simulations based on this approach can detect rare high-amplitude single event transients that would be impossible to uncover with standard transient simulators. [ABSTRACT FROM PUBLISHER]

Analog components are fundamental blocks of smart systems, as they allow a tight interaction with the environment, in terms of both sensing/actuation and communication. This impacts on the design of the overall system, and mainly on the validation phase, that thus requires the joint simulation of digital and analog aspects. In this scenario, this paper proposes the automatic conversion of analog models to C++-based languages, to remove the overhead of co-simulation with traditional virtual platform tools. The proposed methodology allows to convert a given analog description to either: 1) a fully equivalent description or 2) an abstract representation for faster simulation which models only the aspects of interest. Effectiveness and correctness have been proved on a number of case studies that highlight the effectiveness and potentiality of the proposed methodology. [ABSTRACT FROM AUTHOR]

This paper studies the techniques for modeling modular multilevel converter (MMC) based multi-terminal HVDC (MTDC) systems in the electromechanical transient mode. Firstly, the mathematical model of the MMC and its corresponding equivalent circuit are established, which are similar to those of the two level converters. Then, a power flow calculation method for AC/DC systems containing MMC-MTDC systems is developed. Two dynamic models for MMC-MTDC systems are developed in the paper. One is the detailed model, taking into account of the AC side circuit, the inner controllers, the modulation strategies, the outer controllers and the MTDC circuit. The other is the simplified model, which only reserves the outer controllers and partial dynamics of the MTDC circuit based on a quantitative analysis of the detailed model's dynamic processes, and it can be used in electromechanical transient simulation with a larger step size. Both the detailed and the simplified models are implemented on PSS/E and compared with the accurate electromagnetic transient models on PSCAD in a four terminal MMC-MTDC system; the result proves the validity of the developed models. Lastly, a stability study of a modified New England 39-bus system is executed, and the result shows that the AC fault can be isolated well in an MMC-MTDC asynchronously connected AC grid. [ABSTRACT FROM PUBLISHER]

A new, nonlinear, frequency-domain behavioral model, based on Padé approximation theory, is presented in this paper. The new Padé model is similar in concept to the X-parameter method, but it uses a rational function instead of the X-parameter model's polynomial expression. The basic theory of the proposed Padé model and the model extraction methodology are provided. The proposed Padé approach increases the available modeling space beyond that available to the X-parameter method, and the performance of a selection of this family of models under various loading conditions is described in this paper. Along with the examples displaying the ability of the new model to predict fundamental frequency behavior, a second-harmonic example is also provided, with simulation results presented in both the frequency domain and the time domain. Based on the simulation studies and experimentally measured results, the new Padé model shows good accuracy and a high level of stability. All of these characteristics show that the proposed Padé model has high potential in RF design. [ABSTRACT FROM AUTHOR]

Reliable and accurate photovoltaic (PV) models are essential for simulation of PV power systems. A solar cell is typically represented by a single diode equivalent circuit. The circuit parameters need to be estimated accurately to get an accurate model. However, one circuit parameter was assumed because of the limited information provided by commercial manufacturing datasheets, and thus the model accuracy is affected. This paper proposes a parameterization approach for PV models to improve modeling accuracy and reduce implementation complexity. It develops a method to accurately estimate circuit parameters, and thus improving the overall accuracy, relying only on the points provided by all commercial modules datasheet. The proposed modeling approach results in two simplified models demonstrating the advantage of fast simulation. The effectiveness of the modeling approach is thoroughly evaluated by comparing the simulation results with experimental data of solar modules made of mono-crystalline, multi-crystalline, and thin film. [ABSTRACT FROM PUBLISHER]

We have developed a circuit particle-in-cell (PIC) coupled model for simulating a pulsed power system, based on a circuit algorithm of a pulsed power supply and a PIC simulation for a magnetically insulated transmission line (MITL) system. The coupled algorithm comprises an external circuit algorithm based on BERTHA and a coupled algorithm for the PIC and circuit interface based on the Mur absorbing boundary condition. In this paper, a simple coaxial MITL with a single linear transformer driver (LTD) was simulated to validate the coupled model compared with PSPICE and BERTHA simulations. The numerical results show that the circuit–PIC coupled model achieved almost the same outputs on the load. The coupled model was then applied to an MITL system driven by ten LTD cavities. The simulation results and experimental results were in agreement, which confirms that the circuit–PIC coupled model could provide a reference for the structural design of experimental apparatuses. [ABSTRACT FROM PUBLISHER]

By the logical statements and linear inequalities, a new modeling method named bi-switching status modeling (BSM) method is presented to model the dc–dc converters in this paper. Compared with other modeling methods, such as the state-space averaging method and the mixed logical dynamical (MLD) method, first, the BSM method can describe continuous conduction mode and discontinuous conduction mode operations of the dc–dc converters as a unified bi-switching status model. Second, the BSM method is more precise than the state-space averaging method because there is no approximate assumption. Third, the constrains of the operating modes in the BSM method can be simplified as a consolidated inequality, which means that the model obtained by the BSM method is more concise than that obtained by the MLD method. Simulation and available experiments of a buck converter verify the effectiveness of the proposed BSM method. [ABSTRACT FROM PUBLISHER]

In this paper, average modeling and analysis of a dual-supercapacitor bank, actively balanced by a bidirectional buck–boost converter, is presented. In such a system, natural balancing is achieved when the converter is operated in open loop with 50% duty cycle, eliminating the need for measuring the voltage of each storage device. Nevertheless, excessive currents arise even for slight voltage misbalance because of the highly underdamped nature of the system. In order to remedy this drawback, bidirectional pulse-by-pulse inductor current limitation is introduced, which is equivalent to adding a peak-current-mode-like control loop to the system. Since the duty cycle never exceeds 50%, compensation ramp is not required to maintain stability. On the other hand, while the uncontrolled system dynamics is linear, introducing the current limit mechanism turns the closed-loop dynamics into a nonlinear one, burdening the analysis task and thus calling for suitable average model to perform fast simulations for system analysis. Therefore, dynamical equations of the system are developed in order to derive the switching-cycle-averaged model and reveal the tradeoff between current limit level, balancing time and efficiency for the worst case of imbalance. Simulations and experiments support the presented findings. [ABSTRACT FROM PUBLISHER]

A recently reported modeling methods for a switched capacitor converter either assume output as “firm” voltage or a resistor to facilitate calculation. When the size of output filter capacitor is moderate, accompanied by noticeable output ripple, previous modeling results may not provide accurate prediction and design guidelines. In this paper, a new modeling technique taking into account the output capacitor effect is proposed for simple dual-phase switched capacitor converters without complex coupling loops. The proposed model employs transient calculation, takes charge redistribution phase into account, and includes the duty cycle, switching frequency as well as output capacitor simultaneously in the final output impedance formula, which enhances accuracy of the model. It is suitable for interleaved and noninterleaved switched capacitor converters. The simulation and experimental results for the unity gain SC converter are provided to verify the proposed theory. [ABSTRACT FROM PUBLISHER]

Transient simulation programs, either nodal analysis-based electromagnetic transient program (EMTP-like) or state-variable-based, are used very extensively for modeling and simulation of various power and energy systems with electrical machines. It has been shown in the literature that the method of interfacing machine models with the external electrical network plays an important role in numerical accuracy and computational performance of the overall simulation. This paper considers the state-variable-based simulation packages, and provides a constant-parameter decoupled RL-branch equivalent circuit for interfacing the ac induction and synchronous machine models with the external electrical network. The proposed interfacing circuit is based on the voltage-behind-reactance formulation which has been shown to have advantageous properties. For the synchronous machines, this paper describes both implicit and explicit (approximate) interfacing methods. The presented case studies demonstrate the advantages of using the proposed interfacing method over the traditional qd-models that are conventionally used in many simulation packages. [ABSTRACT FROM AUTHOR]

This paper proposes a model that adequately describes the operation of the transformer at deep saturation, suitable for power-electronics applications, and a method for determining its parameters. Simulation and experimental results are presented to confirm the validity of the model and the method. [ABSTRACT FROM PUBLISHER]

Switched-mode power supplies (SMPS) are becoming an essential part of many electronic systems as the industry drives toward miniaturization and energy efficiency. However, practical SMPS design courses are seldom offered. In this paper, a generalized MATLAB/SIMULINK modeling technique is first presented. A proposed practical SMPS design course at Lunghua University, Taiwan, which incorporates this technique, is then described. In order to validate the correctness of the proposed modeling technique, four prototype SMPS are provided in this paper. These prototype circuits also serve as the laboratory section of the proposed course. The main objective of the course is to teach final-year undergraduate students and first-year Master's students how to design an SMPS in real life. The positive response from students indicates that the proposed technique is useful for SMPS design courses. [ABSTRACT FROM PUBLISHER]

This paper suggests a pedagogical approach to teaching the subject of behavioral modeling of switch-mode power electronics systems through simulation by general-purpose electronic circuit simulators. The methodology is oriented toward electrical engineering (EE) students at the undergraduate level, enrolled in courses such as “Power Electronics,” “Industrial Electronics,” or the like. The proposed approach is demonstrated by simulation example of a realistic active power factor corrector (APFC) system. The paper discusses the derivation of PSPICE/ORCAD-compatible behavioral models, their software implementation, and fast time domain, frequency domain, and stability analysis simulation techniques suitable for virtual study of complex nonlinear feedback systems. Some “tricks of the trade” are also suggested. The paper can be helpful to instructors of a “Virtual Power Electronics Laboratory” course wanting to conduct a software experiment on a PFC system. [ABSTRACT FROM AUTHOR]

This paper presents an improved semitheoretical fluorescent lamp model by including the effect of the lamp tube temperature on the lamp electrical parameters at different dimming levels. The experimental results have verified that the lamp tube temperature is a linear function of the lamp's input power and has significant influence on the lamp's electrical parameters during the dimming process. The comparison on the simulation and measurements shows that the improved lamp model can predict the lamp electrical characteristics accurately in a wide dimming range under both low- and high-frequency operations. [ABSTRACT FROM AUTHOR]

Process variations increasingly challenge the manufacturability of advanced devices and the yield of integrated circuits. Technology computer-aided design (TCAD) has the potential to make key contributions to minimize this problem, by assessing the impact of certain variations on the device, circuit, and system. In this way, TCAD can provide the information necessary to decide on investments in the processing level or the adoption of a more variation tolerant process flow, device architecture, or design on circuit or chip level. In this first of two consecutive papers, sources of process variations and the state of the art of related simulation tools are reviewed. An approach for hierarchical simulation of process variations including their correlations is presented. The second paper, also published in this issue, presents examples of simulation results obtained with this methodology. [ABSTRACT FROM AUTHOR]

This paper presents the evaluation of the performance, in terms of uncertainty, of a tool designed to estimate the main parameters of a model of a photovoltaic panel (PVP) under real and/or simulated working conditions. The presented tool permits the characterization of the panel, and it is useful to predict its behavior in whatever working condition; in this way, it is possible to compare the actual and expected performance to prevent any decrease in the output power, so permitting the replacement of the monitored module before it goes out of order or its efficiency falls under a given threshold. The well-known two-diode model is used to estimate the parameters of the electrical equivalent circuit of the PVP and to simulate the I–V and P–V characteristic curves in any given environmental condition of irradiance and/or temperature. The model and the estimation algorithm are implemented with MATLAB functions, whereas data acquisition and result presentation are managed by a LabVIEW graphics user interface. The presented tool has been validated against an experimentally characterized PVP. The environmental parameters of the model such as irradiance and temperature have been set (with their respective uncertainties) during simulations or directly measured during the outdoor tests, whereas the others parameters have been evaluated using a best-fit algorithm on the measured data. The estimation is based on the minimization of a new objective function and on a modified expression of the model resistances, which differ from those mentioned in the available literature. After a review of the state of the art, this paper provides the description of the estimation technique and its validation by means of simulations and experiments. Some results are also provided to illustrate the performance of the proposed test method. [ABSTRACT FROM AUTHOR]

Great interest has been devoted to the study of nonlinear transmission lines (NLTLs) for radio-frequency generation. The two better known configurations of NLTLs are a dispersive line consisting of sections with nonlinear components and a continuous nondispersive line called gyromagnetic line. The goal of this paper is to study the gyromagnetic line through the effects of changing the NLTL parameters. This is done based on an analytical model supported by SPICE circuit simulations and validation of results with numerical analysis, focusing on the pulse rise time compression. Different models are studied by comparing simulations with corresponding results found in the literature. Such a technique could be used for the design of NLTL for space applications and mobile defense platforms of compact size. [ABSTRACT FROM AUTHOR]

This paper proposes a new method of decoupling and subdividing electrical circuits, containing power-electronics devices, in order to achieve fast and accurate real-time simulation. In this technique, each state variable can be discretized using different discretization methods. Combining implicit and explicit ODE solvers, state-space equations are decoupled while remaining accurate and stable. Unlike most traditional decoupling techniques previously proposed, the proposed one does not require artificial delay or supplementary states to be added in order to decouple the system. Furthermore, this technique is meant to be implemented with commercially available simulation software. By doing so, a large and complex circuit containing several hundreds of state variables can be easily and accurately simulated with minor modification to the existing models. Finally, stability and accuracy of the proposed technique are thoroughly demonstrated in a numerical example during steady state and under faulty conditions. [ABSTRACT FROM PUBLISHER]

The need for multidisciplinary virtual prototyping in power electronics has been well established, however, design tools capable of facilitating a rapid iterative virtual design process do not exist. A key challenge in developing such tools is identifying and developing modeling techniques which can account for 3-D geometrical design choices without unduly affecting simulation speed. This challenge has been addressed in this paper using model order reduction techniques and a prototype power electronic design tool incorporating these techniques is presented. A relevant electrothermal power module design example is then used to demonstrate the performance of the software and model order reduction techniques. Five design iterations can be evaluated, using 3-D inductive and thermal models, under typical operating and start-up conditions on a desktop PC in less than 15 min. The results are validated experimentally for both thermal and electrical domains. [ABSTRACT FROM PUBLISHER]

The efficiency of multiterminal dc (MTDC) grid simulation decreases with an expansion of its scale and the inclusion of accurate component models. Thus, the variable time-stepping scheme is proposed in this paper to expedite the electromagnetic transient computation. A number of criteria are proposed to evaluate the time-step and regulate it dynamically during simulation. Meanwhile, as the accuracy of results is heavily reliant on the switch model in the modular multilevel converter, the nonlinear behavioral model with a greater accuracy is proposed in addition to the classic ideal model, and their corresponding variable time-stepping schemes are analyzed. Circuit partitioning is effective in accelerating the MTDC grid simulation via fine-grained separation of nonlinearities. A subsequent large number of identical circuits enabled a massively parallel implementation on the graphics processing unit, which achieved a remarkable speedup over the CPU-based implementation. The inclusion of variable time-stepping schemes eventually makes the simulation of MTDC grid with highly detailed nonlinear switch models feasible. The results are validated by commercial device-level and system-level simulation tools. [ABSTRACT FROM AUTHOR]

The modular multilevel converter (MMC) has attracted extensive research in recent years. An appropriate model is necessary to analyze stability or to design MMC controllers. Several published MMC models have been derived in single-phase form to simplify the modeling mathematics. However, little attention is given to the zero-sequence voltage, which introduces coupling in the single-phase model and leads to significant error. In this paper, after revealing the mechanism behind the zero-sequence voltage, a more accurate generalized single-phase MMC model is proposed, which eliminates the zero-sequence voltage coupling effect and is linearized based on harmonic state space (HSS) theory to precisely characterize the internal harmonic features of MMC. A systematic HSS modeling process is presented for both open-loop and closed-loop conditions. And the proposed model is generalized as it can incorporate different control strategy by controller transfer function substitution. Hence it is valuable to analyze MMC stability and dynamics. Model effectiveness is verified by simulation results. [ABSTRACT FROM AUTHOR]

In this paper, we formulate and solve the ac optimal power flow (AC-OPF) as an equivalent circuit problem in terms of current, voltage, and admittance state variables. The generator models are represented using conductance and susceptance state variables, and the operational and network constraints are translated to corresponding current/voltage constraints without loss of accuracy or generality. To understand the physics behind the optimality conditions of the optimization problem, we extend the linear adjoint circuit theory to translate them to equivalent circuit domain. It is shown that the operating point that defines the equivalent circuit solution precisely represents an AC-OPF solution. We then further exploit the equivalent circuit representation to use power flow simulation techniques to robustly solve the optimization problem. The efficiency of our approach is demonstrated for several AC-OPF benchmark test cases (up to 70 k buses) under nominal and congested operating conditions, and the runtime and scalability properties are presented. [ABSTRACT FROM AUTHOR]

Rail accelerators are superior to classical gas-driven accelerators with regard to attainable terminal velocity, ignition delay variation, and controllability. The behavior is generally described with a system of nonlinear differential equations, which can be solved in many ways. This is done in order to describe an existing launcher, to predict its performance when parameters change, or to estimate the properties of such a system in the design phase. This paper presents a simplified electromechanical system of differential equations in a novel form. This form enables scientists to solve the equations using one of the following software: Scilab, MATLAB, or a similar one. The model is robust and parameter changes have a low impact on the solving time. This makes it a reliable tool for parametric studies. The model comprises pulsed power capacitors, the pulse-forming network, cables, and the launcher itself. At first, the electrical part is described with its circuit equivalent and coupled with the mechanical process. Second, the system is analytically transposed to a standard form. This form is then transferred into the simulation software, which solves the equations. It can simply be adapted to other launchers and modified to comprise nonlinear side effects. The simulation results are compared with experimental results from the augmented rail accelerator at the French-German Research Institute of Saint-Louis, France. [ABSTRACT FROM PUBLISHER]

Visualizing the magnetic flux paths for wireless power transfer systems enables researchers and engineers to understand the operations and design the geometrical dimensions of the practical systems. However, time-domain transient simulations of 3-D electromagnetic fields of complex wireless power transfer systems with multiple coil-resonators are extremely time-consuming. This paper describes a fast hybrid approach that combines the time-domain coupled circuit modeling and the magnetostatic analysis to form a fast time-domain analytical tool for studying complex wireless power transfer systems. The proposed methodology has been successfully applied to several wireless domino-resonator systems. For the first time, the time-varying magnetic flux variations of wireless power domino-resonator systems can be visualized in computer simulations. [ABSTRACT FROM AUTHOR]

This paper presents an electric circuit-based battery and a capacity fade model suitable for electric vehicles (EVs) in vehicle-to-grid applications. The circuit parameters of the battery model (BM) are extracted using genetic algorithm-based optimization method. A control algorithm has been developed for the battery, which calculates the processed energy, charge or discharge rate, and state of charge limits of the battery in order to satisfy the future requirements of EVs. A complete capacity fade analysis has been carried out to quantify the capacity loss with respect to processed energy and cycling. The BM is tested by simulation and its characteristics such as charge and discharge voltage, available and stored energy, battery power, and its capacity loss are extracted. The propriety of the proposed model is validated by superimposing the results with four typical manufacturers’ data. The battery profiles of different manufacturers’ like EIG, Sony, Panasonic, and Sanyo have been taken and their characteristics are compared with proposed models. The obtained battery characteristics are in close agreement with the measured (manufacturers’ catalogue) characteristics. [ABSTRACT FROM PUBLISHER]

Owing to the lack of feasible fault modeling method, hard (open and short) faults, and discretized parametric faults are still the mostly used fault models. These models cannot characterize all soft (parameter shifting) faults because that the parameter of analog element be of continuity character. To address this concern, a complex field fault modeling method is presented first. If fault happens to passive element xi in linear analog circuit, the real (Ur) and imaginary (U\!j) parts of faulty voltage phasor \mathopU\kern0pt^\!\!\!\circ(\mathopU\kern0pt^\!\!\!\circ=Ur+j U\!j) must satisfy binary quadratic function Fi(Ur,U\!j)=0, which is independent from the value of element xi and uniquely determined by its location and the nominal circuit under test. Hence, the binary quadratic function can model any continuous parameter shifting (soft) or hard fault. Second, to avoid calculating the explicit expression of binary quadratic function, a simulation-based method is given to obtain the locus of the change in the function Fz in the complex plane. Besides, the nominal (fault-free) point, the loci determined by the binary quadratic functions might intersect with each other. It is referred to as aliasing problem in this paper. This problem can be solved by adjusting the frequency of the input signal. Therefore, a constraint optimization method is proposed to select optimal test frequencies. The proposed test generation and compression methods, when combined with the complex field modeling method, can pinpoint much more fault components with less test points and frequencies when compared with the other methods. [ABSTRACT FROM PUBLISHER]

Resonant power conversion leads to advantages such as soft switching and high-frequency operation; however, analysis and design of a resonant converter require an efficient methodology. In general, conventional methodologies use a design-oriented architecture, which requires previously specifications and iterative circuit-level simulations. This procedure is the simplest; notwithstanding, it can be time consuming and inaccurate for more complex systems, as resonant converters. This paper proposes a result-oriented architecture that is independent of specifications; in other words, real circuit parameters are waived in exchange for generalized results. A normalization procedure is proposed by using an equivalence transformation to modeling the system with a state vector composed of terms as the square roots of the stored energy in the reactive components. The system is represented in a dimensionless state-space model, in which the terms of the state-space matrices are composed of resonant parameters, such as normalized resonant frequencies and quality factor; thereby, the system is independent of circuit parameters, such as inductances, capacitances, and resistances. The sixth-order hybrid Ćuk converter is used to derivate the equations. Simulation results and an implementation of a 500-kHz hybrid buck converter are shown to compare theoretical, simulation, and experimental results. [ABSTRACT FROM AUTHOR]

In this paper, a straightforward methodology to modeling high power factor (HPF) ac–dc converters is presented. The proposed methodology is based on the averaging technique directly applied to the converter under modeling. An averaged large-signal equivalent circuit is thus generated, which is useful to perform extremely fast simulations. From the large-signal model, both a steady-state and a small-signal analysis can be carried out to completely model the converter, achieving any desired steady-state characteristic and small-signal transfer function. The presented methodology is very intuitive and allows designers to achieve a natural understanding of the converter behavior. The methodology is illustrated with a HPF buck–boost converter operating in discontinuous conduction mode. Simulation and experimental results are provided to validate the proposed methodology. [ABSTRACT FROM AUTHOR]

In this paper, we present a physics-based model for accurate simulation of intermodulation distortion (IMD) in GaAs pseudomorphic HEMTs at 2 GHz. We combine the surface-potential-based drain-current model previously developed by us with the standard topology used in these devices for accurate nonlinear simulations. The proposed model is in excellent agreement with measured IMD data at multiple dc bias points varying from close-to cutoff voltage to the high-conduction region. We also analyze the impact of various model elements and physical effects on IMD behavior of the device. Furthermore, the popular Volterra series coefficients for the drain current nonlinearity are analyzed and their relative importance with respect to the overall device nonlinearity is assessed. [ABSTRACT FROM PUBLISHER]

This paper presents a multiphysics simulation and layout design technique for complementary metal–oxide–semiconductor–microelectromechanical systems (MEMS) (CMOS-MEMS) based on an electrical circuit simulator. An equivalent circuit model for the mechanical equation of motion has been translated into a Verilog-A-compatible hardware description language (HDL) in the Cadence Virtuoso environment to attain new designing capabilities such as automatic mask-layout synthesis, design rule check, and layout-versus-schematic verification for MEMS structures. Microelectromechanical components such as parallel-plate actuator and bending suspension, whose analytical equation models are already known, are also interpreted into HDL-coded equivalent circuits. Behavior of a MEMS device, including the electrostatic displacement hysteresis and the negative spring constant effect, is numerically simulated as a lumped mass-and-spring system, which has been verified to quantitatively agree with that of the corresponding analytical simulation results. A multiphysics model for the Colpitts oscillator circuit has been built in the developed simulation environment by replacing a quartz resonator with a compact model of an electrostatic silicon resonator, and its self-excited resonance has been confirmed by the simulation after the coordination of the device and circuit parameters. A prototype conversion tool for MEMS parameterized cell has also been developed to demonstrate automatic generation of mask layouts for a silicon resonator, which has been cross-checked against the experimental measurements to verify the simulation accuracy.\hfill[2012-0365] [ABSTRACT FROM AUTHOR]

The performance of a photovoltaic (PV) module is mostly affected by array configuration, irradiance, and module temperature. It is important to understand the relationship between these effects and the output power of the PV array. This paper presents a MATLAB-Simulink-based PV module model which includes a controlled current source and an S-Function builder. The modeling scheme in S-Function builder is deduced by some predigested functions. Under the conditions of nonuniform irradiance, the model is practically validated by using different array configurations in testing platform. The comparison experiments indicate that I–V and P–V characteristic curves of simulation match the measurements from outdoor experiment well. Under the conditions of nonuniform irradiance, both simulation and experiment show that the output power of a PV array gets more complicated due to multiple peaks. Moreover, the proposed model can also simulate electric circuit and its maximum power point tracking (MPPT) in the environment of MATLAB-Simulink. The experiments show that the proposed model has good predictability in the general behaviors of MPPT under the conditions of both nonuniform and uniform irradiance. [ABSTRACT FROM AUTHOR]