混沌振荡与真空断路器动作特性之间相互作用的研究

本文主要研究了真空断路器的动作特性与混沌振荡之间的相互作用.以一个简化的电力系统模型为例,从系统分歧的观点出发,研究了在不同参数条件下,断路器的断开所引起的系统动态演变过程,并探讨了在混沌振荡制式条件下断路器的工作状况.     

Real‐time chaotic circuit stabilization via inverse optimal control

In this paper, an efficient approach is developed for real‐time global asymptotic stabilization of the chaotic Chen's circuit, as a typical example for chaotic circuit control. Based on a recently introduced methodology of inverse optimal control for nonlinear systems, a very simple stabilization control law, a linear state feedback, is electronically implemented for the desired global asymptotic stabilization. Both Chen's chaotic system and the designed controller are synthesized and realized by analog electronic components, with the aim of evaluating the physical performance of the real‐time control law and demonstrating the practicality of the control method, which is robust to some input uncertainties. Copyright © 2008 John Wiley & Sons, Ltd.     

Poles–zeros analysis and broadband equivalent circuit for on‐chip spiral inductors

Poles and zeros of the transfer function determine the performance and the key features of the circuit network, such as phase, gain, and bandwidth. In this paper, the contribution of the poles and zeros to the transfer function has been shown. The factors η_p and η_z are proposed to account for the poles contribution to the peak and the zeros contribution to the valley of transfer function, respectively. A novel broadband equivalent circuit combining the physics‐based circuit model and behavioral macro‐model (black‐box) network is proposed for accurately characterizing on‐chip spiral inductors. The physics‐based elements are extracted using the linear dependence of a set of characteristic functions on variables (such as ω²) or other functions in a certain frequency range. The macro‐model network described by rational functions is determined using vector fitting approaches. The proposed modeling method is validated by the on‐chip spiral inductor fabricated with 0.13‐µm SiGe BiCMOS aluminum process. Excellent agreements are obtained between the measured data and calculation for the proposed model up to 40 GHz. Copyright © 2015 John Wiley & Sons, Ltd.     

Data‐driven tuning of linear parameter‐varying precompensators

Methods for direct data‐driven tuning of the parameters of precompensators for linear parameter‐varying (LPV) systems are developed. Since the commutativity property is not always satisfied for LPV systems, previously proposed methods for LTI systems that use this property cannot be directly adapted. When the ideal precompensator giving perfect mean tracking exists in the proposed precompensator parameterization, the LPV transfer operators do commute and an algorithm using only two experiments on the real system is proposed. It is shown that this algorithm gives consistent estimates of the ideal parameters despite the presence of stochastic disturbances. For the more general case, when the ideal precompensator does not belong to the set of parameterized precompensators, another technique is developed. This technique requires a number of experiments equal to twice the number of precompensator parameters and it is shown that the calculated parameters minimize the mean‐squared tracking error. The theoretical results are demonstrated in simulation. Copyright © 2009 John Wiley & Sons, Ltd.     

Circuit implementation and model of a new multi‐scroll chaotic system

In this paper, a multi‐scroll chaotic system from the improved Chua's system is proposed. Moreover, non‐linear dynamics are analyzed including phase‐space trajectories, bifurcation diagrams, Poincaré maps and so on. The most important thing is that we discovered phase‐space trajectories, bifurcation diagrams and Poincaré maps are unified and closely related, which can describe different aspects of the multi‐scroll chaotic system. Furthermore, the corresponding improved module‐based circuits are designed for realizing two to four‐scroll chaotic attractors, and the experimental results are also obtained, which are consistent with the numerical simulations. Copyright © 2012 John Wiley & Sons, Ltd.     

Adaptive control for a class of uncertain linear parameter‐varying flight aircraft systems

The concept of linear parameter‐varying (LPV) model has been developed as a convenient framework to describe a special class of uncertain LPV flight aircraft systems. In this paper, an adaptive control method for a class of uncertain LPV systems whose state‐space matrix elements are unknown affine functions of a set of measurable scalar parameters is presented. Firstly, the scalar parameters are separated from the state matrices such that the LPV model is rewritten as general unknown parameter model, then state feedback adaptive control laws, in both cases: the matched uncertainty and the unmatched uncertainty, are designed with the aim of controlling the system state to follow a desired trajectory. The sufficient condition of stability is derived using a Lyapunov equation, not a parameterized Lyapunov equation. Simulation tests based on a simple example and a nonlinear model of a transport aircraft are given to illustrate the effectiveness of the control algorithm and to demonstrate that the adaptive controller satisfies the performance requirement for an aircraft control system. Copyright © 2016 John Wiley & Sons, Ltd.     

Complete bifurcation analysis of a chaotic attractor in an electric circuit with piecewise‐smooth characteristics

We investigate the bifurcation phenomena of chaotic attractors observed in electric circuits with piecewise‐smooth characteristics. First, we present a circuit model whose switching action depends on its own state and on the clock interval. Next, we explain the behavior of the waveform. Following this, we sample the waveform at every clock period to define the return map, which is vital for a detailed understanding of the circuit dynamics. Finally, bifurcation phenomena of chaotic attractors are classified into four cases with a focus on the invariant interval. In particular, we discuss the characteristics of each bifurcation phenomenon, and then clarify the bifurcation structure of the chaotic attractor. Moreover, some of the numerical results are verified experimentally. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

一种空间用双向直流斩波电路拓扑

针对空间环境应用的限制,提出一种空间用双向直流斩波电路拓扑。将放电变换器和充电变换器结合在一个变换器拓扑中,使得空间用电源系统体积更小、重量更轻以及功率密度更高。对提出的电路拓扑双向工作原理进行详细分析,对其升压过程和降压过程的电路增益进行理论推导。采用电压外环和电流内环的双环控制策略实现电路的升压和降压,完成电源系统的放电和充电过程。搭建计算机仿真模型和物理实验平台进行仿真和实验验证,结果表明提出的拓扑正确可行。     

Physics‐based model of lithium‐ion batteries running on a circuit simulator

The authors developed a physics‐based equivalent circuit model of a lithium‐ion battery (LIB) whose parameters are continually updated, reflecting the theoretical calculation results of the Butler‐Volmer equation, diffusion equations of the lithium‐ion and lithium, and Nernst equations of the liquid and solid phases. The developed model was applied to the charge/discharge simulations of an LIB, and the experimental and simulated results of constant current discharges and pulsed‐charge/discharge were found to be in excellent agreement. In particular, using the developed model, analyzing transient responses of the LIB derived from the transition of the electric double layer charging to the electrode reaction is possible. These results demonstrate that the electrochemical performance of an LIB can be calculated on a circuit simulator using the developed model.     

Efficient extraction of equivalent circuit parameters for interconnect structures based on the Battle‐Lemarie scalet in the method of moments

Battle‐Lemarie father wavelet is used as a basis function in the method of moments (MoM) for solving interconnect and packaging problems and extracting circuit parameters needed in signal integrity. As the Battle‐Lemarie father wavelet or scalet is continuous, symmetric, and much more smooth compared with other wavelets like Franklin, Daubechies, and Coifman wavelets, it is more suitable as a basis function in the MoM for the electromagnetic modeling and simulation of interconnect structures because the unknown functions are involved in derivative operators in the integral equations. Also, the Battle‐Lemarie scalet is easier to construct and implement compared with multiwavelets, which are also continuous and smooth; hence, it requires less computational costs. The numerical examples for the circuit parameter extraction of single trapezoidal interconnect and asymmetric dual interconnects are presented to demonstrate the robustness of the scheme. Copyright © 2010 John Wiley & Sons, Ltd.     

The design and implementation of a multi‐wing chaotic attractor based on a five‐term three‐dimension system

The last two decades have seen great progress about the generation and circuit realization of multi‐wing chaotic attractor. In this paper, several multi‐scroll chaotic attractors are generated from a five‐term system by adding a piecewise linear function. Moreover, some basic properties in terms of symmetry and dissipation, equilibrium points, eigenvalues of the Jacobian matrices, Lyapunov exponent spectrum, bifurcation diagram, and Poincaré map are studied. In particular, an analog circuit is designed to implement the proposed multi‐scroll attractors, which are different from the traditional attractors. Furthermore, an integrated circuit diagram is designed to realize the fractional‐order multi‐scroll attractors. Finally, the performed experimental results confirm the theoretical analysis, and our work lends itself to many potential applications in engineering. Copyright © 2015 John Wiley & Sons, Ltd.     

A matrix‐exponential decomposition‐based time‐domain method for band structure calculation of one‐dimensional periodic structures

A time‐domain method for calculating the band structure of one‐dimensional periodic structures is proposed. During the time‐stepping of the method, the column vector containing the spatially sampled field data is updated by multiplying with an iteration matrix. The iteration matrix is first obtained by using the matrix‐exponential decomposition technique. Then, the small nonzero elements of the matrix are pruned to improve its sparse structure, so that the efficiency of the matrix–vector multiplication involved in each time‐step is enhanced. The numerical results show that the method is conditionally stable but is much more stable than the conventional finite‐difference time‐domain (FDTD) method. The time‐step with which the method runs stably can be much larger than the Courant–Friedrichs–Lewy (CFL) limit. And moreover, the method is found to be particularly efficient for the band structure calculation of large‐scale structures containing a defect with a very high wave speed, where the conventional FDTD method may generally lose its efficiency severely. For this kind of structures, not only the stability requirement can be significantly relaxed, but also the matrix‐pruning operation can be very effectively performed. In the numerical experiments for large‐scale quasi‐periodic phononic crystal structures containing a defect layer, significantly higher efficiency than the conventional FDTD method can be achieved by the proposed method without an evident accuracy deterioration if the wave speed of the defect layer is relatively high. Copyright © 2016 John Wiley & Sons, Ltd.     

Real‐time identification of nonlinear multiple‐input–multiple‐output systems with unknown input time delay using Wiener model with Neuro‐Laguerre structure

In this article, a real‐time block‐oriented identification method for nonlinear multiple‐input–multiple‐output systems with input time delay is proposed. The proposed method uses the Wiener structure, which consists of a linear dynamic block (LDB) followed by a nonlinear static block (NSB). The LDB is described by the Laguerre filter lattice, whereas the NSB is characterized using the neural networks. Due to the online adaptation of the parameters, the proposed method can cope with the changes in the system parameters. Moreover, the convergence and bounded modeling error are shown using the Lyapunov direct method. Four practical case studies show the effectiveness of the proposed algorithm in the open‐loop and closed‐loop identification scenarios. The proposed method is compared with the recently published methods in the literature in terms of the modeling accuracy, parameter initialization, and required information from the system.     

Advanced closing switch for three‐phase short‐circuit test of a very fast current limiter

Advanced closing switch for three‐phase short‐circuit test was developed for very fast current limiter using power electronics devices. The conventional short‐circuit test method was used for verification of the current interrupting device with longer time duration to interrupt fault current after the separation of contacts. In the conventional short‐circuit test method, a deviation of the closing time between each phase closing switch with a mechanical driving was regulated so that the breaking performance of the conventional switching device could be examined. However, in the new current limiter with very short fault current interruption time, the deviation time between each phase must be reduced less than the regulated time by the conventional test method. For this purpose, the advanced closing switch for three‐phase short‐circuit test method was developed. In the advanced test method, power electronics devices were used for the initiation of three‐phase short‐circuit fault. Results of the short‐circuit test showed that the advanced circuit had very small deviation time between the initiation of each phase fault. Also, the very fast current limiter with power electronics devices was shown to have an intended interrupting performance. © 1999 Scripta Technica, Electr Eng Jpn, 130(1): 68–75, 2000     

Implementation of the symmetric doped double‐gate MOSFET model in Verilog‐A for circuit simulation

Recently we developed a model for symmetric double‐gate MOSFETs (SDDGM) that, for the first time, considers the doping concentration in the Si film in the complete range from 1×10¹⁴ to 3×10¹⁸ cm⁻³. The model covers a wide range of technological parameters and includes short channel effects. It was validated for different devices using data from simulations, as well as measured in real devices. In this paper, we present the implementation in Verilog‐A code of this model, which allows its introduction in commercial simulators. The Verilog‐A implementation was optimized to achieve reduction in computational time, as well as good accuracy. Results are compared with data from 2D simulations, showing a very good agreement in all transistor operation regions. Copyright © 2009 John Wiley & Sons, Ltd.     

CMOS weak‐inversion log‐domain glycolytic oscillator: a cytomimetic circuit example

This paper presents a 3 V, 1.21μW subthreshold log‐domain circuit which mimics the oscillations observed during the biochemical process of glycolysis due to the phosphofructokinase enzyme. The proposed electronic circuit is able to simulate the dynamics of the glycolytic oscillator and represent the time‐dependent concentration changes of the reactants and the products of the chemical process based on nonlinear differential equations which describe the biological system. By modifying specific circuit parameters, which correspond to certain chemical parameters, good agreement between the biochemical and electrical model results has been reached. The paper details the similarities between the equations that describe the biochemical process and the equations derived from the circuit analysis of a transistor and a source‐connected linear capacitor, a topology also known as the Bernoulli Cell. With the use of the Bernoulli Cell formalism, the chemical equations which describe the biochemical system have been transformed into their electrical equivalents. The analog circuit, which implements the whole process, has been synthesised, and simulation results including Monte Carlo analysis are provided, in order to verify the robustness of the proposed circuit and to compare its dynamics with prototype biological behaviour. Copyright © 2012 John Wiley & Sons, Ltd.     

Direct design from input/output data of a fault‐tolerant control system based on GIMC structure

This paper deals with a method for the design of a fault‐tolerant control system based on the Generalized Internal Model Control (GIMC) structure, consisting of a standard outer loop feedback controller and an extra inner loop controller. The distinguishing feature of the GIMC structure is that controller design for performance and robustness may be performed separately. The outer loop controller is designed for nominal performance using some controller synthesis to meet the (nominal) control specification, while the inner loop controller is designed to make a trade‐off between robustness and performance. This feature is suitable for fault‐tolerant control. The outer loop controller is designed for the fault‐free case, and the inner loop controller for the fault‐time case. In the conventional methods, the inner loop controller is designed to maximize the robust stability margin without fault information. Therefore, the performance in the fault‐time case tends to become conservative. In this paper, the inner loop controller is directly designed from experimental data collected from the faulty system. Since the collected data contains information on the fault, conservativeness in the conventional methods is decreased. The inner loop controller is designed by Virtual Reference Feedback Timing (VRFT). VRFT is a method of direct design from input‐output data without identifying any models. Since the complexity of the controller can be specified by the designer, no complexity reduction is necessarily required, which is advantageous in implementation. The effectiveness of the proposed design method is confirmed by an experiment. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(4): 53–62, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20929     

Non‐linear circuit modelling via nodal methods

We discuss in this paper several interrelated nodal methods for setting up the equations of non‐linear, lumped electrical circuits. A rather exhaustive framework is presented, aimed at surveying different approaches and terminologies in a comprehensive manner. This framework includes charge‐oriented, conventional, and hybrid systems. Special attention is paid to so‐called augmented node analysis (ANA) models, which somehow articulate the tableau and modified node analysis (MNA) approaches to non‐linear circuit modelling. We use a differential–algebraic formalism and, extending previous results proved in the MNA context, we provide index‐1 conditions for augmented systems, which are shown to be transferred to tableau models. This approach gives, in particular, precise conditions for the feasibility of certain state‐space reductions. We work with very general assumptions on device characteristics; in particular, our approach comprises a wide range of resistive devices, going beyond voltage‐controlled ones. Copyright © 2005 John Wiley & Sons, Ltd.     

Theoretical and experimental analysis of a simple PWM‐1 controlled interrupted electric circuit

In this paper, we analyze a simple PWM‐1 controlled interrupted electric circuit in order to essentially understand the circuit fundamental characteristics. First, we explain the circuit dynamics, and then we define the return map by using the exact solution. Next, we focus on the existence region of the solution (invariant interval) and bifurcation phenomena in the circuit. In particular, we find the circuit has three types of the invariant interval depending on the parameter. We also clarify that the period‐doubling bifurcation and the border‐collision bifurcation effect in the existence region of the periodic solution in a wide parameter plane. Finally, the mathematical results are verified by the laboratory experiment. Copyright © 2012 John Wiley & Sons, Ltd.     

Effects of output power fluctuation on short‐circuit current of induction‐type wind power generators

Effects of the fluctuation inherent in wind speed are studied by a probabilistic method. The random variation in wind speed is responsible for random behavior in output power and internal voltage of a wind power generator. In case of fault occurrence at the instant of high internal voltage, the resultant short‐circuit current will be big, and vice versa. The DC component is also affected. According to the study, 2.4% and 1.3% increase of short‐circuit current in AC and DC components are observed respectively in a large variation case. This implies that the wind speed variation should be considered for accurate short‐circuit study. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(3): 27–36, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20721