温度对IMU微机械陀螺仪零偏影响及标定补偿

围绕对变温环境IMU中微机械三轴陀螺仪的零偏值误差进行补偿,由于零偏值程的非线性趋势,常规线性拟合方法无法精确进行补偿。首先通过实验和资料分析得到影响零偏值的各个因素,并推导出零偏的模型。为对零偏值进行精度补偿,提出线性拟合法和分段插值法。在温度-25～＋40℃采用线性方法和分段拟合方法分别补偿,通过两种方法补偿结果对比得出,分段拟合方法的精度比线性拟合方法的精度在x、y、z轴分别提高0.1053°/s、0.2574°/s、0.2339°/s,从而选择分段插值方法进行补偿,补偿结果比较理想。     

A new decoupling design of self‐tuning multivariable generalized predictive control

A novel robust decoupling method with multivariable generalized predictive control (MGPC) for a class of nonlinear systems is presented in an adaptive version. The cross‐coupling action and the non‐linear actors of the system are identified on‐line by a neural network. A feedforward compensation based on generalized predictive control, is proposed for decoupling control. A modified recursive least‐squares (RLS) algorithm can be used to estimate the linear parameters for time‐varying systems. Simulations are carried out and the results show the effectiveness of the proposed algorithm. Copyright © 1999 John Wiley & Sons, Ltd.     

Leader-following consensus of fractional-order multi-agent systems via adaptive control

This article focuses on the consensus problem of leader-following fractional-order multi-agent systems (MASs) with general linear and Lipschitz nonlinear dynamics. First, the distributed adaptive protocols for linear and nonlinear fractional-order MASs are constructed, respectively. We allow the control coupling gains to be time varying for each agent. Moreover, the adaptive modification schemes for the control gain are designed, which renders smaller control gains and thus requires smaller amplitude on the control input without sacrificing consensus convergence. Second, based on fractional-order Lyapunov stability theorem and Barbalat's lemma, two novel sufficient conditions in terms of linear matrix inequalities are provided to ensure that the leader-following consensus can be obtained in the case for any undirected connected communication graph. Furthermore, we show that the proposed algorithm also works for consensus of agents with intrinsic Lipschitz nonlinear dynamics. As a result, the proposed framework requires no global information and thus can be implemented in a fully distributed manner. Finally, the numerical simulations are given to demonstrate the effectiveness of obtained the theoretical results.     

UPFC智能控制系统结构设计

通过分析现有统一潮流控制器UPFC(Unified Power Flow Controller)控制系统结构和常用的控制策略，描述了常规比例积分PI(Proportion Integration)控制等策略中存在的非线性和强耦合问题。基于智能控制领域的重要分支仿人智能控制理论HSIC(Human—Simulated Intelligent Control，提出了UPFC智能控制系统的结构设计，同时将电力控制系统分解为非线性系统和线性随动系统2个子系统，用以解决控制中的非线性和强耦合问题。     

互信息在电力系统中长期负荷预测中的应用

传统电力负荷预测方法常以电力负荷自身的历史序列特征外推预测未来负荷,或者用确定性相关关系来模拟少数几种电力负荷关联因素的影响,导致对负荷变化规律的把握存在缺陷.信息领域中的互信息理论用于分析两个随机变量间的相互依赖程度,其中包含了线性和非线性关联关系,用以描述电力负荷及其影响因素的关联程度,为进一步的预测工作提供依据.应用互信息理论,建立了电力负荷预测的互信息网络模型,根据各影响因素与电力负荷间的互信息对其量化、比较和逐层筛选,在得到各经济社会指标与负荷之间的关联程度的基础上,对未来负荷进行预测.将本模型应用于实际电力系统预测,得到了令人满意的预测结果.     

A Generalized Ritz Method and Its Application to Certain Nonlinear System Problems

Using the Ritz method (or Principle of Harmonic Balance), equations relating amplitude and phase to system parameters and driving function parameters are developed for an equation of the form x + 2wcoog(i) + w4f(x) = A cos wt, where g and f are monotonically increasing. The object of the development is to show the analogy to the linear case, and hence to extend the students' intuition for linear second-order systems to the above-mentioned class of nonlinear second-order systems.     

基于近似牛顿方向的多区域无功优化解耦算法

针对多区域电力系统的无功优化问题，提出了基于近似牛顿方向和GMRES算法的无功优化解耦算法。该算法以非线性原对偶内点法为基础，在迭代计算过程中构造近似牛顿方向，实现弱耦合系统的完全解耦，保证算法具有局部线性收敛特性，且其计算速度要比非线性原对偶内点法快。对于不能实现解耦的强耦合系统，以近似牛顿方向为初值和解耦对角阵作为预处理器，采用GMRES法求解，使算法具有良好的收敛性和较快的计算速度。以708节点系统作为试验系统验证所提算法的正确性和有效性，得到了满足所有等式和不等式约束的最优可行解。并以树型子系统分解法对其进行分解，对不同分解方案的计算结果进行了比较分析。     

Nonlinear FXLMS algorithm for active noise control systems with saturation nonlinearity

In active noise control (ANC) applications, the saturation effect of the loudspeaker in the secondary path is considered as the most serious problem that could degrade performance of standard filtered‐x least mean square (FXLMS) control algorithm. When the loudspeaker exhibits nonlinearities, the linear modeling approach fails to identify the secondary path accurately. In the literature, the nonlinear FXLMS (NLFXLMS) algorithm has been proposed to update the ANC controller with a block‐oriented secondary path model. This model consists of nonlinear and linear filters whereby the nonlinear part which represents the saturation effect of the amplifier‐loudspeaker system is modeled by a scaled error function (SEF). The NLFXLMS algorithm requires an exact copy of the linear and nonlinear models of the secondary path. However, NLFXLMS cannot be implemented in real time because the modeling of the SEF cannot be realized. In this paper, a new method to model the secondary path using the Hammerstein model structure and tangential hyperbolic function (THF) is proposed. The THF can represent the SEF to a certain degree of accuracy. Furthermore, the modeling of the THF can be realized using least mean square (LMS) algorithm and utilized in the NLFXLMS control scheme. Simulation results show that the performance of the THF‐based NLFXLMS algorithm is comparable with the SEF‐based NLFXLMS. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Frequency-domain analysis of ground electrodes buried in an ionized soil when subjected to surge currents: A MoM-AOM approach

A frequency-domain method is proposed for the transient analysis of grounding systems with ionized soil. The method involves two stages. First, the grounding system is transformed into a nonlinear equivalent circuit, in which the frequency-domain circuit parameters of the grounding electrodes are extracted by the method of moment (MoM) and the nonlinear part of the equivalent circuit represents the soil ionization. Soil ionization is represented by a nonlinear load whose characteristics can be specified based on either experimental data or theoretical models, without any limitations in the order of nonlinearity. In the second stage the nonlinear equivalent circuit is treated using the arithmetic operator method (AOM). The AOM uses a linear matrix transformation of spectra to perform basic arithmetic operations in the frequency-domain. The main feature of the proposed method is its efficiency in dealing with the nonlinear behavior of soil ionization in the frequency-domain solution of grounding systems by the MoM. It also enables one to consider the actual nonlinear behavior of soil ionization specified by experimental data or appropriate theoretical models.     

Physical time domain representation of powers in linear andnonlinear electrical circuits

This paper presents a time domain model for the representation of powers in linear and nonlinear electrical circuits. The model can account, in a physical (or engineering) sense, for “active and reactive powers” as functions of time. The model is based on the time domain decomposition of the instantaneous power p(t) into two components: p(f)=a(t)+r(t). Where, a(t) represents the instantaneous power consumed by the (linear or nonlinear) load. The information regarding the store/restore process is contained in r(t). In contrast with the traditional frequency domain model, in which powers are defined orthogonally (i.e. S²=P²+Q²+D² +…) and therefore they do not interact with each other, the proposed model permits the interaction of active and reactive powers at every instant. Using the model of the paper, the authors can obtain the instantaneous power needed for compensation of both wave shape and power factor     

中国颜色体系样品色度坐标标准值的确定

本文依据中国颜色体系试验样品测量值，参照国际上其它颜色体系的指导原则，遵照颜色视觉规律，用数学方法计算确定了中国颜色体系样品的颜色标号值（ＨＶＣ）和国际照明委员会（ＣＩＥ）三刺激值及色度坐标（Ｙ，ｘ，ｙ）之间的关系，即中国颜色体系颜色样品理论值。该值已在国家标准《中国颜色体系》中作为中国颜色体系颜色样品标准值采用。     

Nonlinear dynamics of semiconductor lasers with mutual optoelectronic coupling

Mutually coupled oscillators are currently of great interest because of the important insight they provide into coupled physical, chemical, and biological systems. Two semiconductor lasers with optoelectronic feedback are used as two nonlinear oscillators, and the effect of mutual coupling on these lasers is found to be significant. Depending on the operating conditions, mutual coupling can act as a negative feedback to stabilize the coupled oscillators, or it can increase the complexity of the system inducing a highly complex chaos. A quasi-periodicity and period-doubling bifurcation, or a mix of them, is found in such a system. Although the chaotic waveforms are very complex with broad spectra, a high quality of synchronization between the chaotic waveforms is observed. Such synchronization is achieved because of the effect of mutual coupling and the symmetric design between the two lasers. It is found that the time delay of coupling plays an important role on the dynamics and synchronization in the mutually coupled semiconductor lasers.     

Nonlinear analysis of heart rate and respiratory dynamics

The authors' findings show that quantitative measures of complexity (correlation dimension, CD) and predictability (Lyapunov exponent, LE) provide significant information about autonomic nervous system (ANS) processes. There is well-organized nonlinear behavior of heart rate variability (HRV) and respiratory movements (RESP), which can be interpreted with regard to terms such as nonlinear stochastic, regular deterministic, and chaotic. The clear identification of a physiological process only on the basis of a measured time series is difficult. Distinguishing between chaotic and nonlinear correlated stochastic processes, in particular, needs more information than that of a positive LE, noninteger CD, and nonlinearity. The additional considerations of model investigation and phase locking make chaotic underlying processes of HRV and RESP in S1 probable. The hypothesis that deviations from the normal function lead to a decreased complexity and increased predictability could be confirmed quantitatively by the estimation of CD and LE during S2 and S3. This information, which can not be found by a linear approach to time series analysis, is important for the understanding of normal and pathologically disturbed functions. The authors do not claim that their analysis replaces linear methods, but rather that a consideration of both linear and nonlinear properties may improve diagnostic classifications. The potential usefulness of dynamic nonlinear analysis presented herein is in the improved understanding of the complex processes of the ANS, and in the resulting medical concepts with regard to pathophysiological disturbances and their treatment     

含电动汽车充电站商业型虚拟电厂的日前调度优化策略研究

研究商业型虚拟电厂运行机制能为新能源电源入网提供一定的技术支撑。将风力发电系统、光伏发电系统、储能系统、电动汽车充电站整合为一个虚拟发电厂,可显著降低因新能源单独并网时的出力不确定性及电动汽车无序充电对电网造成的不良影响,减轻电网压力,并可有效促进新能源消纳。以虚拟电厂经济效益最优为目标,在满足各约束条件的前提下,对其进行调度优化策略研究。通过线性惯性权重粒子群算法及非线性惯性权重粒子群算法对所提模型进行求解,结果表明采用非线性惯性权重粒子群算法不仅能避免过早收敛陷入局部最优而且得到的效益更高。通过算例验证了该模型的合理性及求解方法的有效性。     

基于隐马尔科夫树模型的小波域压缩采样信号重构方法

压缩传感理论利用信号的稀疏性,对其非自适应线性投影进行压缩采样,通过最优化问题准确重构原始信号。传统重构算法仅利用了信号的稀疏性,而未对转换后的信号结构进行分析。提出了一种基于4状态的隐马尔科夫树模型的小波域压缩采样信号的重构方法,相对2状态的隐马尔科夫树模型,该模型能够获取相邻尺度小波系数的更多相关特性,通过仿真结果表明,该算法具有更高的重构精度。     

Adaptive sliding mode observers for sector-bounded nonlinear systems

This article introduces a novel sliding mode observer design for sector bounded nonlinear systems. The proposed observer can simultaneously estimate both states and unknown parameters in the presence of disturbances and measurement noise. The observer is developed by using a time-averaged Lyapunov (TAL) functional to analyze the effect of noise (Gaussian) and to adequately reduce its effect on the system. The TAL averages the Lyapunov analysis over a small finite time interval, allowing for intuitive analysis of noises and disturbances acting on the system. The TAL is shown to satisfy all the requirements of a Lyapunov candidate function. The article focuses on the observer design for sector bounded nonlinear systems since several nonlinearities can be modeled using a sector bound. An optimization approach is also developed to provide a tight bound on the effect of the uncertainty on the estimated parameters. The conditions for the existence of the observer are presented in the form of linear matrix inequality (LMI), which can be explicitly solved offline using commercial LMI solvers. Furthermore, the LMI design is also extended to a specific case of a dissipative nonlinear system. The observer design has also been extended to the case where the input disturbance is correlated with the sensor noise.     

基于轨迹模式空间解耦及模式能量序列的振荡分析(一)理论基础

针对电力系统振荡行为的分析,揭示互补群群际能量观点与特征频率正弦幅值观点的异同,严格证明两者在哈密顿单机无穷大系统中的一致性。但非线性因素则可能在线性化分析中引入大误差,而时变因素及饱和等本质非线性因素还可能使平衡点特征根方法完全失效。为了克服这些困难,从实际受扰轨迹的互补群群际能量的观点出发,描述了复杂受扰系统的振荡特性。多机系统轨迹可以通过互补群惯量中心—相对运动(CCCOI-RM)变换,严格映射为一系列时变单机映象轨迹,并通过各映象系统的振荡能量反映原多机系统的振荡行为,包括多频率的时变非线性振荡。     

The effect of nonlinearities on the response of asingle-machine-quasi-infinite busbar system

A single-machine quasi-infinite busbar power system is formulated taking into consideration quadratic and cubic nonlinearities. The model equation contains parametric (time-varying coefficients) and external (inhomogeneous terms) excitations. The method of multiple scales is used to approximate the response of the system to simultaneous principal parametric resonances and subharmonic resonances of order one-half. In contrast with the linear analysis, the nonlinear analysis shows that the response can exhibit: (1) limit cycles instead of infinite motions; (2) multivaluedness that can lead to jumps; (3) subcritical instabilities; and (4) constructive and destructive interference of resonances     

单元机组负荷非线性预测控制及其仿真研究

大型单元机组负荷控制系统存在着强耦合、非线性等特性,常规线性控制策略难取得满意的控制效果。为此,该文提出了一种新的基于模糊模型和免疫优化的非线性预测控制方法,将离线辨识到的全局模糊模型作为预测模型,然后利用实数编码的免疫优化算法在线实现非线性预测控制的滚动优化,给出每个采样时刻的最优控制量。该方法还可通过修正的遗传算子方便地解决控制量受限问题。通过对一个500MW单元机组负荷控制系统的仿真试验,验证了该非线性预测控制方法的有效性。     

Experimental studies with a generalized neuron-based power system stabilizer

Artificial neural networks (ANNs) can be used as intelligent controllers to control nonlinear, dynamic systems through learning, which can easily accommodate the nonlinearities and time dependencies. However, they require large training time and large number of neurons to deal with complex problems. To overcome these drawbacks, a generalized neuron (GN) has been developed that requires much smaller training data and shorter training time. Taking benefit of these characteristics of the GN, a new power system stabilizer (PSS) is proposed. Results show that the proposed GN-based PSS can provide a consistently good dynamic performance of the system over a wide range of operating conditions.