Arbitrary full-state hybrid projective synchronization for chaotic discrete-time systems via a scalar signal

In this paper we present a new projective synchronization scheme, where two chaotic （hyperchaotic） discrete-time systems synchronize for any arbitrary scaling matrix. Specifically, each drive system state synchronizes with a linear combination of response system states. The proposed observer-based approach presents some useful features： i） it enables exact synchronization to be achieved in finite time （i.e., dead-beat synchronization）; ii） it exploits a scalar synchronizing signal; iii） it can be applied to a wide class of discrete-time chaotic （hyperchaotic） systems; iv） it includes, as a particular case, most of the synchronization types defined so far. An example is reported, which shows in detail that exact synchronization is effectively achieved in finite time, using a scalar synchronizing signal only, for any arbitrary scaling matrix.

Local Hybrid Linear State Estimation for Electric Power Systems Using Stream Processing

The increasing penetration of renewable energy resources with highly fluctuating outputs has placed increasing concern on the accuracy and timeliness of electric power system state estimation(SE).Meanwhile,we note that only a fraction of system states fluctuate at the millisecond level and require to be updated.As such,refreshing only those states with significant variation would enhance the computational efficiency of SE and make fast-continuous update of states possible.However,this is difficult to achieve with conventional SE methods,which generally refresh states of the entire system every 4–5 s.In this context,we propose a local hybrid linear SE framework using stream processing,in which synchronized measurements received from phasor measurement units(PMUs),and trigger/timingmode measurements received from remote terminal units(RTUs)are used to update the associated local states.Moreover,the measurement update process efficiency and timeliness are enhanced by proposing a trigger measurement-based fast dynamic partitioning algorithm for determining the areas of the system with states requiring recalculation.In particular,non-iterative hybrid linear formulations with both RTUs and PMUs are employed to solve the local SE problem.The timeliness,accuracy,and computational efficiency of the proposed method are demonstrated by extensive simulations based on IEEE 118-,300-,and 2383-bus systems.

Near-field characteristics of highly non-paraxial subwavelength optical fields with hybrid states of polarization

The vectorial structure of an optical field with hybrid states of polarization （SOP） in the near-field is studied by using the angular spectrum method of an electromagnetic beam. Physical images of the longitudinal components of evanescent waves are illustrated and compared with those of the transverse components from the vectorial structure. Our results indicate that the relative weight integrated over the transverse plane of the evanescent wave depends strongly on the number of the polarization topological charges. The shapes of the intensity profiles of the longitudinal components are different from those of the transverse components, and it can be manipulated by changing the initial SoP of the field cross-section. The longitudinal component of evanescent wave dominates the near-field region. In addition, it also leads to three-dimensional shape variations of the optical field and the optical spin angular momentum flux density distributions.

Complete Bell-state analysis for a single-photon hybrid entangled state

We propose a scheme capable of performing complete Bell-state analysis for a single-photon hybrid entangled state.Our single-photon state is encoded in both polarization and frequency degrees of freedom.The setup of the scheme is composed of polarizing beam splitters,half wave plates,frequency shifters,and independent wavelength division multiplexers,which are feasible using current technology.We also show that with this setup we can perform complete two-photon Bell-state analysis schemes for polarization degrees of freedom.Moreover,it can also be used to perform the teleportation scheme between different degrees of freedom.This setup may allow extensive applications in current quantum communications.

Inverse full state hybrid projective synchronization for chaotic maps with different dimensions

A new synchronization scheme for chaotic（hyperchaotic） maps with different dimensions is presented.Specifically,given a drive system map with dimension n and a response system with dimension m,the proposed approach enables each drive system state to be synchronized with a linear response combination of the response system states.The method,based on the Lyapunov stability theory and the pole placement technique,presents some useful features：（i） it enables synchronization to be achieved for both cases of n 〈 m and n 〉 m;（ii） it is rigorous,being based on theorems;（iii） it can be readily applied to any chaotic（hyperchaotic） maps defined to date.Finally,the capability of the approach is illustrated by synchronization examples between the two-dimensional H′enon map（as the drive system） and the three-dimensional hyperchaotic Wang map（as the response system）,and the three-dimensional H′enon-like map（as the drive system） and the two-dimensional Lorenz discrete-time system（as the response system）.

Estimation Method of State-of-Charge For Lithium-ion Battery Used in Hybrid Electric Vehicles Based on Variable Structure Extended Kalman Filter

Since the main power source of hybrid electric vehicle（HEV） is supplied by the power battery,the predicted performance of power battery,especially the state-of-charge（SOC） estimation has attracted great attention in the area of HEV.However,the value of SOC estimation could not be greatly precise so that the running performance of HEV is greatly affected.A variable structure extended kalman filter（VSEKF）-based estimation method,which could be used to analyze the SOC of lithium-ion battery in the fixed driving condition,is presented.First,the general lower-order battery equivalent circuit model（GLM）,which includes column accumulation model,open circuit voltage model and the SOC output model,is established,and the off-line and online model parameters are calculated with hybrid pulse power characteristics（HPPC） test data.Next,a VSEKF estimation method of SOC,which integrates the ampere-hour（Ah） integration method and the extended Kalman filter（EKF） method,is executed with different adaptive weighting coefficients,which are determined according to the different values of open-circuit voltage obtained in the corresponding charging or discharging processes.According to the experimental analysis,the faster convergence speed and more accurate simulating results could be obtained using the VSEKF method in the running performance of HEV.The error rate of SOC estimation with the VSEKF method is focused in the range of 5% to 10% comparing with the range of 20% to 30% using the EKF method and the Ah integration method.In Summary,the accuracy of the SOC estimation in the lithium-ion battery cell and the pack of lithium-ion battery system,which is obtained utilizing the VSEKF method has been significantly improved comparing with the Ah integration method and the EKF method.The VSEKF method utilizing in the SOC estimation in the lithium-ion pack of HEV can be widely used in practical driving conditions.

基于Hybrid State A^(*)与增强安全管道的直升机低空航迹规划

直升机低空突防已逐渐成为现代空战察打任务的核心,而低空航迹规划算法是实现该技术的关键。尽管现有的航迹规划算法已经被应用于实际低空突防任务,但基于“前端-后端”式的传统航迹规划算法依然存在规划航迹机动执行性差与复杂动态场景下易碰撞的缺陷。针对上述问题,本文提出一种基于Hybrid State A^(*)与增强安全管道的改进算法。首先,基于Hybrid State A^(*)算法的联合轨迹优化,可以在状态空间中完成兼顾直升机机动特性的初始航迹高效搜索,有效保证直升机航迹的可达性。其次,基于初始航迹膨胀的增强安全管道,将后端航迹优化参数限制在安全的可行域内,进而有效提升复杂动态场景下规划航迹的安全性。在实验环节,本研究结合ROS机器人仿真环境与Rviz数据可视化工具完成仿真验证,通过算法间的综合对比实验,论证了本研究所提算法对规划的航迹机动性与安全性有明显的提升。

Carbon nanotube supported PtOx nanoparticles with hybrid chemical states for efficient hydrogen evolution

Efficient electrocatalysts for hydrogen evolution reaction(HER) in alkaline solution are highly required for water splitting.Here we design an ultra-small PtOx nanoparticle with hybrid Pt chemical states on carbon nanotubes as highly efficient alkaline HER catalyst,which shows a low overpotential of 19.4 mV at 10 mA cm^(-2),a high mass activity of 5.56 A mg_(Pt)^(-1) at 0.1 V, and a stable durability for at least 20 h.The HER performance is better than that of the benchmark 20 wt% Pt/C while the Pt content in the catalyst is only about one tenth of that in Pt/C.It also represents one of the best catalysts ever reported for HER in alkaline solution.Synchrotron radiation X-ray absorption spectroscopy reveals that the efficient and stable alkaline HER performance can be attributed to the favorable design of hybrid chemical states of Pt with carbon nanotubes,which exhibits abundant surface Pt-O as active catalytic sites and forms stable Pt-C interfacial interaction to both anchor the NPs and improve the synergistic effect between catalyst and substrate.

Bias-induced reconstruction of hybrid interface states in magnetic molecular junctions

Based on first-principles calculations,the bias-induced evolutions of hybrid interface states inπ-conjugated tricene and in insulating octane magnetic molecular junctions are investigated.Obvious bias-induced splitting and energy shift of the spin-resolved hybrid interface states are observed in the two junctions.The recombination of the shifted hybrid interface states from different interfaces makes the spin polarization around the Fermi energy strongly bias-dependent.The transport calculations demonstrate that in theπ-conjugated tricene junction,the bias-dependent hybrid interface states work efficiently for large current,current spin polarization,and distinct tunneling magnetoresistance.But in the insulating octane junction,the spin-dependent transport via the hybrid interface states is inhibited,which is only slightly disturbed by the bias.This work reveals the phenomenon of bias-induced reconstruction of hybrid interface states in molecular spinterface devices,and the underlying role of conjugated molecular orbitals in the transport ability of hybrid interface states.

Hybrid entanglement concentration assisted with single coherent state

Hybrid entangled state （HES） is a new type of entanglement, which combines the advantages of an entangled po- larization state and an entangled coherent state. HES is widely discussed in the applications of quantum communication and computation. In this paper, we propose three entanglement concentration protocols （ECPs） for Bell-type HES, W-type HES, and cluster-type HES, respectively. After performing these ECPs, we can obtain the maximally entangled HES with some success probability. All the ECPs exploit the single coherent state to complete the concentration. These protocols are based on the linear optics, which are feasible in future experiments.

Quantum Teleportation via Hybrid Entangled States

In this paper, we study quantum teleportation of atomic states via a hybrid entangled state （HES） involving an atom and a cavity field. And we investigate how to implement controlled phase （CP） gates between atomic internal states and coherent states of cavity field. We also discuss the methods of distinguishing coherent states [±α〉 in a cavity. Finally, a brief discussion about the feasibility of this scheme in experiment is presented.

Quantum state transfer via a hybrid solid–optomechanical interface

We propose a scheme to implement quantum state transfer between two distant quantum nodes via a hybrid solid–optomechanical interface. The quantum state is encoded on the native superconducting qubit, and transferred to the microwave photon, then the optical photon successively, which afterwards is transmitted to the remote node by cavity leaking,and finally the quantum state is transferred to the remote superconducting qubit. The high efficiency of the state transfer is achieved by controllable Gaussian pulses sequence and numerically demonstrated with theoretically feasible parameters.Our scheme has the potential to implement unified quantum computing–communication–computing, and high fidelity of the microwave–optics–microwave transfer process of the quantum state.

燃料电池-锂电池混合供电系统的无源控制策略及参数设计方法

多源混合供电技术可有效地利用不同供电单元性能,在电气化交通系统中得到广泛应用。然而,随着越来越多的恒功率特性及强脉动特性负载接入供电系统,系统的稳定性难以得到保证。针对传统线性控制方法难以保证系统的大信号稳定性,而现有非线性控制的研究仍缺乏兼顾稳定性和动态性能的控制参数设计方法的问题,该文对燃料电池-锂电池混合供电系统设计基于无源控制和扩张高增益状态观测器的复合控制方法,并对控制器和观测器参数进行了设计,有效地保证了系统的动静态性能。在实验室搭建一套额定功率为3 kW的燃料电池-锂电池混合供电系统实验平台进行测试,结果验证了所提控制策略和参数设计方法的有效性和正确性。

基于MMC的超级电容与蓄电池混合储能系统及其混合同步控制策略

为满足储能系统提供惯量和一次调频支撑功能需要对多类型储能介质集中配置和优化调控的需求,针对基于模块化多电平换流器(modularmultilevelconverter,MMC)的新型混合储能系统(hybrid energy storage system,HESS)MMC-HESS,提出了混合同步控制(hybrid synchronous control,HSC)整体策略。MMCHESS采用模块化设计,将超级电容和蓄电池分别安置在高压直流母线侧和子模块内,具备高功率密度和高能量密度的优势。阐述了混合储能系统的拓扑结构和工作原理并采用混合同步控制策略提供系统惯量和一次调频功能及故障限流时的同步能力和孤岛并网切换功能,采用滤波器实现储能功率分配,采用荷电状态(state of charge,SOC)均衡控制实现蓄电池能量均衡。最后,基于硬件在环实验平台,验证了所提拓扑结构与控制策略的可行性和有效性。实验结果表明:所提混合储能系统及其控制策略具备惯量与频率支撑能力,在故障限流、正常并网、孤岛运行之间可灵活切换,能够有效发挥混合储能的综合优势,在中压配电网中具有良好的应用前景。

混合储能系统平抑光伏功率波动控制策略

论文提出了一种新的混合储能(HESS)功率分配控制策略,当光伏输出功率波动或者负载变化时,基于超级电容响应速度快、功率密度大的特点,优先让超级电容来平抑功率波动,然后将蓄电池作为后备储能装置,将超级电容的荷电状态(SOC)作为下垂(Droop)控制的输入,来保证超级电容工作在合理的荷电状态(SOC)区间内,论文通过与基于低通滤波算法的分频控制策略进行了对比,结果验证了论文的方法既降低了蓄电池的放电功率和充放电次数,也提高了蓄电池的循环使用寿命。

计及初始荷电状态的含混合储能微电网双层调度研究

针对含混合储能微电网调度中忽略光伏/风电出力波动及荷电状态变化,导致并网波动超限及混合储能内能量调度效率降低等问题,提出一种计及初始荷电状态的双层跟踪调度方法。上层控制通过预测控制模型对微电网内光伏/风电出力进行优化,建立微电网跟踪调度模型。基于上层调度模型,下层控制中确定混合储能调度日的荷电状态初值,应用动态规划算法对混合储能中蓄电池、超级电容的容量进行分配,并将荷电状态变化量反馈至上层预测控制模型,优化并网功率交互。以并网功率波动最小与混合储能系统的荷电状态偏差最小为目标对系统进行仿真实验。实验分析结果表明:采用的控制策略具有并网抑制功能,实现了良好的跟踪调度,兼顾了混合储能内不同储能元件的充放电特性,实现混合储能内功率协调配置。

铁路再生制动能量利用控制策略研究

随着电气化铁路的不断发展,节能降耗关乎铁路运营效益。本文以铁路机车再生制动能量为研究对象,通过对大秦铁路再生能量现状及变电所负荷特性进行分析,研究由能量融通装置和混合储能装置组成的再生制动能量利用系统方案;对系统结构、工作原理、分部控制策略以及对既有供电设备的保护方案进行阐述,并提出基于SOC反馈的模糊控制策略,对储能系统功率进行二次修正,使其充分利用混合储能系统的物理特性。通过结合实测数据的仿真,验证所提策略的有效性和可行性。

特高压混合三端直流输电系统定功率MMC交流故障穿越策略

送端采用电网换相换流器(LCC),受端采用模块化多电平换流器(MMC)的特高压混合直流输电系统是直流输电技术重要的发展方向之一。在该系统中,各换流站每极均由高、低两个阀组直流侧串联而成。当其受端MMC发生网侧故障时,现有穿越策略或将引起定有功功率MMC阀间均压环节失效,从而导致子模块电容过压的问题。针对该现象,首先梳理了系统在故障工况下面临的主要问题和矛盾;接着,重点针对阀间均压环节失效的内部机理进行了研究,并提出了一种基于有功功率限幅值的站间协调穿越策略,此外,为使其能够较好地适用于不对称故障,采用了一种零序电压注入的方法,以平衡不对称故障下相单元间的桥臂电流直流分量;最后,基于PSCAD/EMTDC仿真平台搭建了相关模型,通过仿真对比,验证了本文策略能够兼顾不同受端站的桥臂过流和子模块过压风险,实现交流故障的可靠穿越,并尽可能地提升了故障期间的功率传输能力。

State Flow混杂系统的BUCK变换器设计

尝试用包含连续状态变量和离散开关变量的混杂动态系统模型描述BUCK型DC-DC变换器。依据混杂系统的概念和模型,基于BUCK电路理论,采用一种新型控制方法,给出混杂系统的控制边界,建立BUCK电路中的变化器和控制器两个单元混杂机器。通过数学表达式对模型进行描述,阐述两个单元混杂机器联合工作流程。以24-12 V降压变换器的BUCK电源设计为例使用State Flow仿真和实验研究,验证了该方法的有效性。与传统平均法相比,基于混杂动态系统的模型中没有线性近似处理,理论上可以得到更加精确的模型,更高效实现对电力电子电路的控制。

基于光纤光栅传感技术与混合固态三维激光雷达扫描技术的隧道安全综合监测系统研究(上)

为解决传统的隧道变形监测方法存在测量效率低、可视化和自动化程度不高、实时性差等问题,在介绍光纤光栅传感技术原理和混合固态三维激光雷达扫描技术原理的基础上,提出基于光纤光栅传感技术与混合固态三维激光雷达扫描技术相结合的隧道安全综合监测系统总体结构,分析设备配置和工作原理。以云南省某铁路隧道1个月的实际数据为例,分析隧道安全综合监测系统监测数据,结果表明:由混合固态三维激光雷达扫描仪得到的可视化三维点云数据,能够完整展示隧道全息变形情况;采用布拉格光纤光栅传感器,能够实时动态监测隧道截面位移变化情况。通过以上2种监测方法的“点面结合”,经过综合分析,认为该时间段内该隧道结构安全稳定。研究成果对于提高隧道变形监测的智能化及准确性具有重要参考价值和现实意义。