Sliding Mode Control Approach for Electrically Controllable Clutch of AMT Based on the Feedback Linearization

A sliding mode control approach based on the feedback linearization is proposed for the electrically controllable clutch of AMT vehicles. The nonlinear dynamic model for the hydraulic actuator associated with clutch is established. By means of the exact feedback linearization procedure of differential geometry, an equivalent, fully controllable and linear model is derived via a homomorphic transformation for the AMT clutch system.Furthermore, a sliding mode control is introduced to improve robustness. The tracking tests are performed using the sliding mode control on a Santana LX passenger car, and the experimental results prove that this nonlinear controller is of fine robustness and high degree of tracking accuracy.

For Propulsion Applications It Is Possible to Utilize Both the Torque Output of the Rotor and the Reactional Torque Acting on the Stator of the Driving Electric Motor by Linearizing the Stator

This paper presents a novel idea of utilizing the reactional torque of the conventional electric motor as a linear output for propulsion in addition to the conventional torque output of the rotor. The idea is demonstrated by a theoretical proposal of linearizing the stator of one of the most used motors in Electrical Vehicles and Hybrid Vehicles. The proposed Linear Stator Motor is a simple modification without involving any functional change of the conventional motor. Though theoretical, the indicated possible input energy saving of more than 75% as compared to the conventional motor is no surprise, as by linearizing the stator, an almost equal linear propulsion output is added to the conventional rotor output. In addition to this remarkable saving in input energy, the proposed Linear Stator Motor that suits all types of vehicles, can maintain propulsion without the need for a mechanical transmission system. Also, in the case of watercraft and aircraft vehicles, no external mechanical propulsion drive system is required. It is just an internal force that can push the vehicle forward, backward, or laterally, while the conventional rotor output can be utilized for energy recovery by driving a DC generator.

Fault Diagnosis Based on Graph Theory and Linear Discriminant Principle in Electric Power Network

In this paper, we adopt a novel topological approach to fault diagnosis. In our researches, global information will be introduced into electric power network, we are using mainly BFS of graph theory algorithms and linear discriminant principle to resolve fast and exact analysis of faulty components and faulty sections, and finally accomplish fault diagnosis. The results of BFS and linear discriminant are identical. The main technical contributions and innovations in this paper include, introducing global information into electric power network, developing a novel topological analysis to fault diagnosis. Graph theory algorithms can be used to model many different physical and abstract systems such as transportation and communication networks, models for business administration, political science, and psychology and so on. And the linear discriminant is a procedure used to classify an object into one of several a priori groupings dependent on the individual characteristics of the object. In the study of fault diagnosis in electric power network, graph theory algorithms and linear discriminant technology must also have a good prospect of application.

Nonlinear Control Model of Synchronous Motor with Excitation and Damper Windings

In this paper, a new control method for synchronous motor with excitation and damper windings is presented. It is based on one type of nonlinear control; feedback linearization control. To make a realization in the sense of electric drive, symmetricM space vector PWM （pulse width modulation） is applied. Estimation of damper winding currents via Lyapunov function for the whole estimated system is done. The aim of control is to make tracking system for rotor speed and square of stator flux. Simulation of motor starting to predefined operating points is done, and also maintaining these points during step change of load torque is obtained. Simulations give good results.

Design, Construction and Ocean Testing of Wave Energy Conversion System with Permanent Magnet Tubular Linear Generator

In this paper, the design, construction and ocean testing of a wave energy conversion system are studied. Based on the motion characteristics of double buoys in ocean waves, a wave energy conversion system with permanent magnet tubular linear generator （PMTLG） is proposed to convert ocean wave energy into electricity. The wave energy conversion system was installed in the Yellow Sea near Lianyungang, China. The ocean test re- suits indicate that it had dynamic and static performance, and obtained an expected amount of electricity. The calcu- lation result indicates the average output power was about 1 000 W, and the conversion efficiency from wave en- ergy into electricity was 1.4%. In addition, the wireless data communication, mechanics and oceanography were also discussed.

Image Processing System for Air Classification Using Linear Discriminant Analysis

An air classifier is used in the recycling process of covered electric wire in the recycling factories, in which the covered electric wires are crushed, sieved, and classified by the air classifier, which generates wastes. In these factories, operators manually adjust the air flow rate while checking the wastes discharged from the separator outlet. However, the adjustments are basically done by trial and error, and it is difficult to do them appropriately. In this study, we tried to develop the image processing system that calculates the ratio of copper (Cu) product and polyvinyl chloride (PVC) in the wastes as a substitute for the operator’s eyes. Six colors of PVC (white, gray, green, blue, black, and red) were used in the present work. An image consists of foreground and background. An image’s regions of interest are objects (Cu particles) in its foreground. However, the particles having a color similar to the background color are buried in the background. Using the difference of two color backgrounds, we separated particles and background without dependent of background. The Otsu’ thresholding was employed to choose the threshold to maximize the degree of separation of the particles and background. The ratio of Cu to PVC pixels from mixed image was calculated by linear discriminant analysis. The error of PVC pixels resulted in zero, whereas the error of Cu pixels arose to 4.19%. Comparing the numbers of Cu and PVC pixels within the contour, the minority of the object were corrected to the majority of the object. The error of Cu pixels discriminated as PVC incorrectly became zero percent through this correction.

AN ANALYSIS OF AXISYMMETRIC MAGNETIC FIELD OF LINEAR OSCILLATION MOTOR

In this paper, using axial field finite analysis method, the field of a movable core type linear oscillation motor is analyzed. The program of axial field finite analysis is worked out. Using this program, we analyze various fields, including the field excited by permanent magnet materials, the field by two coils respectively, and the fields with the core moving to various positions.

Multi-objective optimization for electric water heater using mixed integer linear programming

Due to the capacity of thermal storage,electric water heater(EWH)is one of the best candidates for demand response programs.However,few attentions are given to the modeling and optimization of EWHs with thermostatically-controlled automatic water mixer(TCAWM).In this paper,differential thermodynamic model is established for EWHs with TCAWM and a piecewise linear approximation method is performed for the nonlinear thermodynamic model.The multi-objective optimization model is established by introducing an index reflecting the comfort degree of users,so that the optimal energy usage of the EWH can be obtained by mixed integer linear programming.Testing examples verify the effectiveness of the proposed method.

Linearized model for optimization of coupled electricity and natural gas systems

In this paper,a combined optimization of a coupled electricity and gas system is presented.For the electricity network a unit commitment problem with optimization of energy and reserves under a power pool,considering all system operational and unit technical constraints is solved.The gas network subproblem is a medium-scale mixed-integer nonconvex and nonlinear programming problem.The coupling constraints between the two networks are nonlinear as well.The resulting mixed-integer nonlinear program is linearized with the extended incremental method and an outer approximation technique.The resulting model is evaluated using the Greek power and gas system comprising fourteen gas-fired units under four different approximation accuracy levels.The results indicate the efficiency of the proposed mixed-integer linear program model and the interplay between computational requirements and accuracy.

Electrical-field induced nonlinear conductive behavior in dense zirconia ceramic

The effect of the applied electric field on the conductive behavior of zirconia ceramics is studied by measuring its initial current-voltage curve at various temperatures. The results show that when the field strength is higher than the threshold for flash-sintering, the curves exhibit a nonlinear behavior by having an additional current on top of the linear current according to Ohm＇s law. Analyzing its transport behavior reveals that the additional current density is due to the extra oxygen vacancies induced by the electric field. The formation rate of the extra vacancies and associated current was related to the field strength.

Time interval measurement with linear optical sampling at the femtosecond level

High-precision time interval measurement is a fundamental technique in many advanced applications,including time and distance metrology,particle physics,and ultra-precision machining.However,many of these applications are confined by the imprecise time interval measurement of electrical signals,restricting the performance of the ultimate system to a few picoseconds,which limits ultrahigh precision applications.Here,we demonstrate an optical means for the time interval measurement of electrical signals that can successfully achieve femtosecond(fs)level precision.The setup is established using the optical frequency comb(OFC)based linear optical sampling(LOS)technique to realize timescale-stretched measurement.We achieve a measurement precision of 82 fs for a single LOS scan measurement and 3.05 fs for the 100-times average with post-processing,which is three orders of magnitude higher than the results of older electrical methods.The high-precision time interval measurement of electrical signals can substantially improve precision measurement technologies.

Bound Polaron in a Quantum Well Under an Electric Field

We conduct a theoretical study on the properties of a bound polaron in a quantum well under an electric field using linear combination operator and unitary transformation methods, which are valid in the whole range of electron-LO phonon coupling. The changing relations between the ground-state energy of the bound polaron in the quantum well and the Coulomb bound potential, the electric field strength, and the well width are derived. The numerical results show that the ground-state energy increases with the increase of the electric field strength and the Coulomb bound potential and decreases as the well width increases.

感性工学视域下外卖配送电动车造型设计

目的提出符合用户感性需求特征的外卖配送电动车造型设计方案。方法基于感性工学理论,将感性需求转化成定性分析与定量分析,采用SDM(语意差异法)方法制作调查问卷,收集并筛选描述外卖配送电动车造型的感性意象词汇与样本图片,并结合主成分分析法,提取影响造型设计的主要因子和外卖电动车造型元素,构建感性意象数学模型;通过多元线性回归法,借助SPSS统计软件对四个主要造型构成要素与感性意象进行量化处理。结果对外卖配送电动车的前面板、前大灯、车身架和座垫的造型元素展开分析,设计出与用户“时尚”和“速度”情感需求最匹配的梯形前面板、变异多边形前大灯、多边形车身架和细长型座垫造型元素。结论感性工学不仅能有效挖掘用户需求,而且还能直观表达出感性感受与数值的对应关系,对外卖配送电动车造型要素进行有目的的设计和调整。

多次部分充电策略下双车型车辆配送路径研究

针对物流配送过程中燃油车和电动车并存的实际情况,综合考虑多次部分充电策略下双车型、充电设施、碳排放等因素,构建了以车辆使用成本、运输成本(含充电成本)、燃油车碳排放成本之和最小为目标的混合整数线性规划模型。选择某市配送中心为算例进行研究,采用CPLEX求解算例。结果表明:采用多次部分充电策略能进一步缓解“里程焦虑”,提高电动车装载率。之后进行单因素灵敏性分析,分析电动车的续航里程、额定载重量、充电站位置与数量对双车型路径优化结果的影响。

分支定界搜索信息深度引导的电-气互联系统调度决策加速求解方法

电-气互联系统调度决策问题旨在实现天然气系统和电力系统中可调节资源的最佳配置,其精准性与高效性直接影响电-气互联系统运行的安全性与经济性。为描述可调节资源离散状态、非线性运行特性等物理性质,电-气互联系统调度决策问题中含有规模庞大的离散决策变量,模型复杂度高,使得现有依赖于商业混合整数线性规划(MILP)求解器的电力系统运筹优化技术面临“组合爆炸”的计算负担。为此,该文提出一种分支定界搜索信息深度引导的电-气互联系统调度决策加速求解方法。所提方法利用分支定界初始搜索阶段的信息构建小规模辅助MILP模型,并内嵌于分支定界搜索过程,引导剪除更多冗余搜索空间,在不损失最优性的前提下加速收敛。基于RTS-GMLC电力系统和天然气系统不同负荷水平及线性分段数下的30个算例仿真结果说明,相比于直接使用商业MILP求解器,所提方法在不损失最优性的前提下可实现平均4.20倍的加速,验证了所提方法的有效性。

基于5G技术的舰船电力调度自动化系统研究

考虑舰船电力系统线路复杂、设备多样,调度数据冗杂且规模巨大,在此情况下为实现舰船电力系统快速、有效自动化调度,设计基于5G技术的舰船电力调度自动化系统。系统使用由RTU远动终端设备采集电力系统的线路、设备运行信息后,由5G通信网关发送至调度器;调度器结合目前电力系统运行信息,使用基于线性求解器的电力系统自动化调度模型,构建以快速实现断电负载故障合理恢复为调度目标的目标函数,由线性求解器自动化求解满足目标函数条件的电力系统开关动作方案,以故障重构的方式实现舰船电力调度自动化管理。实验中该系统调度下,舰船电力系统失电负荷为0 kW,5G通信网络的整体效用值不受调度数据业务数据包数量的约束,高达0.9,能够稳定、高效地支持大规模调度数据的传输。

基于电荷泵和电场增强层的滑动式直流摩擦纳米发电机的性能提升

针对直流摩擦纳米发电机(DC-TENG)自身性能的局限性以及静电击穿的优化,提出了一种简便、通用的将电荷泵和电场增强层与DC-TENG耦合的策略(CE-DC-TENG),以提高DC-TENG的输出性能。交流摩擦纳米发电机(AC-TENG)被用作电荷泵,在DC-TENG中引入一层增强电场的导电层并与电荷泵连接,以积累电荷和增强静电击穿的电场。在研究过程中,设置了运动频率与竖直压力这两个参数,并通过改变参数的大小测试了对应的输出性能。结果表明在1.0 Hz的运动频率和25 N竖直压力下,CE-DC-TENG输出电流约为0.67μA,七个周期的转移电荷量约为0.95μC。这个结果分别约为基于静电击穿DC-TENG的5倍和2倍。并且,该器件的输出功率在负载电阻600 MΩ左右获得最大值,达到54μW。CE-DC-TENG的峰值输出功率约是DC-TENG的18倍。通过线性滑动模式CE-DC-TENG验证了该方法的有效性。

含循环换电负荷及充电站的微电网多目标优化调度

电动换电重卡由于具有充电功率高、周期性强的循环换电负荷特性,一旦短时大量接入微电网中,将带来经济性和安全性的挑战。首先讨论电动汽车充电、循环换电负荷的不同特性,建立含循环换电负荷及充电站的微电网模型;提出一种综合考虑微电网经济性及联络线功率波动性的多目标调度优化方法;采用线性加权方法将多目标问题转化为单目标问题;最后利用CPLEX工具对仿真算例进行求解,仿真算例表明,所提优化方案可有效求解综合考虑不同权重下微电网净利润、联络线交换功率及换电站内电池最优调度问题,能在尽可能减小微电网与上级电网交换功率波动性的同时,使得微电网获得最大净利润。

一种基于线性零磁场的动脉血管扫描成像方法仿真

基于磁电耦合效应的血流检测及血管成像是实现心血管疾病早期诊疗的有效方法之一。该文基于磁场与血流耦合电效应,设计一种用于动脉血管扫描成像的组合线圈结构,产生带有零磁场线(FFL)区域的线性梯度磁场;在此结构的基础上,通过控制激励电流驱动FFL实现成像区域双向扫描;结合卷积神经网络(CNN)实现磁电耦合信号与血管信息的非线性映射,进而提出一种基于线性零磁场的动脉血管扫描成像新方法。采用多物理场仿真软件COMSOL对基于线性零磁场的血管扫描成像方法进行建模,求解磁电耦合信号,验证了所提出方法的合理性和有效性。结果表明,线性梯度磁场模式下的磁电耦合信号含有血管位置、半径等信息;CNN重建血管位置误差平均值为1.5694 mm,重建血管半径的方均误差(MSE)和相关系数(CC)平均值分别为0.0548和0.9870。研究结果可用于血管成像装置设计及后续相关临床应用提供研究支撑。

基于联合仿真的电励磁同步电机线性自抗扰控制

针对电励磁同步电机(EESM)在车用电机控制方向的研究,通过Maxwell设计EESM有限元模型,基于Simulink搭建电机控制系统模型。然后,根据凸极EESM的电机特性和电磁转矩分析,在控制系统中采用最大转矩电流比(MTPA)矢量控制方式在Simulink-Maxwell进行EESM控制系统的联合仿真验证。同时,控制系统电流环应用线性自抗扰控制(LADRC),基于电机已知参数在LADRC中设计模型辅助—扩张状态观测器(MA-LESO),以观测和消除系统扰动变量。仿真实验表明,采用MTPA矢量控制的电机在带载时转速波动降低,带载能力增强;在电流环中采用MA-LESO的LADRC控制器能使电机转速在稳态时波动更小,在带载时的抗干扰性能更强,电机运行过程相对稳定;电机负载转矩和定子电流在空载、负载时的波形更稳定,显著提升了电机运行性能。