直流分流器与直流分压器结构原理及现场应用分析

分流器是测量直流电流用的,分流器实际就是一个阻值很小的电阻,当有直流电流通过时,产生压降,供直流电流表显示;直流分压器用于电力系统及电气、电子设备制造部门测量直流高电压。本文主要分析直流分流器与直流分压器的工作原理及其内部组成结构,并根据实测波形着重研究直流分压器的现场应用。     

家用小功率光伏发电系统的设计

文中首先介绍了光伏发电系统的国内外研究现状,并得出了理论研究较多,涉及到实际产品研发较少的结论。在此背景下分析了光伏发电系统基本架构和逆变器拓扑结构,重点对比研究了工频变压器隔离并网型（DC/AC+AC/AC）、非隔离式并网型（DC/DC+DC/AC）、高频变压器隔离并网型（DC/AC/DC+DC/AC）等3种常见逆变器结构;然后结合家用这一实际情况对这3种结构进行了一一剖析,在此基础上提出了DC/DC+DC/AC/DC+DC/AC的3级架构设计方案,其中包括斩波电路、推挽升压电路、逆变电路三部分;最后以STM32ZET6单片机为系统核心控制器件,设计并完成光伏发电系统中各个硬件板卡的焊接和调试功能,通过测试样机得到实验数据。实验结果表明文中提出的DC/DC+DC/AC/DC+DC/AC架构设计方案易实现,实验样机能源利用效率和稳定性较高,体积小,能够满足家用要求。     

城市直流配电工程拓扑结构的研究

本文简要介绍了城市直流配电系统的优势和特点，介绍了国内外研究的两端“点对点”柔性直流配电系统、辐射形直流配电网、“手拉手”直流配电网、珠海三端柔性直流配电网等几种城市直流配电系统拓扑结构。在总结以上直流配电系统拓扑结构优缺点的基础上，研究设计了一种多端、中低压、交直流混合、接入多种分布式能源的城市直流配电系统拓扑结构，并应用于贵州城市直流配电示范工程。对该拓扑结构的特点、电压等级、运行方式、效能和可扩展性进行了介绍，指出该拓扑结构对于研究直流配电系统分布式能源的就地消纳，交直流配电的能效对比、运行方式的灵活性方面具有显著优势。通过自主研发的智能配电网半实物仿真平台，实现任意柔性互联交直流配电网的模拟，解决了现在直流配电网作为示范工程应用研究重复建设问题。     

车载大功率DC/DC电源变换器半实物仿真验证测试方法

介绍了一种车载大功率DC/DC电源变换器(以下简称DC/DC)的测试方法,运用V模式理念并结合半实物仿真验证测试方法对DC/DC的技术方案进行了全数字仿真验证测试、对DC/DC的控制电路部分进行了快速控制原型仿真验证测试、对DC/DC的功率电路部分进行了硬件在环仿真验证测试、对集成功率及控制电路的DC/DC进行了功率硬件在环验证测试,并根据测试结果又进行了迭代验证测试。通过半实物验证测试,对DC/DC各项设计参数的正确性及性能指标符合性进行验证测试,保证DC/DC技术方案的合理可行。     

PWM型DC/DC变换器中混沌控制的仿真研究

该文研究如何利用OGY混沌控制技术来消除DC/DC变换器的混沌状态.首先利用数据采样方法得到系统的离散模型,利用计算机技术由该离散模型进行可以得到系统的分叉图,从分叉图中可以看到DC/DC变换器发生了混沌、分叉等非线性现象,然后从理论上说明了如何利用OGY混沌控制策略把工作在混沌状态的DC/DC变换器控制到周期状态,最后利用计算机对DC/DC变换器进行仿真研究,仿真结果证明了该文中基于OGY方法DC/DC变换器混沌控制策略的有效性.     

含恒功率负荷的直流微电网系统性稳定性研究

传统的直流微电网稳定性分析法主要集中于基于阻抗匹配准则的小信号稳定性研究,现以含有恒功率负荷的直流微电网为研究对象,对直流微电网稳定性进行系统性分析,即在直流微电网满足大信号稳定性的基础上再去讨论其小信号稳定性。根据直流微电网稳态数学模型,通过李雅普诺夫间接法分析直流微电网满足大信号稳定性时的区域条件;提出一种基于高通滤波的有源补偿方法来增大系统阻尼,减小恒功率负载的负阻尼效应对直流母线电压稳定性的影响;建立含有有源补偿器的直流微电网的小信号模型,采用阻抗匹配准则分析加入有源补偿方法后直流系统的小信号稳定性。仿真结果验证了有源补偿方法对直流母线电压的补偿效果。     

一种环境自适应控制的直流电机控制系统设计

针对智能家居、智慧农业等应用领域对直流电机的环境自适应控制需求,设计了一种基于单片机小系统(AT89C51)的环境自适应控制的直流电机控制系统;该系统由直流电机控制系统由限位开关、复位按钮模块、无线遥控模块、水滴感应模块、直流电机控制模块、蜂鸣器报警模块、光线检测模块和单片机最小系统模块等组成;可实现2种模式的直流电机控制模式,一是根据光线强度、雨滴等环境因素自适应控制直流电机正/反转,另一种是利用按键功能模块手动控制直流电机的正/反转;经测试发现,当环境的光照强度的感知幅度值在10～600 lx之间变化时,该控制系统能够按照设定值实现直流电机的自动控制或者手动控制;同时,通过水滴感应模块,判断雨滴的有无和大小,实现直流电机的自动控制或者手动控制;因此,该环境自适应控制的直流电机控制系统具有响应特性好、可靠性高、成本合理等优点,可广泛应用于智能家居、智慧农业等领域.     

基于Zigzag变压器的交直流叠加输电线路特性研究

基于Zigzag变压器的交直流叠加输电技术,能有效解决直流功率注入普通变压器二次侧易引发的直流偏磁问题,可较大程度提高现有交流输电网络的输电能力,实现交直流功率的灵活传输。给出基于Zigzag变压器的交直流叠加输电系统的拓扑结构及输电原理,分析Zigzag变压器避免磁饱和的机理;与纯交流输电方式比较下,研究交直流叠加输电系统线路的稳态运行特性,得出系统满足一定电气条件时,该系统具有更小的电压降和功率损耗。搭建交直流叠加输电系统仿真模型,仿真结果表明研究得出的特性的正确性。     

DC／DC变换单神经元自适应PID控制器仿真研究

为解决传统PI控制对具有时变、非线性特性的DC/DC变换器动态控制性能不佳的问题,将人工神经网络与PID控制理论相结合,为DC/DC变换器设计了一种单神经元自适应PID控制器。该控制器算法简单,通过对加权系数的在线调整来实现自适应、自学习功能,从而满足DC/DC变换器的时变及非线性特性。以BUCK型变换器为例,建立了DC/DC变换器智能控制系统的仿真模型,在不同负载及参数变化的情况下与常规PI控制效果进行对比分析,结果表明,单神经元自适应PID控制器对DC/DC变换器具有很好的控制效果和鲁棒性。     

Passive piezoelectric DC sensor applicable to one-wire or two-wire DC electric appliances for end-use monitoring of DC power supply

A passive, non-contact piezoelectric DC electric current sensor to satisfy the increasing needs of DC power supply for monitoring the electricity consumption by either one-wire or two-wire appliance cord was proposed, and the sensing principle was schematically described and experimentally verified. A micro magnet was integrated into the proposed DC sensor and the appropriate position for locating the micro magnet was theoretically pinpointed. A prototype DC sensor was fabricated, and an impulse piezoelectric voltage output was detected when a DC electric current was applied to a two-wire electrical appliance cord, by using the constructed measurement setup for demonstration. A linear relationship between the detected peak value of the impulse output voltage and the applied DC electric current was further obtained based on the empirical measurements. In light of the above preliminary results, the proposed piezoelectric DC sensor is thus believed to be useful to various kinds of DC electricity end-use monitoring systems without consuming power electricity and using cord separators even in the case of the two-wire appliances.     

基于改进模糊PI控制的双有源桥DC-DC变换器

在直流微电网中,针对直流负载扰动的过程会造成直流电压动态响应速度缓慢;同时,负荷投切时会引起直流电压超调量大的问题。采用改进模糊PI控制,并将其应用在直流微电网中储能单元的双有源桥DC-DC变换器。首先,在现有模糊PI控制中加入预处理环节,该环节对直流电压的误差大小进行及时判断与跟踪,使直流母线电压迅速达到参考值,提高了直流电压的动态响应速度;其次,分析了现有模糊PI控制算法的规则表对参数调节过程中存在精确度不足的规则,对其进行修改得到改进模糊PI控制的规则表,以减小直流电压的超调量;最后,对所提的改进模糊PI控制进行仿真对比验证。仿真结果表明:对现有的PI控制器和模糊PI控制器而言,改进的模糊PI控制器在稳态响应速度、超调量以及抗干扰性能上得到显著提高,提高了直流母线电压质量。     

Supervisory control design for systems of multiple sources of energy

This paper describes a supervisory control strategy for electrical energy transfers in multisource renewable energy systems. The sources are coupled onto a DC bus through DC/DC power converters. The aim is to control the energy transfers, according to the sources power and load variations. The controller determines the operating mode of the system. Then, it calculates the power ratio provided by each source and drives the DC/DC power converters with local current and voltage loops in order to regulate the voltage on the DC bus according to a reference value. The main contributions are to use the duty cycle values of the DC/DC power converters as decision criteria to switch the power sources and drive the power ratios, and to present the complete strategy in a single hierarchical control scheme with three stages. A non linear model of the closed loop system is also detailed in order to work out sufficient conditions for asymptotic stability. Finally, the proposed control scheme is validated with an experimental device developed by GREAH Research Group for the control of energy transfers in multi-source renewable energy systems.     

Intrinsic Power Management Strategy based improvement of power stability in a single-phase AC–DC converter system

Nowadays the size of the use of electronic devices like laptops, cell phone chargers, electric vehicles and UPS is rapidly increasing. So AC–DC converters need to incorporate the power factor correction along with voltage regulation. There are many AC–DC converter control methods available, but these methods do not perform well. Therefore In this paper, a smooth transformation on switching will be characterized by a high power factor in a single phase AC–DC converter by the use of intrinsic power management strategy. The proposed AC–DC converter's circuit topology is obtained by integrating a boost and buck converter. The Boost Converter's switching frequency does power factor correction to get less current harmonics at the input line. In this single phase AC–DC converter, the buck-boost converter is an important component that increases system power quality based on advanced PWM technique. So in this work, the Intrinsic Power Management Strategy (IPMS) is proposed to enhance the control over the DC–DC converter performance during unstable or transient operation. Rather than making a quick Pulse Width Modulation (PWM) signal, the computerized signal processor just creates a moderate changing DC signal to decide the PWM ramp function. The power factor correction model has been created and simulated by utilizing MATLAB programming. The simulation model demonstrates that the power factor is improved and the converter has regulated DC output voltage. To validate this simulation, a 1000 W prototype converter has been developed to feed a DC motor and the analysis of the results are presented.     

Model checking Duration Calculus: a practical approach

Model checking of real-time systems against Duration Calculus (DC) specifications requires the translation of DC formulae into automata-based semantics. The existing algorithms provide a limited DC coverage and do not support compositional verification. We propose a translation algorithm that advances the applicability of model checking tools to realistic applications. Our algorithm significantly extends the subset of DC that can be checked automatically. The central part of the algorithm is the automatic decomposition of DC specifications into sub-properties that can be verified independently. The decomposition is based on a novel distributive law for DC. We implemented the algorithm in a tool chain for the automated verification of systems comprising data, communication, and real-time aspects. We applied the tool chain to verify safety properties in an industrial case study from the European Train Control System (ETCS).     

基于DSP无刷直流电机控制系统的研究及其仿真

无刷直流电机(BLDCM)是一个多变量、非线性系统。本文以无刷直流电机为研究对象,重点研究了无刷直流电机的控制系统及其仿真,并在最后对仿真结果进行了分析。在分析了无刷直流电机(BLDCM)的数学模型的基础上,文章中提出了一种以DSP芯片TMS320F2812为控制器的无刷直流电机双闭环控制设计的方案。文章中对此电机控制方案进行了软硬件的设计,并且在MATLAB上通过Simulink进行了系统仿真。仿真结果表明,控制系统运行平稳有较好的动态和静态特性,我们提出的控制方案正确可行。     

基于信息技术的燃料电池电源变换技术研究

电源变换技术是DC/DC、DC/AC、AC/AC、AC/DC的总称。当前的DSP技术,广泛应用于DC/DCDC/AC变换模块,已经解决了很多原来不能解决的客观问题,产生了积极的效应。本文结合燃料电池课题,阐述了信息技术在电源变换技术中的应用,对基于DSP的船舶用双向DC/DC变换器进行了深入分析,为燃料电池技术应用于船舶用电力推进提供了理论依据。     

Passive piezoelectric single-side MEMS DC current sensor with five parallel PZT plates applicable to two-wire DC electric appliances without using cord separator

A passive (power-less), non-contact macro-scale piezoelectric bimorph DC current sensor to satisfy the increasing needs of DC power supply for monitoring the electricity consumption by either one-wire or two-wire appliance cord was proposed at our laboratory previously. In present study however, a MEMS-scale piezoelectric single-side DC current sensor, comprised of five parallel PZT plates, was further proposed and micro-fabricated for preliminarily examination. A micro magnet was fixed by manipulator onto the PZT cantilever tip to the theoretically pinpointed position of the center plate. Different from the results of the macro-scale piezoelectric bimorph DC current sensor, impulsive piezoelectric output voltages accompanying with a gradual decrease in decay were detected when the applied DC electric current was varied from 0.5 to 2.5 A. A linear relationship between the detected peak value of the impulse output voltage and the applied DC electric current was also obtained but with a higher slope compared to the result of the macro-scale piezoelectric bimorph DC current sensor.     

Passivity‐based control for large‐signal stability of high‐order switching converters

This article presents a new passivity‐based control law that stabilizes the output voltage of a high‐order DC‐DC converter. Such nonlinear control law assures robust large‐signal stability, provides zero steady‐state error despite uncertainty in converter parameters and has enough degree of freedom to satisfy the usual transient specifications of DC‐DC converters. This new integral control is derived in three steps. First, a static law is obtained. Second, a positive semidefinite storage function is synthesized to guarantee zero steady‐state error of the output voltage. Finally, the storage functions of the first two steps are combined to derive the new control law for high‐order DC‐DC converters. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

燃料电池车载大功率DC/DC变换器的设计与应用

燃料电池的输出特性偏软,电压偏低,难以直接与电动机驱动器匹配,采用DC/DC变换器改善其输出特性,提高输出电压,将燃料电池转换成稳定可控的直流电源,变换器所处的电磁环境较为恶劣,电磁干扰因素居多,采用Motorola(Freescale)16位车用微控制器MC9S12D64作为DC/DC的控制单元,使DC/DC具有良好的抗干扰性能和可靠的运行性能。     

含电动汽车充电站的多端直流微电网研究

为未来大规模能源互联网的形成以及多种新能源的接入提供技术支撑,设计直流微电网的拓扑结构,提出了一种四端口环网的直流电网拓扑结构,实现交流电网、储能单元、直流负荷、风力发电和光伏发电与直流电网的互联。首先研究了交流电网与直流电网的接口方式和相关技术参数,提出了光伏发电、风力发电和储能单元等接口的技术配置。其次,研究了整个直流微电网的启停时序,设计了直流电网的接线方式、电压等级和容量,最后基于MATLAB Simulink平台搭建了直流园区系统仿真模型,然后对典型工况进行了仿真分析：（1）储能单元由放电到能量为零;（2）储能单元由充电到能量充满;（3）VSC1变换器功率反转;（4）负荷跳变;（5）储能单元由放电到充电。这些工况基本包涵了直流微电网可能出现的运行状态,对直流微电网的运行管理有较高的参考价值。