FD-110A型涡轮分子泵控制器串口通信的实现与应用

本文基于串口通讯的原理,并以DF-110A型涡轮分子泵控制器为模型,介绍了使用CSerialPort类实现串口通讯的步骤,分析和讨论了计算机与单片机进行通讯的协议,且在VC 6.0的基础上运用多线程串口编程工具CSerialPort类实现PC机与单片机之间的串口通讯编程.通过协议改变时,模型做很小的修改就能够很方便的移植到不同的应用系统中,具有很好的扩展性.同时,模型中利用多线程技术设计了一个串口监视的线程,能实时的监视串口状态和数据,因此具有很好的实时性.     

基于高性能单片机的功率直流开关电源的设计

基于高性能单片机设计数字控制的功率直流开关电源。首先介绍该电源的原理及整体设计方案,其次介绍部分关键电路的硬件设计,采用软件方式来实现功率直流电源的数字控制。该电源具有输出电压连续可调、精度高、电路简单、操作灵活等优点。     

一种小型离子泵电源的设计

真空行业的迅速发展对离子泵电源提出了新的需求与挑战,小型轻量、智能控制和节能高效的离子泵电源将成为行业发展趋势。本文提出了一种通用性强的小型离子泵电源的设计方案,介绍了系统组成与拓扑结构,给出了电路参数计算和分析说明,并对该电源进行工程上的测试验证。实践表明,该电源能适配多种型号的离子泵,工作稳定可靠。     

新型直流标准源的研究

本文介绍了以 80 5 1为核心的新型直流标准源系统 ,从硬件和软件上提出了解决智能仪表精确度和抗干扰的几个方法。新型直流标准源具有精度高 ,互操作性好 ,适用范围广的特点     

涡轮分子泵三频发电机组中频电源

涡轮分子泵中频电源,原系中国科学院科学仪器厂仿制进口西德的电子变频器。由于我国目前电子元件质量所造成的电子变频器经济技术指标不能令人满意,我厂考虑了三频发电机组中频电源的方案。 中频电源技术指标: 三速电动机功率:0.4/1.1/1.5(千瓦) 电压:380伏 频率:50Hz 相数:3 发电机功率:0.37/0.75/1.5(千 瓦) 电压:10.5/21/42 电流:21 相数:3 频率: 100/200/400Hz 涡轮分子泵电动机功率:450(瓦) 电压:42伏 电流:6.2安 频率:400Hz 相数:3 此电源大体上分为三部分: (一)发电机组: 该发电机组由一同轴的单绕组三速异步电动机(节距、连接方式…     

涡轮分子泵电源分析与研究

本文主要对一种F-150型涡轮分子泵电源设计要求和工作原理进行详细地分析和讨论。     

基于小型高效直流开关电源的设计

目前,各种各样的开关电源以其小巧的体积、较高的功率密度和高效率正越来越得到广泛的应用。伴随着电力系统自动化程度的提高,特别是其保护装置的微机化,通讯装置的程控化,对电源的体积和效率的要求也在不断提高。可以说,适应各类开关电源的控制集成电路功能正在不断完善,集成化水平不断提高,外接原件也是越来越少。开关电源的研制生产正在日趋简化,成本也日益下降。     

通信电源技术探讨

随着通信网络在各行业发展中逐步体现的支撑作用,人们对通信系统的安全性和可靠性要求也越来越高。作为通信局站的重要组成部分,通信电源的稳定可靠与否,直接关系到通信设备是否可以安全运行。一般的通信设备发生故障,其影响是局部的,但通信电源发生问题,带来的则是整个局站的通信中断。电源技术的可靠性影响着通信技术的应用,反过来,通信信息技术的迅速发展,也极大地推进了电源技术进步,特别是电源监控技术的普及应用,使得通信电源设备可以具备无人值守、故障自诊断、故障自动报警、电池自动管理等等功能。     

敏感用户高品质交-直流级联供电方案研究

工业过程中大量使用的变频器(variable frequency drive,VFD)在采用传统交流供电时易受到电压暂降影响,传统治理方式存在检测延时、控制复杂等问题。为此,该文从敏感负荷变频器在电网扰动工况下的供电需求量化出发,围绕供电拓扑设计、DC/DC变换器的控制策略及储能单元容量配置等方面,构建一种实用化工业用交-直流级联供电方案。该文利用电压暂降过程中直流供电回路与敏感负荷间的压差自感应控制,实现交-直流供电回路无扰动切换,提高电压暂降治理响应的快速性;采用两相交错并联DC/DC变换器接入集中式储能,减少储能系统纹波系数,并给出两相均流控制方法。最后,通过Matlab/Simulink中的建模仿真与样机的实验测试,验证所提方案能够在交流系统发生不同严重程度电压暂降过程中为各类敏感负荷提供稳定的连续供电,为解决工业敏感用户高品质供电问题提供可实用的新思路。     

采用微机分布式控制的阳极化电源系统的研究

阳极化电源是军工产品在进行硬质极化时频繁使用的关键设备之一，过去硬质阳极化过程中使用单机电源，工作人员需要经常进入非常恶劣的工作环境之中长时间工作，这对他们的身体健康是不小的威胁，而且效率十分低下。本文提出了一种采用微机分布式控制的阳极化电源系统解决了上述问题，详细介绍了该系统的三个主要组成部分的功能及其特点，分别论述了三者的设计方案。实际应用表明，该系统对提高工作效率、降低工作人员的劳动强度和增加系统可靠性具有重要作用。     

离子溅射用高频PWM电源及其控制系统的设计

介绍了一种用于真空镀膜的等离子溅射高频PWM电源,并对其硬件电路包括主电路和控制电路的设计、软件程序开发及电源设计中的系统抗干扰等问题进行了阐述.     

基于模糊控制和PID控制的电弧炉直流电源的研究

本文针对真空电弧炉直流电源在熔炼阶段数字PID控制存在电流超调与响应速度矛盾的问题,提出了模糊控制和PID控制相结合的控制策略,着重介绍了模糊控制方法的应用,并在Matlab中对单个电源模块进行仿真.实验结果证明了这种控制方式的可行性和优势,具有良好的应用前景,且符合直流电源智能化、模块化的发展趋势.     

A modified circuit topology for inductive pulsed power supply based on HTSPPTs

High temperature superconducting pulsed power transformer (HTSPPT) provides an efficient method for inductive energy storage and current multiplication. The primary inductor of HTSPPT used for energy storage is made of high temperature superconducting coils, and the secondary inductor used for current pulse generation is made of normal conductor coils. In the initial circuit, the secondary inductor generates current pulse by switching out the coupled primary superconducting inductor. However, during the switching period, the leakage flux caused by imperfect coupling and the sudden change in primary current induce a voltage across the opening switch which exceeds the affordability of modern solid-state switches. In previous studies, a half-cycle oscillatory discharge circuit is proposed to mitigate these problems by using a capacitor to recapture the energy in the leakage flux and to slow down the turnoff of current in the primary. However, there are still some problems should be settled. For example, the output pulse cannot be adjusted, the residual energy cannot be recovered and the capacitor branch circuit may have an impact on the charging process. In the paper, a modified discharge circuit topology is introduced to solve these problems. A multi-module system comprising of several HTSPPTs charging in series connection and discharging in parallel is also designed and simulated. This system can be used to power an electromagnetic emission device.     

A method for designing power supply chain networks accounting for failure scenarios and preventive maintenance

A power grid is vulnerable and failures are inevitable. Failures decrease the power supply with an adverse effect on meeting the demand for electricity. Therefore, there is a need for a method to design power grid networks that result in the least possible disruption to the power supply when a failure occurs. In the literature, the focus has been on the design of the generation system without considering the transmission system or failures in the transmission system. Since power grids are integrated generation and transmission systems, each system will affect the other, so both generation and transmission systems need to be considered, as they are in this article. Methods developed for the structural modelling and analysis of supply chains are shown to be useful. The focus in this article is on describing a method using the supply chain construct for designing power grids that are relatively insensitive to failure in the integrated generation and transmission system. The efficacy of the method is illustrated using data from the Tehran Regional Electric Company. One of the findings is that targeted failures have a higher impact on decreasing the performance of the power grid than random failures. However, the focus is on the method rather than the results per se.     

A systematic review of China’s belt and road initiative: implications for global supply chain management

China’s Belt and Road Initiative (BRI) is one of the world’s largest infrastructure projects, with its potential political and economic impact being widely discussed since its inception in 2013. Yet the phenomenon has received only limited attention in the Supply Chain Management (SCM) literature. In response, we first conduct a broad systematic review of the literature to assess how China’s BRI is portrayed. Using this as a backdrop, we then distil the likely impact of the BRI on location decisions and supply chain flows. Finally, in a broader discussion of the SCM literature, we explore the implications of the BRI for future research in four key areas: supply chain configuration, supply chain resilience, sustainable SCM, and cross border SCM. While these areas are not new, the BRI presents a unique context that can be used to enhance theory and understanding in each area. The BRI reduces time distance independent of geographical distance by diverting supply chain flows from established routes to new routes via far less accessible regions. This introduces new risks and sustainability issues that call for multi-criteria decision support systems. Another important issue is the adoption and diffusion of the BRI since this will ultimately determine project success.     

A SCOR-based model for supply chain performance measurement: application in the footwear industry

Supply Chain Operations Reference (SCOR) is a widely employed model for SC performance assessment, regardless its generic nature. This article presents a SCOR-based model for performance measurement in supply chains (SC) and apply it in the context of Brazilian footwear industry. The model has two dimensions: SCOR processes (source, make, deliver and return) and performance standards adapted from original SCOR (cost, quality, delivery and flexibility). This structure delivers a 4 × 4 matrix, with each component assessed under analytical hierarchy process. Using focus groups, SC’s experts weighted each component of the matrix regarding their relevance. Thereafter, SC’s managers indicated respective results. The SC’s overall performance was obtained by adding the performance of all indicators. The model application embraced one focal footwear manufacturer, four suppliers, three distribution channels and a return channel, with 85 indicators assessed. The achieved performance for the whole SC is 75.29%.The main gaps were found in deliver process (12.78 percentual points of difference between relevance and achieved proportions) and in flexibility performance (9.82). Further application is recommended in order to find consolidated results.     

A decision support framework for global supply chain modelling: an assessment of the impact of demand,supply and lead-time uncertainties on performance

We developed a decision support framework for a global manufacturer of specialty chemicals to study the relative impact of demand, supply and lead-time uncertainties on cost and customer service performance. Our approach combines optimisation and simulation methodologies as follows: mathematical models provide optimal plans via a novel approach to the supply chain planning mechanism of the Company. Simulation models execute the supply chain plans so as to allow the examination of the outcomes under the various sources of uncertainty. The iterative use of optimisation and simulation methodologies allows the user the benefit of obtaining optimal solutions while revealing the impact of uncertainties on system performance. Our results indicate that demand uncertainty has the greatest negative impact on performance for the supply chain that we modelled in this study, emphasising the importance of effective forecasting. The relative importance of supply and lead-time uncertainties varies according to the performance measures. While our results are valid for the specific supply chain and the operating environment we modelled, our study emphasises the importance of the ability to model supply chains realistically to obtain valid and useful results.     

A multi-objective optimisation approach for order management: incorporating activity-based costing in supply chains

Most of the supply chain order management decision making models proposed in the literature are based mainly on the material flow and capacity constraints without any consideration to the profitability factor. In this paper, we develop a multi-objective mixed-integer programming (MIP) model which considers profitability in order to effectively manage order acceptance decisions in supply chains, subject to capacity constraints by using activity-based costing (ABC). While there are a numbers of decision-making models in literature integrating ABC in supply chains, this study expands the previous models with a more customer-oriented approach. The proposed model fulfils a desirable amount of orders completely and accepts selective number of orders partially with an objective of minimising the amount of residual capacity and increasing the profitability.