当前位置:文档之家› 基于LabVIEW的虚拟仪器外文翻译

基于LabVIEW的虚拟仪器外文翻译

基于LabVIEW的虚拟仪器模拟风力太阳能系统混合动力站(节选)介绍在最简单的层面上,数据采集可以手动完成如使用纸笔记录读数或任何其他工具。

对于某些应用这种形式的数据采集是足够的。

然而,数据记录中的应用这需要大量的数据读数,非常频繁的录音是有必要的,它包括了仪器或微控制器获取和记录数据准确(1995里格比和多尔比,)。

急诊化验室虚拟仪器工程平台(LabVIEW)是一个功能强大的灵活的仪器仪表和分析应用软件工具,(美国国家仪器仪表,2002)在今天这新兴技术并被广泛采用的学术界,工业LabVIEW已成为一个重要的工具,已代替了政府实验室数据的标准采集,仪器控制和分析软件。

现有的1.5千瓦的额定风力太阳能混合动力站显示(图1)。

设计与施工的可再生能源发电系统报告(磐诚,等铝,2000)。

在大学校园的平台上,有良好的教育机会本科生和研究生以现有的风力太阳能知识,学生们在协同研究基于风力太阳能发电站的传统的电网火力发电厂。

特别是在一些组件可再生能源如蓄电池和直流电源逆变器,可导致供电质量和电网出现一些问题,当太阳风稳定性出现问题时,根据汽轮机和发电机(帕特尔,1999)的电力系统与化石燃料这些相互作用都是由于大量的不同动力学参与的风力涡轮机和蒸汽涡轮机。

图1显示了photovol TAIC(PV)与太阳能电池板120个W评级,mastmounted1千瓦的风力涡轮机,和风速计,包括风方向和速度传感器的风能太阳能发电站并行运作,并收取12 V电池组包括六个深循环铅酸电池。

太阳面板安装在机架上的轨道,白天太阳光从320个0度的初始位置度。

该系统还包括基于固态器件的一个1.5kVA额定直流到交流电源逆变器,保护设备如交流和直流电路断路器,熔断器,避雷器,一套线性和非线性负载,连接电缆,和接线盒。

在国家的电压和电流系统学生们介绍了稳定的研究,说明了电能质量由于小的线性和非线性负荷的影响(磐诚和蒂默曼,1999)。

太阳风混合发电站已被用来作为大学本科电气部分电力和机械实验室内容以及示范单位高中和社区访问大学生(磐诚,等,2003)。

虽然电力系统和项目的可再生能源的内容有助于可再生能源的教学现实世界的应用,计算机辅助测量和数据采集模块的缺乏阻碍我们发展状态的艺术监控数据处理系统1999。

本文将主要集中在最近完成的LabVIEW监测和处理后系统的状态变量为基础的数据采集模块:直流电压,直流电流,交流电压,交流电流,风速,风向,直流电源,从现有的风力太阳能发电站的交流电源。

该仪器系统提供了一个机会,获得美国国家仪器实践经验的学生(Ni)的数据采集硬件,和LabVIEW软件版本6i的直流电压,直流电流的实时监测,风速,风向,DC和AC电源波形。

该项目的其他最有用的好处包括学生接口设备如电压和电流传感器在交流和直流侧,并使用隔离放大器之间的传感器输出和输入电脑。

该系统不仅被用于数据采集和仪器控制应用,而且对于一般用途的应用如数据库开发,数据分析程序,网络通信。

例如,计算机执行的风光互补发电系统的实时虚拟仪器网络化对高校的服务器,并可以访问任何校园远程计算机通过网络进行实时监控的目的。

校友调查的毕业生近15年覆盖完成2001夏季大学工业技术部。

调查工具被送往120校友参与其各自公司的机电/电子系统。

完成的调查数据从70(的目标组58.33%)和58(占82.86%的受访者)的人表示,雇主宁愿雇用与模拟或数字数据采集工作知识的毕业生,分析和解释。

他们还表明,一个有能力制定一系列其他问题的解决方案,以及机电和电子系统的特定的计算机素养是一个加号。

测量仪器是不包括在本文。

工业咨询委员会成员的工业技术部在2003学年也显示数据采集技能的员工的必要性。

因此,在LabVIEW仪表系统将帮助学生发展中的数据采集技术,分析。

计算机辅助测量和风接口—太阳能发电系统目的是将六个实验变量:直流电压,直流电流,交流电压,交流电流,风速,风向成计算机可读的存储和显示,实时的结果。

直流电源和交流电源需要计算和通过其他预定的变量使用LabVIEW的编程能力监测。

信号调理硬件条件和隔离电压和风信息信号之前被连接到数据采集板将在整体系统的虚拟仪器发挥重要作用。

风的太阳能发电站的仪器相包括下列硬件:cr4110-10真有效值交流电流传感器和一个cr5210 50直流霍尔效应电流传感器从CR磁,电压和电流分配器和缩放电路,一个风监测装置称为风速仪,LabVIEW 6i专业开发系统为Windows NT/98,pci-6071e I / O板,一个DAQ驱动软件,一个SH 100100屏蔽电缆,SCSI - II的连接器,一个scb-100屏蔽连接器块,一个隔离放大器电路,和一个PC。

用示波器检查模拟信号也将是非常有用的。

图2说明了整个仪表系统的框图。

四太阳能电池板和风力发电机产生的直流电压被施加到电池组。

一个年轻的05103v风速计提供两个电压信号对应的风向和风速值。

这些风的信号被馈送到ad21oan隔离放大器和输出应用到国家仪器的scb-100数据采集(DAQ)。

两个电压信号,一个从电池输出和一个来自逆变器的输出也适用于隔离放大器通过其相应的电压缩放电路。

两个电流信号,一个来自电池的输出通过一个直流霍尔效应电流传感器,和其他从逆变器的输出通过一个真有效值交流电流传感器直接输入到数据采集板。

CR 5210-50直流霍尔电流传感器可以提供0 - 5 V直流输入0-50直流电流。

同样,Cr 4110-10交流电流传感器可以提供一个信号输入为一个AC。

图3电流0~5伏直流描绘的逆变器和交流负载银行,包括奔腾III计算机,各种高效节能荧光灯,白炽灯等,一个电加热器,和一个风扇。

的交流负载的总功率约1400 W的仪器系统主要利用电脑的电源是由风能和太阳能混合动力系统提供的。

在实际的范围视图显示波形的预处理信号,需要适当的校准使用算术或逻辑功能期货可在LabVIEW?图6描述了为下午5:15到32 PM时间段的数据采集VI前面板。

如图7所示,直流电源具有值241.97当交流电源具有值238.65W的差对应的损失通过逆变器。

发电和相应的监测值增加至1500 W在充分的阳光和/或风力条件。

风向为逆时针从北。

5.2英里每小时的平均风速记录在6:25 PM时间6:26 PM。

阅读每分钟数可以通过调色板在前面板上显示IntroductionAt the simplest level, data acquisition can be accomplished manually using paper and pencil, recording readings from a multimeter or any other instrument. For some applications this form of data acquisition may be adequate. However , data recording applications that require large number of data readings where very frequent recordings are necessary must include instruments or microcontrollers to acquire and record data precisely (Rigby and Dalby, 1995). Lab oratory V irtual I nstrument Engineering W orkbench (LabView™) is a powerful and flexible instrumentation and analysis software application tool which was developed in 1986 by the National Instruments (National Instruments, 2002). LabView™ has become a vital tool in today’s emerging technologies and widely adopted throughout academia, industry, and government laboratories as the standard for data acquisition, instrument control and analysis software.An existing 1.5 kW rated wind-solar hybrid power station is shown in Figure 1. The design and construction of the renewable energy based power system was reported earlier (Pecen, et al., 2000). The existing wind-solar testbed at UNI campus has been an excellent educational opportunity for undergraduate and graduate students to study complex interactions in the electrical power grid between conventional coal-fired power plants and wind-solar based power stations.Particularly some components in the renewable energy plants such as batteries and dc-to-ac power inverters can lead to power quality and grid stability problems when wind-solar power systems are tied to fossil-fuel based turbine and generators (Patel, 1999). These interactions are mostlydue to the vast dynamics differences involved in wind turbines and steam turbines. Figure 1 shows four Photovoltaic (PV) solar panels with a power rating of 120 W for each, one mastmountedwind turbine with 1 kW, and an anemometer that includes a wind direction and a speed sensor. The hybrid wind-solar power station operates in parallel, and charges a 12 V battery bank which includes six deep cycle lead acid batteries. The solar panels are installed on a frame whichtracks the sun light during the day from an initial position of 0 degree to 320 degree. The system also includes a 1.5kVA rated dc-to-ac power inverter based on solid-state devices, protectionequipment such as ac and dc circuit breakers, fuses, surge arrester, a set of linear and non-linear loads, connecting cables, and junction boxes. Students are introduced to the studies of steady state voltage and currents in the system, illustrating power quality problems due to small linear and nonlinear load effects (Pecen and Timmerman, 1999). The wind-solar hybrid power station has been used as part of the undergraduate electrical power and machinery laboratory content as well as a demonstration unit for visiting high school and community college students (Pecen, et al., 2003).Although the power system and renewable energy content of the project have helped in teaching real-world applications of the renewable energy, the lack of computer aided instrumentation and data acquisition modules prevented us from developing a stateof-the-art data monitoring and processing system in 1999. This paper will focus mainly on recently completed LabView™ based data acquisition module for monitoring and processing the following system state variables: dcvoltage, dc current, ac voltage, ac current, wind speed, wind direction, dc power, and ac power from the existing wind-solar power station.The instrumentation system provides students with an opportunity to gain practical experience on National Instruments (NI) data acquisition hardware, and the LabView™ Version 6i software for the real-time monitoring of dc voltage, dc current, wind speed, wind direction, dc and ac power waveforms. Other most useful benefits of the project include the students’ ability to interface devices such as voltage and current sensors on both ac and dc sides, and the use of isolation amplifiers between sensor outputs and computer inputs. The developed system has not only been used for data acquisition and instrument control applications, but also for general purpose applications such as database development, data analysis programs, and network communications. For example, the computer executing the real-time virtual instrumentation of the windsolar power system is networked to the university server, and can be accessed by any remote computer on campus through the network for real-time monitoring purposes.An alumni survey covering last 15 year of graduates was completed in summer 2001 in the Department of Industrial Technology at UNI. The survey instrument was sent to 120 alumni who are involved in electromechanical/electronic systems of their respective companies. The completed survey data was obtained from 70 (58.33% of the targeted group) and 58 (82.86% of total respondents) of them indicated that employers prefer hiring of graduates with a working knowledge of analog or digital data acquisition, analysis and interpretation. They have also indicated that an ability to formulate a range of alternative problem solutions, and computer literacy specific to electromechanical and electronic systems is a plus. Survey instrument is not included in this paper. Industrial advisory board members of the Industrial Technology Department during the academic year of 2002-2003 have also indicated the necessity of data acquisition skills for their prospective employees. Thus, this LabView™instrumentation system will help the students to develop skills in data acquisition, and analysis.Computer Aided Instrumentation and Interface of the Wind-Solar Power SystemThe objective is to transform the six experimental variables: DC voltage, DC current, AC voltage, AC current, wind speed, and wind direction into a form readable by the computer, display and store the results in real time . The DC power and AC power need to be calculated and monitored through the other predetermined variables using LabView’s programming capabilities. The signal conditioning hardware to condition and isolate the voltage and wind information signals before being connected to the DAQ board will play a significant role in the virtual instrumentation of the overall system. The instrumentation phase of the wind-solar power station includes the following hardware: One CR4110-10 True RMS AC Current Transducer and one CR5210- 50 DC Hall-Effect Current Transducer from CR Magnetics, voltage and current divider and scaling circuits, one wind monitoring device called anemometer, a LabView 6i Professional Development System for Windows NT/98, one PCI-6071E I/O Board, one NI-DAQ Driver Software, one SH 100100 Shielded Cable, SCSI-II Connectors, one SCB-100 Shielded Connector Block, one isolation amplifier circuit, and a PC. A DMM and an oscilloscope to check the analog signals would also be very useful. Figure 2 illustrates a block diagram of the overall instrumentation system. DC voltage generated by four solar panels and one wind generator is applied to the battery bank.A Young 05103V Anemometer provides two voltage signals corresponding to wind speed and wind direction values. These wind signals are fed to AD21OAN Isolation Amplifiers and the output is applied to National Instrument’s SCB-100 Data Acquisition Board (DAQ). Two voltage signals, one from battery output and one from inverter output are also applied to isolation amplifiers through their corresponding voltage divider-scaling circuits. Two current signals, one from battery output through a DC Hall-Effect current transducer, and the other from inverter output through one true rms AC current transducer are fed directly to the DAQ board. The CR 5210-50 DC Halleffect current transducer may provide 0- 5.0 V DC for an input current of 0-50 A DC. Similarly, the CR 4110-10 AC current transducer may provide a signal of 0-5 V DC for an input current of 0-10 A AC. Figure 3 depicts the inverter and AC load bank which includes a Pentium III computer, a variety of energy efficient fluorescent lights, several incandescent lights, one electrical heater, and a fan. The total power rating of the AC loads is about 1400 W. The instrumentation system basically uses a computer whose power is supplied by wind and solar hybrid system.To view the displayed waveforms in actual ranges, the preconditioned signals require appropriate calibration using the arithmetic and/or logic function futures available in LabView™ Figure 6 depicts the front panel of the data acquisition VI for the time period of 5:15 pm to 5:32 pm. As seen in Figure 7, the DC power has a value of 241.97 W while the AC power has a value of 238.65 W. The difference corresponds to losses through the inverter. The power generation and corresponding monitoring values increase up to 1500 W during full sun and/or wind conditions. The wind direction is shown as counter clock wise from north. An average wind speed of 5.2 mph was recorded during the time period of 6:25 pm to 6:26 pm. The number of readings per minute can be adjusted through the palette as shown in the front panel.。

相关主题