【正文】 when io changes from negative to positive and equals to 0, the value of id is the phase error. For the same principle, the relationship is equal to the voltage signal U, and ud. showed in . a and b is represent the ratio error and phase error separately. the TA39。 4） the magnitude of the sample resistance should make the sampled standard current and error current in pro rata and should not have too much difference. The sampled resistance is set by experiment: R, is the secondary standard current sampling resistance and can be , R, is the error current sampling resistance and can be, R, is the burden resistance and it depends on the TA being measured. E$ sampling the voltage uo and U, on R, and R, respectively, the ratio error and phase error are showed on the LED through some process and calculations.According to the TA error39。s resistance of standard TA, error current detecting resistance, burden resistance of TA being measured respectively. To and K, Tb. T, are voltage sampling points which can calculate the current In this paper, only voltage between K and T, voltage between Tb and T, are being measured and they represent the voltage on R, and R, respectively.In general, the TA calibrator39。 main characteristics are flexibility, multifunctions, multiple uses for one PC puter, giving high performance, and is less costly. In this paper, the VI technology is applied to the test and measurement of instrument current transformer (TA). By using the LabVIEW, the TA accuracy calibrator was developed. This virtual calibrator can automatically measure the accuracy of and can indicate the ratio error and phase error curves. The tests and calibration for the TA show that the virtual TA calibrator can be used in place of the traditional calibrator and is much better than the traditional one.Keywords：Instrument current transformer (TA), TA calibrator, Virtual Instruments, LabVIEW.I. INTRODUCTIONSince 1992 the VXIbus standard was established by the United States and LabVIEW was presented by the National Instruments co.(Nl), the Virtual Instrument (VI) have lain the foundation for its mercial use. The main characteristic of Virtual Instrument is that it makes instruments by software. Most of the traditional instrument can be developed by VI. The VI is a real instrument made by the personal puter.The Instrument current transformer (TA) is widely used in all kinds of current measurement and it has the functions of protection, isolation and extending the measuring range. With the rapid development of puter measurement and control technology, and with the sequent emergence of current transformer and transducer, there is an increasing number of current transformers with high accuracy and low secondary current. The standard TA secondary current is usually 1A or 5A: some nonstandard TA secondary current may be 0 1A or lower. Although we have the technique to make this kind of calibrator by means of hardware such as single chip puter and electronic circuit, DSP and so on, it will cost too much money for these nostandard calibrator and will take too much time and the calibrator made by these hardware mill not be satisfactory in both function and practicality for designing all kinds of new TA.The calibrator that adopts VI technology not only can meet the requirements of the traditional one but also can satisfy customers with such advantages as multifunctions, convenience, and high ratio between performance and cost. The experiment results indicate that the virtual calibrator can provide excellent condition for TA measurement and design. The VI technology and personal puter must be widely used in the area of calibration on instrument transformer.Ⅱ. THE WORKING PRINCIPLE OF TA CALIBRATORThe error of TA includes ratio error and phase error. The measuring of the error of TA or the calibration of the accuracy of TA usually applies differential measuring method. The method needs a standard TA except the measured TA and a TA calibrator. There is the same turn ratio between the standard and measured T4 and the standard TA39。在設(shè)計(jì)期間，主任經(jīng)常詢問(wèn)進(jìn)度，并為我們解決了許多實(shí)際問(wèn)題。在學(xué)習(xí)和論文的研究過(guò)程中，自始至終得到了她的悉心指導(dǎo)、鼓勵(lì)、關(guān)心和幫助。 在設(shè)計(jì)過(guò)程中，仿真軟件也存在一些問(wèn)題，它沒(méi)有考慮到路面的摩擦力的變化，也可以看為把高速、低速，轉(zhuǎn)向過(guò)程路面對(duì)智能車的摩擦都視為恒值對(duì)待，考慮到智能車與路面的摩擦影響是設(shè)計(jì)仿真的研究是本課題的下一個(gè)目標(biāo)。并且設(shè)計(jì)了自己的控制方案，最后對(duì)賽車仿真運(yùn)行過(guò)程中出現(xiàn)的問(wèn)題進(jìn)行了研究。由于智能車的運(yùn)行速度很快，這些狀態(tài)在以相當(dāng)高的頻率變化，特別是速度表所指示的速度，和實(shí)際測(cè)試一樣，也不能的對(duì)運(yùn)行過(guò)程進(jìn)行分析。它主要為模擬傳感器檢測(cè)賽道功節(jié)點(diǎn)、控制算法功能節(jié)點(diǎn)，智能車運(yùn)動(dòng)模型模擬節(jié)點(diǎn)，智能車的顯示功能節(jié)點(diǎn)。要想成功實(shí)現(xiàn)智能車仿真必須有以下幾個(gè)前提：一是設(shè)計(jì)好賽道功能模塊中的圖像顯示，這個(gè)需要以點(diǎn)的形式存儲(chǔ)賽道，兩個(gè)相關(guān)聯(lián)的點(diǎn)之間的距離定義為分辨率，分辨率是連續(xù)賽道的數(shù)字量化的量度，賽道的具體體現(xiàn)是認(rèn)為兩個(gè)相連的點(diǎn)之間是直線連接的，在分辨率設(shè)置很低的情況下，這樣，即使是曲線的賽道也可以近似為直線，不會(huì)對(duì)仿真精度產(chǎn)生多大的影響。下一步需要研究的東西還很多，因?yàn)槲也胖皇亲龀隽艘稽c(diǎn)點(diǎn)東西，要想在現(xiàn)在基礎(chǔ)上做出智能車模擬仿真系統(tǒng)還需要很多的努力。雖然已經(jīng)掌握了C語(yǔ)言的編程技巧和思想，但是不經(jīng)過(guò)細(xì)致的學(xué)習(xí)LabVIEW也無(wú)法熟練的運(yùn)用它進(jìn)行編程。由于對(duì)LabVIEW的掌握不夠充分，在剛開(kāi)始經(jīng)歷了許許多多失敗，始終無(wú)法領(lǐng)會(huì)LabVIEW的精髓，沒(méi)有掌握其開(kāi)發(fā)軟件的思想。邊學(xué)邊做東西，讓我對(duì)學(xué)習(xí)到的東西不斷加深，有了比較深層次的了解，不用過(guò)后在復(fù)習(xí)。由于先前沒(méi)有接觸過(guò)LabVIEW，在設(shè)計(jì)之初，我打算先把LabVIEW學(xué)會(huì)再開(kāi)始設(shè)計(jì)，于是前一個(gè)月我把精力都放在了學(xué)習(xí)當(dāng)中，幸好這時(shí)候李老師發(fā)現(xiàn)了我的這個(gè)缺點(diǎn)，她教導(dǎo)我邊學(xué)邊做，這樣才是一個(gè)好的學(xué)習(xí)新東西的方法。為滿足程序編寫、編譯、調(diào)試和燒寫，很好地掌握了LabVIEW。根據(jù)老師的指導(dǎo)和在論壇找到的資料，經(jīng)過(guò)自己的努力，在C語(yǔ)言思想的指導(dǎo)下，獨(dú)立設(shè)計(jì)出了智能車調(diào)試系統(tǒng)，并能夠?qū)崿F(xiàn)了一些具體功能。1） 在認(rèn)真學(xué)習(xí)和研究LabVIEW的基礎(chǔ)上，制定了智能車開(kāi)發(fā)的總體方案，在具體編程設(shè)計(jì)過(guò)程中完成了智能車調(diào)試系統(tǒng)。 本文基于對(duì)智能車大賽的設(shè)計(jì)過(guò)程，并且利用了虛擬儀器軟件LabVIEW，為智能車比賽開(kāi)發(fā)了一個(gè)比賽仿真以及理論試驗(yàn)平臺(tái)。右鍵單擊While循環(huán)，從快捷菜單中選擇替換為For循環(huán)，可將While循環(huán)替換為For循環(huán)。創(chuàng)建While循環(huán)后，可使用移位寄存器將值從上一個(gè)循環(huán)傳遞到下一個(gè)循環(huán)。如選擇執(zhí)行過(guò)程控制Express VI和結(jié)構(gòu)選板上的While循環(huán)并將其放置在程序框圖上，程序框圖上還將出現(xiàn)已與條件接線端相連的停止按鈕。如循環(huán)計(jì)數(shù)超過(guò)2147483647或231，計(jì)數(shù)接線端將保持值為2147483647，不會(huì)改變?？蔀闂l件結(jié)構(gòu)創(chuàng)建多個(gè)輸入輸出隧道并指定默認(rèn)條件分支。對(duì)于每個(gè)分支，使用標(biāo)簽工具在調(diào)節(jié)結(jié)構(gòu)上方的條件選擇器標(biāo)簽中輸入值、值列表或值范圍。2） 條件結(jié)構(gòu)單擊選擇器標(biāo)簽中的遞減和遞增箭頭可滾動(dòng)瀏覽已有的條件分支。不可在平鋪式順序結(jié)構(gòu)的各個(gè)幀之間拖曳隧道。右鍵單擊平鋪式順序結(jié)構(gòu)，從快捷菜單中選擇替換為層疊式順序，可將平鋪式順序結(jié)構(gòu)轉(zhuǎn)換為層疊式順序結(jié)構(gòu)。平鋪式順序結(jié)構(gòu)在程序框圖上顯示每個(gè)幀，故無(wú)需使用順序局部變量即可完成幀與幀之間的連線，同時(shí)也不會(huì)把代碼隱藏起來(lái)。x或y？是x和y的邏輯或。3） 或（函數(shù)）x、y必須為布爾值或數(shù)字。x y?返回運(yùn)算的布爾結(jié)果。通過(guò)復(fù)合運(yùn)算函數(shù)可添加兩個(gè)或多個(gè)值。連接其它數(shù)據(jù)類型作為輸入時(shí)，該節(jié)點(diǎn)將恢復(fù)為原來(lái)的函數(shù)。得到的VI圖標(biāo)相同，但其中包括與矩陣相關(guān)的算法。x+y是x與y的和。其中：1） 加（函數(shù)）x可以是標(biāo)量數(shù)字、定點(diǎn)數(shù)字、數(shù)字?jǐn)?shù)組或簇、數(shù)字簇?cái)?shù)組或時(shí)間標(biāo)識(shí)等。但是，如應(yīng)用程序需要盡可能快地傳輸數(shù)據(jù)，同步執(zhí)行操作將獨(dú)占調(diào)用線程。 從或向設(shè)備同步傳輸數(shù)據(jù)時(shí)，調(diào)用線程在數(shù)據(jù)傳輸期間將被鎖定。右鍵單擊節(jié)點(diǎn)并從快捷菜單中選擇同步I/O模式187。源表示錯(cuò)誤或警告的源，大多數(shù)情況下表示出現(xiàn)錯(cuò)誤或警告的VI或函數(shù)名。如狀態(tài)的值為TRUE，代碼將為非零錯(cuò)誤代碼。狀態(tài)的值為TRUE（叉）時(shí)表示錯(cuò)誤，為FALSE（勾）時(shí)表示警告或無(wú)錯(cuò)誤。否則，表明VI或函數(shù)中出現(xiàn)的錯(cuò)誤狀態(tài)。錯(cuò)誤輸出包含錯(cuò)誤信息。更多信