畢 業(yè) 設 計（論 文）外 文 參 考 資 料 及 譯 文
譯文題目： Based on the research of PLC temterature control system of boiler
以PLC為基礎的鍋爐溫度控制系統(tǒng)的研究
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2016年 3 月 6 日
Based?on?the?research?of?PLC?temperature?control?system?of?boiler
Abstract:?from?the?development?condition?of?boiler,?PLC?type?selection,?system?software?and?hardware?design,?communication?up?and?down?a?machine,?the?configuration?program?design?is?presented?in?several?aspects,?such?as.?By?the?temperature?control?system?of?PLC?debugging?the?advantages?of?the?simple,?low?cost,?easy?to?maintenance,?and?easy?to?expand?to?the?corresponding?field?of?industrial?control,?good?portability?is?of?great?importance?to?the?industrial?development
Key?words:?PLC;?The?sensor;?Temperature;?The?automatic?contro?
With?the?continuous?development?of?economy,?the?environment?problem?increasingly?prominent.?Boiler?as?the?heating?system?is?one?of?the?most?important?ener ?combustion?of?more?than?one?third?of?total?energy?consumption.?At?present,?the?domestic?most?of?the?urban?heating?system?in?the?operation?of?the?boiler?equipment?aging?basic?rely?on?manual?operation,?automation?level?is?low,?safety?performance?is?poor,?the?combustion?efficiency?is?not?high,?the?air?pollution?is?very?serious.?Therefore,?the?configuration?of?automatic?temperature?control?system?for?boiler?in?today's?increasingly?serious?environmental?pollution?situation?is?extremely?important.?gy?conversion?device?energy?consumption?is?huge,?every?year?the?national?boiler
1?boiler?temperature?control?based?on?PLC?is?introduced???
This?system?is?based?on?PLC?boiler?temperature?control,?through?the?boiler?internal?sensor?for?temperature?and?flow?rate?feedback?to?system?parameters?such?as?temperature?control,?the?automatic?control?of?boiler?temperature?is?realized.?
??PLC?programmable?controller?is?a?kind?of?combined?relay?controller?and?computer,?through?the?installer,?central?processing?unit?CPU?as?the?core?and?I/O?devices?connected?to?its?use?in?the?field?of?industrial?control?computer?is?slightly?different?with?ordinary?computer,?mainly?by?the?CPU,?memory?cell,?basic?components?such?as?the?I/O?interface?circuit,?power?supply,?plus?extension,?programmer,?external?equipment,?etc.?PLC?programmable?controller?can?not?only?replace?the?ordinary?relay,?but?also?has?A?variety?of?extensions,?such?as?A/D?module,?etc.?Therefore,?the?use?of?PLC?for?automatic?control?of?boiler?provides?a?new?solution,?some?advanced?control?method?to?the?application.???
Using?PLC?programmable?controller?for?boiler?system,?realize?the?automatic?control?of?the?temperature,?on?the?one?hand?can?improve?combustion?efficiency,?reduce?fuel?use?and?emissions?of?harmful?gas?in?flue?gas,?reducing?the?air?pollution;?PLC?control?system,?on?the?other?hand,?through?a?variety?of?sensors?inside?the?boiler?temperature,?pressure,?flow?and?other?related?parameters,?realized?the?automatic?control?of?the?parameters?such?as?temperature.?Reduces?the?manual?labor,?basically?just?in?the?engine?room?control?room?can?fully?understand?the?operation?of?the?boiler,?reduce?the?manpower?cost,?improve?the?level?of?the?automation?management?system.?
2?the?temperature?control?system?design?
2.1?the?temperature?control?system?design?
??This?design?by?Siemens?S7-300?programmable?controller?for?the?next?bit?machine,?two?industrial?control?machine?for?PC.?PC?through?industrial?control?software?to?realize?early?warning?functions?such?as?alarm,?under?a?machine?adopts?Siemens?S7-300?programmable?controller,?realize?automatic?control,?such?as?temperature,?flow?rate?in?the?boiler?control?level?and?safety?guaranteed.?
??System?for?the?temperature?of?the?object,?and?using?PT100?type?thermal?resistance?sensors?inside?the?boiler?water?temperature,?and?then?passed?to?EM235?module?temperature?transmitter,?convert?the?signal?through?the?PID?arithmetic,?adjusted?to?get?a?stable?PID?parameter?values,?then?the?input?signal?to?the?silicon?controlled?voltage?regulator?to?control?the?voltage?of?the?heater,?achieve?the?purpose?of?regulating?temperature.?
2.2?the?temperature?control?system?hardware?design?
??1)?the?host?system.?Using?two?sets?of?industrial?control?computer?host,?one?of?them?as?the?main?control?machine,?another?one?is?complementary?host,?make?double?insurance.?Configuration?software?WINCCSP26.0?using?Siemens?industrial?control?configuration?software.?
?2)?PLC?programmable?controller.?Systems?use?Siemens?SP?-?300?-?PLC?programmable?controller.?Its?modular?structure,?easy?to?implement?distributed?configuration?and?high?cost?performance,?strong?electromagnetic?compatibility,?resistance?to?shock?impact?performance?is?good,?in?a?wide?range?of?industrial?control?field,?become?a?kind?of?economical?and?practical?solution.?Variety?of?increasing?performance?of?CPU?and?rich?with?many?convenient?features?I/O?extension?module?(including?SM?signal?module,?communication?processor?CP,?IM?interface?module,?etc.).?The?user?can?choose?according?to?actual?application?module.?
??3)?the?instrument?equipment.?In?order?to?improve?the?anti-interference?ability,?type?selection?of?instrument?meter?DDZ?-?IH?45?ma?current?output?for?0123,?to?ensure?the?reliability?of?the?system.?Instrument?include:?flow?transmitting,?pressure?transmitter,?temperature?transmitter,?liquid?level?transmitter,?micro?oxygen?transmitter,?pressure?transmitter,?etc.?
??4)?the?frequency?conversion?control?room.?Mainly?includes:?power?supply?control?cabinet,?frequency?conversion?control?cabinet,?boiler?circulating?pump?frequency?conversion?control?cabinet,?control?cabinet?is?equipped?with?various?types?of?relay?contactor,?relay,?etc.,?low?voltage?electrical?equipment?to?complete?the?motor?start?and?stop.
2.3?the?temperature?control?system?software?design?
2.3.1?PID?instruction?algorithm?
??PID?controller?according?to?the?error?of?the?system?parameter?values,?calculated?by?proportional?integral?and?differential?control?quantity?to?control,?so?called,?PID?control?and?PID?control.?In?the?field?of?industrial?control,?PID?is?still?in?wide?use.?Three?kinds?of?control?volume?have?different?characteristics,?separately?to?exist?advantages?and?disadvantages?are?clearly,?when?used?with?various?restrictions?would?have?problems,?how?to?adjust?the?PID?parameter?of?the?stability,?becomes?the?current?control?of?the?most?important?step.?
2.3.2?characteristics?of?PID?control?algorithm?
??1)?the?proportion?(P)?control.?Proportional?(P)?control?is?one?of?the?most?simple?control?method,?the?controller?output?to?the?input?error?signal?is?proportional?to?the?relationship.?Controller?will?happen?if?skewed,?adjust?the?control?output,?the?accused?to?reduce?the?amount?of?deviation?in?the?direction?of?change.?Deviation?reduce?speed?determined?by?proportional?coefficient?Kp,?Kp?the?faster,?the?greater?the?deviation?decrease.?But?this?will?cause?oscillation,?especially?in?the?hysteresis?link?is?larger,?the?proportional?coefficient?Kp?reduce?the?possibility?of?oscillation?will?be?reduced,?but?at?the?same?time?can?also?lead?to?slow?adjustment.?Proportional?control?weakness?is?can't?eliminate?the?steady-state?error,?integral?control?must?be?available?to?assist.?
??2)?the?integral?(I)?control.?The?output?of?the?controller?in?the?integral?control?is?proportional?to?the?input?of?the?error?signal?integral?relationship.?After?entering?the?steady?state,?if?exist?steady-state?error?control?system,?in?order?to?eliminate?the?steady-state?error?of?the?system,?the?integral?item?must?be?added.?As?time?increases,?the?integral?term?will?also?increase,?so?even?the?relatively?small?error?integral?item?will?also?be?increased?with?the?increase?of?time,?it?will?further?reduce?the?steady?state,?the?existence?of?error?to?zero.?So?the?proportional?integral?(PI)?controller?can?make?the?system?enter?the?steady-state?no?steady-state?error.??
??3)?differential?(D)?control.?Under?differential?control,?the?controller?output?differential?increases,?the?input?error?signal?differential?will?also?increase.?The?automatic?control?system?for?error?control,?there?will?be?other?unnecessary?problems?such?as?movements?will?more?serious?instability.?That?is?to?say,?in?the?controller?only?introduced?"ratio"?is?often?not?enough.?Proportional?action?is?only?magnified?error?amplitude,?but?join?differential?item?to?avoid?large?errors.?Because?it?can?predict?the?direction?of?the?error?change,?but?the?differential?control?can?enlarge?the?high?frequency?noise,?lower?signal-to-noise?ratio?in?the?system,?resulting?in?a?decline?in?the?ability?of?the?system?suppress?interference.?That?is?to?say,?differential?control?can't?eliminate?the?residual.?
2.3.3?PID?parameter?setting?
??PID?parameters?setting?is?mainly?to?adjust?P,?Pi,?Pt.?To?change?the?system?characteristic?and?causing?the?system?to?achieve?satisfaction?index.?
2.3.4?PID?algorithm?program?implementation?
??In?the?SP?-?300?-?PID?function?is?accomplished?by?PID?instruction?function?block,?by?regularly?perform?PID?function?block.?According?to?the?PID?operation?rule,?according?to?a?given?at?the?time,?proportional?integral?differential?data,?calculate?the?control?quantity.?
3?the?PID?program?design?
??Siemens?PLC?control?program?is?to?use?the?programming?software?S7V5.?3.
??First?input?analog?signals,?the?boiler's?current?voltage?by?numerical?display.?Second?watch?boiler?the?current?temperature?is?normal,?alarm?indicator?lamp?whether?can?normal?use.?Initiator,?observation?after?the?start?position,?initialize?the?PID?parameters,?close?the?program,?zero?analog,?continue?to?stop?boiler?heating?but?still?shows?the?temperature.?Set?temperature,?the?interrupt?program,?adjust?PID?parameter,?output?PID?arithmetic?as?a?result,?the?output?analog?signals.?
4?the?configuration?module?design?
??1)?Configuration?software?design.?Select?the?configuration?design?of?this?system?software?is?Siemens?WINCC?configuration?software,?WINCC?is?a?powerful,?has?the?very?good?open?software.?All?kinds?of?complex?task,?WINCC?can?handle.?WINCC?belongs?to?man-machine?interface?configuration?tool,?its?biggest?characteristic?is?to?system?integration?on?the?basis?of?the?configuration.?As?long?as?the?preset?of?various?software?modules?for?simple?configuration,?you?can?easily?implement?each?function?of?monitoring?layer,?shortens?the?time?of?system?integration?to?improve?the?working?efficiency.?
??WINCC?configuration?software?with?Microsoft?system?as?a?platform,?provide?powerful?editing?functions,?and?itself?contains?rich?graphics?resources,?convenient?design?all?kinds?of?industrial?used?figure,?and?easy?to?edit,?at?the?same?time?with?the?computer's?versatility,?reducing?the?workload.?Users?can?design?and?editing?function,?make?full?use?of?the?open?sexual?function.?Because?belong?to?Siemens,?when?using?WINCC?configuration?software?can?easily?to?create?S7-300?PLC?in?the?system?variables,?edit?and?modify,?greatly?convenient?for?the?user.?
?2)?please?communication?up?and?down.?Connect?the?PLC?and?the?computer?connection,?after?the?completion?of?the?set?up?communication?in?software.?
??3)?the?system?debugging.?Again?and?again,?after?the?completion?of?up?and?down?a?machine?connection?adjust?PID?temperature?control?parameters,?in?order?to?get?the?optimal?PID?parameter?values.?Oscillation?phenomenon?occurring?in?a?system,?by?adding?differential?adjustment,?multiple?optimal?PID?parameters?resulting?from?the?debug.
以PLC為基礎的鍋爐溫度控制系統(tǒng)的研究
摘要：從鍋爐的發(fā)展情況，PLC選型,系統(tǒng)軟硬件設計，上下位機通信，組態(tài)程序開發(fā)設計等幾個方面進行介紹。通過PLC實現(xiàn)的溫度控制系統(tǒng)具有調(diào)試簡單、成本低、易維修等優(yōu)勢，并且容易拓展到相應的工業(yè)控制領域，較好的可移植性對產(chǎn)業(yè)發(fā)展具有重要的意義。
關鍵詞：PLC;傳感器；溫度；自動控制?
隨著經(jīng)濟的不斷發(fā)展，環(huán)境問題日益突出。鍋爐作為加熱系統(tǒng)中最重要的能源消耗裝置能源消耗巨大，每年全國鍋爐燃燒消耗的能源占總產(chǎn)量1/3以上。目前，國內(nèi)大部分城市采暖系統(tǒng)中運行的鍋爐設備老化，基本依靠手工操作，自動化水平低，安全性能差，燃燒效率不高，空氣污染十分嚴重。因此，為鍋爐配置自動溫度控制系統(tǒng)在當今日益嚴重的環(huán)境污染下就顯得極為重要。
1．介紹基于PLC的鍋爐溫度控制?
這個系統(tǒng)是基于PLC的鍋爐溫度控制，通過對鍋爐內(nèi)部傳感器溫度、流量等參數(shù)的反饋來對系統(tǒng)溫度進行控制，實現(xiàn)鍋爐溫度的自動控制。?
PLC可編程控制器是一種將繼電器控制器和計算機組合起來，通過安裝程序,CPU中央處理單元為核心與I/O設備相連接，使用在工控領域的計算機其構成與普通計算機略有不同，主要是由CPU、存儲單元、I/O接口電路、電源等基礎部分,外加擴展部分、編程器、外部設備等方面組成。PLC可編程控制器既能替代普通的繼電器，又具有多種擴展功能，如A/D模塊等。因此，PLC的運用為鍋爐的自動控制提供了新的解決辦法,使一些先進的控制方法得以應用。
使用PLC可編程控制器對鍋爐系統(tǒng)進行改造,實現(xiàn)溫度的自動控制,一方面可以提高燃燒效率，減少燃料使用和煙氣中有害氣體的排放量,減少空氣污染；另一方面，PLC控制系統(tǒng)通過各種傳感器檢測鍋爐內(nèi)溫度、壓力、流量等相關參數(shù)，實現(xiàn)了對溫度等參數(shù)的自動控制。減少了手工勞動，基本上只要在機房控制室內(nèi)就可以全面了解鍋爐的運行，降低了人力成本、提高了自動化管理系統(tǒng)的水平。
2．?溫度控制系統(tǒng)設計?
2.1?溫度控制系統(tǒng)設計?
該設計采用西門子S7-300可編程控制器為下位機，上位機為兩臺工業(yè)控制機。上位機通過工控軟件來實現(xiàn)報警功能，下位機采用西門子S7-300可編程控制器，實現(xiàn)鍋爐內(nèi)溫度、流量等自動控制，保證鍋爐控制水平及安全性。?
系統(tǒng)為對象的溫度，使用PT100型熱電阻傳感器檢測鍋爐內(nèi)部水溫，然后傳遞給EM235模塊溫度變送器，經(jīng)過PID的運算轉(zhuǎn)換信號,調(diào)節(jié)后得到穩(wěn)定的PID參數(shù)值,然后輸入信號給可控硅電壓調(diào)節(jié)器，以控制加熱器的電壓，達到調(diào)節(jié)溫度的目的。
2.2溫度控制系統(tǒng)硬件設計?
1）主機系統(tǒng)。使用兩套工業(yè)控制計算機控制主機，其中一個作為主控制機，另一個作為輔主機，構成雙保險。采用西門子工業(yè)控制組態(tài)軟件WINCCSP26.0。?
2）PLC可編程控制器。系統(tǒng)選用西門子的SP-300PLC的可編程控制器。它的模塊化結構，便于實現(xiàn)分布式的配置以及高性價比、強大的電磁兼容性、耐沖擊沖擊性能好，使其在廣泛的工業(yè)控制領域中，成為一種經(jīng)濟實用的解決方案。多種性能遞增的CPU和豐富的且?guī)в性S多方便功能I/O擴展模塊(包括信號模塊SM、通信處理器CP、IM接口模塊等)。用戶可以根據(jù)實際應用選擇模塊。?
3）儀表設備。為了提高抗干擾能力，儀器儀表DDZ-IH選型電流輸出為0123?45mA電流，保證系統(tǒng)的可靠性。儀表主要包括：流量變送、器壓力變送器、溫度變送器、液位變送器、含氧量變送器、微壓變送器等。?
4）變頻控制室。主要包括：電源控制柜、鍋爐變頻控制柜、循環(huán)泵變頻控制柜、控制柜內(nèi)配有各類斷電器接觸器、繼電器等，低壓電器設備，完成電機的啟動、停止。
2.3溫度控制系統(tǒng)軟件設計?
2.3.1??PID指令算法?
PID控制器根據(jù)系統(tǒng)參數(shù)的誤差值,通過比例積分、微分計算出控制量來進行控制，故稱為PID控制，或者PID調(diào)節(jié)。在工業(yè)控制領域中，PID現(xiàn)在還在廣泛使用。三種控制量具有不同的特點，分別存在明顯的優(yōu)點與缺點，一起使用時又會有各種約束限制的問題，如何調(diào)節(jié)出穩(wěn)定的PID參數(shù)，就成為電流控制中最為重要的步驟。?
2.3.2??PID控制算法的特點?
1）比例(P)控制。比例（P）控制是最簡單的一種控制方法，控制器輸出與輸入的誤差信號成正比關系。若產(chǎn)生偏差，控制器就發(fā)生作用調(diào)節(jié)控制輸出，使被控量向減小偏差的方向變化。偏差減小的速度由比例系數(shù)Kp來決定，Kp越大偏差減小的越快。但這樣會引起振蕩，特別是在遲滯環(huán)節(jié)比較大的時候，比例系數(shù)Kp減小振蕩發(fā)生的可能性就會減小，但同時也會導致調(diào)節(jié)速度變慢。比例控制的缺點是不能消除穩(wěn)態(tài)誤差，必須要有積分控制來輔助。?
2）積分（I）控制。在積分控制中控制器的輸出與輸入誤差信號的積分成正比關系。進入穩(wěn)態(tài)后，如果控制系統(tǒng)存在穩(wěn)態(tài)誤差，為了消除系統(tǒng)中存在的穩(wěn)態(tài)誤差，必須加入積分項。隨著時間增大，積分項也會增大，因此即便誤差比較小積分項也會隨著時間的增加而加大，它的存在會進一步減少穩(wěn)態(tài)，誤差直至為零。所以比例積分（PI）控制器可以使系統(tǒng)進入穩(wěn)態(tài)后無穩(wěn)態(tài)誤差。?
3）微分（D）控制。在微分控制下，控制器輸出的微分增加了，輸入誤差信號的微分同時也會增加。而自動控制系統(tǒng)在對于誤差的控制來說，會出現(xiàn)別的不必要的問題比如波動更嚴重的會失穩(wěn)。這就是說，在控制器中僅引入“比例”項往往是不夠的。比例項的作用僅是放大誤差的幅值，但是加入的微分項卻能夠避免較大的誤差出現(xiàn)。因為它可以預測誤差變化的方向，但是微分控制會放大高頻
噪聲，降低系統(tǒng)的信噪比，導致系統(tǒng)抑制干擾的能力下降。也就是說微分控制不能消除余差。?
2.3.3?PID參數(shù)設置?
PID參數(shù)的設置主要是為了調(diào)節(jié)P，Pi，Pt。改變系統(tǒng)的特典，使得系統(tǒng)達到滿意指數(shù)。?
2.3.4?PID算法程序?qū)崿F(xiàn)?
在SP-300中PID功能是通過PID指令功能來實現(xiàn)的，通過定期執(zhí)行PID功能塊。根據(jù)PID運算規(guī)律,根據(jù)當時的給定，比例-積分-微分數(shù)據(jù)，計算控制量。?
3?PID方案設計?
PLC控制程序是采用西門子編程軟件S7V5.3。?
首先輸入的模擬信號，通過數(shù)值顯示鍋爐的電流電壓。其次觀看鍋爐目前溫度是否正常，報警指示燈是否能正常使用。啟動程序，觀察起始位置，初始化PID參數(shù)，關閉程序，清零模擬量，停止鍋爐繼續(xù)供熱但仍顯示溫度。設定溫度值，中斷程序，調(diào)節(jié)PID參數(shù)，輸出PID運算結果,輸出模擬信號。
4?組態(tài)模塊設計?
1）組態(tài)軟件設計。本系統(tǒng)的組態(tài)設計軟件部分選擇的是西門子WINCC組態(tài)軟件，WINCC是一個功能強大，具有很好的開源的軟件。各種復雜的任務，WINCC都可以處理好。WINCC屬于人機界面的配置工具,其最大的特點是能夠以組態(tài)方式進行系統(tǒng)集成。只要對各種軟件模塊進行簡單配置預設，就可以方便地實現(xiàn)監(jiān)控層的各項功能，縮短系統(tǒng)集成時間，提高了工作效率。?
WINCC組態(tài)軟件以微軟系統(tǒng)作為平臺，提供了強大的編輯功能，而且本身含有豐富的圖形資源，方便設計各種工業(yè)用圖，而且方便編輯，同時因為與計算機的通用性，減少了工作量。用戶可以自行設計編輯函數(shù)，充分利用了開放性功能。因為都屬于西門子公司，使用WINCC組態(tài)軟件可以輕松對S7-300PLC系統(tǒng)中的變量進行創(chuàng)建,編輯和修改，大大方便了用戶。?
2）上下機位通信。鏈接PLC與計算機，在軟件上建立通信。???
3）系統(tǒng)調(diào)試。上下位機連接完成后，一次又一次調(diào)整溫度控制PID參數(shù),以獲得最佳的PID參數(shù)值。系統(tǒng)中出現(xiàn)震蕩現(xiàn)象，通過加入微分調(diào)整，多次調(diào)試后得到最好的PID參數(shù)。