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1、<p>  模糊控制軟啟動器設(shè)計相關(guān)翻譯資料</p><p>  [1] INTRODUCTION TO FUZZY LOGIC & FUZZY CONTROL</p><p>  "Fuzzy logic" has become a common buzzword in machine control. However, the term itsel

2、f inspires a certain skepticism, sounding equivalent to "half-baked logic" or "bogus logic".Some other nomenclature might have been preferable, but it's too late now, and fuzzy logic is actually v

3、ery straightforward.Fuzzy logic is a way of interfacing inherently analog processes, that move through a continuous range of values, to a digital computer, that likes to see things as well-defined discrete numeric valu&l

4、t;/p><p>  For example, consider an antilock braking system, directed by a microcontroller chip. The microcontroller has to make decisions based on brake temperature, speed, and other variables in the system. T

5、he variable "temperature" in this system can be divided into a range of "states", such as: "cold", "cool", "moderate", "warm", "hot", "very hot&q

6、uot;. Defining the bounds of these states is a bit tricky. An arbitrary threshold might be set to divide "warm" from "hot", but this would result in a discontinu</p><p>  With this scheme

7、, the input variable's state no longer jumps abruptly from one state to the next. Instead, as the temperature changes, it loses value in one membership function while gaining value in the next. At any one time, the &

8、quot;truth value" of the brake temperature will almost always be in some degree part of two membership functions: 0.6 nominal and 0.4 warm, or 0.7 nominal and 0.3 cool, and so on. The input variables in a fuzzy cont

9、rol system are in general mapped into by sets of membershi</p><p>  IF brake temperature IS warm AND speed IS not very fast THEN brake pressure IS slightly decreased.</p><p>  In this example, t

10、he two input variables are "brake temperature" and "speed" that have values defined as fuzzy sets. The output variable, "brake pressure", is also defined by a fuzzy set that can have values

11、like "static", "slightly increased", "slightly decreased", and so on. This rule by itself is very puzzling since it looks like it could be used without bothering with fuzzy logic, but rememb

12、er the decision is based on a set of rules: </p><p>  All the rules that apply are invoked, using the membership functions and truth values obtained from the inputs, to determine the result of the rule. <

13、/p><p>  This result in turn will be mapped into a membership function and truth value controlling the output variable. </p><p>  These results are combined to give a specific ("crisp") a

14、nswer, the actual brake pressure, a procedure known as "defuzzification".</p><p>  This combination of fuzzy operations and rule-based "inference" describes a "fuzzy expert system&qu

15、ot;. Traditional control systems are based on mathematical models in which the the control system is described using one or more differential equations that define the system response to its inputs. Such systems are ofte

16、n implemented as "proportional-integral-derivative (PID)" controllers. They are the products of decades of development and theoretical analysis, and are highly effective. If PID and othe</p><p>  [

17、1] 對模糊邏輯和模糊控制的介紹</p><p>  “模糊控制”技術(shù)已經(jīng)成為機電控制的核心內(nèi)容,在機器控制中應(yīng)用廣泛。然而,詞的本身聽上去好象和“半邏輯”或“偽邏輯”相等 ,使人產(chǎn)生懷疑態(tài)度。一些其他的命名法雖然可以令人滿意,但是,現(xiàn)在太晚了,并且,模糊邏輯實際上非常簡單。模糊邏輯的定義我們可以看成是把不連續(xù)的數(shù)據(jù)通過計算機模擬界面轉(zhuǎn)化成連續(xù)的數(shù)據(jù)的一種方法。</p><p>  例如,

18、認為剎車系統(tǒng)的抱閘微控制器系統(tǒng)的接頭是根據(jù)微控制器的抱閘溫度,速度和其他的變量進行決定的。這個系統(tǒng)里的“溫度”能類似的被分為一組“狀態(tài)”的變量:“涼”、“適度的”、“寒冷”、“假熱”、“熱” 、“非常熱”。定義這些狀態(tài)的界限是相對的,當輸入度值通過規(guī)定臨界值的時候順序從“ 熱”到“溫暖的”分配的每一套的任意的臨界值,但是這中結(jié)果將是不連續(xù)的變化。這種電路狀態(tài)換句話說是“模糊”的概念,使他們由1狀態(tài)逐漸地變成到下一個你能夠定義的類似的以下

19、“數(shù)據(jù)全體”起作用的輸入的溫度狀態(tài)。</p><p>  用這種方法,輸入變量的狀態(tài)不在從1狀態(tài)突然急速的變到下一個變量,反而,如同溫度變化的那樣,得到下一個有用的價值,它失去了1狀態(tài)在任何1時間的應(yīng)用價值,抱閘溫度的“真實評價”將在一些2的狀態(tài):0.6的狀態(tài)部分和0.4加熱的狀態(tài)或0.7中總的狀態(tài),并且,0.3的變涼,與其他是相同的。</p><p>  模糊的監(jiān)督體制里的輸入變量是有模

20、式的,一般來說,“模糊”的編入與其他有相似的功能。使最開始的輸入值改變?yōu)槟:闹档倪^程被叫做“模糊規(guī)則” 。另外,監(jiān)督體制是可以有輸入的,總是將自然有的用其模擬輸入和這樣的開斷等于1和0的真實值的輸入,但是希望能和他們象作為任何一個1值的簡化的模糊功能那樣分成的開斷或“是-否”的各種形式或其他的。得到輸入的變量的“映像”成為狀態(tài)模式和真實值,然后微控制器把決定做成需求的行動放在“規(guī)則”的一套形式的每個中:</p><

21、p>  抱閘溫度不高,并且,如果速度不太高時閘壓力輕微的減少形成牢固不太高。就這個例子來說,2輸入的變量是把值定義為模糊的模式的“溫度減少”和“速度剎住”。另外,變量輸出的“壓力剎住”能讓人把值控制在適合的“ 靜電噪聲”和“輕微地增加”及“輕微地減少”等等的模糊的定義 。這源于本身的規(guī)則非常邏輯,它好像是能不為模糊邏輯的事心緒不寧而使用,但是決定應(yīng)根據(jù)這套規(guī)則使用:</p><p>  適用的全部規(guī)則都適用

22、從輸入被得到,為決定規(guī)則結(jié)果的狀態(tài)模式和真實值被可求。</p><p>  結(jié)果將按順序被編入在控制輸出的變量的狀態(tài)和真實值表中 。</p><p>  這些結(jié)果給了特定回答的實際的閘壓力,這個過程被結(jié)合 。</p><p>  這中模糊的操作和規(guī)則是根據(jù)“推理”相結(jié)合描述的“模糊系統(tǒng)專家” 。傳統(tǒng)性的控制系統(tǒng)基于假設(shè)的數(shù)學式樣,系統(tǒng)給予定義回答系統(tǒng)的描述的使用的一

23、個或更微分的樣式的控制其輸入方法。這樣的系統(tǒng)象“PID”操縱器那樣經(jīng)常被實現(xiàn) 。他們所基發(fā)的理論上的分析對10年的產(chǎn)品非常有效 。如果PID和其他的傳統(tǒng)性的控制系統(tǒng)如此好好地發(fā)展,為什么還為模糊控制系統(tǒng)而發(fā)愁?它有許多優(yōu)點,在很多的例子中,不可以存在或者也許不太有關(guān)計算機處理能力和記憶控制過程的數(shù)學模型,并且,根據(jù)實踐經(jīng)驗的規(guī)則的系統(tǒng)也許更有效。此外,模糊邏輯好好地適應(yīng)是根據(jù)便宜的傳感器的低成本而實現(xiàn)的,低分辨率的?!獢?shù)轉(zhuǎn)換器和4位或者

24、8位的一個接頭的微控制器接頭的應(yīng)用。這樣的系統(tǒng)能通過為了改善應(yīng)用,或者加新特點加新規(guī)則簡單地升級。在很多的例子,模糊控制能被用來利用目前的傳統(tǒng)性的操縱器系統(tǒng)進行把智能的額外的層加到現(xiàn)在的控制方法上。</p><p>  [2] FUZZY CONTROL IN DETAIL </p><p>  Fuzzy controllers are very simple conceptually.

25、 They consist of an input stage, a processing stage, and an output stage. The input stage maps sensor or other inputs, such as switches, thumbwheels, and so on, to the appropriate membership functions and truth values. T

26、he processing stage invokes each appropriate rule and generates a result for each, then combines the results of the rules. Finally, the output stage converts the combined result back into a specific control output value.

27、 The most com</p><p>  Consider a rule for a thermostat: </p><p>  IF (temperature is "cold") THEN (heater is "high")This rule uses the truth value of the "temperature&q

28、uot; input, which is some truth value of "cold", to generate a result in the fuzzy set for the "heater" output, which is some value of "high". This result is used with the results of other r

29、ules to finally generate the crisp composite output. Obviously, the greater the truth value of "cold", the higher the truth value of "high", though this does not necessarily mean that the output itsel

30、f will be set</p><p>  There are several different ways to define the result of a rule, but one of the most common and simplest is the "max-min" inference method, in which the output membership fun

31、ction is given the truth value generated by the premise. Rules can be solved in parallel in hardware, or sequentially in software. The results of all the rules that have fired are "defuzzified" to a crisp value

32、 by one of of several methods. There are dozens in theory, each with various advantages and drawbacks. The "centroid</p><p>  [2] 詳細的模糊控制</p><p>  模糊操縱器的概念非常簡單 。他們由輸入界面,處理界面和輸出界面構(gòu)成 。輸入界面如類似

33、開關(guān),對適當?shù)臓顟B(tài)和真實值等等的傳感器或其他的輸入模式。處理界面要求每個適當規(guī)則保護,產(chǎn)生的每個結(jié)果都是規(guī)則的結(jié)果,然后結(jié)合 。最終,輸出界面轉(zhuǎn)換合并所有的結(jié)果成為特定的控制輸出值 。另外,階梯形狀和0曲線度被使用,盡管狀態(tài)的最大共同的形狀是三角形,但是形狀一般地不那么比曲線度和他們的安排的數(shù)字重要。從3~7曲線度一般地為了用模糊的形式遮蓋輸入值或“全部數(shù)值”范圍適當 。如同以前被討論的那樣處理界面,以如果、結(jié)束陳述的形式根據(jù)邏輯規(guī)則的

34、模式在什么地方的部分被叫做“前例”并且,部分被叫做“必然的結(jié)果”。典型的模糊控制系統(tǒng)有許多的規(guī)則 。</p><p>  考慮恒溫器的規(guī)則:(溫度“冷”)、(加熱器“高”)等如果這中規(guī)則作為一些“寒冷的”真實值的“溫度”輸入的真理值來在模糊的模式中作為一些“高度的”值 的“加熱器”輸出產(chǎn)生結(jié)果 。這中結(jié)果為了產(chǎn)生最初混成的輸出用其他的規(guī)則的結(jié)果最終被使用。明顯地更大真實的“寒冷”評價,雖然這未必是表示輸出的本身,

35、將從這被放到“高度”上,真實值在表中僅僅是1規(guī)則的更高的。在一些例子中狀態(tài)相等的修改 。共同的包括“在附近”、“大致”、“微小地”、“非?!?、“極端地”和“稍微”的。雖然這個定義能在不同的實現(xiàn)之間相對的變化,這些操作可以有明確的定義。例子1正方形的狀態(tài)“非常”有效;真實值總是1以下,這把狀態(tài)功能變窄 。“極端地”三字方時候“稍微”拿平方根放寬功能是為了形成非常窄的值。在實踐中,模糊的規(guī)則的模式通常讓幾個被結(jié)合的前例使用,模糊操作員雖然定

36、義再一次傾向于變化,并且,在1中的定義僅僅使用全部前例時候或評價最大的使用時最重要。從給予“互補的”功能的1另外有減去狀態(tài)功能的“非”運算符。</p><p>  用推理方法輸出的狀態(tài)功能得到的真理值用定義規(guī)則,但是,最多1最簡單的結(jié)果“最大最小限度”的不同的方法。規(guī)則能平行在硬件中或者按順序軟件中被解答。全部激發(fā)的規(guī)則的結(jié)果都給最初的值所定幾個方法。理論上各種的優(yōu)點和缺點每個里都有。質(zhì)心法與規(guī)則非常的結(jié)合輸出,

37、另一方面高度方法明顯地賜與規(guī)則最合適的輸出值。</p><p>  [3] Soft Starters for Induction Motors </p><p>  Soft Starters</p><p>  A soft starter is another form of reduced voltage starter for A.C. induction

38、 motors. The soft starter is similar to a primary resistance or primary reactance starter in that it is in series with the supply to the motor. The current into the starter equals the current out. The soft starter employ

39、s solid state devices to control the current flow and therefore the voltage applied to the motor. In theory, soft starters can be connected in series with the line voltage applied to the motor, or can be </p><

40、p>  Voltage Control </p><p>  Voltage control is achieved by means of solid state A.C. switches in series with each phase. These switches comprise either:</p><p>  Solid state switchesThese S

41、olid State Switches are phase controlled in a similar manner to a light dimmer, in that they are turned on for a part of each cycle. The average voltage is controlled by varying the conduction angle of the switches. Incr

42、easing the conduction angle will increase the average output voltage. Controlling the average output voltage by means of solid state switches has a number of advantages, one of the major advantages being the vast improve

43、ment in efficiency relative to th</p><p>  Switching Elements</p><p>  The switching elements must be able to control the current applied to the motor at line voltage. In order to maintain a hig

44、h level of reliability on a real industrial type supply, the switching elements need to be rated at least 3 times the line voltage. On a 400 volt supply, this means that the requirement is for 1200 Volt devices, and 600

45、Volt devices on a 200 volt supply. It is also important that the switching elements have a good transient current overload capacity.1200 Volt triacs with go</p><p>  Closed Loop Control </p><p>

46、;  Closed Loop starters monitor an output characteristic or effect from the starting action and dynamically modify the start voltage profile to cause the desired response. The most common closed loop soft starter is the

47、controlled current soft starter where the current drawn by the motor during start is monitored and controlled to give either a constant current, or a current ramp soft start. A much rarer closed loop format is the consta

48、nt acceleration soft start where the motor speed is monitored b</p><p>  A constant current starter will start initially at zero volts and rapidly increase the output voltage until the required current is de

49、livered to the motor, and then adjust the output voltage while the motor is starting until either full voltage is reached, or the motor overload protection operates. Constant current starters are ideal for high inertia l

50、oads, or loads where the starting torque requirements do not alter.The current ramp soft starter operates in the same manner as the constant curr</p><p>  [3] 模糊控制軟啟動器</p><p>  柔性軟啟動器的作用是在電器的開始

51、運行時減少電壓使其運行,柔性軟啟動提供給電動機的主要方面是控制抵抗或電抗的危害。柔性軟啟動的控制電流是可調(diào)的,為控制電流的固定的裝置,因而,產(chǎn)生的電壓使用與電動機。在理論中,柔性軟啟動控制應(yīng)用的每個電壓,能與被控電動機的電壓進行有效的成直線排列的連接,或者,在電機的內(nèi)部進行連接。以實現(xiàn)其作用。</p><p><b>  電壓控制</b></p><p>  電壓控制

52、以固定的裝置A.C被完成與每個階段成直線排列的開關(guān)都有兩個:(略)</p><p><b>  固定開關(guān)</b></p><p>  這些固定的開關(guān)給出了一定的值,他們在每個部分的周期以相似的方法控制每個階段。平均的電壓通過改變開關(guān)的傳導角度控制 ,增加傳導角度將增加平均的輸出電壓 。以固定的開關(guān)控制有相當數(shù)量的平均輸出電壓和抵抗最初者有關(guān)的效率里,固定的控制開關(guān)能改

53、變電壓大小是主要的優(yōu)點。典型的控制中,初始者電壓是需要進行有效的抵御的,另一個固體的開關(guān)主要的優(yōu)點是為了有適合的平均電壓必須在電機啟動開始能簡單地被改變 。隨著傳導角度的變化,輸出電壓能被增加,或者減少,并且,還能利用電子學自動控制完成??刂齐娮訉W為了解決電機的啟動根據(jù)計算時間的連續(xù)性(開環(huán))特別設(shè)定電壓高低的預訂程序或者為了控制電流和速度(閉環(huán))進行靈活的控制輸出電壓。</p><p><b>  轉(zhuǎn)

54、換要素</b></p><p>  轉(zhuǎn)換的要素必須能控制到發(fā)動機在線路中被應(yīng)用的電流 。為了用真正技術(shù)提供維持可信賴性高水平的設(shè)備,被確定為至少有3個轉(zhuǎn)換的要素是必要計算時間的線路電壓。</p><p>  在400伏提供上,這表示必要條件為1200伏裝置和600 伏裝置在200伏以上提供。另外,轉(zhuǎn)換的要素有轉(zhuǎn)瞬即逝的好處,現(xiàn)在的超載容量這很重要 ?,F(xiàn)在轉(zhuǎn)瞬即逝的超載特點達到1

55、200伏是不容易地,但可以利用,另外,選擇在SCR-Diode和 SCR-SCR之間進行使用。這些操作有一些適當,但是,他們不是簡單地能到達的。SCR-SCR和SCR-Diode任意選擇之間的主要的差異是輸出電壓的價格和協(xié)調(diào)的內(nèi)容。當SCR-Diode方法從技術(shù)角度模糊的時候,提供從技術(shù)角度合乎需要的左右對稱的輸出的SCR-SCR向控制干擾和噪聲提供商業(yè)上更有效而且更容易實現(xiàn)。聲學和偏執(zhí)狂已經(jīng)在今天市場上徹底地減少了,SCR-Diode

56、型的柔軟啟動的數(shù)字還存在。技術(shù)不總是簡單地如此,用類似的被用來和在描述 SCR-SCR系統(tǒng)的6脈沖技術(shù)相反描述SCR-Diode系統(tǒng)的3脈沖技術(shù)的詞是可以識別的。</p><p><b>  閉環(huán)控制</b></p><p>  閉環(huán)系統(tǒng)是監(jiān)視來自開始的輸出的特性或效果,把開始的電壓從側(cè)面靈活的得到回答。大部分的軟啟動器的閉環(huán)系統(tǒng)是在發(fā)電機在開始期間里監(jiān)視電流,為了給

57、以被控對象把設(shè)備的軟啟動器的電流以斜面的形式出現(xiàn)。更稀少的閉環(huán)系統(tǒng)加裝了是監(jiān)視發(fā)電機的速度和起點的加速度的A編碼裝置和控制發(fā)電機加速度或線性的比率,軟啟動器的控制是通過時間改變電流水平。</p><p>  在最基本的系統(tǒng)中的軟啟動中,軟啟動是實現(xiàn)控制對象與標準的數(shù)值進行比較以監(jiān)視設(shè)備的運行狀況,如果電流超過規(guī)定的點,那就顯示錯誤,綜合的閉環(huán)系統(tǒng)將監(jiān)視全部的3個階段上的電流,靈活的改變輸出電壓使之訂正為合適的電流

58、。這個系統(tǒng)能增加和減少,為了適合應(yīng)用減少開始電壓。</p><p>  電機的啟動電流是軟啟動器交給發(fā)電機的,其電流將從0伏開始出發(fā),訊速的增加到輸出電壓,于是,可以看出,任何一個完整的電壓都被接觸到調(diào)整發(fā)電機的輸出電壓和進行電動機的超載控制保護的操作。電動機的啟動條件是保持必要的轉(zhuǎn)矩是實現(xiàn)電機運行的理想條件,我們是有在一定的時間內(nèi)的時期,在控制模式中,限制被加斜面上的電流和以前是一樣的。從最開始的啟動,限制電流

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