【正文】 cage motors and standard motors in the case of drives not requiring such precise control.The search for brushless motors that could be used in servo drives has been underway since themidseventies.A reversal of the principle of the conventional DC motor appeared to be a promising solution:armature in the stators,fieldexcitation in the brushless DC motor or electronic mutator motor was born.In principle,this motor is a permanentfield synchronous motor that requires a simple position encoder issuing 6 signals per revolution to determine the position of the rotor.In addition to electronic mutation and the consequent low rate of wear,this type of drive has the following advantages:q lower moment of inertia through the use of unwound rotorsq simpler cooling,as power loss occurs in the stators rather than the rotorsq greater efficiency,as there is no loss caused by the excitation windingElectronic mutation of the current produced by the stator winding occurs every 60176。 is controlled by the position DC blocks are mutated,this principle is also called block additional encoder is required to control speed.In parallel with these developments,further work has also been carried out to develop the AC squirrelcage motor as a brushless servo type of motor is cheap to manufacture and has the additional advantage of being able to operate in the fieldweakening range.Another way towards the brushless drive was the development of what is known as the sinusoidally mutated servo drive:The principle behind this motor is also the permanentfield synchronous motor,with its advantages as mentioned position encoder for the rotor in this case,however,is a resolver,the output signal from which controls the sinusoidal stator current.Examples of all three of these principles for brushless servo drives are in use today and have almost pletely replaced drives with brushes since the start of the nineties.The decisive factor in their success has been the progress that has been made in the field of development of highly integrated,highspeed processor systems and nonvolatile memory modules has facilitated the introduction of digital or not some functions are required more often or less often in individual systems is no longer significant as far as cost is software instead of a multiplicity of bits of hardware can be used to implement everything.The power section in the controller for all three types of brushless systems is basically the same:a frequency inverter that is controlled by the machine rather than the selfcontrolled inverters used for standard only functional differences are in the areas of openloop and closedloopcontrol.Developments in power transistors since the early nineties have also made it possible to connect the servo controller directly to the mains voltage without having to use a mains transformer.Asynchronous motor with squirrelcage rotor and fieldoriented controlThe asynchronous motor with squirrelcage rotor and fieldoriented control is also termed an AC servo its basic structure and mode of operation this motor corresponds to the wellknown threephase asynchronous motor with squirrelcage rotor.As servo motors,asynchronous motors are designed with lowinertia,lowleakage and lowslip rotors and are operated with a special control which ensures that stator and rotor flux are always perpendicular to one allows the asynchronous motor to be operated at almost breakdown torque whenever dynamic responses are required,making it highly suitable for highdynamic applications.The disadvantage of this motor(pared with the permanentfield machine)is its lower efficiency and somewhat greater unit volume in relation to the losses occur in the rotor which do not occur with a permanentfield of the higher losses(efficiencyη) and the magnetizing requirements(power factor cosφ)of the asynchronous machine,it requires an inverter output higher by the inverse ratio of ηcosφFurther heat dissipation measures have to be taken especially in the range of lower motors are then usually provided with forced cooling fans or the speed control range or torque isreduced.The costs pared with other systems are higher due to the plexity of the signal processing involved in highdynamic is mainly the highresolution encoder and the fast and efficient microprocessors which are responsible for processor must continually calculate the stator currents from the rotor position and the required torqueproducing and magnetizing ponents.Previously these drives were generally used as highoutput main drives in the machine tool industry.However,the use of these drives can be expected to increase because electronic ponents are being cheaper and the motors can be produced more economically.翻譯：伺服電機的設(shè)計與選擇在電子和材料加工領(lǐng)域的發(fā)展已改變了驅(qū)動技術(shù)的世界局勢. 伺服技術(shù)，至今主要采用直流永久永磁電機 。對交流電機相比，最大的缺點是他們的劣勢直流電動機速度控制功能 。最近的事態(tài)發(fā)展在電子領(lǐng)域，尤其是微控制器，意味著一個適當?shù)目刂葡到y(tǒng)，現(xiàn)在可以包括彌補這一點。這些事態(tài)發(fā)展導致了重點在遠離直流驅(qū)動系統(tǒng)對交流電動機的轉(zhuǎn)變. 這對交流的趨勢，特別是在同步電動機伺服系統(tǒng)是，這是顯而易見的實施以前幾乎總是用直流技術(shù)。 新的，釤鈷，釹鐵硼永磁材料可以作出功能強大的增加，作為其高能量密度電機性能的結(jié)果，而在同一時間，降低了發(fā)動機質(zhì). 因此，該驅(qū)動器的動態(tài)性能得到改善電機蔚，幀大小減少伺服技術(shù)的定義 許多應(yīng)用程序的地方就在現(xiàn)代驅(qū)動技術(shù)的高要求： q定位精度 q速度精度 q速度控制范圍 肌力值穩(wěn)定 q過載能力 q動態(tài)性能 在驅(qū)動器的動態(tài)特性要求，換句話說它的時間響應(yīng)，出現(xiàn)了越來越快的加工過程的結(jié)果，在加工循環(huán)的增加和生產(chǎn)效率相關(guān)的機器. 該驅(qū)動器的精確度往往決定了它的驅(qū)動器的工具系統(tǒng)可以使用的應(yīng)用程序。 一個現(xiàn)代化的，動態(tài)驅(qū)動系統(tǒng)必須能夠滿足這些要求。 伺服驅(qū)動器的定義 伺服驅(qū)動器的驅(qū)動系統(tǒng)，顯示較廣泛的速度范圍內(nèi)的動態(tài)，準確的反應(yīng)，也是具有過載情況下的應(yīng)對能力。 單詞“伺服”來自拉丁文“塞爾武斯”，可譯為仆人，奴隸或幫手。 在機床行業(yè)，伺服驅(qū)動器主要是輔助驅(qū)動器。 不過，這種情況已經(jīng)改變，所以，現(xiàn)時推行的主要驅(qū)動器也采用伺服技術(shù)。 在這個量，我們已經(jīng)使用了“伺服驅(qū)動器”和“動態(tài)驅(qū)動器”是指同一個東西. 他們總是指交流永久性場同步電動機及其相關(guān)控制系統(tǒng)。 伺服驅(qū)動器開發(fā) 術(shù)語“伺服驅(qū)動”意味著某種形式的輔助驅(qū)動，這很可能是40年以前真正在機床行業(yè)，當時電機，eglathes，往往仍用手工驅(qū)動。氣動，液壓或固定速度僅用于交流電機的扭矩在水平要求高。這是該車工技能和手工測量和檢查，他指出，決定如何進行快速，準確的工件可以加工。 在另一邊是主要的驅(qū)動器，它采用氣動，液壓或電氣的手段來實現(xiàn)或多或少不變，主軸轉(zhuǎn)速控制 伺服驅(qū)動器的技術(shù)發(fā)展 起初，液壓和氣動伺服驅(qū)動器市場占主導地位. 直流驅(qū)動器變得更加重要再次與硅半導體的60年代來臨。伺服驅(qū)動器也受到這一事態(tài)發(fā)展的影響：在對改善動態(tài)響應(yīng)要求認為，發(fā)展開始走在兩個不同的方向。 第一次看到在對在形狀電機慣性質(zhì)量矩規(guī)定減少極短的，圓盤狀和鐵無轉(zhuǎn)子。第二個集中在一個長，很瘦轉(zhuǎn)子。 在這兩種情況下，更高效的結(jié)果。 采用什么類型的控制設(shè)備？起初，功率晶體管線性放大器，輸出電壓高達100伏左右，后來，晶閘管轉(zhuǎn)換器被用來作為良好，在接近70年代末，直流轉(zhuǎn)換器基于斬波開關(guān)晶體管來脫穎而出。 補償，為