Geri Dön

Doğru akım motoruyla hız ve gergi kontrolü

Başlık çevirisi mevcut değil.

  1. Tez No: 75272
  2. Yazar: HAKAN EDİS
  3. Danışmanlar: PROF. DR. R. NEJAT TUNCAY
  4. Tez Türü: Yüksek Lisans
  5. Konular: Elektrik ve Elektronik Mühendisliği, Electrical and Electronics Engineering
  6. Anahtar Kelimeler: Doğru akım motorları, Hız denetimi, Direct current motors, Speed control
  7. Yıl: 1998
  8. Dil: Türkçe
  9. Üniversite: İstanbul Teknik Üniversitesi
  10. Enstitü: Fen Bilimleri Enstitüsü
  11. Ana Bilim Dalı: Elektrik-Elektronik Mühendisliği Ana Bilim Dalı
  12. Bilim Dalı: Belirtilmemiş.
  13. Sayfa Sayısı: Belirtilmemiş.

Özet

ÖZET Doğru akım motoruyla hız ve gergi kontrolü başlığı altında, öncelikle serbest uyarmalı doğru akım motorlarının karakteristikleri incelenmiş ve ilgili denklemler verilmiştir. İkinci bölümde tez boyunca incelediğimiz Allen-Bradley marka dijital doğru akım sürücülerinin genel özellikleri, mevcut tipleri ve bu tiplere göre gerek alan devresinde kullanılan tek fazlı tam dalga doğrultuca, gerekse, armatür devrelerinde kullanılan ikili tip çevirici incelenmiş ve ilgili devre şemaları ve denklemler verilmiştir. Üçüncü bölümde tahrik sistemleri ve özel olarak dönme hareketi ile sancı çalışmasıyla ilgili karakteristikler ve denklemler sunulmuştur. Dördüncü bölümde ise. doğru akım sürücüleriyle ilgili genel karakteristiklerin ve eşitliklerin yanısıra kullanım alanları ortaya konmuştur. Beş numaralı bölümde öncelikle armatür kontrollü ve sonrasında alan kontrollü serbest uyarmalı doğru akım motoruyla ilgili lineer matematiksel modeller çıkarılmıştır. Altıncı bölümde, Allen-Bradley marka dijital doğru akım sürücülerinin moment ve proses trim çalışma modlarına göre matematiksel modeller ortaya konmuştur. Burada bazı çalışma modları birbirinin tıpkı olduğundan, tekrardan kaçınmak amacıyla, konu başlığı altında tekrardan sunulmamışlardır. Yedinci bölümde, Allen-Bradley doğru akım sürücülerinin özelliklerinden biri olan parametre kestirimi ve fonksiyon testleri konusuna sadece bir fikir vermesi amacıyla değinilmiş, ayrıntıya girilmemiştir. Sekizinci bölümde ise. bu bölüme deyin gelen anlatılardan istifade ederek, öncelikle hız ve gergi kontrolü yapılan bir proses incelenmiş ve proseste kullanılan, Allen-Bradley PLC ve In-Touch scada proramlanyla ilgili özet bilgi verilmiş, sonrasında prosesin izlenmesi için oluşturulmuş scada sayfaları ve geçmişe yönelik olarak sancı ve sistem ile ilgili bazı analog değerler grafiksel olarak sunulmuştur. Tezin sonuna konan ekde ise, sancı motoruyla ilgili yapılan gözlemler tablo olarak verilip, örnek prosesde yalnızca hız ve gergi kontrolünü gerçekleştiren PLC programı sunulmuştur. xvuı

Özet (Çeviri)

SUMMARY THE SPEED AND TORQUE CONTROL OF DIRECT CURRENT MOTORS The main elements of an electric drive are the controller, converter, motor, mechanical system and the power supply. The essential elements of the mechanical system and power supply are known, but the controller, converter, and motor must be designed or chosen by the designer. However it is important that the mechanical system is clearly specified. When a preliminary design of a desirable drive system has been carried out, it may be discovered that the available electric power supply is inadequate. Therefore, the appropriate kinds of mechanical system and power supplies must be evaluated. Once the speed-torque characteristic demanded by the load has been determined, it is possible to consider which motor-controller combination would be most suitable. This choice would also be influenced by the nature of the available power source. Direct current motors are still a common choice ifa controlled electrical drive operating over a wide speed range is specified. This is due to their excellent operational properties, control characteristics, and economic considerations specified by the over all system design. Allen-Bradley digital dc drives have a field circuit ( single phase full converter ), and an armature circuit ( dual converter ). Single phase fully controlled converter circuit is shown in figure 1. Vac O /N Vdc Figure 1. Single phase fully controlled converter circuit In an inductive load; Vdc = Vdo.cosa 1 The maksimum voltage (Vdo) is obtained when a is zero. Equation I indicates that we can control the mean output voltage by controlling a. We aiso see that when a is greater than 90 the mean output voltage is negative. This facility allows the converter to return energy from the load to the supply, and this is important when we want to use the convener with a dc motor in the regenerating mode. XIXA single full-converter provides unidirectional current at the dc terminals, but the voltage of the dc terminals can be reversed. It is thus capable of providing only two quadrant operation. If two full converters are connected back to back, both the voltage and the current at the dc terminals can reverse, and therefore the system will provide four quadrant operation. Such a system, shown in figure 2, is called a dual converter. İs İs Is + Va Vb Vc İS Is Is SL SL SL Vdi Vd2 SL SL SL Va Vb Vc Figure 2. Dual converter This type coverters have two different operation mode; - Operation with circulating current -Operation without circulating current This system is normally used for high power dc drives, for speed control in both directions. In fact, the dual converter is the static version of the Ward-Leonard motor- generator set. An arrangement for controlling a dc motor with a three phase full wave thyristor converter is shown figure 3. The current iq flowing in the motor and the voltage vq applied to it by the converter in figure 3. When current is flowing in the motor, the following equations holds Lq.(diq/dt) + Rq.iq = Vmsinoat - eq 2 xx»Cvc ast 3&ş ?- TMrlft W" lavcRfw SPEED FEEDBACK SIGNAL Figure 3. Thyristor driven speed regulating system From figure 3 and 4a, average motor current iq and the average thyristor converter output voltage Vd during discontinuous conduction of a motor current given by the following equations iq/(3.Vm/:tX) = (X/R).{ cos[(tt/3) + a] - cos [(7t/3)+a+01] - (eq/Vm).91 } 3 <**° /WmSinu» ^'N\r:&ı. ^ 'YWW ~>9,- U) (b) Figure 4. Waveforms under both discontinuous and continuous conduction states of current (a) Discontinuous current (b) Continuous current XXIVq/Vm = (3/71). { cos[(tc/3) + a] - cos [(7t/3)+a+ei] - (eq/Vm).91}+(eq/Vm)4 On the other hand, during the continuous conduction of a motor current, the following equations can be derived from figure 3 and 4b iq/(3. Vm/7t.X) = (X/R). [ cosa-(7teq/3. Vm) ] 5 Vq/Vm = (3/7t).cosa 6 The most common arrangement, which is used with only minor variations over almost the whole size range from small drives of say 0.5 kW up to the largest industrial drives of several MW, is the so-called two loop control. This has an inner feedback loop to contrl the current ( and hence torque ) and an outer loop to control speed. Speed Ref. Speed Cont. Encoder Figure 5. Schematic diagram of basic controlled speed drive with current and speed feedback control loops The current loop is to make the actual motor current follow the current reference signal (Iref). It does this by comparing a feedback signal of actual motor current with the current reference signal, amplifying the difference, and using the resulting amplified current error signal to control the firing angle a and hence the output voltage of the converter. Te = Kmiq 7 Torque is directly proportional to armature current ( equation 7 ), so the current controller is in effect also a torque controller. The configuration of a current loop, which includes a nonlinear compensation subloop. during discontinuous conduction is shown figure 6. The loop consist of two control subloops: one searhes for a compensating firing angle Ace which is an given relation to motor current iq and compansates for the nonlinear load characteristics during xxnThis assumes that there is no speed variation effect, because the current response of a dc motor is faster than the speed response. From eq.8, the codition under which the system in figure 7 becomes stable is obtained as follows: Ki<Kp+Rq/Kt 9 Eq.9 indicates that system stability cannot be achieved unless the nonlinear compensation subloop gain Ki smaller than the sum of equivalent resistance Rq over the thyristor converter gain Kt plus the PI compensation gain Kp. The other loop provides speed control speed feedback is provided by an encoder and the actual and required speeds are fed into the speed error amplifier. Any difference between the actual and desired speed is amplified, and the output serves as the input to the current loop. Hence if for example the actual motor speed is less than the desired speed, the speed amplifier will demand current in proportion to the speed error, and the motor will therefore accelerate in an attempt to minimise the speed error. As the speed comes up to target, the speed error reduces, and the final speed is approached smoothly. The speed will be held at the value set by the speed reference signal for all loads up to the point where full armature current is needed. If the load torque increases any more the speed will drop because the current loop will not allow any more armature current to follow. Conversely, if the load attempted to force the speed above the set value, the motor current will be reversed automatically, so that the motor acts as a brake and regenerates power to the mains. Flowchart of speed control. !/ - - V -(over speed y PROTECTION NO PI COMPENSATION I CURRENT LIMIT CROSSOVER LOGIC XXIVThis assumes that there is no speed variation effect, because the current response of a dc motor is faster than the speed response. From eq.8, the codition under which the system in figure 7 becomes stable is obtained as follows: Ki<Kp+Rq/Kt 9 Eq.9 indicates that system stability cannot be achieved unless the nonlinear compensation subloop gain Ki smaller than the sum of equivalent resistance Rq over the thyristor converter gain Kt plus the PI compensation gain Kp. The other loop provides speed control speed feedback is provided by an encoder and the actual and required speeds are fed into the speed error amplifier. Any difference between the actual and desired speed is amplified, and the output serves as the input to the current loop. Hence if for example the actual motor speed is less than the desired speed, the speed amplifier will demand current in proportion to the speed error, and the motor will therefore accelerate in an attempt to minimise the speed error. As the speed comes up to target, the speed error reduces, and the final speed is approached smoothly. The speed will be held at the value set by the speed reference signal for all loads up to the point where full armature current is needed. If the load torque increases any more the speed will drop because the current loop will not allow any more armature current to follow. Conversely, if the load attempted to force the speed above the set value, the motor current will be reversed automatically, so that the motor acts as a brake and regenerates power to the mains. Flowchart of speed control. !/ - - V -(over speed y PROTECTION NO PI COMPENSATION I CURRENT LIMIT CROSSOVER LOGIC XXIV

Benzer Tezler

  1. Tez No

    11640

    Senkron motorda döner alanın yarı iletkenlerle oluşumunun tasarımı ve uygulaması

    The Design of obtaining the rotating field with semiconductor devices and applications in the synchron motor

    ABDULLAH YAYLIOĞLU

    Yüksek Lisans

    Türkçe

    Türkçe

    1990

    Elektrik ve Elektronik MühendisliğiGazi Üniversitesi

    Elektrik-Elektronik Eğitimi Ana Bilim Dalı

    YRD. DOÇ. DR. İSMAİL COŞKUN

  2. Tez No

    6885

    A Transistorized switched reluctance motor drive

    Başlık çevirisi yok

    A.SERDAR ŞENTÜRK

    Yüksek Lisans

    İngilizce

    İngilizce

    1989

    Elektrik ve Elektronik MühendisliğiOrta Doğu Teknik Üniversitesi

    PROF. DR. BÜLENT ERTAN

  3. Tez No

    35514

    Interactive boundary layer calculation over and airfoil and its resulting wake

    Knat profili üzerinde ve ARD-İZ bölgesinde sınır tabakasının etkileşimli olarak hesaplanması

    SERKAN ÖZGEN

    Yüksek Lisans

    İngilizce

    İngilizce

    1994

    Uçak MühendisliğiOrta Doğu Teknik Üniversitesi

    Havacılık Mühendisliği Ana Bilim Dalı

    PROF. DR. H. NAFİZ ALEMDAROĞLU

  4. Tez No

    3602

    Modelling and analysis of the feeddrive system of a CNC lathe driven by a DC motor

    Başlık çevirisi yok

    MOSTAFA MEHRABI

    Yüksek Lisans

    İngilizce

    İngilizce

    1988

    Makine MühendisliğiOrta Doğu Teknik Üniversitesi

    DOÇ. DR. BÜLENT EMRE PLATİN

  5. Tez No

    84995

    Bulanık mantık ile doğru akım motor kontrolünün incelenmesi

    Fuzzy logic control of direct current motors

    KADİR ERKAN

    Yüksek Lisans

    Türkçe

    Türkçe

    1999

    Elektrik ve Elektronik MühendisliğiYıldız Teknik Üniversitesi

    Elektrik Mühendisliği Ana Bilim Dalı

    YRD. DOÇ. DR. M. HADİ SARUL

Geri Dön