Üniversal motorda hız kontrolü ve doğru akım kıyıcısıyla sürülen motor uygulaması

Abstract

Dünyada her sene milyonlarca adet üretilen universal motor büyük ölçüde evlerimize girmiş bulunan ev aletleri (domestic, household appliances)' sektöründe tahrik makinesi olarak kullanılmaktadır. Günümüzde toplum refah düzeyinin artması beyaz eşyaya olan talepte de bir patlama getirmiştir. Dolayısıyla hız ayar imkanları çok geniş olan universal motor gündeme gelmiştir. Özel maksat motorları olarak imal edilen universal motorlar yükle akuple olarak çalışırlar. Belirli bir anma yük momenti ve devir sayısı için imal edilen bu motorlarda devir sayısı yüke son derece bağımlıdır. Teknoloji alanındaki gelişmeler elektrik motorlarının tasarımında da yenilikler getirmiştir. Özellikle iş istasyonları (work-stations) üzerinde çalışan büyük paket programlar[Oersted, Magneto(IES), Ansys(SASI), FEM(SDRC), Maxwell(ANSOFT) vb.] manyetik analizde yeni bir dönem açmışlar ve elektrik makineleri manyetik devrelerinin optimum şekilde tasarlanmasını sağlamışlardır. Optimum bir verimle elde edilen universal motorların hız kontrolünü sağlayan güç elektroniği düzenleri de hi-tech ürünü komponentlerle her geçen gelişmekte, aynı zamanda seri imalatla bu ürünlerin piyasaya çıkması da kolaylaşmaktadır. Bu yüksek lisans tezinde konuların işlenişi şu sırayı takip etmiştir: öncelikle universal motor tanıtılmış ardından hız kontrolünün nasıl yapıldığı anlatılarak karşılaştırmalı olarak imkanlar anlatılmış ve örnekler verilmiştir. Bunun yanında mikroişlemcilerin universal motora uyarlanması ve güç elektroniğinin yapı taşlarından olan IGBT ele alınmıştır. Doğru akım kıyıcısı (chopper) ile sürülen universal motor önemi gözönüne alınarak ayrı bir bölümde işlenmiştir. Son olarak güç elektroniğinden kaynaklanan harmonikler ve bunların kaynak ve motor açısından bir değerlendirilmesi yapılmıştır.

The Universal Motor Speed Control and the Application of Universal Motor Driven by DC Chopper The main objective in this master thesis is to study universal motor and its speed control using power electronics devices. Nowadays universal motors are finding many applications in household appliances, hence the speed control of universal motors are also gaining importance. Some of its familiar applications are washing machines, vacuum cleaners, sewing machines, hair dryers, portable drills, household mixers and many other small electric devices. The series speed-torque characteristics are of definite advantages in certain cases, e. g. in a vacuum cleaner which will run at a high speed, or in a washing machine which requires high starting torque. Due to its great importance, speed control of universal motors is a valid topic of today. Some conventional methods used in the speed control of universal motors are as follows: -adding variable resistance in series with motor, [ e. g. in sewing machines ] -using tapped field winding at various points, [ e. g. in washing machines ] -using centrifugal mechanism, [ e. g. in household mixers ] -using solid state power electronics devices ( converters, choppers etc. ) containing electronic components ( thyristor, triac or IGBT ). IX The request for solid state speed control is rapidly increasing because of the advantages of infinitely variable motor speed, the facility for maintaining a set speed while subject to varying loads by means of feedback, and the ease with which automatic control may be applied. It is confidently predicted by other sources that older methods of speed control such as tapped field windings and series resistors will be replaced within a few years, and the trends in the market replace these methods by those based on thyristors or triacs. There is considerable activity in applying solid state control to series and shunt motors and the art of designing control circuits for this purpose has reached a high level. This is not to say, however, that there are no difficulties associated with thyristor or triac control. The problem of extra heating of1 the motor is well known to affect the commutation process in an adverse, and sometimes disasterous. In modern electric drives the universal motor speed is controlled by semiconductor converters either in the armature or in the field circuit. The motor terminal voltage consists of a dc and an ac component. The harmonic contents (spectrum) of the ac component depends on the converter type used in the speed control. For line commutation converters, the frequency of the first (predominant) harmonic is equal to the line frequency multiple, and it usually ranges between 50-60 Hz and 300-360 Hz. In chopper-controlled electric drives, motor voltage consists of rectangular pulses with duty cycle from zero to one with the frequency usually not exceeding 5 kHz. In this thesis the subjects are mentioned in the following order: first of all the universal motor is introduced and consequently how the speed control is achieved, is explained with different alternative possibilities and examples. Below given figure the universal motor speed control application using TDA2086 integrated circuit was shown: u. ft 5 Z 3 LU 3 v) Z -o ? o- © H3- =1 I«* \^ IvJ I- @i* -( - h HI1 HI 8§1 D? ^ S 8 Hh a|"I 5* 0*5 0| 4h Hl - c aS 56 if < * tt c o CO O Î (D v. O O "io Xlll One of the integrated circuits used in speed control is TDA2086. This is a silicon integrated circuit designed for use in closed or open loop phase control circuits of AC with resistive or inductive loads. In closed loop systems analog voltage or tacho frequency feedback may be used. The circuit was primarily designed for motor speed control in power drills, food mixers, washing machines etc. In the event of an open circuit tacho generator connection the TDA2086 will demand full speed/power. The features of the TD A 2086 can be summarized as follows: -Power Direct from AC Mains or DC Line, - 5 V Supply Available for Ancillary Circuitry, -Low Supply Current Consumption, -Average or Peak Load Current Limiting, -Ramp Generator to Provide Controlled Acceleration, -Negative Triac Firing Pulses 100 mA Guaranteed Minimum -Warning LED Drive Circuit, -Actual Speed Derived from Tachogenerator Frequency or Analog Feedback, -Well Defined Control Voltage&Phase Angle Relationship, -Inhibit Input for use with Thermistor Temperature Sensors. xn Below given figure the universal motor speed control application using TDA2086 integrated circuit was shown: u. ft 5 Z 3 LU 3 v) Z -o ? o- © H3- =1 I«* \^ IvJ I- @i* -( - h HI1 HI 8§1 D? ^ S 8 Hh a|"I 5* 0*5 0| 4h Hl - c aS 56 if < * tt c o CO O Î (D v. O O "io Xlll One of the integrated circuits used in speed control is TDA2086. This is a silicon integrated circuit designed for use in closed or open loop phase control circuits of AC with resistive or inductive loads. In closed loop systems analog voltage or tacho frequency feedback may be used. The circuit was primarily designed for motor speed control in power drills, food mixers, washing machines etc. In the event of an open circuit tacho generator connection the TDA2086 will demand full speed/power. The features of the TD A 2086 can be summarized as follows: -Power Direct from AC Mains or DC Line, - 5 V Supply Available for Ancillary Circuitry, -Low Supply Current Consumption, -Average or Peak Load Current Limiting, -Ramp Generator to Provide Controlled Acceleration, -Negative Triac Firing Pulses 100 mA Guaranteed Minimum -Warning LED Drive Circuit, -Actual Speed Derived from Tachogenerator Frequency or Analog Feedback, -Well Defined Control Voltage&Phase Angle Relationship, -Inhibit Input for use with Thermistor Temperature Sensors. xn Below given figure the universal motor speed control application using TDA2086 integrated circuit was shown: u. ft 5 Z 3 LU 3 v) Z -o ? o- © H3- =1 I«* \^ IvJ I- @i* -( - h HI1 HI 8§1 D? ^ S 8 Hh a|"I 5* 0*5 0| 4h Hl - c aS 56 if < * tt c o CO O Î (D v. O O "io Xlll One of the integrated circuits used in speed control is TDA2086. This is a silicon integrated circuit designed for use in closed or open loop phase control circuits of AC with resistive or inductive loads. In closed loop systems analog voltage or tacho frequency feedback may be used. The circuit was primarily designed for motor speed control in power drills, food mixers, washing machines etc. In the event of an open circuit tacho generator connection the TDA2086 will demand full speed/power. The features of the TD A 2086 can be summarized as follows: -Power Direct from AC Mains or DC Line, - 5 V Supply Available for Ancillary Circuitry, -Low Supply Current Consumption, -Average or Peak Load Current Limiting, -Ramp Generator to Provide Controlled Acceleration, -Negative Triac Firing Pulses 100 mA Guaranteed Minimum -Warning LED Drive Circuit, -Actual Speed Derived from Tachogenerator Frequency or Analog Feedback, -Well Defined Control Voltage&Phase Angle Relationship, -Inhibit Input for use with Thermistor Temperature Sensors.