Gerilim bozulmalarının tarımsal sulamada kullanılan farklı besleme türlerine sahip asenkron motorlar üzerindeki etkilerinin araştırılması
Öz
Türkiye’nin tarımsal arazilerin çok yüksek bir oranının mevcut olduğu GAP uygulama bölgesinin sulama ağı
çok yetersizdir. Bu nedenle sulama işlemi, çiftçilerin kendi olanaklarıyla kurdukları, derin kuyulardan yer
altı suyunun yüksek güçlü asenkron motorlar ile yeryüzüne çıkarıldığı tesislerle yapılmaktadır. Bu çalışmada
sulama dönemlerinde şebekede meydana gelen gerilim dalgalanmalarının asenkron motorların performansı
üzerindeki etkileri analiz edilmiştir. Bu etkilerin analizi için Türkiye’nin Güneydoğu Anadolu Bölgesinde
Kızıltepe Ovasında tarımsal sulamanın yapıldığı bir tesis pilot olarak seçilmiştir. Ele alınan tesisi besleyen
dağıtım hattındaki gerilim değişimleri kaydedilmiştir. Bu tesiste kullanılan pompa-asenkron motor grubu
MATLAB/Simulink’te modellenmiş ve benzetim çalışması yapılmıştır. Benzetim çalışmalarında, dağıtım
sisteminden kaydedilmiş gerilim bozulmalarının asenkron motorun performansı üzerindeki etkileri
incelenmiştir. Motor-pompa grubu bozuk şebeke gerilimine doğrudan ve gerilim kaynaklı altı adımlı AC
sürücü üzerinden bağlanarak motor çıkış parametreleri incelenmiştir. Sonuçlara bağlı olarak şebeke
geriliminde dalgalanmayı azaltma yönünde asenkron motor sistemlerinde alınabilecek önlemler
tartışılmıştır.
Anahtar Kelimeler
Impacts of voltage distortion on used different feed types in induction motors for agricultural irrigation
Abstract
In the application field of Southeastern Anatolia
Project (GAP) which consist approximately %20 of
the economic irrigation area throughout Turkey, a
large part of the irrigation projects was not
completed. Roughly %15 of irrigation projects of
GAP is in process. Inadequency of the irrigation
structure which relies on the project, leaves farmers
no choice but watering with their own ways. For
that purpose, the asynchronous engines which have
average 100 kw power are commonly used.
Insufficiency of electricity distribution substructure,
defective construction of pump-motor facilities
according to engineering services and with the
reason of lack of capacity in transmission system,
important quality problems occur. The quality
problems affect very high-tension lines and
interconnected network, also. The most common
quality problems of electiricity energy are power
cuts and voltage disorders. The energy quality
problems in network affect closely asynchronous
engines. While this impact is reflected to the
performances of the engines, it affects the network
negatively because of the load characteristic of the
asynchronous engine. Thus, the vicious cycle comes
out of.
One way to reduce the impacts of disorderedness of
tension is feeding the asynchronous engine via a
driver. The drivers of asynchronous engine are the
systems which are used commonly in industry
especially in the variable-speed applications.
Variable-speed drivers are also used in pump-motor
mechanism. These drivers have features like highdynamic
performance, flexible usage and energy
saving. The driver of asynchronous engines affect
positively the system’s efficient functioning in
critical tension disorderedness. In most of the
tension disorderedness, voltage doesn’t go down
under its nominal rate %70 and disorderedness lasts
less then 300 ms. In these conditions of tension
disorderedness, VSDs have ability to work without
any loss of moment and without any power cut in
speed control time.
In this work, the situations of the 100kw
asynchronous engines which work under disordered
tension are analysed. To determine the
performances of the asynchronous engines under
changing tensions in the network, a pilot region is
discussed. Depending on 34.5 kw distribution line,
an irrigation facility which is feeding from Dikmen
transformator center in Kızıltepe plain is chosen as
a research area. The simulation model of
asynchronous motor-pump mechanism which is used
in watering, is created by the help of MATLAB
simulink software. In the simulation model, real
tension rates which is measured on the feeding
distrubution line during watering time, are used. In
the discussed irrigation facility asynchronous
engines are given ways by connecting directly to the
network, although it is not appropriate. That’s why
this research analyses the asynchronous engines
which are given way directly. Beside, it is discussed
the same asynchronous engine’ feeding with six
stepted driver which has a tension source. The
analyze determines asynchronous engines’ the stator
flows, electromagnetic moment, the speed of rotor
and the changings of active and reactive powers
which it absorbs from the network. In this way,
under the measured disordered tension, the conduct
of the asynchronous engine which is fed by direct
and variable-speed driver, is analyzed. The
performances of the used drivers on tension changes
and the impact on the outputs of the system are
studied and compared.
Keywords
