The research was
depended on the concept of Partial Relative Indicators (PRI) for the
resulting harmonics as a new way to detect the fault through
determination of relative indicator PI of each type of harmonics that
result during the operation of motor at the different loads.
Induction motors are the most widely used electrical motors due to their reliability,
low cost and robustness. However, induction motors do not inherently have the capability
of variable speed operation. Due to this reason, earlier dc motors were a
pplied in most of
the electrical drives. But the recent developments in speed control methods of the induction
motor have led to their large scale use in almost all electrical drives.
Out of the several methods of speed control of an induction such as pole changing,
frequency variation, variable rotor resistance, variable stator voltage, constant V/f control,
slip recovery method etc, the closed loop constant V/f speed control method is most widely
used. In this method, the V/f ratio is kept constant which in turn maintains the magnetizing
flux constant so that the maximum torque remains unchanged. Thus, the motor is
completely utilized in this method.
Due to scientific and technical advances in industrial electronics, SRMs have become one of the most attractive motors in recent decades.
The study of electromagnetism in electrical machines is critical, especially in the field of
design, investment and optimal performance. To achieve this, there are many ways in which
varying degrees of accuracy . The main aim of this piece of resea
rch is to study electromagnetic
fields distribution in 3ph-induction machines using computational numerical methods and proper
software, because these fields form the basic principle in machine 's work. It has been used the
finite element method aided computer to solve magnetic equations (Maxwell equations).
The simulation of magnetic field in induction machine performed by ANSYS-software. The
paper shows technique for finding the electromagnetic fields distribution in all parts inside 3phinduction
machine to get optimal design.
النظر للدور الكبير الذي تؤديه المحركات التحريضية عالية الاستطاعة في الوقت الحاضـر
في مختلف فروع الصناعة فمن المهم جداً دراسة سلوك هذه المحركات في مختلف حـالات
التشغيل، خاصة في الحالات العابرة، و ذلك من أجل إيجاد السبل لاستثمارها بالشكل الأمثل و
ال
حفاظ على استقرارها و تجنب الخسائر التي يمكن أن تنجم عن تعطلها عن العمل. و نظـراً
لأن عمل المحركات التحريضية يتعلق إلى حد كبير بالتأثير المتبادل بينهـا و بـين شـبكة
التغذية لذلك كان الهدف من هذا البحث هو دراسة استقرار المحركات التحريضـية عاليـة
الاستطاعة التي تعمل في ظروف شبكات التغذية الصناعية عن طريق حساب التوتر الحرج،
مع الأخذ بالحسبان تأثير تغير توتر التغذية و نسبة تحميل المحركات التحريضية في درجـة
استقرارها.
The deep-well pumps are practically and widely used to pump water up
from wells. These pumps are driven by squirrel-cage induction motors
where the pump is directly connected with the induction motor it drives.
They form a pump-motor set or a deep
-well set.
Economioally, the cost of digging a well proportionates with the diameter
of the hole opening.
This diameter is related to the deep-well set dimensions. Whenever the
dimensions of the deep-well set are small, the cost of digging a hole will
be notably less.
From here, in this research we shall test the possibility of desiging a
deep-well induction motor with a voltage of f =150 Hz frequency in a
small size. and in trifold speed of the induction motor which has same
power and functions as the motor with a voltage of f = 50 Hz frequency
and where the essential parameters of the motor aren’t worse than the
motor with f = 50 Hz Frequency.
