The presented paper deals with an implemented speed sensorless direct vector control (DVC) technique based on stator flux orientation algorithm to estimate and control rotor speed of three phase induction motor (IM). The driver system is presented in
this paper has a three phase bridge uncontrolled rectifier and space vector pulse width modulated (SV-PWM) inverter to drive and control the speed of the (IM) at different mechanical load conditions. The rotor speed has been obtained by slip frequency estimation instead of use feedback speed sensor. The structure of Volt/Freq via PI-controller is used to control and adjust speed accuracy between required and estimation rotor speed to precise speed response. The proportional and time integration controller values obtain by Ziegler-Nichols closed-loop tuning method. Computer simulation results with Matlab/Simulink program show an acceptable speed control response, minimum error at steady state and dynamic condition, a results show also the stator voltage, current and flux estimated in direct-quadrate of stationary and synchronous reference frame at variation in load up to (10 N.m) beside the synchronous, slip and rotor speed estimation are varied between (250-1486 rpm).
Keywords: Induction Motor Drive System, Direct Vector Control, Speed Sensorless.
In this research, a research and educational tool for studying the sensitivity of the vehicle's suspension system to the properties and parameters of the suspension’s components is developed. This tool is a program that can study different models cre
ated using the Matlab/Simulink software package with its various libraries. Different types of models can be analysed, such as differential equation models expressing a mathematical model, block diagrams, or state space models. The tool also enables students to identify the suspension’s components, and its basic design parameters, and choose these parameters. Researchers and students will be able to test their models in terms of response, overshoot, and sensitivity, when conducting simulations in different working conditions.
Electric energy is very important for sustaining the good life on the planet's surface, especially since civilization has become associated with this type of energy. Solar photovoltaic (PV) is one of the most suitable applications for converting sunl
ight into electrical energy. The appropriate use of solar energy is an important topic for reducing dependence on fossil energy sources that are used to generate electricity, and thus reducing the emissions of greenhouse gases on the planet's surface. Globally, because of environmental conditions, other methods of generating energy being searched for that are less harmful than traditional methods, which rely on a large percentage of them on generating stations that run on fossil fuels. This research discusses electrical power generation using solar energy cells and the effect of these cells on the Syrian electrical grid so that a study of a solar energy farm project provides the data required when working on implementing such a project, and these data are voltage control, load flow, total harmonic distortion coefficient levels. To implement such a project, the model must be designed and we chose the ETAP program for that.
In this research, the relation which describes the electric permittivity of
emulsion was theoretically found. After that, a Matlab code was used to study
the behavior of mixed permittivity changes versus the ratio between forming
layer thickness a
round particle to its radius. We noticed from the graph that
the contribution of heterogeneous term in electrical permittivity take values in
the range corresponding to particle size in the range
at definite value of concentration C =0.01. In addition, the
contribution of heterogeneous term in electrical permittivity is proportional
with the forming layer and inversely with particle radius.
This study has multi-field application as: oil products, pharmacy materials,
nutrients and cosmetic materials
This research aims to achieve the observability of any electrical network by the
possibility compensation the lost measurements due to a defect, allowing the possibility of
state estimation of the electrical network ,ie, obtaining a single solution
for a state
estimation. This is done by means of the network observability analysing using the
available set of measurements and adding virtual pseudo-measurements if the network is
not observable. this is done using a numerical algorithm that ensures obtaining the
minimum and optimal number of added critical pseudo-measurements so that the result of
state estimation was not adversely affected. The algorithm depends on solving the
equation of the linear state estimation and the analysing to the triangular factors of the gain
matrix and an easy way to arrange the axis of the jacobian matrix ,ie, the measurements
matrix to ensure getting the minimum set of candidate pseudo- measurements to be added
to real measurements, the numerical algorithm was acheived by environment in the
MATLAB and tested to present the results on the network observabilty analysing and
adding the pseudo-measurements algorithm on state estimation .The results of the program
were tested on IEEE-14 network, and they showed that if a number of measurements were
lost, they would be compensated by critical and pseudo-measurements. The results of state
estimation showed small error ratio between estimated values using the real measurements
and the estimated values after added the critical pseudo-measurements.
في المشكلة التي نعالجها, تحتاج شركة اتصالات إلى بناء مجموعة من الأبراج الخلوية لتوفير خدمة الاتصالات الخليوية للسكان في منطقة جغرافية. تم تحديد عدد من المواقع المحتملة لبناء الأبراج. يعتم اختيار هذه المواقع على عدة عوامل ، بما في ذلك مدى اتساق البرج
مع البيئة المحيطة وارتفاع التضاريس, تتمتع الأبراج بمدى تغطية ثابت ، وبسبب قيود الميزانية ، لا يمكن بناء سوى عدد محدود منها . بالنظر إلى هذه القيود ، ترغب الشركة في توفير تغطية لأكبر قدر ممكن من السكان, والهدف هو اختيار في أي من المواقع المحتملة يجب أن تقوم الشركة ببناء الأبراج.
إن المشكلة التي شرحناها يمكن نمذجتها لتصبح أحد أمثلة مشكلة 0/1 knapsack الشهيرة لذلك شرحنا في الحلقة مفهوم مشكلة 0/1 Knapsack والطرق المستخدمة في الحل, وتوسعنا في الشرح عن خوارزمية Branch and Bound كونها تعتبر أفضلها.
محرك الخطوة من أكثر المحركات المستخدمة في أنظمة التحكم عندما يراد
التحكم بالحركة و الموضع معاً، و لعل المحرك الخطوي الهجين يعتبر من أهم هذه
الأنواع ، و موضوع أنظمة التحكم الخاصة بعمل هذا النوع من المحركات يعتبر
مهماً جداً خاصة مع استخدام مفهوم الأ
تمتة في هذه الأيام، لذا فإن تصميم نموذجٍ
لنظام التحكم و محاكاته باستخدام برنامج MATLAB يعد تطبيقاً عملياً لنظام التحكم
بعمل المحرك الخطوي الهجين، و دراسة العوامل المؤثرة عليه ببساطة و سهولة و بتوفير
للوقت و الجهد و الكلفة إضافة لإمكانية التأكد من صحة النتائج و دقتها.
The work includes the development of a program in an advanced – programming
language. to solve two none linear related partial differential equation that form a
mathematical model that describes the dynamic status of laser ,so that we can study the
properties of radiation density through this type the related program ,as well as the
population inversion inside the homogeneous medium of laser . We have studied the
strength f the out put power as well as the population inversion in the case of pulse –
working of the solid state laser Nd:YAG and the population inversion change as a function
of the diameter and length of the effective medium of laser .
This paper presents an analytical and laboratory study of the
behavior and evolution of the symmetrical components of both
voltage and current of a three-phase induction motor as a function of
the load torque applied to it and to increasing in the
imbalance which
effect the electrical grid. The effect of unbalanced voltages in the
voltage source will be also examined on the distribution of motor
currents in the three lines and on its performance.
Phase Shifting Transformer has played an important role in electrical networks to improve
their efficiency because it has the ability to control power flow in electrical transmission network
that can lead to power loss minimization. PST technology
is considered as mature technology
which is used by transmission system operators. These transformers provide an integrated solution
to control power due to the advantages of low economic and high reliability.
In this research an exposure to the classification of phase shifting transformers and their
application then a simple model for Phase shifting transformer is suggested without seeking in the
details of transformer, this model presents the result for using PST via modeling phase shifting
voltage, this model is performed using Matlab/Simulink program according to differential
equation. Depending on the mathematical model which has been built in an Matlab environment
we have a model shows the impact of this transformer through the representation of output voltage
, results are verified using Neplan program via a case study demonstrated the role of this type of
transformers in controlling power flow in transmission system achieving remarkable power loss
reduction and improving voltage profile
