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.
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
Gas turbines are used as main engines to convert fuel energy into
mechanical energy used to move the generator and thus produce
electrical power at the power plants. When you use a gas turbine in
the power plants, it must maintain a constant speed
of the turbine
and thus fixed frequency output of the current also must maintain
the parameters of the turbine such as pressures and temperatures at
the limits and thus extend the life of the turbine components and
increased efficiency. there was a need for the design of control
systems maintain a constant speed of the turbine and to avoid
operating at others and allowed values. In this research, we modeled
the gas turbine and solving the model using MATLAB/ SIMULINK
program, and then design a proportional integral differential
controller for gas turbine operating In Gandar Station
In this research a proportional integral differential classic (PID
controller) and state feedback controller was designed to control the in
the inverted pendulum and a comparison between all the cases and
choose the most suitable controller using MATLAB / SIMULINK
program
We used the general theory of electrical machines to facilitate the
study and representation of the real machine and complex phenomena in which
it occurs during transient situation where we represent the real machine other
machine ideal equivalent to represent the physical phenomena in these model
machine similar to those that occur in the real machine.
In this paper, the structure and
operation principle of BLDC motors are introduced, a simple mathematical model is figured,
a speed PI controller was designed, a simulation model to control 3-phase BLDC
motor speed in Matlab/Simulink was built, an
analytical study of the Speed, Current,
Electrical Torque, Back-Emf waveforms, during no load was done, the effect of adding
external load in different load torque values are studied. The effect of adding external
load torque during operation is studied also.
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.
This research deals with improving the efficiency of solar photovoltaic (PV) power
systems using a Maximum Power Point Tracker controller (MPPT controller), based in his
work on the Maximum Power Point Tracking techniques via the direct control met
hod.
Which used to control the duty cycle of DC-DC Voltage Converter, to achieve the
photovoltaic system works at a Maximum Power Point under different atmospheric
changes of the solar insolation and ambient temperature. In this context, our work is
focused on the simulation of the components of the power generating system, such as the
photovoltaic system, DC-DC Boost Converter and a MPPT controller in Matlab/Simulink
environment. The simulating of the MPPT controller was based on several algorithms such
as: Constant Voltage algorithm, Perturb and Observe algorithm and Incremental
Conductance algorithm by using Embedded MATLAB function. The simulation results
showed the effectiveness of the MPPT controller to increase the photovoltaic system power
compared with non-use of a MPPT controller. The results also showed the best
performance of MPPT controller based on Perturb and Observe and Incremental
Conductance algorithm, compared with constant voltage algorithm in tracking the
Maximum Power Point under atmospheric changes.
The development of gas turbine needs to studying and development
each of its components. In this paper we will focus on the study of
the compressor used in gas turbines. So we can study it we will be
using mathematical modeling, which aims to find
a mathematical
description of the system studied and study the dynamic behavior of
it in order to improve his performance, and use mathematical
modeling to save time and cost at the improvement and
development of products or in the case of the creation of new
products through simulation that enrich us all costly and timeconsuming
testing stations. Also it helps us to clarify the physical
phenomena or unwanted effects and enable us to determine the full
parameters required in accurate design.
