Rateb Issa - Academia.edu (original) (raw)

Papers by Rateb Issa

Research Journal of …, 2010

Research Journal of Applied Sciences, Engineering and Technology 2(6): 603-613, 2010 ISSN: 2040-7... more Research Journal of Applied Sciences, Engineering and Technology 2(6): 603-613, 2010 ISSN: 2040-7467 © Maxwell Scientific Organization, 2010 Submitted Date: July 21, 2010 Accepted Date: August 20, 2010 Published Date: September 10, 2010 ... Corresponding Author: ID ...

Research Journal of Applied Sciences, Engineering and Technology, 2015

The efficiency of induction motor drives operating under variable conditions can be improved by p... more The efficiency of induction motor drives operating under variable conditions can be improved by predicting the optimum flux that minimizes the losses. In this study, a Loss-Minimization Controller (LMC) and a Search Controller (SC) are combined. The output from the controllers would drive the field oriented control inverter in order to achieve the optimum flux in the motor that minimizes the losses. For this purpose, a mathematical model for calculating the total power losses as a function of magnetic flux and a factor to obtain feedback as a function of optimum flux were discussed. An LMC-SC vector-controlled induction motor drive system was modelled, simulated and tested. The results have validated the effectiveness of this system in minimizing the motor operating losses, especially at light and medium loads. The proposed controller can be implemented in adjustable speed induction motor drive systems with variable loads, operating below rated speed.

International Journal of Computer Applications, 2013

This paper has presented a mathematical-based scheme for induction motor drive system leading to ... more This paper has presented a mathematical-based scheme for induction motor drive system leading to efficiency optimization. The proposed scheme uses information on torque of the squirrel cage motor to generate the appropriate voltage amplitude that maximizes the motor efficiency. A constantV/f efficiency controller model has been configured and built depending on a set of experimental data, based on the motor equivalent circuit, using Matlab computer program. The model was validated by simulation using a typical induction motor drive model implemented with Matlab/Simulink. The aim of this paper is the drive system performance improvement by designing optimal efficiency controller; this will supply stator of the motor with proper voltage and frequency under different loading conditions using appropriate algorithm.

The influence of silicon carbide SiC abrasive particles of 20, 30, 40, 50 and 60 mµ size on carbu... more The influence of silicon carbide SiC abrasive particles of 20, 30, 40, 50 and 60 mµ size on carburized digger tooth steel was studied. Four types of steel, with different hardness, were tested at two constant linear sliding speeds and under various loads of 10, 20, 30, 40 and 50N. Tests were carried out for sliding time of 0.5, 1.0, 1.5, 2.0 and 2.5min. Experimental results showed that there was consistent reduction in abrasive wear as the hardness of the materials was increased. It was found that wear increased with the increase of applied load, linear sliding speed and sliding time. Also, it was noticed that the wear increased with increase in abrasive particle size, and the most effective size was 40 mµ. SEM observations of the worm surface showed that the cutting and ploughing were the dominant abrasive wear mechanisms.

This paper presents Electronic Workbench (EWB) model used for parametric speed control of Separat... more This paper presents Electronic Workbench (EWB) model used for parametric speed control of Separately Excited DC Motor, namely armature voltage, armature resistance and field current control methods. The speed time response and the armature current time response were investigated during start up period. The speedtorque characteristics were plotted. The study is carried out using one model contacting four functional blocks. The results should be implemented in electric drive laboratory at Al-Balqa Applied University.

The efficiency of induction motor drives under variable operating conditions can be improved by p... more The efficiency of induction motor drives under variable operating conditions can be improved by predicting the optimum flux that guarantees loss minimization. In this paper, a loss-minimization scalar controller, based on determining of modulation index of IGBT inverter-based AC-to-AC converter, which corresponds to optimum flux, is proposed. For this purpose, mathematical models for total power losses as a function of magnetic flux, optimum flux as a function of operating speed and load torque, and modulation index as a function of optimum flux were analytically derived. Loss-minimized, scalar-controlled induction motor drive system was modeled, simulated and experimentally tested. The results have validated the effectiveness of this system in minimizing the motor operating losses, especially at light and medium loads. Also, the dynamic performance of the drive system has been improved. The proposed controller can be implemented in adjustable speed induction motor drive systems wit...

Intelligent Control and Automation, 2011

Energy efficiency optimization techniques of electrical drive systems improve the overall efficie... more Energy efficiency optimization techniques of electrical drive systems improve the overall efficiency and reduce the hardness of mechanical characteristics of the drive system. It is therefore important to reduce the slip of induction motor to maintain its stable operation at different frequencies and loads. In this paper a slip compensator, based on fuzzy logic incremental controller has been developed to improve the steady state performance of efficiency-optimized three-phase induction motor drive system. The slip control is accomplished through a fuzzy controller with 9 rules, taking speed error and speed error variation as inputs, to produce the frequency. The proposed controller reduces the slip occurring at low frequencies and light loads to certain value, and also reduces the energy efficiency of the system.

2009 Second International Conference on the Applications of Digital Information and Web Technologies, 2009

This work presents a new topology of delta modulation technique. This kind of modulation techniqu... more This work presents a new topology of delta modulation technique. This kind of modulation technique is usually used to improve the power factor of Pulse Width Modulation (PWM) converters used for supplying A.C. drives. Many new topologies have been presented trying to obtain a cost-effective solution to reduce the input current harmonic content and to make it sinusoidal and in phase with the input voltage of AC-DC converters. Each one of them has its application range due to the inherent characteristics of the topology (See [2-3]). Obviously, not every converter is useful for the same application. Hence, this paper tries to show the most appropriate topology of different variants of modulation technique used for power factor correction. This technique which is used to generate the PWM control signals for the main devices of the PWM converter has the advantage of yielding instantaneous current control, resulting in a fast response [3], [4]. However, the switching frequency is not constant and varies over a wide range during each half-cycle of the A.C. input voltage. Furthermore, the frequency is also sensitive to the values of the circuit components, which is also addressed in this paper. This new delta modulation technique topology proves to give great stability performance over other variants of delta modulation or other modulation techniques.

2009 6th International Symposium on Mechatronics and its Applications, 2009

This paper employs a strategy based on Hardware-in-the-Loop (HIL) concept to control 3-phase indu... more This paper employs a strategy based on Hardware-in-the-Loop (HIL) concept to control 3-phase induction motor on-line. The strategy in this work is divided into 3 stages: on-line identification, off-line controller design, and on-line control. The scope of this paper is limited to the controller part and therefore addresses the last two stages of the strategy. The implementation of the strategy was accomplished using HIL within a Simulink environment. Experimental results for different speed profiles are presented which show the validity of the proposed strategy. Advantages include optimizing time resources and minimizing the cost. This is a result of designing the controller offline and applying different virtual controllers to the system.

2008 5th International Symposium on Mechatronics and Its Applications, 2008

Abstract-Induction motors are widely used in the industry. However, due to their involved mathema... more Abstract-Induction motors are widely used in the industry. However, due to their involved mathematical models those depend on difficult to measure parameters such as leakage inductance. Therefore, simplified model approximations are usually used instead. In this paper, a ...

Simulation Modelling Practice and Theory, 2010

This paper describes a strategy for identification and control of three-phase squirrel cage induc... more This paper describes a strategy for identification and control of three-phase squirrel cage induction motors. The strategy in this work is divided into 3 stages: on-line identification, off-line controller design, and on-line control. First, the transfer function is identified online. Next, the controller design is performed in a pure simulation environment using the identified transfer function. Finally, the designed controller is applied to the real system. Simulation and experimental results are presented to show the validity of the proposed strategy. Advantages of the proposed strategy include high accuracy in the identified system, simplicity, and low cost.

International Journal of …, 2011

Based on the popular constant volts per hertz principle, two improvement techniques are presented... more Based on the popular constant volts per hertz principle, two improvement techniques are presented: keeping maximum torque constant or keeping magnetic flux constant. An openloop inverter-three-phase squirrel-cage induction motor drive system that provides constant maximum torque or increased maximum torque and reduced slip speed at frequencies below the nominal frequency has been modeled, simulated and tested. Load performance analysis of the proposed system under different operation conditions was provided. These principles of operation are extended to the case of operation from variable frequency or variable voltage control method. Finally, the effects of the non-sinusoidal voltage and/or current wave shapes are covered. The results show that both suggested improvement techniques (constant torque or constant flux) improve the steady-state performance A.C. drive system with squirrel cage induction motors. The slip speed has been decreased and the starting torque and maximum torque have been increased, which means that the suggested control techniques can be used in drive systems with short time operating mode under light loads.

American Journal of Applied Sciences, 2006

An inverter-three-phase squirrel-cage induction motor drive system with improved mechanical chara... more An inverter-three-phase squirrel-cage induction motor drive system with improved mechanical characteristics is presented. The proposed system provides mechanical characteristics with constant maximum torque or increased maximum torque and reduced slip speed at frequencies below the nominal frequency. The control algorithm is based on the constant volts per hertz principle using two improvement techniques: keeping maximum torque constant or keeping magnetic flux constant. Performance analysis of the system under different operation conditions was provided. For this purpose, a standard state-space model of three-phase squirrel-cage induction motor, with respect to a synchronously rotating d-q reference frame was derived. The correctness and validity of the derived model of induction motor was verified. The inverter was considered as a static linear element and modeled through its input-output equation based on the modulation index. Three types of controllers were modeled, simulated and experimentally tested. The results show that both suggested control methods improve the system performance. The slip speed has been decreased and the starting torque and maximum torque have been increased. Controller with constant maximum torque can be used in drive systems working with constant load, while controller with constant flux can be used in drive systems working with constant power.

International Journal of Computer Applications, 2010

This research presents two mathematical-based optimal control systems for induction motor drives ... more This research presents two mathematical-based optimal control systems for induction motor drives leading to stator current optimization and energy saving. The first is a classical optimal control system, which uses information on torque of the motor to generate the appropriate voltage amplitude that minimizes the induction motor stator current. The second is a genetic algorithmbased optimal control system, which uses information on torque of the motor to generate the appropriate minimum stator current according to fitness function. The constant f V optimal stator current controller models have been configured and built depending on a set of experimental data using MATLAB computer program, the models were validated by simulation using a typical induction motor drive model implemented with MATLAB/Simulink toolbox. The aim of this research is the industrial machineries performance improvement by analyzing and designing the induction motor optimal stator current controller, this will minimize the stator current under different loading conditions. Depending on the motor shaft mechanical load torque in order to minimize the stator current, the controller will supply stator of motor with proper voltage and frequency using appropriate control algorithm for industrial machinery.

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The paper considers controlling DC motor speed using LabVIEW-based frequency locked loop control ... more The paper considers controlling DC motor speed using LabVIEW-based frequency locked loop control algorithm which consists of a set of virtual instruments. Power interface circuit is required to supply the motor. In order to realize frequency-lock; a software digital integrator is used by implementing up-down counter. Proportional control term is included in order to control the depth of integral action. The result of the experiment shows acceptable startstop time characteristics and that motor speed is hold constant independent of motor load changes.