Mahmoud Awad - Academia.edu (original) (raw)
Papers by Mahmoud Awad
Journal of Electrical Engineering and Technology, 2015
INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY, 2005
This study, discuss the stability problem of Resha generation plant. The length of the transmissi... more This study, discuss the stability problem of Resha generation plant. The length of the transmission line which connect Resha with Haranah station, decrease the power transferred capacity that increase the risk of transient disturbance on the system, especially when the generators loaded at full load. Beside that several solutions were suggest in order to improve system stability and raise the capacity of transmitted power.
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.
Modern Applied Science, 2012
This paper introduces the terminology and various issues related to 'power quality'. The interest... more This paper introduces the terminology and various issues related to 'power quality'. The interest in power quality is explained in the context of a number of much wider developments in power engineering: deregulation of the electricity industry, increased customer-demands, and the integration of renewable energy sources. After an introduction of the different terminology power quality disturbances are discussed in detail: voltage dips and harmonic distortion. For each of these two disturbances, a number of other issues are briefly discussed, which are characterisation, origin, mitigation, and the need for future research.
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.
Journal of Electrical Engineering and Technology, 2015
INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY, 2005
This study, discuss the stability problem of Resha generation plant. The length of the transmissi... more This study, discuss the stability problem of Resha generation plant. The length of the transmission line which connect Resha with Haranah station, decrease the power transferred capacity that increase the risk of transient disturbance on the system, especially when the generators loaded at full load. Beside that several solutions were suggest in order to improve system stability and raise the capacity of transmitted power.
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.
Modern Applied Science, 2012
This paper introduces the terminology and various issues related to 'power quality'. The interest... more This paper introduces the terminology and various issues related to 'power quality'. The interest in power quality is explained in the context of a number of much wider developments in power engineering: deregulation of the electricity industry, increased customer-demands, and the integration of renewable energy sources. After an introduction of the different terminology power quality disturbances are discussed in detail: voltage dips and harmonic distortion. For each of these two disturbances, a number of other issues are briefly discussed, which are characterisation, origin, mitigation, and the need for future research.
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.