MOHAMED ABDALRAHEIM MOHAMED BADR

Mahmoud A. Attia, Mostafa I. Marei

01/11/2019

Improving the control of Photovoltaic (PV) power plants is an increasing interest worldwide. This improvement would hopefully help in reaching the maximum benefit of PV performance all the time. A lot of challenges are facing the control of PV systems such as Maximum Power Point Tracking (MPPT) of PV. Partial shading has become recently one of the most important challenges facing MPPT. This calls for improving the control strategy of PV power plants to cope with it. The work in this paper utilizes a relatively new optimization method which is the Cuttlefish Algorithm (CFA) to tune a Second Order Amplifier (SOA) for enhancing the PV system performance. The CFA has proved to be a very effective and fast optimization technique that can reach an accurate optimum solution with minimum effort and time. In addition, the SOA also has been found capable of enhancing the PV system performance at any condition if well-tuned. The main objective of this paper is to enhance the performance of a PV system under partial shading conditions through the use of a well selected combination of both the CFA and SOA. The needed mathematical models along with the required computer simulations are developed and the obtained results are analyzed. The reached at conclusions prove that the proposed control system and strategy are successful in achieving the declared objectives of the paper.

MOHAMED ABDALRAHEIM MOHAMED BADR

Sameh,M.A, Marei,M.I, Attia,M.A

01/11/2019

Improving the control of Photovoltaic (PV) power plants is an increasing interest worldwide. This improvement would hopefully help in reaching the maximum benefit of PV performance all the time. A lot of challenges are facing the control of PV systems such as Maximum Power Point Tracking (MPPT) of PV. Partial shading has become recently one of the most important challenges facing MPPT. This calls for improving the control strategy of PV power plants to cope with it. The work in this paper utilizes a relatively new optimization method which is the Cuttlefish Algorithm (CFA) to tune a Second Order Amplifier (SOA) for enhancing the PV system performance. The CFA has proved to be a very effective and fast optimization technique that can reach an accurate optimum solution with minimum effort and time. In addition, the SOA also has been found capable of enhancing the PV system performance at any condition if well-tuned. The main objective of this paper is to enhance the performance of a PV system under partial shading conditions through the use of a well selected combination of both the CFA and SOA. The needed mathematical models along with the required computer simulations are developed and the obtained results are analyzed. The reached at conclusions prove that the proposed control system and strategy are successful in achieving the declared objectives of the paper

MOHAMED ABDALRAHEIM MOHAMED BADR

Marei,M.I, Attia,M.A

01/11/2018

In general, optimization control is a relatively new trend where an optimization technique is used to tune the controller parameters for a given system under study. The optimization control is proved to be better than traditional adaptive control in many ways as discussed in this paper. This research work presents optimization control schemes for a Photovoltaic (PV) system. Two optimization techniques are proposed to find the optimum gain values of the controller in a hybrid approach. These techniques are Particle Swarm Optimization (PSO) and Cuttlefish Algorithm (CFA). In addition, two different controllers are considered which are the Proportional-Integral (PI) and the Proportional-Integral-Acceleration (PIA) controllers. Different results are presented and analysed to evaluate the dynamic performance of the proposed control schemes. Finally, robustness tests are carried out to prove the stability of the proposed controllers.

MOHAMED ABDALRAHEIM MOHAMED BADR

R.H. Shehata, A.Y. Abdelaziz

01/10/2018

A superior optimization technique called whale optimization algorithm introduced in 2016 which belongs to swarm intelligence family is used and implemented in this paper with some improvements to solve the problem of capacitor allocation in radial distribution feeders. In order to show the effectiveness of the proposed technique, three test distribution feeders are used (15 bus, 34 bus and 69 bus test systems). The obtained results are compared with other optimization techniques prove that the proposed method gives the optimal results; most reduction in system power losses, voltage profile enhancement and lower annual cost among the other techniques applied to the same distribution feeders.

MOHAMED ABDALRAHEIM MOHAMED BADR

  M.M. Abdelzaher, H.M. Mahmoud, A.Y. Abdelaziz, S.F. Mekhamer, M.A.L. Badr

01/08/2018

Worldwide, renewable energies are witnessing a huge expansion especially for power generation driven by different factors including the increased demand on fossil fuels and the depletion of its resources, the increase in its cost and the need to preserve the environment. Variable Renewable Energies (VRE) especially depending on wind and solar resources are intermittent by nature and this intermittency can have severe impacts on the operation of the power systems. Power systems are thus required to have a sufficient degree of flexibility to deal with this intermittency especially in the generation side. This paper introduces a hybrid Flexibility Enhanced Priority List-Mixed Integer Linear Programming (FEPL-MILP) method to solve the Unit Commitment (UC) problem and study the impact of the generation mix flexibility on the integration of renewable energies. Results show that, increasing the flexibility of the thermal energy mix used for power generation will have positive technical and economic impacts on the integration of renewable energies into the power system.

MOHAMED ABDALRAHEIM MOHAMED BADR

EL-Shimy,M.I, Kelany.M

01/11/2017

The analysis of reactive demands of high voltage transmission links connecting wind farms to the central grid is considered in this paper. Both High Voltage Alternating Current (HVAC) and High Voltage Direct Current (HVDC) options as well as overhead and cable transmission alternatives are considered in the analysis. Therefore, the presented work is applicable for both onshore and offshore installations considering various transmission technologies. The sizing of the required reactive power compensators for the transmission system is the main objective of the manuscript. The target is to keep acceptable operating voltage limits through appropriate amounts of reactive power injection or absorption at the wind farms interface bus. The considered wind farm is made up with Doubly Fed Induction Generators (DFIGs). Based on the reactive power capability limits of the DFIGs comprising the wind farm, the minimum rating, and type of external reactive power compensating devices are determined for various transmission options. In addition, the reactive power loading on the compensators at various operating conditions of the wind farm is determined. The salient conclusions are listed in the results, and conclusions sections.

MOHAMED ABDALRAHEIM MOHAMED BADR

Hamed, A. S., Marei, M. I

01/11/2017

This paper presents an interfacing system of a photovoltaic (PV) array with an electrical grid based on a dual cascaded inverter. The PV array is connected to the main inverter through a boost converter, for maximum power extraction, while the dc-side of the auxiliary inverter is connected to a capacitor bank. The main and auxiliary inverters are controlled to deliver the harvested maximum power from the PV array to the grid and simultaneously regulating the dc-side voltage of the auxiliary inverter at a constant ratio from the dc-link voltage of the main inverter. Four Hysteresis controllers are proposed for the three-phase currents fed to the grid and the dc-side capacitor voltage of the auxiliary inverter. Two switching control methods are adopted for the dual cascaded inverter: the conventional Hysteresis Current Control (HCC) and the Space Vector Modulation (SVM) based HCC. The later technique offers reduced switching numbers for both inverters compared with the conventional HCC. Simulation results show fast dynamic response and accurate performance of the proposed controllers.

MOHAMED ABDALRAHEIM MOHAMED BADR

M. A. Algabalawy ; A.Y. Abdelaziz

01/12/2016

The importance of the hybrid power generation systems (HPGS) increased especially in the last few years. HPGS are used to distribute the load between many different energy sources (e.g. utility grid (UG), wind turbine (WT), photovoltaic (PV), fuel cell (FC), and storage battery (SB)). These power sources are combined together in different configurations to form the HPGS. There are two common operation modes for these hybrid power systems; the first one is called as a standalone mode, in which the distributed power sources are combined together to supply the power without any supporting from the utility grid. The other mode is known as the utility grid connect mode, where the combination of these power sources is paralleled connected to the utility grid. This paper introduces a new contributions on the design of the HPGS, where the proposed hybrid system includes for the first time another energy utility such as the natural gas piping network. All operations conditions of this network are considered through the design of the HPGS. Applying modern meta-heuristic optimization techniques for the first time in the sizing of the HPGS. The applied techniques are; the ant lion optimizer (ALO) and grey wolf optimizers (GWO). MATLAB software has been used to execute the optimization process using ALO and GWO, and a detailed comparison is occurred between the results of applying the above mentioned techniques and another two modern optimizations techniques; Cuckoo search algorithm (CSA) and flower pollination algorithm (FPA) to show the effectiveness of applying both of ALO and GWO.

MOHAMED ABDALRAHEIM MOHAMED BADR

Madbouly, S. O, Soliman, H .F

01/04/2016

for three phase (3-ph) induction motors based on direct torque control (DTC). The main function of the DTC is to control the flux, developed torque and the direction of rotation. Many industrial applications require a precise speed control. Most of the available controller techniques could not grantee keeping the 3-Ph induction motor speed constant, while subjected to mechanical load disturbances. A high rejection of the effect of mechanical disturbance is achieved through using the proposed technique with an excellent motor speed regulation as shown in the simulation results. Different speed trajectories have been carried out to verify the robustness of the controller. A variable gain PI controller is introduced to cover all speed references and provide to be an efficient controller. Keywords— Speed Control; 3-Ph Induction Motors; Direct Torque Control; and Variable Gain.

MOHAMED ABDALRAHEIM MOHAMED BADR

A. Y. Abdelaziz, M. A. Algabalawy

01/09/2015

—The global solution becomes the dream of the researchers, who are interested in optimization techniques. They believe that, the global solution will provide the optimum conditions for the operation. Operations research is the main umbrella for the optimization techniques that study the shortest and critical path to achieve the activities of a project. Thus, the researchers concern the optimization techniques development; especially the meta-heuristic techniques. Researchers aim to obtain the techniques that provide the global solution with minimum time of operation. Firefly algorithm (FA) has been considered one of the meta-heuristic techniques developed to solve the optimization problems using the simulation of the behavior of the fireflies. Much searches prove the high accuracy and quality of the results of the optimization techniques solved by the FA. This paper analyses and summarizes most of these developments and applications. This paper gives a literature survey for different combinations of HPGS that consist of different combinations of PV, WT, SB MT, diesel generator, and Fuel Cell.

MOHAMED ABDALRAHEIM MOHAMED BADR

Ahmad,M., Elshimy,M

01/04/2015

The analysis of reactive demands of high voltage transmission links connecting wind farms to the central grid is considered in this paper. Both High Voltage AC (HVAC) and High Voltage DC (HVDC) options as well as overhead and cable transmission alternatives are considered in the analysis. Therefore, the presented work is applicable for both onshore and offshore installations considering various transmission technologies. The sizing of the required reactive power compensators for the transmission system is the main objective of the manuscript. The target is to keep acceptable operating voltage limits through appropriate amounts of reactive power injection or absorption at the wind farms interface bus. The considered wind farm is made up with DFIGs. Based on the reactive power capability limits of the DFIGs comprising the wind farm, the minimum rating, and type of external reactive power compensating devices are determined for various transmission options. In addition, the reactive power loading on the compensators at various operating conditions of the wind farm is determined.

MOHAMED ABDALRAHEIM MOHAMED BADR

Mohamed EL-Shimy, Mai Ahmed

01/09/2014

This paper presents an improved mathematical model required for evaluation of the steady-state power characteristics and loading capability limits of doubly-fed induction generators (DFIGs). Unlike the previous models, this model takes into consideration the effect of the losses, rotor power flow, and power factor settings of the grid-side converter (GSC). The impact of various variables and parameters on the loading capability is determined through detailed analysis of the loading capability limits as well as a parametric analysis. Simulation results show that DFIGs can provide a continuous controllable reactive power support to electrical grids. In addition, the results set rules for enhancing the reactive power capability of DFIGs based on its sensitivity to various parameters and variables of the machine and its controls. Although, squirrel-cage induction-generators (SCIGs) that connected directly to the grid do not have a reactive power capability and their reactive power consumption is uncontrollable, its loading characteristics are also presented for illustrating the value of the partial-scale converter in operational flexibility enhancement in DFIGs based systems.

MOHAMED ABDALRAHEIM MOHAMED BADR

Mostafa I. Marei

01/01/2014

Microturbine Units (MTU) are used widely as distributed generators for their proved advantages. This paper presents an interface system for the Microturbine Unit (MTU) based on back-to-back converter to operate in grid connected and islanding modes. Besides regulating the active power fed from the MTU, during the grid-connected mode, the proposed interface system regulates the Point of Common Coupling (PCC) voltage at its rated value. Moreover, the proposed interface system is controlled to have a Low Voltage Ride-Through (LVRT) capability by feeding the grid with reactive power during grid faults. Furthermore, the proposed interface system keeps the voltage and frequency at the load terminal during the islanding mode of operation with the same control structure. Simulation results are provided to evaluate the dynamic performance of the proposed MTU interface system at the different modes of operation.

MOHAMED ABDALRAHEIM MOHAMED BADR

Mahmoud A Mostafa; Walid El-Khattam;

01/01/2014

Distributed Generations (DGs) have spread widely in electric distribution systems due to their positive impacts on the system. One of the main benefits is using DGs as an alternative element in electric distribution expansion planning. Thus, this paper investigates the optimal solution of sizing and siting of DG units in electric distribution system using the Particle Swarm Optimization (PSO) technique. It takes into consideration minimizing the distribution network losses, improving the voltage profile, and improving economic and environmental aspects. Two electric distribution systems are used to evaluate the proposed PSO technique. The first system is used to verify the proposed PSO technique by comparing the obtained results with a previously studied Numerical technique. The second system is a practical distribution system (Borg El-Arab substation; a part of the Egyptian National Electricity network) where the proposed PSO technique is implemented. The obtained results are evaluated and discussed. Finally, conclusions are reported.

MOHAMED ABDALRAHEIM MOHAMED BADR

Mohamed Kareem AlAshery, Walid EI-Khattam,

01/11/2013

Countries in the Arab region are planning to meet their increasing electricity demands by increasing both nuclear and Renewable Energy (RE) contributions in electricity generation. In the planning phase of siting both new Wind Farms (WFs) and Nuclear Power Plants (NPPs), many benefits and challenges exist. An important aspect taken into consideration during the NPP siting is the existence of ultimate heat sink which is sea water in most cases. That is why most NPPs are sited on sea coasts. On the other hand, during WF siting, the main influential aspect is the existence of good wind resources. Many coastal areas around the world fulfill this requirement for WF siting. Coupling both NPPs and WFs in one site or nearby has many benefits and obstacles as well. This coupling can help in the geographical distribution of WFs along the countries territories by installing WFs at or near to the NPP area. This geographical distribution will make use of the low density population area around NPPs and smoothen the WF’s output power injected into the grid. Due to wind speed fluctuations, the value of the output of WFs’ power is less than their installed capacity. Thus, WFs’ capacity credit is evaluated to find out the corresponding value of the thermal power plants to be installed in the grid in order to satisfy the required system reliability. In this paper, the implementation aspects of NPP and WF coupling/adjacency will be discussed in detail. Based on international experience and literature reviews, the benefits and obstacles of this coupling/adjacency are studied and evaluated. Various case studies are carried out to verify the coupling/adjacency concept. The benefits of WF geographical distribution are examined on two candidate sites in Egypt. The WF capacity credit is calculated by implementing the PJM method using actual three-year hourly wind data. The obtained results are evaluated to study their applicability in the Egyptian environment and their applicability for countries in the Gulf region. Finally, both the coupling idea and the capacity credit values can be used to help decision makers in the planning phase as well as in the selection of WT characteristics as discussed in this paper.

MOHAMED ABDALRAHEIM MOHAMED BADR

O.S. Ebrahim ; M.F. Salem ; P.K. Jain ;

01/01/2010

Realisation of a digital control system, which implements a complete state feedback control strategy for the voltage-source inverter-fed induction motor (IM) drive, is reported. The controller design is based on the application of the linear quadratic regulator (LQR) theory to a linearised state-space model for the machine in the synchronous frame. The control objective is to achieve rotor speed control and orientation of the stator flux vector at constant magnitude by adjusting the stator voltage and frequency. To overcome the detrimental effects of inevitable modelling errors and disturbances, the structure of the feedback controller used here resembles that of the classical proportional-integral controller but is more versatile. The control system design considers the inverter-s output limits and proposes an anti-windup scheme to avoid instability risk under integral windup. A supplementary feedforward control loop is provided to enhance transient response of the controlled drive by utilising few future values of the speed reference and load torque signals in advance. The hardware implementation of a controller is discussed and experimental tests are presented, along with computer simulation results, to verify the validity of the method.

MOHAMED ABDALRAHEIM MOHAMED BADR

Sayed O. Madbouly ; Hussein F. Soliman ; Hany M. Hasanien

01/01/2010

This paper presents a new fuzzy logic control algorithm to improve the dynamic performance of the brushless doubly fed induction generator (BDFG). Also, an independent control of the active and reactive power is achieved. The system under study consists of a BDFG driven by a voltage source bi-directional converter. The machine model in d-q power winding (PW) synchronously rotating reference frame is formulated in Matlab/Simulink. Both, the active and reactive control paths are implemented using Fuzzy logic controllers (FLC). Meanwhile each path includes two fuzzy logic controllers, one is used for the outer control loop and the other for the inner control loop. The dynamic performance of the BDFG has been tested when the overall system is subjected to a step change in active and reactive power respectively. The simulation results show that the FLC enhance the dynamic response of the overall system compared with conventional proportional plus integral controller. It achieves also independent control of the active and reactive power with reduced cross coupling effect.

MOHAMED ABDALRAHEIM MOHAMED BADR

Osama S. Ebrahim ; Ali S. Algendy ;Praveen K. Jain

01/10/2009

This paper investigates the opportunity for energy saving in a three-phase induction motor (IM) driving pump load and proposes an improved loss model control (LMC). Compared with other power-loss reduction algorithms for IM, the presented one has the advantages of fast and smooth flux adaptation, high accuracy, and versatile implementation. The performance of LMC depends mainly on the accuracy of modeling the motor drive and losses. In this paper, the derived loss model considers the surplus power loss caused by inverter voltage harmonics using closed-form equations and also includes the magnetic saturation. An artificial neural network controller is synthesized and trained offline to determine the optimal flux level that achieves maximum drive efficiency. The drive's voltage and speed control loops are connected via the actual stator frequency, making the scheme comparatively reliable. Simulation and experimental studies are performed on 5.5-kW test motor using the proposed control method. The test results are provided and compared with the fixed flux operation to validate the effectiveness.

MOHAMED ABDALRAHEIM MOHAMED BADR

T M K Amer; Hassan Mohamed Mahmoud; Almoataz Y. Abdelaziz; M M Mansour

01/04/2009

Artificial Neural Networks (ANNs) are being advantageously applied for power system problems. They possess the ability to establish complicated input-output mappings through a learning process, without any explicit programming. In this paper, two ANNs for Subsynchronous Resonance (SSR) analysis are presented. The designed ANNs measure the possibility of SSR occurrence. The effectiveness of this approach is tested by experimenting it on the first bench mark model proposed by IEEE Task Force on SSR. I. INTRODUCTION Series capacitor compensation is employed in electric power systems to raise the power transmission limit of long EHV lines. This, however, may lead to the phenomenon of subsynchronous resonance (SSR) [1-2]. SSR occurs when a natural frequency of a series compensated transmission system aligns with the complement of one of the torsional modes of turbine-generator [3-5]. This happens at sub-synchronous frequencies. Under such circumstances, the turbine-generator oscillates at a frequency corresponding to the torsional mode frequency, and unless corrective action is taken, the torsional oscillations can continue for a long time and may result in the failure of the turbine-generator shaft [6-8]. There are several countermeasures proposed in the literature to avoid such a condition like torsional motion relay, armature current relay, static block filter and generator circuit series reactance [9-12]. Eigenvalue analysis is computationally intensive and the modeling complexity required for this method of analysis is quite high. Hence, it is necessary to design effective technique for eigenvalue analysis for the study of SSR which could avoid the conventional computation of eigenvalues and alleviate the modeling complexity as well. Note that there are two modes of oscillations corresponding to the electrical network one in subsynchronous range and the other in supersynchronous range; we only interested with the subsynchronous range. In this paper, two multi-layer feed forward ANN's are presented and used to detect and analyse the SSR conditions .

MOHAMED ABDALRAHEIM MOHAMED BADR

Sayed O. Madbouly; Hussein F. Soliman; Hany M. Hasanien

01/01/2009

This paper presents a new fuzzy logic control algorithm to improve the dynamic performance of the brushless doubly fed induction generator (BDFG). Also, an independent control of the active and reactive power is achieved. The system under study consists of a BDFG driven by a voltage source bi-directional converter. The machine model in d-q power winding (PW) synchronously rotating reference frame is formulated in Matlab/Simulink. Both, the active and reactive control paths are implemented using Fuzzy logic controllers (FLC). Meanwhile each path includes two fuzzy logic controllers, one is used for the outer control loop and the other for the inner control loop. The dynamic performance of the BDFG has been tested when the overall system is subjected to a step change in active and reactive power respectively. The simulation results show that the FLC enhance the dynamic response of the overall system compared with conventional proportional plus integral controller. It achieves also independent control of the active and reactive power with reduced cross coupling effect.

MOHAMED ABDALRAHEIM MOHAMED BADR

T. M. K. Amer, H. M. Mahmoud; . Y. Abdelaziz; M. M. Mansour

01/01/2009

Artificial Neural Networks (ANNs) are being advantageously applied for power system problems. They possess the ability to establish complicated input-output mappings through a learning process, without any explicit programming. In this paper, two ANNs for Subsynchronous Resonance (SSR) analysis are presented. The designed ANNs measure the possibility of SSR occurrence. The effectiveness of this approach is tested by experimenting it on the first bench mark model proposed by IEEE Task Force on SSR.

MOHAMED ABDALRAHEIM MOHAMED BADR

A. Y. Abdelaziz, A. M. Abdeen

01/05/2008

Steady state voltage stability analysis is effectively used to determine a stability margin that shows how close the current operating point of a power system to the voltage collapse point. The energy function technique represents a powerful method to assess voltage stability of multi-machine power systems. The sparse network formulation of this method retains the original structure of the system network and avoids network reduction. This permits the system loads to be modeled as they exist in practical life. Neglecting these models may lead to misleading results; e.g. the system appears to be stable while it is actually unstable. This paper investigates this serious problem and shows the significant effect of load modeling on power system voltage stability. A closed form expression of the energy function is obtained. The proposed technique is applied to Ontario-Hydro real power system (Canada).

MOHAMED ABDALRAHEIM MOHAMED BADR

Mohamed EL-Shimy

01/01/2008

Induction machines continue to be one of the most important inventions for mechanical power production when operated as motors and for electric power production when operated as generators. This paper presents a linearized model for a simple system consisting of an induction generator (IG) connected to an infinite bus through a linear passive transmission network. This model is used for studying small signal stability and for modal analysis of the system as affected by the network parameters and initial operating conditions. The considered network parameters are the series impedance of the interconnecting network and the shunt capacitive susceptance at the generator terminals. Moreover, a general algorithm is given for selecting the external network parameters that secure system stability and generator terminal voltage level. The work in this paper is valuable in both the design stage and analysis of induction generator based systems.

MOHAMED ABDALRAHEIM MOHAMED BADR

01/01/2007

Efficiency optimization control of a three phase induction motor

MOHAMED ABDALRAHEIM MOHAMED BADR

01/01/2006

This paper presents the steady state operation of the axial laminations switched reluctance motor (ALSRM). The performance of the motor is studied under constant speed operation and different values of both the switching turn on and off angles. The response of the motor is obtained at low, high, and very high speed in order to illustrate the performance of the motor. The ALSRM is used for high speed applications.

MOHAMED ABDALRAHEIM MOHAMED BADR

01/01/2006

Speed control of axial lamination switched reluctance motor provided with digital pole placement controller