Omar H. Abdalla Copyright (c) 2012 All rights reserved. http://works.bepress.com/omar Recent documents in Omar H. Abdalla en-us Sun, 05 Feb 2012 01:39:17 PST 3600 Steady-State and Transient Performance of Oman Transmission System with 200MW Concentrated Solar Power Plant http://works.bepress.com/omar/13 http://works.bepress.com/omar/13 Sat, 04 Feb 2012 00:04:53 PST The paper presents steady-state and transient studies to assess the impact of a 200MW Concentrated Solar Power (CSP) plant connection on the Main Interconnected Transmission System (MITS) of Oman. The CSP plant consists mainly of a solar field with parabolic trough collectors, two thermal storage tanks, heat exchangers, piping systems, steam turbine, and electric generator. Two proposed locations are considered to connect the CSP plant to MITS: Manah and Adam 132/33kV grid stations in Al-Dakhiliah region. The transmission grid model of 2015 has been updated to include the simulation of the proposed 200MW CSP at either Manah or Adam. The DIgSILENT PowerFactory professional software is used. The results include percentage of transmission line loadings, percentage of transformer loadings, busbar voltages, grid losses, in addition to 3-phase and 1-phase fault levels. Also, simulation studies have been performed to assess the transmission system transient responses to the CSP outage. Steady state and transient analyses have shown that the connection of the CSP plant at Manah or Adam to the transmission system is acceptable. The transient responses have proved that the system remains stable when it is subjected to the CSP plant outage.

]]> Omar H. Abdalla et al. Renewable Energy Steady-State and Dynamic Performance of Oman Transmission System with Diesel-Engine Driven Distributed Generation http://works.bepress.com/omar/12 http://works.bepress.com/omar/12 Fri, 03 Feb 2012 23:39:09 PST The paper presents simulation studies of installing a number of diesel-engine driven generating units at selected locations in the main transmission system of Oman. A total of 300MW generator units are proposed on a temporary basis to aid in meeting the peak demand in summer 2011. A digital model is developed to simulate the system including central power plants, transmission system, loads and the proposed Distributed Generation (DG). The model includes representation of governor and excitation systems. The simulation studies are performed by using the DIgSILENT PowerFacrory software package. The objective of the studies is to demonstrate effects of the DGs in improving system performance in terms of voltage profile, line and transformer loadings, and transmission losses. The sizes and locations of DGs have been selected based on practical considerations; including availability of spacing, short-circuit ratings of existing switchgears, circuit capacity, feasibility of connection, operation noise, site access roads for fuel delivery, environmental effects, etc. A number of performance indicators are defined to assess the contribution of the selected DGs. These include transformer loading index, line loading index, and voltage deviation index. In addition, active and reactive transmission losses are calculated and used for assessing the benefits of the DGs. The results include comparison of the contribution of individual distributed generation at each site and the case with all proposed DGs. In addition the system dynamic performance is assessed by simulating various DG outages at peak demand.

]]> Omar H. Abdalla et al. Transmissiom Systems Modeling and Control of a Wind Farm and Electrolyzer System Connected to an Electrical Gird http://works.bepress.com/omar/11 http://works.bepress.com/omar/11 Sun, 20 Jun 2010 11:00:50 PDT This paper presents modeling and control analysis of a combined Wind-H2 system connected to an electrical grid and supplying a local electric load. The system consists of a wind farm for electricity generation and an electrolyzer to produce hydrogen for a filling station. A computer program has been developed in MATLAB for simulating the operation and control of the integrated system. Energy balances and hydrogen flow balances are calculated for each time step based on a system model and the specified control strategy. The input of this program are hourly wind speed, characteristics of wind turbine generators, hourly load demand, maximum grid capacity, rated power of electrolyzer, and minimum operating power of electrolyzer. The hydrogen produced will be supplied to a filling station where local vehicles can be filled. Hydrogen production is evaluated and the number of cars served per year is estimated.

]]> Omar H. Abdalla et al. Renewable Energy Stability Analysis of a Unified Power Flow Controller http://works.bepress.com/omar/10 http://works.bepress.com/omar/10 Fri, 18 Jun 2010 04:41:00 PDT The paper concerns with stability analysis of a Unified Power Flow Controller (UPFC). A nonlinear model is described in the abc-reference frame and then transformed into the dq0-reference frame. The model includes shunt and series compensators of the UPFC. Stability analysis is presented first in a three-dimensional space of system parameters. A linearized model is obtained in state-space form to be used in small-signal stability studies. Effects of system parameters on stability are investigated using eigenvalue analysis. These include resistance, reactance, and modulation indices of the shunt and series components of the UPFC. Simulation results show that the stability of the UPFC can be affected by these parameters. The results are useful for UPFC designers and engineers who set technical specifications of these control devices.

]]> Omar H. Abdalla et al. Flexible AC Transmission Systems (FACTS) Steady State Analysis of Unified Power Flow Controllers http://works.bepress.com/omar/9 http://works.bepress.com/omar/9 Fri, 18 Jun 2010 04:02:19 PDT The paper presents a tutorial review of the basic operation, control functions and steady state performance of a Unified Power Flow Controller (UPFC). A typical circuit arrangement of a UPFC is given and principles of controlling active and reactive powers are described. The main functions of UPFC are analyzed; including voltage regulation, series reactive compensation, phase compensation, and combined actions. A simplified two-bus power system is considered to demonstrate the main effects of the UPFC. Studies and results are presented to show the wide range capabilities of the UPFC in controlling transmission active and reactive powers simultaneously and/or independently.

]]> Omar H. Abdalla et al. Flexible AC Transmission Systems (FACTS) APPLICATION OF A RAPID NEURAL NETWORK FOR IDENTIFICATION OF A MICRO-MACHINE SYSTEM http://works.bepress.com/omar/7 http://works.bepress.com/omar/7 Fri, 18 Jun 2010 03:15:16 PDT This paper describes the application of a rapid neural network for identification of a micro-machine system from the experimental input-output data. The advantage of the rapid learning algorithm is that it does not need repetitive iterations as most learning algorithms. It is capable of achieving a good solution in one training scan. Identification accuracy is assessed by direct comparison between the actual output of the system and the output of the neural network identifier. The results of the rapid neural network are compared with the results of the conventional feed forward neural network with back-propagation learning algorithm. The results show excellent performance of the rapid neural network for an input/output model identification of the micro-machine system from experimental data.

]]> Refaat S. Ahmed et al. Applications of Artificial Intelligent to Power Systems Development of a Digital Model for Oman Electrical Transmission Main Grid http://works.bepress.com/omar/6 http://works.bepress.com/omar/6 Thu, 17 Jun 2010 23:53:45 PDT This paper describes the development of a digital computer model representing the main electric transmission system in Oman. A commercially available DIgSILENT power system computation package is employed. A brief description of system is given, which includes generating units, transformers, transmission lines and loads. The system is connected with a number of internal industrial plants to exchange electric power in addition to the interconnection between Oman and UAE. The model is used to perform computer studies such as load flows, short circuit analysis, stability, transient responses, etc. The simulation results are used for evaluating system performance and strategic planning purposes. Sample results are presented to show the capabilities of developed model.

]]> Omar H. Abdalla et al. Transmissiom Systems Performance of Oman Transmission System with Distributed Generation http://works.bepress.com/omar/5 http://works.bepress.com/omar/5 Thu, 17 Jun 2010 23:29:43 PDT The paper presents simulation studies of installing distributed generation (DG) at a number of grid stations in the main transmission system of Oman. The diesel-engine driven generator units are required on a temporary basis to aid in meeting the peak demand. A digital model is developed to simulate the system including power plants, transmission system, loads and the proposed DG. The simulation studies are performed by using the DIgSILENT software package. The objective of the studies is to demonstrate effects of the DG in improving system performance in terms of voltage profile, line and transformer loadings, and transmission losses. The results include comparison of the contribution of individual generation at each site and the case with all proposed distributed generators installed.

]]> Omar H. Abdalla et al. Transmissiom Systems Key Performance Indicators of a Transmission System http://works.bepress.com/omar/4 http://works.bepress.com/omar/4 Tue, 17 Nov 2009 08:20:16 PST The paper concerns with formulae and calculations of a selected group of Key Performance Indicators (KPIs) for the main electricity transmission system in Oman. These include the following service quality, reliability, security, and financial indicators [1]:

&#; System Average Interruption Frequency Index (SAIFI)

&#; System Average Interruption Duration Index (SAID)

&#; Customer Average Interruption Duration Index (CAIDI)

&#; Average Interruption Time (AIT)

&#; Overhead Lines Maintenance Cost Index (OHLMCI)

&#; Substation Maintenance Cost Index (SSMCI)

Results of the main transmission grid in Oman, over the last 3 years, are presented. The results are useful in indicating trends of the KPIs and determination of future targets to improve transmission system performance.

The goal of presenting the paper at the GCC 09 is to open a discussion among transmission utilities in the Gulf region for the possibility of introducing common KPIs to evaluate system performance. This could provide an excellent opportunity to establish acceptable benchmarks of the proposed KPIs.

]]> Omar H. Abdalla et al. Transmissiom Systems Development of Measuring and Computer Interface System for an Industrial Electrostatic Precipitator http://works.bepress.com/omar/2 http://works.bepress.com/omar/2 Thu, 12 Mar 2009 12:10:21 PDT The paper describes the design and practical implementation of a measuring and digital computer interface system for an electrostatic precipitator (ESP) filter used in a large cement factory. The objective is to develop a digital computer control system to replace an old analog controller for the ESP filter mounted on a cement production rotary kiln inside the National Cement Company. The main concern is to develop a modern technology for a real ESP controller designed and implemented locally in Egypt. The first phase of this research project is described in this paper.

The computer interface system is developed to facilitate measurements of voltages and currents at both low voltage and high voltage sides of the transformer/rectifier power circuit of the high voltage unit in the EPS. Hardware, software, electronic circuits and interface systems are described. Practical results of the real precipitator filter are presented to show the validity of the designed system.

]]> Omar H. Abdalla et al. Control of Industrial Systems Coordinated Design of Power System Stabilizers and Static VAR Compensators in a Multimachine Power System using Genetic Algorithms http://works.bepress.com/omar/1 http://works.bepress.com/omar/1 Thu, 12 Mar 2009 08:28:49 PDT This paper presents a procedure to coordinated design of PSSs and SVCs in a multimachine power system. The aims of the proposed method are to find the best location and the optimal parameters of these compensators in order to improve the steady state and transient performances and also to increase the system damping over a wide range of operating conditions. The objective function of the GA allows the selection of the PSSs and SVCs to shift critical closed loop eigenvalues to the left-hand side in the complex s-plane. The multimachine power system considered in this study consists of nine buses, three generating units (steam, hydro and nuclear) and three static loads. Digital simulation studies show that the proposed design procedure provides good damping for the power system at different operating conditions, and moreover improves steady-state and transient performance of the system.

]]> Omar H. Abdalla et al. Power System Stability