The ability to maintain the system frequency within specified operating limits is crucial for the stability and proper operation of power systems. Any small deviation out of the permissible frequency range must be well-mitigated by the automatic generation control (AGC) system, otherwise it may result in disruption of operation and/or damage to the power grid equipment. The data required by the AGC control system is sent to the control center through communication links which are susceptible to cyber attacks. Therefore, such AGC systems have to be well-protected against false data injection (FDI) attacks. In this paper, the use of a simultaneous input and state estimation based algorithm to detect and concurrently compensate for FDI attacks against the measurements of AGC systems is investigated. Throughout the use of this algorithm, the FDI attack signal is dealt with as an unknown input and its value is estimated accordingly. Then, the estimated value for the FDI is used to compensate for the effect of the attack so that the control center makes its decision based on the corrected sensor signals, and not the manipulated ones. The proposed approach is tested under different types of FDI attacks and the simulation results for a 2-area and a 4-area practical system confirm its ability to detect, estimate FDI attacks and successfully compensate for it.

The research for alternative fuels increased rapidly to mitigate the pollution problems resulting from using conventional fuels in internal combustion engines. Natural gas (NG) appears the most promising alternative due to its low prices and availability around the world. In this paper, a two-zone, zero-dimensional (0-D) model for the simulation of dual fuel NG-diesel engine is developed to study the performance of the engine with a proposed technique of NG early direct injection. The model is composed of several sub-models that are based on semi-empirical formulas. NG is modeled as being directly injected at the beginning of the compression stroke. The model is applied to study the performance of HELWAN M-114 diesel engine using dual fuel of NG and diesel fuels as a case study. The results indicate that using NG early direct injection technique (EDI) results in increasing the volumetric efficiency and hence the brake power of the engine compared to the intake manifold induction (IMI) of NG with air through the intake manifold. The percentage increase in brake power is 8.7% at NG mass ratio in the total fuel (the supplement ratio (SR)) of 90% at full load. To evaluate the proposed technique, results obtained by varying the engine load and the SR. Results indicate that the slow burning rate of NG results in decrease in the brake thermal efficiency by 3.5% and increases in brake specific fuel consumption with a percentage of 10.2% at 90% SR and full load. However, a great advantage of increasing the SR is the reduction in NOx and soot emissions particularly at high engine loads where they were reduced with percentages of 28.6% and 86%, respectively at 90% SR and full load condition.

A move toward renewable energy sources has become a global trend due to the economic and the environmental inconveniences of fossil fuels. Solar energy receives a great share of research focus owing to its availability and eco-friendly characteristics. Different approaches are advised and implemented for converting solar energy into electricity. Photovoltaic (PV) and concentrated solar power (CSP) systems are the most promising technologies in this field. PV is simply direct conversion of solar energy into electricity. It gains the advantages of size/power versatility. Meanwhile, CSP converts solar energy to electricity indirectly via thermal energy. This article introduces a comprehensive comparison between PV and CSP types regarding technical and economic feasibility of utility-scale solar power plants. Kingdom of Saudi Arabia is taken as a case study. The different types of either CSP or PV have been tested under hourly climatic data of 10 locations throughout the Kingdom of Saudi Arabia by using system advisor model software from National Renewable Energy Laboratory in order to identify the appropriate type of these systems to Saudi Arabia. The article produces fairly accurate forecasting for utility-scale solar energy market in Saudi Arabia. Several significant conclusions are presented that could act as reference for solar energy projects. For example, solar PV and parabolic trough are preferred candidates in Saudi energy market due to the lowest levelized cost of electricity. The minimum cost of electricity was found to be 0.06$US/kWh that was generated by solar trough technology in the Solar Village site.

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The compatibility between the needed structural designed dimensions of the work and the dimensions of the water stream or the canal in which the irrigation work will be located has a great importance from more than one point of view. As it is well known, the main aim of the designer of such works is to reach the optimum design for maximum performance efficiency with economical cost, and minimize negative technical impacts that may be harmful to the safety of the whole work. Since the complete suitability between the obtained designed dimensions of the different construction elements of the work, and the original properties and dimensions of the canal in which the work will be constructed, is rarely occurring. The designer always has to make some changes in the original engineering properties and dimensions of canals, such as bed width, bed level, and/or inside side slope, to reach the needed suitable compatibility between the structural design and the natural original canal cross section. For the economical purposes, the design always needs less width of the work, than the width of the bed of the original stream cross section, so a contraction may be needed where the work will be constructed; the literature indicated that, such a contraction must not be less than 0.6 of the original bed width. That contraction, of course, has a direct impact on the different hydraulic parameters, such as water depth, velocity, and flow regime in the location of the work. Changes of such hydraulic parameters may exceed their safe permissible values, and so the whole structure may face some dangerous situations, which must be overcome. In this paper, we present a technical survey of the previous research concerning canal width contraction, with the needed technical comments, and comparisons as a logical approach for a master-thesis under the same title.

The compatibility between the needed structural designed dimensions of the work and the dimensions of the water stream or the canal in which the irrigation work will be located has a great importance from more than one point of view. As it is well known, the main aim of the designer of such works is to reach the optimum design for maximum performance efficiency with economical cost, and minimize negative technical impacts that may be harmful to the safety of the whole work. Since the complete suitability between the obtained designed dimensions of the different construction elements of the work, and the original properties and dimensions of the canal in which the work will be constructed, is rarely occurring. The designer always has to make some changes in the original engineering properties and dimensions of canals, such as bed width, bed level, and/or inside side slope, to reach the needed suitable compatibility between the structural design and the natural original canal cross section. For the economical purposes, the design always needs less width of the work, than the width of the bed of the original stream cross section, so a contraction may be needed where the work will be constructed; the literature indicated that, such a contraction must not be less than 0.6 of the original bed width. That contraction, of course, has a direct impact on the different hydraulic parameters, such as water depth, velocity, and flow regime in the location of the work. Changes of such hydraulic parameters may exceed their safe permissible values, and so the whole structure may face some dangerous situations, which must be overcome. In this paper, we present a technical survey of the previous research concerning canal width contraction, with the needed technical comments, and comparisons as a logical approach for a master-thesis under the same title.

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