The Ethiopian government started the construction of the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile in Ethiopia in 2011. GERD is said to be able to produce 5,150 Megawatts of electricity, with a water storage reservoir capacity of 74 Billion cubic meters (BCM). The Blue Nile River, which originates from Ethiopia, contributes most of the river Nile's water. It is, therefore, the crucial resource for water, energy, and food security to Sudan as well as Egypt. Whereas few studies have pointed out to the detrimental consequences emanating from GERD, with such large water storage capacity, on Egypt, studies highlighting the possible impacts of GERD on Sudan are lacking. This paper looks into the benefits that Sudan can garner from the GERD on the Blue Nile, in terms of renewable energy provision as well as the adverse hydrological impacts due to the change of water flow patterns in the Blue Nile. The risk management processes of Project Management Body of Knowledge (PMBOK) are employed to maximize Sudan's benefits from GERD, while mitigating the threats due to it. The paper concludes that the benefits of GERD to Sudan and the underlying threats are somewhat not distant apart qualitatively.
In this study, a power generation system was constructed. The system mainly consists of a green hydrogen production system, a carbon dioxide utilization system for carbon dioxide synthesis of methane and methanol, and an integrated solid oxide battery power generation system. This system allows carbon dioxide to be recycled and fully utilized within the system while maintaining high power generation efficiency, providing a solution for global reduction of carbon dioxide emissions. Considering that the system is applied to power generation as a utility with highly predictable revenue cash flows, the discounted cash flow model was chosen for the economic performance calculation. At electricity sold price $0.36/kWh, Rated output of the SOFC system is 750,000 kW, Photovoltaic (PV) capacity is 151,300 kW, discount rate is 0.03, overall system with a 50/50 methanation and methanol synthesis plant has a simple integrated equilibrium payback of 9 years, NPV of 10 years, and DPBP of 18.86 years. Overall, the proposed system turned out to be economically feasible.
The expansion of renewable energy power generation is urgently needed to realize a decarbonized society. However, the high cost of batteries used to adjust electricity fluctuations is hindering the expansion of renewable energy power generation. In this study, we aim to develop a new energy storage method for storing excess electricity by using the unique state change of CO 2 hydrate. CO 2 hydrate is produced at about 0 °C under high pressure of several MPa, and can be dissociated at about room temperature. In the proposed system, the cold and warm heat required for the cooling and heating of CO 2 hydrate is obtained from renewable energy. CO 2 hydrate absorbs CO 2 during its formation and releases high-pressure CO 2 hydrate dissociation. Therefore, the pressure in the reaction vessel becomes high after CO 2 hydrate dissociation. In this study, an expander is driven by the high-pressure dissociation gas of CO 2 hydrate and a generator connected to the expander is operated. The amount of electricity generated in this process will be investigated and compared with the amount of electricity generated when the reaction vessel is filled CO 2 . The amount of electricity generated was greater when CO 2 hydrate dissociated gas was used to generate electricity than when the reaction vessel was filled only with CO 2 .
The quick growth in harmonic distortion levels generated by the usage of nonlinear loads in the system creates a big challenge. As a result of this issue, harmonic filters are required to minimize harmonic levels in accordance with IEEE-519 power quality enhancement guidelines. The goal of this research is to use a passive power harmonic filter to remove prominent current harmonics (5th, 7thand 11th) from a 240V(rms) utility at the point of common coupling. In order to validate the performance of the proposed filter, a number of simulations are provided using the MATLAB/SIMULINK software. By connecting distinct types of non-linear loads in different phases of a three-phase supply, a harmonically unbalanced condition of source current has been generated. In addition, the simulation includes a comparison between the situation of current harmonic without filter and the situation of current harmonic with passive filter. At the end of the research, the harmonics values can be reduced until 30 to 70 percent of the values without filters condition. This study's findings demonstrate that the passive filter is a highly effective option for dominant harmonic mitigation and power quality enhancement.
The intent of this research paper is to examine the AC withstand voltage of palm oil based CuO nanofluids while considering varieties of surfactants. Refined, Bleached and Deodorized Palm Oil (RBDPO) was used in this investigation, whereas mineral oil was used as a reference. This experimental work used Cetyl Trimethyl Ammonium Bromide (CTAB), Sodium Dodecyl Sulfate (SDS) and Oleic Acid (OA) as surfactants. The ratio of the volume concentration surfactant to the nanoparticles was fixed to 1:2. The AC breakdown voltage tests for RBDPO and mineral oil were conducted at gap distance of 1 mm according to ASTM D1816 of which the AC withstand voltage at 1% probability was obtained using Weibull distribution. It is found that the AC withstand voltage at 1% probability is much greater for RBDPO-based CuO with various surfactants than that mineral oil.
This paper is prepared in line with IEEE publication requirements and describes the aspects in which we can improve the way we manage protective relay devices through digitalization. Protection Relays are one of the Safety Critical Elements (SCE) of electrical systems and are designed to protect an electrical system from undesirable disturbance and equipment damage. It is subjected to checking, testing and calibration due to its criticality [2]. Essentially, upon detection of any electrical fault or disturbance the protection relay will send a trip signal to a circuit breaker to isolate the fault. Many industries have experienced protection relay failures in the past that have resulted in production loss and extensive equipment damage due to failures of this SCE equipment to function as required. With digitalization becoming prevalent and demanding nowadays, data centralization and the efforts towards digitalization of control and real time monitoring of protection relays has become crucial and with the advancement of technology and available applications can be realized sooner rather than later. In the case of protection relays in large scale electrical installations, these requirements become essential in supplementing human intervention in daily operations and maintenance activities. By having a centralised digital database supported with analytical tools, managing a wide range of protection relays in large scale electrical installation becomes simpler, more efficient, reporting-friendly, and enables users to take calculated risk for better decision making. Digitalization is a key step towards realizing remote operation of electrical facilities and further reduction in operational costs of such facilities.
Electrical insulation materials are indispensable to the electrical power system's continual and reliable operation. Over both indoor and outdoor applications, electrical insulation materials like silicon rubber and epoxy have been employed extensively for the past 25 years. To improve dielectric performance and reliability, researchers working in the field of electrical insulation are concentrating on hybrid composite insulation materials. A typical hybrid composite insulation material combines nanoparticles and base materials. The insulation characteristics of these materials are further improved by adding nano and microparticles. This study investigates silicone rubber composite incorporated with nano and microparticles with different percentages. The ultimate stress was improved by 29.88% in the hybrid sample with 6% nano- and 20% micro-silica, which also had a maximum breakdown strength of 26.6 kV mm1 and 50% weight loss at the highest temperature of 575 °C. The main objective is the effect of filler concentration on leakage current (LC) of hybrid silicone rubber composite insulators.
Asset manager faced a challenge in managing their transformer population as majority of the units are in aging state condition. In addition, they are also pressure by the stakeholder to reduce the maintenance cost while need to maintain the same transformer reliability. Thus, a systematic maintenance approach needs to be developed to assist asset manager in prioritizing the maintenance task, optimized operation and maintenance cost and at the same time avoid unplanned outage of the transformers. This paper presents the development of Condition Health Index (CHI) and risk index to facilitate the management of transformer population at petrochemical plant. The overall health condition of 100 transformers were assessed and identified using combination of health index and risk index. Finally, the strategic maintenance actions on the transformer population were determined either require maintenance actions or continue for normal operations.
The article is devoted to assessment of voltage harmonic and interharmonic components generated by semiconductor FACTS devices in an active-adaptive network. The analysis of methods for voltage curve distortions assessment of the electrical network has been carried out. The analysis showed that the existing methods solve particular problems and, as a rule, evaluate nonsinusoidality quantitatively, without taking into consideration the qualitative description of processes in the Smart Grid. There are no techniques that comprehensively assess the order and amplitude of harmonics, multiples and non-multiples of the fundamental frequency. The proposed technique combines the communication theory and the signal graph method, the short-time Fourier transform, the projective geometry theory and allows to estimate the order and amplitude of harmonic and interharmonic distortions in an electrical network with nonstationary parameters, as well as qualitatively describe the dynamics of mode changes in the Smart Grid. It is possible to perform both quantitative and qualitative nonsinusoidal voltage assessment in Smart Grid engineering by means of the developed technique.
Increasing demand in huge rate can cause the instability and under voltage become dominant issues in power system. Installation of FACTs device is among popular remedial action to alleviate this condition and maintain as well as secure the delivery of the electricity. This paper describes the optimal placement and sizing of FACTS devices installation for minimization of transmission loss. Three optimization technique which is Evolutionary Programming (EP), Particle Swarm Optimization (PSO) and Multiverse Optimization (MVO) are used as optimization techniques. Comparisons are carried out on IEEE 30-bus RTS based on several case studies considering different number of FACTs device installation for various load conditions. Results demonstrates that PSO and MVO gives a better result compared to EP.
Distributed energy resources (DER) are among important components or additional supplies to an existing power system network. Its installation in an existing power system network will help improve the voltage level in a system, reduce current values through the transmission lines and reduce the total transmission loss. The sizing and locations for the installation of DER or distributed generation (DG) require optimal values. Otherwise, the system will experience either over-compensation or under-compensation phenomena. Thus, a reliable optimization technique is a crucial factor. Several optimization techniques are not reliable enough as they cannot reach optimal solutions and sometimes, they are not accurate. This paper presents a new optimization technique termed Integrated Grasshopper Evolutionary Programming Technique (IGEPT). IGEPT integrates some operators in the grasshopper optimization into the original evolutionary programming (EP). It was validated on the IEEE 30-Bus Reliability Test System (RTS) for voltage maximization effort as the objective function. Several cases were taken into account so as to highlight the robustness of this technique. A comparative study with other techniques is also conducted, which highlights the merit of IGEPT.
Polymeric nanocomposites are being used more frequently to replace traditional insulation because they offer superior mechanical and electrical qualities. An efficient and successful diagnostic method based on time domain measurement is Polarization and Depolarization Current (PDC) measurement, which tracks the behaviour of the dielectric. Finding novel materials with improved dielectric properties is one of the key goals of research in the field of polymer nanocomposite dielectrics. This study uses the Polarization and Depolarization Current (PDC) measuring technique to examine the conductivity variation of LLDPE nanocomposite for formulations of HDPE blends nanocomposites made from polyethylene filled with nanoparticles of Al 2 O 3 . The goal of the experiment was to determine each sample's individual conductivity fluctuations and PDC pattern. The optimal composition for HV insulation in terms of lowest polarization and depolarization current values and lowest conductivity was discovered to be LLDPE/HDPE- Al 2 O 3 at 5 % wt of nanofiller. The findings indicate that adding a certain amount of nanofiller to LLDPE/HDPE-based materials improved the materials' dielectric strength.
In this paper, detailed literature on the methods used to calculate available transfer capability (ATC) is outlined. Two general categories of methods are investigated: static and dynamic, as well as their associated solution quality in terms of speed or accuracy. All the prevailing ATC methods are undergone a critical review, in this paper, as far as the underlying terms, concepts, and conventional definitions are concerned. Eventually, an evaluation of each method's advantages and disadvantages is carried out. The findings of this study allow one to develop new methods that can provide faster and more accurate ATC solutions.
Hybrid solar PV systems with battery backup and grid support are more reliable in their ability to provide uninterruptible power supply. However, to convert, organize and synchronize input supplies for a range of load conditions, there is a need of more sophisticated converter and control system. To address the conversion, transition and synchronization issues, an intelligent control and switching method is required. The target of this project is to develop a smart power converter system for a hybrid PV-grid energy system. A new integration of hardware components and software innovations is suggested to convert a DC power to AC, to track PV current, choose the sources of power, and to transfer the supply power at zero voltage and current. A DC-DC converter circuit, a supervisory controller, a switch-over circuit, and a soft-switching circuit are modeled and constructed to study the effectiveness of the proposed system. The system's implementation demonstrates that by utilizing a smart power converter system, issues that could arise during the changeover of the power source could be resolved.
Economic dispatch study is important in the electric power industry because it is concerned with efficient electrical power production and economics. It is crucial to reduce the operating costs of electric energy because even small savings have a large impact on total generation costs and fuel consumption. This paper presents the proposed algorithm namely Hybrid Evolutionary-Barnacles Mating Optimization (HEBMO) to solve non-convex economic dispatch (ED) problems specifically under the line and generator outages. The evaluation is tested on two types of reliability test systems (RTS), named IEEE 30-Bus RTS and IEEE 57-Bus RTS. HEBMO is compared to a single optimization algorithm, EP and BMO for performance evaluation purposes. The results show that the HEBMO algorithm outperforms EP and BMO in terms of minimizing the generation cost. On the other hand, HEBMO also achieves a convincing performance in terms of fast computational time.
The massive increase in both electrical power demand and the penetration level of renewable-based distributed generation at the distribution system has contributed to large amount of power flow in the grid's utility. As a consequence, part of the transmission networks is congested that led to unexpected outage and the entire grid is operated at the vulnerable condition. Static Synchronous Compensator (STATCOM) is one of the most effective ways to alleviate this problem. The benefits of introducing the STATCOM into the system can be further maximized with an appropriate location and size of the devices. In this work, the optimal number, location and sizing of STATCOM(s) are determined to reduce the real power loss and voltage deviation under several most severe N-1 and N-2 events. The most severe line outage events are determined using the proposed combine severity index (CI). The optimal location and sizing of STATCOM(s) in IEEE 30 bus test system are identified using multi-objective Particle Swarm Optimization algorithm (MOPSO).
The breakdown characteristics of SF 6 /CO 2 /O 2 and SF 6 /N 2 /O 2 ternary gas mixtures were investigated with AC test voltages under both slightly uniform and non-uniform electric fields. In this study, the slightly uniform field represented by a sphere-plane electrode, while a rod-plane electrode configuration provided the non-uniform field. The gap lengths between the electrode varied from 5 mm to 25 mm, and the gas pressure was fixed at 1.0 bar (abs). The tests were measured at various mixing ratios considering a small percentage of O 2 in each gas mixture. The effects of additional O 2 in SF 6 /CO 2 and SF 6 /N 2 on the breakdown voltages were discussed to obtain a reasonable mixing ratio of the ternary gas while maintaining the insulation properties of the gas. The addition of 10% O 2 in the SF 6 /CO 2 mixture showed a significant increase in the breakdown voltage for all gap distances under both electrode configurations. Meanwhile, only 5% of O 2 is required to increase the breakdown voltage in the SF 6 /N 2 mixture under the rod-plane electrode, and 10% of O 2 is required to be added for the sphere-plane configuration. Apart from the experimental work, this paper also discusses a simulation study on the maximum electric field for each breakdown test. It is found that the rod-plane electrode provides a higher electric field compared to the sphere-plane electrode configuration.
Reducing Green House Gas (GHG) emissions has been an area of immense concern due to the abnormal climate changes from global warming. SF6has a stable structure and superior dielectric qualities, which make it a commonly utilized media in the insulation industry. Due to its greenhouse gas effect, restrictions have been implemented on SF6production and usage worldwide, and considerable efforts have been undertaken to find suitable alternative gases to replace SF6. In this research work, the feasibility analysis of C4F7N as a substitute to SF6is performed. Synthetic and non-synthetic gases used for insulation are discussed. Insulation characteristics of C4F7N are summarized in detail in terms of effective ionization coefficient, breakdown voltages, stability, and voltage-time characteristics. Due to the relatively high boiling point, the gas should be mixed with buffering gases. The mixture optimization procedure was also presented. Finally, the feasibility and scope of C4F7N for current applications are analyzed, and further research direction is pointed out.
Port emissions can be considerably reduced with the execution of maritime electrification. This paper studies the optimal berth allocation problem (BAP) combined with an onshore power supply known as cold ironing in response to the growing interest in maritime electrification. The problem is formulated as a mixed integer linear programming (MILP) optimization problem to reduce the total processing time, including the ship's handling and waiting time at the port. The findings from simulation analyses indicate that scheduling ships staying at the berth terminal with a cold ironing service results in a longer waiting time compared to the case without a cold ironing system. However, optimal berth allocation considering shoreside power supply greatly reduces the NOx, SO2, CO2, and PM pollution by 97.7%, 96.7%, 38.4%, and 92.1% respectively.
The unexpected progressing demand in most power system in the world has led to voltage decay phenomenon. This leads the system to operate below the acceptable voltage limit. Under voltage load shedding (UVLS) has been acceptably recognized as the suitable remedial action to alleviate the voltage decay, which consequently causes voltage insecurity condition. Nevertheless, UVLS is the last option. Thus, a robust optimization technique would be the pre-requisite to optimal location and sizing to ensure a reliable and effective approach; without having to victimize the prioritized areas. This paper presents an optimal UVLS using a newly develop optimization technique termed as Integrated Chaotic Clonal Jaya Evolutionary Programming (ICCJEP). This study addresses a pre-developed voltage stability index as the indicator to voltage security improvement, which needs to be minimized. Validation under several combinations of UVLS schemes on the IEEE 30- Bus RTS indicated that the optimal UVLS can improve voltage security in power system indicated by the reduction of FVSI value as the index.
