Hatem H. Zeineldin's research while affiliated with Cairo University and other places

Publications (228)

Article
The fluctuated output power of the large-scale wind farms (WF) and their fault transient characteristics have an adverse effect on the current differential protection systems of the transmission lines. With increased transmission line length and in the case of weak output power from the WF, the differential current between both line ends increases...
Article
The rise in power demand and initiatives towards distributed power generation bring attentiveness to microgrids. The exemplary method for utilizing microgrids is by making their boundaries adaptive. This is essential to meet the desired grid requirements and properly handle high penetrations of distributed resources. The concept of flexible boundar...
Article
This paper proposes a fault location (FL) scheme for a two-terminal double-circuit transmission line using one-terminal current and voltage measurements. As the proposed scheme is formulated in the phase-coordinates, the parallel transmission lines are not required to be decoupled, and the proposed scheme can be applied for transposed or untranspos...
Article
This paper proposes a new approach for optimal operation of an Electric Vehicle (EV) battery-swapping station (BSS) based on Rolling-Horizon optimization (RHO). The BSS has several swapping bays such that each can accommodate an EV for swapping single or multiple battery units. The proposed BSS model considers serving different types of EVs using a...
Article
This paper proposes an energy management strategy (EMS) of a reconfigurable grid-tied hybrid ac/dc microgrid (HMG) architecture for commercial building (CB) applications. This HMG architecture consists of a multi-mode configuration (MMC) with renewable-based distributed generators (DGs), energy storages (ESs), and genset. The main advantage of this...
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This article proposes a novel concept, denoted as virtual charging system (VCS), for electric vehicles (EVs). In a conventional charging system (CCS) with a competitive environment, the competition between charging stations can utilize game theory as a price competition game model. On contrary, charging stations with different ownerships under the...
Article
The wide integration of all battery electric buses (BEB) in the operation of public transit services is identified as one of the most promising means toward decarbonizing public transport systems. In response, public bus transit (PBT) and utility grid operators are currently in need of developing analytical techniques that enable them to conduct tr...
Article
Real-time detection of the microgrid stability is crucial for determining and adjusting the power-sharing droop controllers gains to maintain a sufficient stability margin. Maintaining minimum relative stability should be ensured at different operating conditions to accommodate any sudden system changes. This paper develops a novel subspace-based i...
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This paper considers applying bit loading to multicarrier non-orthogonal multiple access (NOMA) systems. The objective is to maximize the system total throughput while satisfying the users’ individual quality of service (QoS) constraints. Although bit loading is generally non-deterministic polynomial time (NP)-hard problem, even for orthogonal mult...
Article
This paper proposes a multi-objective planning approach to determine the optimal DG locations for droop-based microgrids. A secondary control operating region is mathematically formulated and incorporated in the multi-objective optimization problem to constrain the optimal droop characteristic within the acceptable frequency and voltage thresholds....
Article
CubeSat is a type of nanosatellites used for space research due to lower cost and faster deployment. The successful mission of CubeSats require reliable and fault-tolerant electrical power system (EPS) that powers all the other subsystems and payloads. Several studies have shown that EPS failure has been one of the main contributors for the CubeSat...
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The proliferation of electric vehicles (EVs), owing to their advantages over internal combustion engine vehicles, has introduced many challenges, due to the lack of charging infrastructure that can handle such a large surge of EVs. Therefore, alternative feasible charging solutions, such as EV-to-Grid (V2G) and EV-to-EV (V2V) charging have gained p...
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The main protection equipment in radial distribution networks are non-directional overcurrent relays (NDOCR) and fuses which are coordinated using the conventional protection coordination method. By installing distributed generations (DGs) in the network, reverse short-circuit currents (SCC), injected from DGs, can lead to false tripping of NDOCRs...
Article
Droop control is the most common approach for controlling inverter-based micro-grids. The active power droop gain has always been considered as the main parameter for identifying the micro-grid stability margin. Increasing this margin improves the transient performance and provides robustness to the micro-grid for a wide range of operations. Previo...
Article
The conventional backward/forward sweep method, used for solving the load flow, is only applicable to radial systems. A new load flow method is proposed in this report for islanded droop‐controlled meshed AC microgrids, where the backward/forward sweep (BFS) method is proposed in conjunction with a loop‐breaking approach to determine the power flow...
Article
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Electric vehicle (EV) charging is considered as one of the main issues that face EV drivers. Thus, there should be a facility to suggest the best charging station based on the customer requirements. However, the routing process of EVs in most of the literature was generally implemented centrally based on the charging station/operator perspective. O...
Article
CubeSats have been popular for space research due to lower cost, faster development, and easier deployment. The electrical power system (EPS) is one of the significant subsystem for the CubeSat since it handles power generation, energy storage, and power distribution to all other subsystems. Therefore, the design of EPS becomes crucial for successf...
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The microgrids when connected together form a network known as the Multi-Microgrid (MMG). The interconnection brings higher resilience and support in providing power to the loads. Connecting different microgrids is a challenging task which involves synchronization of voltage magnitude, angle and frequencies at the point of common coupling prior to...
Article
This paper proposes a new model for optimal partitioning of active distribution networks into a number of islanded microgrids. The objective of the developed model is to maximize the minimum value of loadability amongst formed islands to create resilient islanded microgrids against unexpected local disturbances and power mismatches. The model takes...
Article
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Maximization of solar energy harvest and miniaturization of dc/dc converters are essential for low earth orbit (LEO) CubeSats which are constrained by volume and weight restrictions. The state-of-the-art electric power system (EPS) architectures utilize several individual dc-dc converters to maximize solar energy harvest but it has trade-off with t...
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Abstract The main remedial actions to prevent voltage instability problems are load shedding and rescheduling of generating units. In AC/DC networks, the presence of high voltage direct current (HVDC) links equipped with voltage source converter (VSC) provides an efficient active and reactive power support. As the voltage stability is a local pheno...
Article
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This paper presents a novel robust current droop controller (RCDC) using a single droop loop. This scheme is unified supporting dual mode of operation for micro-grids (MGs), including grid connected mode (GCM) and islanded mode (ISM) while ensuring seamless transition between the two modes with proportional power sharing maintained. The proposed co...
Article
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Electric Vehicles (EVs) are being widely adopted to completely replace vehicles with internal combustion engines. However, the development of charging infrastructure to support the growing number of EVs has been lacking primarily due to the high cost of installation. Additionally, the immature and non-uniform deployment of charging stations has led...
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Line-switching operations introduce several concerns to microgrid operators since they trigger reliability and power quality issues in addition to increasing the wear and tear cost of switching devices. This paper proposes a novel methodology for achieving a seamless line-switching in low-inertia islanded microgrids. The proposed methodology aims a...
Article
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The bidirectional power flow through the interlinking converter (IC), in ac/dc hybrid microgrids (HMGs) consisting of distributed generators (DGs) with droop controllers, plays an important role on the stability of such systems during islanding. This paper investigates the impact of the power flow direction on the small-signal stability of islanded...
Article
This paper proposes a gradient descent-based transfer delay frequency-locked loop (GDTD FLL) to effectively address the challenges of existing transfer delay-based FLLs in terms of unacceptable frequency and phase angle overshoots during variations in the supply voltage amplitude and distorted voltage conditions. In the proposed GDTD FLL, a linear...
Article
A multistage approach to passive islanding detection is proposed that utilizes a decision-tree-like classification algorithm. The novelty of the proposed method is centered on the way in which features are passed to subsequent stages of the decision tree (DT). Feature sets extracted using different sized time windows are passed to successive stages...
Article
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Abstract The increasing number of Plug‐in Electric Vehicles (PEV) connected to the grid will create challenges to be addressed and opportunities that can be ceased. One challenge is the load shape dynamics, which might result in increasing the loading level on the distribution lines. On the other hand, there is an opportunity to use the PEV stored...
Article
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This paper proposes a novel stochastic solution method for the static nonconvex power economic dispatch problem. All practical features such as valve point effects, ramp rate limits, prohibited operating zones, multiple fuel options, spinning reserve constraints, and transmission losses are considered. To develop the proposed algorithm, two modific...
Article
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Abstract—CubeSats have been widely used for space research due to lower cost and faster development. Electric power system (EPS) is one of the key subsystem of CubeSat which powers all the other subsystems. One of the important step in the EPS design is the selection of EPS architecture which should be done considering overall efficiency, battery s...
Article
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This paper introduces a new time-domain fault location algorithm for two-terminal parallel transmission lines connected to large scale wind farms. The proposed algorithm employs only a half-cycle data window of synchronized current samples at both line terminals to avoid inaccurate estimation of current phasors due to the generated sub- and inter-h...
Article
This article proposes an auxiliary framework to address the challenges of transformer differential protection for single-phase transformers or three-phase transformer banks. This framework enables the differential scheme to: 1) work properly if transformers or current transformers (CTs) saturate; 2) detect internal and cross-country faults; 3) dete...
Article
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A routine task faced by Microgrid (MG) operators is to optimally allocate incoming power demand requests while accounting for the underlying power distribution network and the associated constraints. Typically, this has been formulated as an offline optimization problem for day-ahead scheduling, assuming perfect forecasting of the demands. In pract...
Conference Paper
In this paper, a variable learning rate least mean square control algorithm has been proposed to control Dynamic Voltage Restorer for compensating the disturbances present in the supply source side of a distribution network. The proposed control algorithm is equipped with an optimization algorithm based on Slime Mould for the tuning of PI controlle...
Article
Inverter-interfaced distributed generators (IIDGs) are characterized by their low fault current contributions that im-pose a major challenge for microgrid protection. This paper pro-poses a new overcurrent protection strategy that utilizes a third harmonic voltage generated by the IIDG controller during short-circuit faults. By generating harmonic...
Article
Synchronverters are inverters that imitate the behavior of synchronous generators to enhance the dynamics of renewable energy sources (RESs) powering microgrids. However, the synchronverter's inrush currents during faults could reach intolerable levels. Limiting the synchronvertery's fault currents could obstruct protection relays from identifying...
Article
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This study proposes a new differential relay characteristic to detect internal faults on bipolar HVDC (high voltage direct current) transmission lines and discriminate accurately and in a timely manner both internal and external faults. In comparison with the conventional differential protection characteristic, the proposed relay characteristic avo...
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Due to environmental and energy security concerns, low emission vehicles present a vital necessity for clean transportation. In particular, electric vehicles (EVs) are the most promising solution due to the fact that the electrical power system is the most ready infrastructure to supply their requirement. Two possible energy delivery solutions to t...
Article
In active distribution networks, system reconfiguration and connection/disconnection of distributed generation (DG) can result in protection coordination failure of overcurrent relays. Determining one set of optimal relay settings that would satisfy all possible network topologies is either infeasible or results in high relay operating times. To ad...
Article
The interest in producing hydrogen from electricity has been recently identified as a potential means for large-scale energy storage, proliferation of hydrogen mobility, and decarbonization of several processes that require hydrogen. Such interest is growing due to the increase of the renewable energy penetration levels and the significant drop in...
Article
Owing to its system independence and unmatched speed, Traveling-wave (TW)-based relaying has become a top contender for transmission and distribution systems. However, existing measurement devices, such as Current Transformers (CTs), are incapable of capturing the full frequency content of TWs, as their bandwidths are limited. Consequently, existin...
Article
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Grid interconnected multi-microgrids provides po-tential benefits to the consumers, where the microgrids (MGs) equipped with distributed generators (DGs), energy storage systems (ESSs), and diesel generators. However, intermittency of DGs, high cost of ESSs, and depleting fossil fuels are the major challenges for the economic operation of interconne...
Article
This paper proposes a novel stochastic solution method for the static nonconvex power economic dispatch problem. The proposed method is efficient enough to introduce a deterministic-like solution to the problem. All practical features such as valve point effects, ramp rate limits, prohibited operating zones, multiple fuel options, spinning reserve...
Article
Full-text available
The design of electrical power subsystem of a satellite is challenging since it involves many components and depends on multiple parameters including mission duration, satellite orbit, eclipse times and etc. In contrast to the existing mission specific designs, we propose a generalized and comprehensive method to design and size key EPS elements: P...
Article
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This letter considers the exact bit error rate (BER) analysis of a two-user non-orthogonal multiple access (NOMA) system using square quadrature amplitude modulation (QAM). Unlike existing work, no constraints are imposed on the modulation order of the QAM symbols for any user. Closed-form expressions are derived for the BER of the successive inter...
Article
Inverter-interfaced distributed generators (IIDGs) introduce a major challenge for the protection of inverter-based islandedmicrogrids (IBIMs) due to their limited fault current contribution. This paper proposes a new strategy for the protection of IBIMs, founded on two novel aspects including a soft current limiter and an interharmonic differentia...
Article
This paper proposes the incorporation of distributed and decentralized control models of generators and converters into the power flow analysis of islanded hybrid microgrids (IHMG). The absence of a slack bus in an islanded microgrid presents challenges to its frequency and voltage regulation as well as power flow calculation. While droop mechanism...
Article
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This paper presents an analysis and solution to the problems of instability and slow dynamic response of a three-phase type-3 PLL. By obtaining the linearized model of the PLL, instability associated with the presence of the voltage amplitude within the PLL control loop is illustrated. Furthermore, analysis of two common techniques employed in impr...
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Conventional orthogonal signal generators (OSGs) employed in single-phase systems exhibit significant delay in tracking the original signal. To tackle this problem, an OSG with fast synchronizing speed is proposed by applying the principle of power definition of sinusoids. The proposed OSG can accurately track the single-phase input signal in less...
Article
This paper develops a set of fast initialization methods to generate candidate preliminary points in the search space of the non-convex economic dispatch problem. These initial points are either the global optimal solution or close enough from this solution to clearly facilitate and accelerate the process of solving the problem while increasing the...
Article
The authors would like to sincerely thank M. Khalid for his thoughtful discussion on our paper [1] . He raises important and excellent points regarding various critical issues encountered with the efficacy of utilizing the reactive power support (RPS) of photovoltaic (PV) inverters. There have been ongoing research works and updates on studying a...
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Blockchain technology is showing a significant potential to disrupt a number of information technology domains. One of the especially interesting areas for blockchain applications is smart grid. A number of early papers have been published in this area, however, there is no systematic analysis of the impact of blockchain technology on decentralizat...
Article
This paper presents a comprehensive design procedure for isolated microgrids with a high penetration of nonlinear loads. The proposed microgrid planning approach simultaneously determines the sizes, locations and types of distributed generators (DGs) and shunt capacitor banks (CBs). The presence of nonlinear loads along with the capacitors of CBs o...
Article
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This paper finds its motivation from the perspective of utility planners, where the flexibility of choice while reconfiguring a distribution system into Multi-Micrgrids (MMGs) is critical. To address the topology planning problem for MMGs from this dimension, a holistic algorithm incorporating graph theory, ordered binary decision diagrams, and a m...
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In this paper, an efficient multi-orbital simulation model is presented for satellite Electrical Power Subsystem (EPS) which is integral to the success of the mission. The model integrates converter models, PV array model, DC bus model and a numerical battery model according to a generalized EPS architecture to form one unified model of the entire...
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Inverter-based microgrids may experience small-signal stability issues as the generation, loading or network topology change in real-time. This paper presents an event-triggered damping recovery scheme to improve the stability of a system with droop-controlled inverters and synchronous machines in the event of poorly damped power flows. The droop c...