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Your search keyword '"Azzouz, Maher A."' showing total 178 results
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178 results on '"Azzouz, Maher A."'

1. An Adaptive Overcurrent Protection for Solar-based DC Microgrids Using IEC 61850

Author

Sanati, Saeed, Azzouz, Maher, and Awad, Ahmed

Subjects
Electrical Engineering and Systems Science - Systems and Control
Abstract

Over-Current (OC) protection is one of the pervasive protections in solar-based DC microgrids. Fast operation is a key advantage of its popularity. On the other hand, utilizing OC in DC microgrids has some challenges that are not in AC grids. Some of these challenges are related to the grounding approach of the DC microgrid, and others are related to the high rise time of the fault current in DC microgrids. Considering these challenges, an adaptive OC scheme with high selectivity and speed is presented in this paper. The proposed scheme is communication-assisted and relies on IEC 61850 protocol. In this scheme, different setting groups for each OC relay are defined, and based on the grid and fault conditions, a setting group is selected. This option is performed considering the data transferred via communication level using IEC 61850 protocol between relays. To evaluate the efficiency of the proposed scheme, simulations using MATLAB software and the experimental tests using OPAL-RT real-time simulator and Zenon software are presented.

Published
2023

16. Optimal dispatch of a mobile storage unit to support electric vehicles charging stations.

Author

Elmeligy, Mohamed M., Shaaban, Mostafa F., Azzouz, Maher A., Azab, Ahmed, and Mokhtar, Mohamed

Subjects
ELECTRIC vehicle charging stations, ELECTRIC vehicles, ELECTRIC units, ENERGY storage, OPERATING costs, REACTIVE power
Abstract

As transportation electrification increases globally, new technologies emerged in the past few years to meet the growth of the electricity demand. Mobile Energy Storage Systems (MESS) offer versatile solutions, aiding distribution systems with reactive power, renewables integration, and peak shaving. An MESS can be utilized to serve electric vehicles (EVs) in different parking lots (PLs), in addition to supplying power to the grid during overloads. The task of multiple stationary units can be achieved using MESS at a relatively lower cost. This paper proposes an MESS owned by multiple PLs sharing the same geographical area and sharing its capital and operational cost. The main objective of the proposed approach is to dispatch the MESS in conjunction with optimal EVs' charging coordination to minimize operational costs and address the extra demand of PLs. A mixed‐integer nonlinear programming (MINLP) problem is formulated and solved. Considering electricity price variations and EVs uncertainties, three different case studies are performed to highlight the efficiency and success of the proposed approach. The simulation results in a huge reduction in the total operation cost and the savings reach up to 27.51% in comparison with the base case. [ABSTRACT FROM AUTHOR]

Published
2024
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19. Cyber Resiliency Enhancement of Overcurrent Relays in Distribution Systems

Author

Pola, Saad, Jovanovic, Marko, Azzouz, Maher A., and Mirhassani, Mitra

Abstract

Directional overcurrent relays (DOCRs) depend on voltage and current measurements to initiate correct protection actions when faults occur. However, cyber-attacks can manipulate those measurements to make DOCRs output false tripping signals that may cause load shedding, power loss, and distribution lines isolation. Therefore, this paper employs Random Forest Decision (RFD), i.e., a machine learning algorithm, to detect and diminish false data injection attacks (FDIAs) and time synchronization attacks (TSAs) on inverse-time and time-current-voltage DOCRs. The employed RFD is trained to tackle grid faults and cyber-attack events as a classification problem. Thus, two classification types are considered: a binary classification that differentiates cyber-attacks from grid faults and a multi-class classification that identifies the attacked phase(s) and specifies the grid fault type. Furthermore, the training process for the binary and multi-class classification accounts for multiple noise levels that may affect the measured voltages and currents. The RFD is trained, validated, and tested on a Canadian benchmark distribution system. The results reveal the RFD’s ability to produce high-accuracy predictions to identify cyber-attacks and verify grid fault conditions without being affected by the system’s operating conditions and measurements’ noise.

Published
2024
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20. Dual Current Control of Renewable Energy Sources for Recent Grid Code Compliance and Reliability Enhancement

Author

Aboelnaga, Abdallah A. and Azzouz, Maher A.

Abstract

Inverter-interfaced renewable energy sources (IIRESs) are controlled to follow low-voltage ride-through requirements during different fault conditions to support grid voltages and enhance stability. However, these requirements could result in improper operation of conventional protection functions, e.g., phase selection, that are designed based on the fault current characteristics of conventional power systems. In this paper, a dual-current controller (DCC) is designed for IIRESs to allow precise operation of the conventional phase selection method (PSM) while following the positive- and negative-sequence reactive current generation (RCG) requirements imposed by recent grid codes (GCs). First, the negative-sequence current reference is designed to comply with GC requirements and inject the minimum value of negative-sequence-active current that secures a correct operation of phase selection. Subsequently, the positive-sequence-reactive current is designed to comply with RCG requirements and allow injecting the maximum combination of the positive-and negative-sequence currents without hindering the proper operation of PSM or RCG requirements. Comprehensive time-domain simulations verify the effectiveness of the proposed DCC in meeting both PSM and recent RCG requirements during different fault types, resistances, and locations.

Published
2024
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21. A New Economic Dispatch for Coupled Transmission and Active Distribution Networks via Hierarchical Communication Structure

Author

El-Sayed, Wael T., Awad, Ahmed S. A., Azzouz, Maher Abdelkhalek, and Shaaban, Mostafa F.

Abstract

Traditionally, the economic dispatch problem (EDP) of the bulk generators connected to transmission networks (TNs) is solved in a centralized dispatching center (CDC) while modeling distribution networks as passive loads. With the increasing penetration levels of distributed generation, coordinating the economic dispatch between TNs and active distribution networks (ADNs) became vital to maximizing system efficiency. This article proposes a hierarchical communication structure, which requires minimal upgrades to the CDC, for solving the EDP of coupled TNs and ADNs. Based on the minimal data transfer between the CDC and distribution network operators, the problem is formulated and solved while considering the network losses in both TNs and ADNs. Furthermore, a sensitivity analysis is conducted to assess the effect of the R/X ratio of the distribution lines on the economic dispatch solution and the operational cost of the system. The numerical results demonstrate the effectiveness of the proposed centralized scheme and highlight the significance of considering the network losses of both TNs and ADNs when solving the EDP. The results show that the proposed framework can achieve savings of up to 17.98% by taking into account the network losses of TNs and ADNs.

Published
2023
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