Ahmed Mohamed Azmy

Tanta University · Department of Electrical Power and Machines Engineering

Recently, few studies were presented to include the effect of repairing periods in the estimation process of technical loss of either radial or ring medium voltage feeders in distribution networks. The previously presented studies are classified into traditional methods or using deduced formulas that need repeating the calculations many times with...

Wide-area damping controllers (WADC) have been shown to be effective in damping interarea oscillation modes. The varying nature of power system operating point requires the design of an adaptive WADC. Majority of the existing control design techniques rely on empirical approaches at one or more of their design stages, which makes it difficult to im...

The virtual power plant (VPP) has the ability to control and manage the electrical energy flow between the aggregated units to obtain better operation of the system. This operation is aiming to minimize the cost of produced energy and therefore enhance the economical operation. To satisfy that, in the planning stage, it is important to select the o...

The paper presents a methodology for hot spinning reserve allocation (HSRA) following expected disconnection of big generators during peak demand. The proposed method includes generation rescheduling, optimal reactive power allocation, and load curtailment to prevent system cascaded outages. Hybrid grey wolf optimization (HGWO) and Marine Predators...

One of the main challenges for electric power distribution utilities is decreasing energy losses. Estimating and decreasing technical energy losses (TELs) is one of the effective methods for decreasing total energy losses. Different researches are presented for estimating TELs in distribution networks. In calculation process, load factor (LF) and l...

It is essential to face the problem of ever-increasing electrical load demand and to find advanced means for load management. Demand side management, as a promising solution, necessitates full monitoring of loads based on intrusive or non-intrusive techniques, to track the daily usage of energy. The V-I trajectory is an effective manner for identif...

This paper proposes a systematic approach for the design of wide-area damping controller for static VAR compensator (SVC). The proposed approach is developed in the form of a two-stage optimization problem. In the first stage, the problem of identifying the optimal feedback signal of the controller is solved, while the second stage is concerned wit...

Small and modular Distributed Generation (DG), such as fuel cells, can be used for onsite service within smart buildings to cover a part of the electrical and thermal load demand. In this case, the optimal capacity and output from the used generating unit(s) can be calculated to supply a part of load demand, where the excess/lack of power is export...

This chapter introduces a framework to define the optimal allocations and permissible hosting capacity of renewable distributed generations (DGs) using genetic algorithm (GA). The investigation is carried out considering inverter-based technologies such as the case of photovoltaic system. The inverter control is exploited to dynamically limit the D...

To ensure the full benefits from wind generation systems, an effective maximum power point tracking (MPPT) technique should be implemented. In this article, an adaptive fuzzy logic controller (AFLC) is presented as a control methodology for producing the peak power from a permanent magnet synchronous generator (PMSG)-based wind turbine (WT). Regard...

With the speedy increase of wind energy in electric networks, many important issues could emerge, where the most important matter is to maintain the connection of wind generators during fault conditions. With different faults in the electrical network, the voltage at the point of common coupling (PCC) decreases causing unwanted transients in the st...

Energy losses represent one of the main challenges for electric power distribution utilities all over the world. Several papers presented different methods for estimating technical losses (TLs) in distribution networks. Due to load variation during normal operation, load factor (LF) and loss factor (LSF) coefficients are considered. In this paper,...

With the speedy increase of wind energy in electric networks, many important issues could emerge, where the most important matter is to maintain the connection of wind generators during fault conditions. With different faults in the electrical network, the voltage at the point of common coupling (PCC) decreases causing unwanted transients in the st...

Improving transmission lines (TL) steady-state stability limit can be achieved by Static Synchronous Series Compensators (SSSC) that work as a converter-based compensator. The modification of the SSSC function to inject both active and reactive power into the TL improves its performance according to different indices. The TL improvement indices inc...

Due to the increase of load demand, the utility tends to utilize DG technology in recent years. The intentional islanding is an appropriate approach to enhance system performance such as reliability and operational flexibility. This research provides a new paradigm for intentional islanding to maximize the efficiency of the power system. The methodol...

Phase-shifting transformers (PST) are exhibited to continuous variations in phase angle. This continuously-varied phase shift can cause miss operation for the current-based differential protection relay by generating false trip signal. This paper discusses the experimental validation of a proposed current differential protection technique. The curr...

This paper presents detailed implementation of static synchronous compensator (STATCOM) based on model predictive control (MPC) for mitigating unbalance in line voltages. The main objective is to evaluate the capability of an enhanced MPC state-space model that can be applied in a general form for any power system. The proposed enhanced MPC state-s...

This paper introduces a study of reduced devices count symmetric multilevel inverter (MLI) under two PWM techniques for AC applications. The MLI uses two DC sources to synthesize five‐level output voltage at a reduced switching devices number. The MLI employs five switching devices comprising the main and auxiliary circuits. The main circuit is a s...

In this paper, the consumers' participation in the demand response program for virtual power plant (VPP) is proposed. A proposed price-based scheduling strategy for optimal day-ahead scheduling of VPP is investigated to maximize the profit of the VPP composed of a set of distributed generation, dispatchable load, and wind turbines. For solving the...

This paper proposes a systematic and integrative decision-making approach for planning and designing hybrid renewable energy-based microgrid (HRE-MG) systems. The approach is combined with an extensive techno-economic optimization analysis. The proposed methodology is validated with an actual case study on an urban city in Egypt, with the developed...

Virtual power plant (VPP) concept, based on smart grid technology, is an important tool to integrate dispatchable and stochastic generating units in addition to controllable or interruptible loads into a single unit. This collection maximizes power energy utilization and enhances energy supply reliability. This paper introduces a price-based unit c...

Fast-growing load demand, environmental issues, high network losses, and low reliability are the main factors to penetrate hybrid renewable energy systems (HRESs) to the electrical grid. HRESs are able to provide an eco-friendly and cost- efficient alternative to conventional energy systems. This paper provides a feasibility study for grid-connecte...

Permanent magnet synchronous generator (PMSG)-based wind turbine is considered as one of the promising technologies for generating electric power from wind energy. This paper presents an artificial intelligent technique based on fuzzy logic controller (FLC) to enhance the maximum power point tracking (MPPT) of PMSG-based wind turbine. The FLC metho...

The concept of distributed generation (DG) has been developed as a hopeful solution to meet the demand increase in distribution systems. The optimal DG deployment in the distribution system can improve the technical benefits. This study presents a framework to find the optimum location and size for different types of DG units to enhance the voltage...

This paper presents a modified shifted-level pulse width modulation (PWM) for an 11-level multilevel inverter (MLI) that used for distributed generation systems and medium and high power energy conversion systems applications because of the flexibility in the voltage level that this converter has been introduced. This converter employs five indepen...

To guarantee efficient and stable operation of a microgrid, overcharging and unbalanced state of charge (SOC) of batteries have to be mitigated. An adaptive droop control scheme is proposed in this study to provide energy management between distributed batteries having unbalanced SOC and different capacities. The proposed approach suggests using a...

This paper presents a new symmetrical single-phase nine-level DC-AC converter for the applications of distributed generation systems (DGS). The proposed multilevel inverter (MLI) utilizes four independent DC sources to generate the nine output voltage levels considering a reduced number of switching devices. The proposed inverter consists of main a...

Background: Placenta accreta spectrum (PAS) disorders have become a significant life-threatening issue due to its increased incidence, morbidity and mortality. Several studies have tried to identify the risk factors for PAS disorders. The ideal management for PAS disorders is a matter of debate. The study objectives were to evaluate the incidence...

The high accuracy of fault location in transmission lines reduces outage time and increases system reliability. Most of the time needed for fixing the fault is consumed in determining the location of the fault. Many fault location methods are usable for single-fault events. This paper presents an advanced fault location algorithm to detect, discrim...

This paper presents a new strategy to improve the economic, technical and environmental aspects of distribution systems (DSs). This strategy depends on using both different types of the distributed generation (DG) units and capacitor banks together to accomplish the best level of improvement with reasonable cost. The problem is formulated through a...

Many researchers investigated the optimum capacity and location of Distributed Generation (DG) considering either normal operation or faulty situations. In this paper, the effect of repairing fault periods (RFP) on the DG optimization process is investigated. Comparisons between optimal DG allocations on low voltage (LV) distribution network based...

In this paper, an adaptive droop controller is developed for DC microgrids in order to balance the state of charge (SOC) for different connected batteries, and also to keep the bus voltage within the allowed limits. A methodology for sizing the photovoltaic (PV) system and battery bank is performed considering the daily energy consumption and the m...

The traditional precautions after islanding process is to disconnect distributed generation (DG) to ensure safe operation. However, disconnection of DGs reduces the island reliability and security. Many of the DG owners prefer to control the islanding process and put certain constraints and regulations for the new isolated system, which is achieved...

This paper presents a proposed algorithm for the differential protection of delta-hexagonal-type phase shifting transformer (PST). The algorithm is advantageous due to its simplicity, where only source and load currents are detected and used to obtain the excitation currents. This is based on the complete analysis of the current relationships betwe...

This paper investigates the utilization of Multilevel Inverter (MLI) to reduce the harmonics of grid-connected photovoltaic (PV) system. MLIs act as a promising interface in medium voltage networks for many usages because their modularity and lower voltage stress towards the switches. In addition, they provide a high-form output with low symmetric...

The deployment level of distributed generation (DG) affects significantly the development of electrical distribution networks. These units could provide good benefits for the system provided that the optimal location and size of DG units are accurately defined. This paper presents a framework to obtain the optimal location and sizing of DG units to...

This paper investigates the dynamic behavior of distribution network regarding intentional islanding, where the islands contain distributed generation (DG) to supply the local load demand. The objective is to ensure that DGs supply the load at high power quality. The distribution system must be equipped with monitoring and control elements to detec...

After several operating years of power transformers, the oil is aged resulting in deterioration in oil properties. This deterioration is attributed to the effect of aging byproducts represented by acidity and moisture content. From this view point, this study aims to mitigate the impact of aging byproducts and enhance the aged oil properties with t...

It is expected that the use of distributed generation (DG) will increase sharply in distribution systems, especially with the realization of smart grids. In spite of the benefits of DG in distribution systems, high penetration level of DGs could cause some challenges for the network. Therefore, the optimal sizing and siting of DGs should be identif...

This paper introduces a proposed procedure to solve the optimal reactive power management (ORPM) problem based on a multi-objective function using a modified differential evolution algorithm (MDEA). The proposed MDEA is investigated in order to enhance the voltage profile as well as to reduce the active power losses by solving the ORPM problem. The...

This paper presents an adaptive differential evolution algorithm to allocate the Thyristor controlled Series Compensator (TCSC) incorporated with the reactive power management problem. In addition, a dynamic updating is applied for scaling and penalty factors to enhance the performance of the multi-objective differential evolution algorithm. During...

The rapid increase of distributed generations (DGs) has many benefits for distribution systems and could result in some negative effects. Identifying the optimum locations and sizes for these units increases the benefits and limits the negative effects. Many researches tried to define the optimal DG siting and sizing. Either normal operation or fau...

Towards the complete vision of smarter distribution grid, advanced distribution automation system (ADAS) is one of the major players in this area. In this scope, this paper introduces a generic strategy for cost-effective implementation and evaluation of ADAS. Along with the same line, fault location, isolation and service restoration (FLISR) is on...

Protection schemes for distribution systems, primarily consisting of fuses, reclosers and relays, have traditionally been designed and coordinated assuming conventional systems to be radial with a single source feeding a network of downstream feeders. In recent years, extra attention is directed to the use of distributed generation (DG) in distribu...

This paper proposes a procedure based on a multi-phase seeker optimization algorithm (MSOA) for optimizing the commitment of transmission system. The under consideration problem is formulated with the aid of AC-based security constrained optimal power flow (SC-OPF) considering system constraints. The target is to detect transmission lines commitmen...

This thesis provides a comprehensive study of grid-tie wind energy conversion system using permanent magnet synchronous generator (PMSG). The proposed type of wind energy conversion system (WECS) is based on generating electrical power with minimum harmonics and minimum power loss. This can be achieved by using maximum power point control technique...

Towards the complete vision of smart distribution grid, this paper presents a generic framework and strategy for the implementation of distribution automation system (DAS). Fault location, isolation and service restoration (FLISR) is one of the most beneficial and desirable applications of DAS for self-healing and reliability improvement of distrib...

Future smart grids will require an observable, controllable and flexible network architecture for reliable and efficient energy delivery. The use of artificial intelligence and advanced communication technologies is essential in building a fully automated system. This paper introduces a new technique for online optimal operation of distributed gene...

With the tendency to move toward automated home energy management systems, the cooperative capacity of the smart grid “SG” became more and more significant. Distributed generation “DG”, in addition to the novel patterns of electricity production, enabled the two-way energy flow. The concern of this paper is on introducing an automated control techn...

Increasing electrical load demand and transition from regulated to deregulated power systems caused many challenges, such as: high transmission line losses and low voltage levels. An effective control of reactive power improves voltage profile, reduces power losses and improves overall system performance. In case of abnormal operations of power sys...

Distributed generators (DGs) provide many benefits for distribution networks. However, they increase the fault current level and cause miscoordination between the protective devices. This paper introduces a general framework to define the optimal locations and permissible capacity limits of inserting DGs in the distribution system using the genetic...

Recently, power quality suffers from many phenomena, especially in distribution system, because of the growing use of nonlinear loads. Therefore, it is essential to simulate and evaluate the harmonic contents in voltage waveforms continuously to consider the actual distortion in distribution power systems in an accurate manner. In this paper, the t...

or the sake of self-healing grid and reliability improvement of medium voltage (MV) distribution networks, fault location, isolation and service restoration (FLISR) is one of the most beneficial and desirable applications of distribution automation system DAS. This paper presents a generic framework and strategy for DAS. The FLISR application is im...

This paper presents a proposed technique to provide an overall vision about a practical and effective solution of the voltage-profile problem in distribution system within smart grid environment. The objective is to monitor and regulate the network voltage centrally, regarding the overall voltage profile of the power system for the online applicati...

The integration increase of distributed generation units (DG) on distribution systems gives great importance for studying the effect of these units under different operating conditions. Many researchers investigated the impacts of DG units under normal operating conditions and proved the capability of DG units to minimize system losses, improve sys...

Smart grid and its promising features for a better intelligent and automated energy infrastructure is under study in several researches and projects. Home automation (HA) and home energy management (HEM) systems with the aid of artificial intelligence and advanced communication technologies are considered as the main branches of the future smart gr...

For the sake of self-healing grid and reliability improvement of medium voltage (MV) distribution networks, fault location, isolation and service restoration (FLISR) is one of the most beneficial and desirable applications of distribution automation system DAS. This paper presents a generic framework and strategy for DAS. The FLISR application is i...