Mostafa I. Marei

Ain Shams University · Department of Electrical Power and Machines

As the world grapples with the energy crisis, integrating renewable energy sources into the power grid has become increasingly crucial. Microgrids have emerged as a vital solution to this challenge. However, the reliance on renewable energy sources in microgrids often leads to low inertia. Renewable energy sources interfaced with the network throug...

The use of communication links between microgrid components has made the transmitted data vulnerable to cyber-attacks. This paper presents distributed cyber-attack detection and mitigation layers integrated with the primary and secondary control loops of a meshed DC microgrid. Voltage and current cyber-attacks mitigation layers based on the Kalman...

The utilization of fuel cells (FC) in automotive technology has experienced significant growth in recent years. Fuel cell hybrid electric vehicles (FCHEVs) are powered by a combination of fuel cells, batteries, and/or ultracapacitors (UCs). By integrating power converters with these power sources, the FCHEV system can overcome the limitations of us...

The utilization of fuel cells (FC) in automotive technology has experienced significant growth in recent years. Fuel cell hybrid electric vehicles (FCHEVs) are powered by a combination of fuel cells, batteries, or/and ultracapacitors (UCs). By integrating power converters with these power sources, the FCHEV system can overcome the limitations of us...

Bridgeless ac‐dc converters are the optimal choice for many applications, as they offer many advantages such as low distorted supply current, high power factor, and improved efficiency. This paper presents a new topology for a single‐phase bridgeless ac‐dc converter. The proposed hybrid topology is based on integrating the inverting and non‐inverti...

In a world where the energy crisis is becoming overwhelming, demand for integrating renewable energy sources is increasing and forming microgrids is becoming an essential solution. The new microgrid systems, which depend mainly on renewable energy sources instead of conventional synchronous generators, come with a low inertia concern. This paper pr...

Due to the growing attention for the environmental impacts and power loss minimization, distributed generators (DGs) have been introduced widely into the electric power system. One of the challenges of integrating with the power system is to determine their optimal placement and sizing, which, when not respected, adversely affects the performance o...

Nowadays, DC microgrids control problems are considered as attracting challenges for the researchers. Thus, a distributed control strategy is presented in this paper for meshed DC microgrids enhancement. The strategy consists of two control layers, a primary control layer and a secondary control layer. The primary controller regulates the terminal...

Voltage regulation is a crucial task for electrical grids in the presence of high penetration levels of renewable energies. The regulation of generator excitation improves the stability of the power system. An essential tool for controlling the excitation of generators is the automatic voltage regulator (AVR). It is advised to use a controller to i...

The wide use of communication layers in DC microgrids to transmit voltage and current measurements of each distributed generator unit (DGU) increases the possibility of exposure to cyber-attacks. Cyber-attackers can manipulate the measured data to distort the control system of microgrids, which may lead to a shutdown. This paper proposes distribute...

This paper proposes a new adaptive communication-less control strategy to enhance the dynamic performance of the interlinking converter (ILC) of a remote hybrid microgrid. The proposed autonomous strategy is based on the continuous mixed P-norm (CMPN) algorithm to simultaneously maintain the frequency of ac-side and the voltage of dc-side of the IL...

One of the challenges of inverter-based distributed generators (DGs) is to keep the voltage and frequency at their specified limits during transitions between grid-connected and islanded modes of operation. This paper presents an integrated seamless control strategy for inverter-based DGs to ensure smooth transitions between the different modes of...

The frequency of power systems is very sensitive to load variations. Additionally, with the increased penetration of renewable energy sources in electrical grids, stabilizing the system frequency becomes more challenging. Therefore, Load Frequency Control (LFC) is used to keep the frequency within its acceptable limits. In this paper, an adaptive c...

In this paper, a soft switching interleaved boost converter (SS-IBC) using auxiliary resonant circuit for electric vehicles (EV) applications is proposed. Several phases of the proposed converter can be connected to make a multiphase interleaved boost converter. The operation of multiphase interleaved boost converter is identical to that of the one...

This paper introduces an interleaved buck-boost converter with reduced power electronics devices count in comparison with the conventional topology. The proposed converter consists of a single buck converter followed by $n$ parallel interleaved boost converters. The buck switch is gated only if any of the boost switches is gated. In addition to t...

This paper introduces an integrated topology of isolated three-port dc-dc converter (TPC) to interface Photovoltaic (PV) and battery for standalone system. To guarantee zero circulating current flow between different ports while permitting bidirectional power flow at the battery port, auxiliary switches are utilized with the active bridges of the p...

Electric vehicles are increasingly growing worldwide as a result of their environmental benefits. However, uncoordinated charging of electric vehicles has several adverse effects on the charging stations and the electric network. So, coordination of electric vehicles charging is essential. These vehicles can operate in two modes, grid-to-vehicle mo...

Dusty weather is a most important disturbance for photovoltaic (PV) systems, that may result in PV panels exposure to partial shading conditions where the PV panel characteristics show several maximum power points. Moreover, dusty weather conditions may lead to rapid changes in solar radiations. Thus, conventional power system tracking algorithms a...

This paper introduces a multifunction interactive PV system that has the ability to feed a nonlinear local load in either grid-tied topology (GTT) or off-grid topology (OGT) and transits between the two topologies are seamless. The interactive PV system utilizes a sliding Fourier transform-based phase-locked loop (SFT-PLL) as an adaptive and robust...

Droop technique is extensively adopted in dc microgrids, for both islanded and grid-connected modes of operation. However, voltage regulation and proper current sharing are considered as the major challenges in droop techniques. Moreover, changes in system parameters and wide load demand variations degrade the operational performance and the effici...

The accelerating spread of distributed energy resources among the LV networks has revealed their adverse impact on voltage profiles, power quality and protections along the network. On the contrary, since they are essentially interfaced with the network through power electronic converters that can be exploited to enhance power quality. Voltage regu...

In this paper, a comparative study assessing net metering and feed-in tariffs is proposed for grid-connected photovoltaic (PV) systems in the Kuwaiti market. This study measures the impact of the two mechanisms as well as a mechanism combining both approaches in deploying solar energy systems in residential areas. The advantages and disadvantages o...

span>Four-leg active power filter is considered one of the greatest vital active filters that are frequently used in industrial applications, especially those that need to be controlled in each individual phase. Also, to control the neutral current that created because of a lot of unbalanced and non-linear loads. In this paper, the used active filt...

Four-leg active power filter (4-LAPF) is considered one of the vital active filters that are frequently used in industrial applications, especially those that need to be controlled in each phase. In addition to control the neutral current that is created because of unbalanced and non-linear loads. In this paper, the active filter is controlled by a...

This article presents a control strategy that enables both islanded and grid-tied operations of a three-phase inverter in distributed generation. This distributed generation (DG) is based on a dramatically evolved direct current (DC) source. A unified control strategy is introduced to operate the interface in either the isolated or grid-connected m...

This paper introduces a simple and accurate seamless transfer control strategy for PV Distributed Generator (DG). This seamless transfer guarantees the stable operation of the critical loads fed by the DG during transition from grid connection to the standalone mode or vice versa. This strategy is based on classical PI controller which operates in...

Future of generation depends on the renewable energy resources due to lack of fuel and the problems of emissions. Photovoltaic (PV) system is a promising type of renewable energy resources. Non uniformity of irradiance, temperature variation, and partial shading conditions are the main disturbances associated with PV systems. Most of literatures fo...

A high-frequency multi-port (HFMP) direct current (DC) to DC converter is presented. The proposed HFMP is utilized to interface a photovoltaic (PV) system. The presented HFMP is compact and can perform maximum power point tracking. It consists of a high-frequency transformer with many identical input windings and one output winding. Each input wind...

This paper presents a photovoltaic (PV) based battery charger utilizing a wireless power transfer (WPT) interface system. The double-sided inductor-capacitor-capacitor (LCC) compensation network is utilized for the inductive power transfer (IPT) system. Because of nonlinear characteristics of the PV, the maximum power point tracking (MPPT) is achie...

During the day, photovoltaic (PV) systems are exposed to different sunlight conditions in addition to partial shading (PS). Accordingly, maximum power point tracking (MPPT) techniques have become essential for PV systems to secure harvesting the maximum possible power from the PV modules. In this paper, optimized control is performed through the ap...

Due to an unfortunate oversight some equations (4, 5, 6 and 7) have been given errorneously.

This paper introduces a novel technique for simplification of a three-dimension space vector pulse width modulation (3D-SVPWM). Conventional SVPWM calculations are based on trigonometric functions or several decomposition matrices. Thus, a very fast embedded controller is needed either for two-dimension space vector pulse width modulation (2D-SVPWM...

This paper presents an isolated high-frequency (HF) multi-port dc/dc converter for PV interfacing systems. In the proposed multi-port converter, an HF transformer with multiple input windings and single output winding is utilized. Each input port is based on a proposed two-quadrant inverter topology which connects a PV module to the HF transformer....

Hybrid ac/dc microgrids have been developed to overcome the drawbacks of either ac or dc microgrid. To profit of the remarkable aspects of ac as well as dc, an inter-linking converter (ILC) is required to transfer the power between the two sides of the microgrids, meanwhile maintain the ac sub-grid frequency as well as the dc sub-grid voltage withi...

Most of Distributed Generators (DGs) use Voltage Source Inverter (VSI) for the purpose of interfacing DG with the grid and producing electricity at the desired voltage and frequency. This paper presents adaptive unified seamless control strategy for a DG based controller. The parameters of the Proportional-Integral (PI) controller are updated onlin...

DC microgrids operate either in standalone mode or grid-connected mode. In order to control the DC microgrid, the droop control is commonly used. However, voltage deviation as well as the error in current sharing are the main problems associated with the droop method. Conventional rating-based control schemes are developed to overcome the droop tec...

This study proposes a new back-to-back (BTB) current source converter (CSC) configuration and presents its application for variable speed wind energy conversion system. The proposed configuration consists of three cascaded ac−dc non-inverting buck-boost converter. The ac side of each converter is connected to an open-end winding of the three-phase...

The droop control is the most effectively used technique for load current sharing in DC microgrid. The disadvantages of the conventional droop controllers are the increased voltage deviation and current sharing errors when the load current is increased. This paper presents two improved techniques for current sharing in DC microgrids. In the first t...

In general, optimization control is a relatively new trend where an optimization technique is used to tune the controller parameters for a given system under study. The optimization control is proved to be better than traditional adaptive control in many ways as discussed in this paper. This research work presents optimization control schemes for a...

This paper proposes a battery charger for an Electric Vehicle (EV) based on Zeta converter. A Zeta converter is a fourth order DC-DC converter which works as a buck-boost converter with a non-inverted output. The Zeta converter is controlled to extract the maximum power from a Photovoltaic (PV) array to charge the EV battery. The PV array is compos...

The Sliding Mode Control (SMC) is used to control variable structure systems such as power electronics converters. This paper presents a fault-tolerant strategy based on the SMC for current controlled AC-DC converters. The proposed SMC is based on three sliding surfaces for the three legs of the AC-DC converter. Two sliding surfaces are assigned to...

In addition to its modular nature, a Hybrid Modular Multilevel Converter (HMMC) assembled from half-bridge and full-bridge sub-modules, is able to block DC faults with a minimum number of switching devices, which makes it attractive for high power applications. This paper introduces a control strategy based on the Root-Least Square (RLS) algorithm...

One of the most widely used techniques for controlling the dc microgrid is the droop control method. The associated problems of the droop based systems such as the current sharing errors and the voltage deviation are solved using current sharing loops and secondary control loop, respectively. This paper presents an adaptive droop scheme for dc micr...

This paper introduces a hybrid maximum power point tracking (MPPT) technique for photovoltaic (PV) arrays working under partial shading conditions (PSCs). This new algorithm can combine a traditional MPPT algorithm, such as perturb and observe (P&O) or incremental conductance (IC), with the artificial neural network (ANN) technique. The proposed hy...

Pulse Width Modulated (PWM) rectifiers play an important role in power conversion systems. However, open-switch faults are one of the main problems that face the operation of a PWM rectifier and its reliability. In this paper, open-switch faults in three-phase current controlled PWM rectifiers are analysed. The Space Vector Modulation (SVM) based H...

Modular Multilevel Converter (MMC) will be extensively used in High-Voltage Direct Current (HVDC) transmission networks because of its superior characteristics over Line Commutated Converter (LCC). Increasing the reliability of the MMC is directly related to the balancing of the MMC sub-module capacitors voltages which guarantees the proper operati...

The increasing demand for high voltage DC grids resulting from the continuous installation of offshore wind farms in the North Sea has led to the concept of multi-terminal direct current (MTDC) grids, which face some challenges. Power (current) flow control is a challenge that must be addressed to realize a reliable operation of MTDC grids. This pa...

This paper presents an interface system based on the Dual Active Bridge (DAB) converter for Photovoltaic (PV) arrays. Two control strategies are proposed for the DAB converter to harvest the maximum power from the PV array. The first strategy is based on a simple PI controller to regulate the terminal PV voltage through the phase shift angle of the...

The training data of the artificial neural network. (DOCX)

This paper presents a novel capacitor voltage estimation using the adaptive linear neuron (ADALINE) algorithm for monitoring of MMC sub-module voltages. The proposed estimation unit requires only three voltage sensors per phase for the arm reactors and the output phase voltages. Measurements of sub-module capacitor voltages and associated communica...

The absence of a reliable current flow control method is one of the main problems that need to be solved to allow the realization of multi terminal high-voltage direct current (HVDC) transmission. Industry leaders and researchers have introduced a few methods of power flow control based on either the control of converter station or the connection o...

New energy polices and the reduction in the prices of photovoltaic (PV) panels, storage batteries and power electronics inverters resulted in a dramatic increase in the penetration level of PV systems connected to the medium voltage (MV) network. Consequently, utility sets a restriction over the injected power fluctuations as well as the requiremen...

The interaction between wind energy turbines and the grid results in two main problems, increasing the short-circuit level and reducing the Fault Ride-Through (FRT) capability during faults. The objective of this paper is to solve these problems, for fixed speed Wind Energy Systems (WECS), utilizing the bridge-type Fault Current Limiter (FCL) with...

The modular multilevel converter (MMC) is expected to be used extensively in high-voltage direct current (HVDC) transmission networks because of its superior characteristics over the line-commutated converter (LCC). A key issue of concern is balancing sub-module capacitor voltages in the MMCs, which is critical for the correct operation of these co...

One of the main problems that need to be solved to allow the realisation of multi-terminal high-voltage direct current (HVDC) transmission systems is the absence of a practical power flow control method. Industry leaders and researchers have proposed a few methods of power flow control based on either the control of converter station or the connect...

The continuous installation of offshore wind farms in the North Sea area in the past few years has resulted in the installation of numerous point to point HVDC links. As a result, the idea of forming Multi-Terminal Direct Current (MTDC) grids by interconnecting these links emerged along with its challenges. Power (current) flow control is one of fe...

This paper presents a new fault detection and localization strategy for Modular multilevel converters (MMC). The proposed fault detection technique depends on the estimation of the sub-module capacitor voltages using the RLS algorithm without the need of extra sensors or special power circuits. The dynamic performance of the proposed strategy is in...

This paper presents an integrated control system for Sparse Matrix Converter (SMC) to interface Permanent Magnet Synchronous Generator (PMSG) based wind turbine unit with the power grid. A carrier based PWM technique is extended and adapted for the SMC. Details of the proposed switching strategy and derivations of the modulation functions for both...

This paper presents an interface system for the grid-connected Photovoltaic (PV) arrays. The proposed interface system is based on the Dual Active Bridge (DAB) converter which is connected to the DC-link of the grid-connected inverter. The Perturb and Observe (P&O) scheme is utilized to obtain the terminal voltage of the PV array that results in Ma...

One of the attractive direct-drive wave energy conversion systems is the Archimedes Wave Swing (AWS) coupled to a Linear Permanent Magnet Synchronous Generator (LPMSG). This paper presents an integrated control strategy for the back-to-back converter interfacing the LPMSG not only to extract the maximum power from the wave, but also to ride-through...

The paper presents a current controlled High Frequency AC (HFAC) link based on Matrix Converter (MC) to interface a photovoltaic (PV) system with the grid. The proposed switching scheme for the MC is based on the hysteresis current control and the sign of the input voltage waveform. A strategy for controlling the HFAC link converter to extract the...

This Paper develops an electromechanical dynamic model of a wind turbine based doubly fed induction generator. Different control and protection schemes are incorporated. This includes controller for the grid-side that is responsible for maintaining the DC link voltage constant regardless of the power flow between the rotor and the grid. A field ori...