Abbas Ketabi

University of Kashan · Department of Power Engineering

Nonlinear, imbalanced, and constant power loads pose significant technical and power quality challenges in both AC and DC microgrids. Hybrid AC/DC microgrids further compound these complexities. In response, this paper presents a novel hierarchical control scheme comprising primary and secondary layers for such microgrids. The proposed scheme intro...

Frequency response characteristics like frequency nadir and rate of change of frequency (ROCOF) are important in designing frequency control schemes. The so-called Frequency Response Model (FRM), widely used in power system frequency studies, has some limitations in calculating these metrics. This paper evaluates and analyses the performance of FRM...

Enhancing the efficiency in the light-emitting-diode (LED) drivers is a noteworthy issue as it not only helps saving energy but also causes the long life span of the drivers. In this paper, a new LED driver with improved efficiency is proposed. Efficiency improvement is achieved without using any active or passive component to perform soft switchin...

Integrating the self‐healing capability realizes the automated protection of smart distribution systems. This article presents a fault location scheme for low voltage (LV) distribution systems based on the information collected from the smart meters. First, a fault condition is detected and classified by processing the current signal at the seconda...

The optimal energy management system (EMS) of individual and networked residential microgrids and multi-energy microgrids (MEMGs) has received a great deal of attention. Several solutions have been studied to mitigate voltage limit violations due to the increasing penetration level of distributed generation resources (DGRs) and other issues. Howeve...

تغییر در آرایش شبکه و حالات بهره¬برداری ریزشبکه¬ها یکی از چالش¬های اساسی سیستم¬های حفاظتی است که می¬توان نقض قیود هماهنگی حفاظتی در برخی از شرایط را به¬دنبال داشته باشد. علیرغم مزایای متعدد طرح¬های مبتنی بر بستر ارتباطی و حفاظت تطبیقی، از آن¬جایی که این¬گونه طرح¬های حفاظتی نیاز به زیرساخت¬های سخت¬افزاری و نرم¬افزاری داشته و از سویی ممکن است با مشکل...

This article develops a stochastic multi-level multi-objective strategy to facilitate the electricity market clearing process among micro-grids considering the environmental impacts of fossil fuel powered generation units. Various types of distributed renewable energy resources (DRERs), plug-in electric vehicles (PEVs) and internet-of-things (IoT)-...

Microgrid properties including bidirectional power flow in feeders, fault level decrease in the islanded mode, and intermittent nature of distributed generators (DGs) result in the malfunctioning of microgrid conventional protection schemes. In the present article, a protection scheme based on impedance is suggested for fault detection in LV and MV...

In this paper, the reliability of cyber-physical energy hubs (CPEHs) is evaluated based on the Monte Carlo simulation (MCS) method. Previous works in the related literature are generally focused on the physical layer of energy hubs (EHs). However, the security of EHs heavily relies on the reliable and safe performance of the cyber system. Therefore...

After the restructuring of the electricity market, one of the challenges of researchers has always been to design markets that can use the maximum potential of smart consumers to improve the economic and technical indicators of the system. Therefore, this article presents a four-stage model in which the scheduling of smart buildings, microgrids and...

Several studies, such as adaptive protection schemes, have been done in the area of smart grids’ protection. However, there is a research gap in developing an adaptive scheme with dual-setting (DS) directional overcurrent relays (DOCRs), considering the limitations of the number of setting groups of protective relays. This research aims to fill suc...

Much attention has been paid to optimizing smart grids (SGs) and microgrids (MGs) protection schemes. The SGs’ operation in different operating modes (especially grid‐connected and islanded conditions) and various system configurations (such as the outage of each of the distribution generations) adversely influence the protection system. The adapti...

The efficiency, power density, and torque of axial flux generators are higher than those of radial flux generators. In this paper, a new axial flux switching generator with a coreless stator is designed for micro wind turbine applications. Generator parts are designed based on nominal values, and their dimensions are determined. Cogging torque is a...

Although the energy hub (EH) concept results in different benefits, the system uncertainties might affect the optimized decisions. Several studies have studied EH’s optimal operation, considering the system uncertainties. However, there is a research gap in proposing a novel EH’s robust optimal operation under various charging modes of electric veh...

The reliability of smart micro‐grids (SMGs), as a cyber‐physical system (CPS), might be influenced by cyber failures and information transmission faults. Several Monte Carlo simulation (MCS)‐based approaches have been reported to assess the reliability of SMGs and smart grids. On the other hand, analytical reliability assessment methods have been p...

In recent years, the evolution of microgrids (MGs) toward a complex interacted cyber-physical system is significant, which has received much attention. Cyber-physical MGs (CPMGs) are vulnerable to various cyber-physical interdependencies mainly. Therefore, the reliability evaluation of such systems is a crucial issue. Several research works have fo...

Increasing the usage of distributed generations (DGs) leads the microgrids (MGs) to develop. Considering the existence of alternating current (AC) loads and sources and concerning increasing direct current (DC) loads and sources, hybrid AC/DC MGs have been used to have the advantages of both AC and DC MGs and reduce the drawbacks of them. By integr...

Much attention has been paid to the deployment of Hydrogen storage systems (HSSs) and Hydrogen vehicles (HVs) in the modernized energy system. However, a research gap exists in the literature about optimal probabilistic planning of microgrids (MGs) equipped with HSS, considering the uncertainties of renewable energy resources and electric vehicle (...

Replacing conventional generating units with inverter-based generation has lowered the natural inertia of power grids and the primary frequency control reserve provided by synchronous generators. Some of the most important consequences include large frequency deviations and large rates of change of frequency (RoCoF) during sudden load and generatio...

2021 11th Smart Grid Conference (SGC) (Article presentation)

Since soiling is a site-specific problem, this paper for the first time performs controlled experiments to determine the characteristics of a dust sample from the desert region of Iran and its impact on the power efficiency of solar photovoltaic modules. Dust characterization experiments are performed using scanning electron microscope, X-ray fluor...

In this article, a novel multi‐port modular multilevel inverter topology is presented for grid‐connected photovoltaic systems, which feature a smaller capacitor size compared with its counterparts. In the proposed MMC topology, each submodule is an individual input port being fed by an independent PV array through a boost converter. This allows mod...

Smart microgrids (SMGs), as cyber–physical systems, are essential parts of smart grids. The SMGs’ cyber networks facilitate efficient system operation. However, cyber failures and interferences might adversely affect the SMGs. The available studies about SMGs have paid less attention to SMGs’ cyber–physical features compared to other subjects. Alth...

Advancement of power electronic systems and DC microgrids (DCMGs) causes a trend toward the realization of smart homes (SHs). Intelligent SHs comprise several renewable energy sources (RESs), energy storage systems (ESSs) and DC loads, which are integrated into the DCMG. In the SH, several loads such as washers and dryers, home appliances, and Heat...

Renewable energy sources (RESs) are playing a significant role in the optimal operation of residential prosumers. Uncertainty of weather parameters such as solar irradiance and wind speed can affect the output power of RESs and consequently day-ahead operation of prosumers. Therefore, in this study, a new energy management system (EMS) has been pro...

Microgrids active characteristics such as grid-connected or islanded operation mode, the distributed generators with an intermittent nature, and bidirectional power flow in active distribution lines lead to malfunction of traditional protection schemes. In this article, an impedance-based fault detection scheme is proposed as the main protection of...

Electric springs (ES) are often known to be demand-side power management systems in decentralized grids with renewable energy sources, which, due to their nature, inject unreliable electricity power into the system. The second type of electrical spring (ES_2) produces an intelligent load by placing it next to a sensitive load, which, in addition to...

Dynamic capacitor (DCAP), as a shunt power quality device, corrects the power factor of the load and reduces the total harmonic distortion (THD) of the source current. A novel control method was presented based on the model predictive control (MPC) to control a three-phase three-wire buck-type DCAP. The injected current of DCAP is the control varia...

Parasitic capacitances in transformers consist of three main groups: winding-to-winding, layer-to-layer, and stray capacitances. Stray capacitance is also made of turn-to-turn and turn-to-core capacitances. This study presents a novel analytical method for calculating the values of turn-to-turn, turn-to-core, and stray capacitances in each winding,...

The optimization of energy systems, including various kinds of energies, based on the concepts of energy hub (EH) has received a great deal of attention. Different methods have been introduced for optimization of EH’s operation, which considered the uncertainties of distributed renewable energy sources(DRESs). However, a knowledge gap exists in dev...

Although much efforts have been devoted to the optimal design of the energy systems, there is a research gap about the multi-year load growth-based optimal planning of microgrids. This paper tries to fill such a research gap by developing a novel method for the optimal design of the grid-connected microgrids based on the long-term load demand forec...

Prosumer microgrids (PMGs) are considered as active users in smart grids. These units are able to generate and sell electricity to aggregators or neighbor consumers in the prosumer market. Although the optimal scheduling and operation of PMGs have received a great deal of attention in recent studies, the challenges of PMG’s uncertainties such as st...

Uncertainties of renewable energy sources (RESs) such as wind turbine (WT) and photovoltaic (PV) units are one of the considerable challenges of prosumer microgrids (PMGs) for the optimal day‐ahead operation. In this study, a new probabilistic scenario‐based method of optimal scheduling and operation of PMGs is developed. In this regard, different...

The deployment of the energy storage systems by prosumers is steadily growing due to uncertainties of renewable energy resources. There is a knowledge gap about the techno-economic analysis of the loss of life (LOL) cost of the battery storage systems (BSSs) in the optimal day-ahead scheduling of the residential and commercial prosumers. This paper...

Many efforts have been made to increase the utilization of renewable energy resources (RESs) in Iran. This paper aimed to evaluate the techno‐economic performance of an introduced hybrid microgrid (HMG) in eight climate zones of Iran. Therefore, ten cities are selected from the eight climate conditions of Iran. An electricity pricing strategy is al...

Energy management systems (EMSs) play an important role in the optimal operation of prosumers. As an essential segment of each EMS, the load forecasting (LF) block enhances the optimal utilization of renewable energy sources (RESs) and battery energy storage systems (BESSs). In this paper, a new optimal day-ahead scheduling and operation of the pro...

A quasi-static approach based on two-dimensional Finite Element Analysis (FEA) is described to calculate the position and speed of the rotor of Variable Capacitance Micromotor (VCM). FEA is performed to compute the overall capacitance of the rotor-stator combination when the stator is excited symmetrically. A continuous curve is fit to energy-angle...

This study suggests an adaptive and optimal control method to achieve the maximum power point tracking (MPPT) in the photovoltaic (PV) systems. For the maximum power transmission under varying the environmental conditions and partially shaded conditions, MPPT technologies are utilized in PV systems. For the improvement of functioning MPPT, a new fo...

During recent years power systems are operated near the nominal capacity of system equipment with low stability margin. Operation of power systems in this condition is extremely risky and power systems lose their stability with any intense failure of system equipment. In bulk power system, it is more critical and may cause a partial or overall blac...

One of the major challenges in protection of the inverter-interfaced islanded microgrids is their limited fault current level. This degrades the performance of traditional overcurrent protection schemes. This paper proposes a fault detection strategy based on monitoring the transient response of the inverter current waveform using a transient monit...

The Low Voltage Ride Through (LVRT) is an important requirement in fault conditions for any power system specially microgrids. When the fault occurs, the overcurrent and unbalanced voltage are yielded and these result in serious damages in inverter-based Distributed Generators (DGs) in the microgrid. To prevent this phenomenon, many types of resear...

In this paper, with taking advantage of electrical properties of a germanene nanoribbon, we propose a germanene nanoribbon field effect transistor (GeNR-FET). Here by tuning the width and geometry of the germanene nanoribbon in the source, drain and channel regions, we investigate theoretically the transistor characteristics, analog and digital per...

Today, the pulsed power systems have been employed in many applications. To meet the requirement of user, the pulse generator should enjoy the advantages of compactness, high flexibility, high pulse repetition rate and cost efficiency. Among all of converters that can be used to generate high voltage pulses, capacitance diode voltage multiplier (CD...

One of the most important challenges in the modern protective requirements is in security and accuracy in the presence of different fluctuations in the network. Therefore, techniques with faster and more accurate estimations have to be developed to measure waveform phasors under steady-state and transient conditions. This paper proposes a new least...

Underfrequency load shedding plays an important role in prevention of the power system blackout. The common load shedding methods are based on measuring the frequency first derivative; therefore, an error in measurement process can highly affect their performance. Also, for proper performance of these load shedding schemes, the exact value of some...

Microgrids are used widely in electric power systems for enhancing the power system operation in both grid-connected and island modes. One of the main problems with microgrid operations in power systems is maintaining the microgrid voltage and frequency within permissible ranges and sharing microgrid loads among participating distribution generatio...

Recently, the pulsed power systems have found wide applications. For this reason, using the pulsed power generators that in addition to responding to the needs of the user, are providing the advantages of compactness, high flexibility, high repetition rate and cost efficiency is inevitable. This paper proposes a converter which is a combination of...

This paper investigates the effect of boosting droop gain on stability of an autonomous microgrid. Boosting droop gain improves power sharing accuracy while decreasing overall system stability. Therefore, to use a high droop gain, a new controller parallel to conventional one is proposed. Applying this controller, oscillatory response of distribute...

تابع ردیابی حداکثر توان این اجازه را می دهد که مقدار دقیق توان سیستم های فوتوولتاییک را در هر شرایط کاری استخراج کنیم. تکنیک اغتشاش و مشاهده یکی از الگوریتم های اصلی بدست آمده در این تابع است.کارکردهای الگوریتم های مبتنی بر اغتشاش و مشاهده وابسته به دو پارامتر مهم در طراحی، یکی دامنه و دیگری فرکانس اغتشاشات می باشد این اغتشاش به صورت پیوسته برای تع...

This paper describes a design procedure that optimizes the three principle functions of a brushless DC (BLDC) motor. The weight, average torque and cogging torque of a 3phase, 6 slot BLDC motor with 4 surface mounted permanent magnet has been optimized by MOGA and DE. The upper and lower limits of the motor geometries are cast into the role of opti...

Using effective and harmless methods to remove contaminants from the environment and water resources have been considered by many researchers. Among the modern methods, corona discharge for creating free radicals and ozone, which is a strong and unstable pollution treatment, is the best method. The corona discharge is created by applying narrow hig...

In this paper, the robust optimization shape and drive of switched reluctance motors (SRMs) are discussed using robust particle swarm optimization (RPSO). The shape optimum goal of the algorithm was found for maximum torque value and minimum torque ripple, following changing the geometric parameters. The drive optimum aim of the algorithm was found...

In this paper, the robust optimization shape and drive of switched reluctance motors (SRM) are discussed using robust particle swarm optimization (RPSO). The shape optimum goal of the algorithm was found for maximum torque value and minimum torque ripple, following changing the geometric parameters. The drive optimum aim of the algorithm was found...

Parameters and configuration of power systems are continuously prone to change. This might negatively affect the performance of load frequency controllers. PI controllers are widely used for load frequency control (LFC) in power systems. Hence, enhancing the performance of these controllers is of great importance. In this paper, an adaptive set-poi...

This paper investigate the properties of the circulating current and load sharing in parallel microgrid inverters. The existing methods cannot minimize efficient circulating current for the case of nonlinear load. The one-cycle control (OCC) technique and virtual complex impedance loop are included in the proposed controller in order to proper load...

New technologies to solve environmental problems are in demand nowadays. Existing methods cannot always be used because they are too expensive, have unwanted byproducts or simply don't work. A new approach is to create active species in situ so transport losses can be avoided. Pulsed corona discharges is such a method. Its principle is that high en...

Single-stage Single-phase grid tied inverter (GTI) is one among types of inverters widely used in photovoltaic (PV) generation system due to the advantages such as ruggedness, reliability, and cost effectiveness they offer. In this paper a modified One-Cycle Control (OCC)-based GTI single-stage PV system is proposed which do not require the service...

The purpose of underfrequency load shedding (UFLS) is to maintain the frequency of an interconnected or island power system within permissible limits in case of severe power deficits. Thus, the proper performance of UFLS scheme is of great importance. In hybrid power systems, disconnecting and connecting the power generation sources and loads resul...

The underfrequency load shedding scheme is an important protective scheme, responsible for maintaining frequency of power systems within permissible limits in case of severe power deficits and as such, its proper performance is of great interest. In microgirds, disconnecting/connecting power generation sources and loads result in variations in the...

One of the most important issues in power system restoration (PSR) is switching overvoltage caused by power equipment energization. This phenomenon may damage some equipment and delay power system restoration. This paper proposes an intelligent estimator which can be used to evaluate and control switching overvoltages. Transformer, shunt reactor, a...

In this paper, a one-cycle control (OCC)-based approach for wind turbines equipped with doubly fed induction generators (DFIGs) is presented. The OCC is used to control back-to-back converter which includes generator-side converter and grid-side converter. The former is used for regulating generator speed, and the latter is used for controlling rea...

In this paper, performance optimization of Switched Reluctance Motor (SRM) was determined using Seeker Optimization Algorithm (SOA). The most efficient aim of the algorithm was found for maximum torque value at a minimum mass of the entire construction, following changing the geometric parameters. The optimization process was carried out using a co...

In this paper an intelligent approach is introduced to study switching overvoltages during transmission lines energization. In most countries, the main step in the process of power system restoration, following a complete/partial blackout, is energization of primary restorative transmission lines. An artificial neural network (ANN) has been used to...

This paper proposes a method for optimal placement of phasor measurement units (PMUs) to have a minimum Mean Square Error (MSE) from state estimation. A Differential Evolution (DE) algorithm is used to do a state estimation for a power system and calculation of MSE from results of state estimation and then determination of a minimum number of PMU n...

a b s t r a c t Seeker optimization algorithm (SOA) is employed to present a new method for optimal placement of power quality (PQ) meters for harmonic state estimation (HSE). Using the same SOA algorithm, HSE was also improved during the proposed placement process. The placement is carried out by minimizing the weighted sum of maximum relative err...

This paper proposes a method for optimal placement of Phasor Measurement Units PMUs in state estimation considering uncertainty. State estimation has first been turned into an optimization exercise in which the objective function is selected to be the number of unobservable buses which is determined based on Singular Value Decomposition SVD. For th...

In this work, voltage evaluation after power components energization such as transmission line, transformer and shunt reactor is analyzed using artificial neural network (ANN)-based approach. Throughout the initial phase of system restoration, unexpected overvoltage may happen due to nonlinear interaction between the unloaded transformer and the tr...

This paper presents an intelligent approach to evaluate switching overvoltages during power equipment energization. Switching action is one of the most important issues in power system restoration schemes. This action may lead to overvoltages that can damage some equipment and delay power system restoration. In this work, transient overvoltages cau...

Overvoltages caused by switching operation of power system equipments might damage some equipment and delay power system restoration. This paper presents a comparison between transmission line (TL) models for overvoltages study and investigates which TL model is most proper for every case study. Both simulation time and accuracy factors of TL model...

This paper proposes a new adaptive control algorithm for a three-phase current-source shunt active power-line conditioner (APLC) operating under unbalanced and distorted network conditions. This control scheme aims at compensation of network’s reactive power, elimination of active power’s oscillating components, compensation of network current and...

This paper proposed an artificial neural network (ANN)-based approach to mitigate harmonic overvoltages during transformer energization. Uncontrolled energization of large power transformers may result in magnetizing inrush current of high amplitude and switching overvoltages. The most effective method for the limitation of the switching overvoltag...

This paper presents an approach to the study of switching overvoltages during power equipment energization. Switching action is one of the most important issues in the power system restoration schemes. This action may lead to overvoltages which can damage some equipment and delay power system restoration. In this work, switching overvoltages caused...

This paper introduces an intelligent-based method using artificial neural network (ANN) to reduce shunt reactor switching overvoltages. In power systems, an overvoltage could be caused by core saturation on the energization of a shunt reactor with residual flux. The most effective method for the limitation of the switching overvoltages is controlle...

Transients caused by shunt reactor switching have been an important parameter in the design of the relevant equipment (reactor, circuit breaker, insulation) of power systems. In a small power system that appears in an early stage of a black ýstart of a power system, an overvoltage could be caused by core ýsaturation on the energization of a reactor...