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Summary: The continuous increase of the distributed energy resources (DERs) penetration levels leads to voltage stability problems in the distribution system. One of the approaches for the mentioned emerging challenge is the proper placement of automatic voltage regulators (AVRs). This paper investigates the optimal placement and sizing of AVRs in a distribution network by presenting a new modification of the teaching‐learning‐based optimization (TLBO) algorithm. The objective functions consist of minimizing the distribution system voltage deviation, energy generation cost, and electrical losses. The modification improves the convergence velocity and accuracy of the TLBO algorithm using the combination of mutation technique and quasi‐opposition‐based‐learning concept. This paper compares the performance of the proposed algorithm with other famous evolutionary algorithms. The test distribution system contains installed DERs that work more efficiently after the placement of AVRs based on the mentioned objective functions by the proposed optimization algorithm. The simulation results display the best optimization algorithms for AVRs placement with a significant level of less than 0.10 (ie, probability‐value). The proposed multiobjective optimization algorithm's considerable merit is the accuracy and convergence velocity in solving this specific optimization problem. [ABSTRACT FROM AUTHOR]

Currently, power electronics and AC machine drive systems are employed in numerous areas, such as in industrial processes, consumer electronics, electric vehicles (EVs), renewable-energy-source (RES)-based distributed generation (DG) systems, and electric power generation systems. As RESs such as wind and solar are attracting relatively more attention due to environmental issues caused by fossil fuel use, various RESs have been integrated into the utility grid (UG) as DG systems. As a result, the concept of a microgrid (MG), which constructs an electrical power system with DGs, energy storage systems (ESSs), and loads, has emerged. Recently, the DG-based MG has been regarded as a promising and flexible technology for those involved in constructing electric power systems. This article presents future technology and recent developments in applied power electronics. In this Special Issue, "The Recent Development of Power Electronics and AC Machine Drive Systems", four papers were published highlighting recent developments in this field. In addition, other topics beyond the coverage of the published articles are highlighted by a guest editor to address other trends and future topics related to the Special Issue. Through an in-depth investigation of recent development trends, this article seeks to encourage related studies in power electronics. [ABSTRACT FROM AUTHOR]

For over a decade, distributed generations (DGs) have sufficiently convinced the researchers that they are the economic and environment-friendly solution that can be integrated with the centralized generations. The optimal planning of distributed generations requires the appropriate location and sizing and their corresponding control with various power network types to obtain the best of the technical, economical, commercial, and regulatory objectives. Most of these objectives are conflicting in nature and require multi-objective solutions. Therefore, this paper brings a comprehensive literature review and a critical analysis of the state of the art of the optimal multi-objective planning of DG installation in the power network with different objective functions and their constraints. The paper considers the adoption of optimization techniques for distributed generation planning in radial distribution systems from different power system performance viewpoints; it considers the use of different DG types, distribution models, DG variables, and mathematical formulations; and it considers the participation of different countries in the stated DG placement and sizing problem. Moreover, the summary of the literature review and critical analysis of this article helps the researchers and engineers to explore the research gap and to find the future recommendations for the robust optimal planning of the DGs working with various objectives and algorithms. The paper considers the adoption of uncertainties on the load and generation side, the introduction of DGs with energy storage backups, and the testing of DG placement and sizing on large and complex distribution networks. [ABSTRACT FROM AUTHOR]

To cope with the increasing energy demand, power systems, especially distribution networks, face many challenges. Recently, these networks have become complex and large, and their stability and reliability are not easy to be handled. The integration of renewable energy resources and at the same time limiting their accompanied high fault currents is one of the approvable suggestions. Many solutions have appeared to restrict the fault currents, but fault current limiters (FCLs) arise as an efficient and promising solution to whether to interrupt or limit the fault currents to allowable limits. This paper presents a literature review of the integration of renewable energy resources as distributed generation units (DGs) and FCLs in distribution networks. The DGs can be categorized based on their size and ability to deliver active or reactive power in addition to their fuel. All of solar, wind, water, biomass, geothermal, and fuel cell are utilized as the main engine for these units. Additionally, a survey about FCLs is provided, including their diverse types and applications in either medium- or low-voltage networks. FCLs are divided into reactor, pyrotechnic, non-superconducting (solid state), and the last-developed ones, superconducting FCLs. In addition, the implemented optimization techniques are summarized to correctly employ both FCLs and DGs. These techniques vary between classical and modern, whereas more methods are developed to suit the renewable energy intermittence and uncertainty and the power system operators' aspirations. Moreover, in this paper, the optimal allocation of diverse types of DGs correlated with FCLs is presented and applied to the real Egyptian distribution network of the East Delta Network (EDN). The results show the avails obtained where the power losses are significantly reduced, with respect to the total load, from 3.59% in the initial case to 0.296%. In addition, the fault current returns to its initial value, removing the percentage of increase of 20.93%. [ABSTRACT FROM AUTHOR]

When a short circuit occurs in the power supply area of a distribution network with a high-permeability distributed generation, the line current will increase, the voltage will drop sharply, and the fault characteristics will be more complex. Therefore, the automatic, quick, and accurate location of fault sections is of great significance to the reliability of power supply. In order to prevent large-scale power outages in the power supply area caused by the failure of feeders and transformers, this paper proposes a novel method to locate fault sections in active distribution networks by taking into account the data of the power supply area. On the basis of the synchronization of calculated and measured time and the observability of the fault state, a limited number of intelligent terminals are reasonably arranged in the distribution network feeder and power supply area. Additionally, the fault location equation is established based on the three-phase voltage change values of the nodes before and after the fault collected by intelligent terminals, so that the fault section is determined by comparing the residuals. Finally, the proposed method is verified by the improved IEEE 37-node and IEEE 123-node three-phase distribution networks. The results show that it has high accuracy in locating fault sections in multiple fault scenarios. [ABSTRACT FROM AUTHOR]

This paper proposes an approach to mitigate adverse effects of the fault management of closed/ring grids with high shares of distributed generation (DG). The approach refers to conventional distance protection relays in particular. The rising share of DG, especially in distribution systems, can lead to overloadings and intolerable voltages. Closed-ring structures increase the grid capacity for DG due to more balanced load and voltages profiles. However, malfunctions of protection relays may occur because fault locating and selective fault clearing can be disturbed. This paper presents a distance protection algorithm for feeder relays that complies with the requirements of closed/ring grids with inter/infeeds. The proposed current comparison method (CCM) bases on the comparison of negative/sequence currents. It needs no voltage measurement and remains unaffected from inter/infeeds and fault resistances. Additionally, for relays located at the ring coupler, where the ring can be opened, a coupling relay method (CRM) is proposed. It locates unsymmetrical faults in closed/ring grids with inter/infeeds and enables fast and selective opening of the ring. This helps maintaining reliable power supply for customers in closed rings. Finally, the paper presents a grading strategy reducing the average fault clearing time. Lab tests prove the capability of both proposed algorithms. [ABSTRACT FROM AUTHOR]

Electric vehicles (EVs) are a very essential part of the automobile industry and play a vital role in the development of the economy of a country. Due to their eco-friendly nature and lower operating cost, EVs have acquired great attention globally. Almost all leading automobile manufacturers are developing costefficient EVs. However, with the increase in the number of EVs day by day, the need for efficient charging stations to deliver economical charging needs to be developed. To charge these EVs from the conventional grids is an additional burden on these grids as more electricity will be required to charge these EVs, which may result in incremental energy production as well as the energy cost for the general consumers. These days, increasing the number of EVs can bring sustainability problems in Pakistan as the considered country already facing the worst electrical energy crisis in the last ten years. For this purpose, we must require some alternate methods for charging the EVs charging to avoid overloading on existing grids. The use of renewable energy resources (RERs) is an effective solution to tackle this shortage of power. Therefore, in this paper, a cost-effective solution is proposed by hybridizing the different types of RERs to charge the EVs from the charging station. A different combination of RERs is used as case studies for a specific area of Pakistan named Kallar Kahar. Simulation is performed on MATLAB/Simulink and energy cost is being compared for different case studies. The proposed hybrid power system used approximately 50% wind, 40% solar, and 10% biogas as RERs. The results show that case 4 is best among all which provides yearly power production of 375,220 kWh at a net annual cost of 43,174.06$/year while the net annual cost to provide the same power with the grid is 59,304$/year. There is a 1.37% reduction in the overall annual cost of the proposed charging station as compared to the utility grid. [ABSTRACT FROM AUTHOR]

The global demands for clean and sustainable energy are rapidly increasing because of population and economic growth. The future of energy essentially requires novel thinking and new systems to transform energy generation, distribution, and consumption. The Internet of Energy (IoE), as a new concept, transforms the way of energy production, supply, and consumption to fulfill high-energy demands via a smart network of industrial energy producers and consumers. The main objective of this paper is to address how the Internet of Things (IoT) would meet the requirements of smart and distributed power generation. We did a comprehensive literature review to provide insights into the IoE applications and enlighten the current challenges. Furthermore, the paper provides deep insights into the existing research challenges to address the current limitations of the IoE security issues, and potential directions are also pointed for future work. The findings of this study include identifying the requirements and enabler factors influencing the IoT-based distributed generation that would be useful for policymakers and decision-makers in the field. [ABSTRACT FROM AUTHOR]

Featured Application: Grid Connected Inverter. As the proportion of distributed generation (DG), including Photovoltaic (PV) generation, in the power grid system increases, there are dropouts of large-scale distributed power generation sources due to some transient conditions that negatively affect the power grid stability and power quality. Accordingly, the inverter for DG generation is in a transition period, requiring more complex control performance. Anti-islanding function requirements in particular are becoming more strict because sophisticated grid-connection requirements are demanded, such as voltage ride-through, frequency ride-through, rate of change of frequency, and other functions. Thus, highly advanced anti-islanding methods are required to detect the islanding condition quickly and accurately to stop the inverter. This paper presents the improved anti-islanding method based on reactive power variation (RPV) under grid-support environments for single-phase DG inverters. In order to verify the validity of the proposed method, PSIM simulation was conducted. The proposed method meets the requirements of IEEE Std. 1547-2018 and KS C 8564:2021 by preventing islanding within 0.007 s under the newly adopted voltage/frequency trip setting, while the conventional RPV method fails. [ABSTRACT FROM AUTHOR]

The rapid growth in renewable energy-based distributed generation has raised serious concerns about the grid's stability. Due to the intrinsic rotor inertia and damping feature and the voltage (reactive power) control ability, traditional bulk power plants, which are dominated by synchronous generators (SG), can readily sustain system instability. However, converter-based renewable energy sources possess unique properties, such as stochastic real and reactive power output response, low output impedance, and little or no inertia and damping properties, leading to frequency and voltage disturbance in the grid. To overcome these issues, the concept of virtual synchronous generators (VSG) is introduced, which aims to replicate some of the characteristics of the traditional synchronous generators using a converter control technique to supply more inertia virtually. This paper reviews the fundamentals, different topologies, and a detailed VSG structure. Moreover, a VSG-based frequency control scheme is emphasized, and the paper focuses on the different topologies of VSGs in the microgrid frequency regulation task. Then, the characteristics of the control systems and applications of the virtual synchronous generators are described. Finally, the relevant critical issues and technical research challenges are presented, and future trends related to this subject are highlighted. [ABSTRACT FROM AUTHOR]

The goal of this review paper will be to address complex optimization functions in the area of overcurrent relay optimization, to inspect and valorize their objectives and to critically examine their application in real distribution networks. Special emphasis will be put on observing the optimization of discrimination time between primary and backup relay pairs, and methods which prevent the latter becoming penalty functions will be shown. Furthermore, the impact of distributed generation units on the overcurrent relay optimization problem will be elaborated in detail. Protection settings of all the existing and new relays must be thoroughly inspected before the connection of new production units, because contributing fault currents may have a significant effect on the solution of the overcurrent optimization problem. This is because the relays being used are of an inverse-type. Next, meshed network operation will be critically assessed in comparison with the actual practice of radial operation, and some topologies will be highlighted for future research, while others will be discarded. The distribution network in mesh operation implicitly suggests using numerical relays on both sides of protected elements (usually lines), so their total number will be much higher than in radial operation. Finally, a relatively new concept of adaptive distribution network protection will be reviewed, and its potential application to the overcurrent relay optimization problem will be examined. The purpose of this review paper will be to lay a groundwork for future research papers by inspecting the overall development of the overcurrent relay optimization problem for contemporary and future active distribution networks. [ABSTRACT FROM AUTHOR]

With the significantly rising demand for alternate energy resources like renewable sources, the power demands are fulfilled at reduced expenses, and increased efficiency. Despite these alternate generation techniques, there are still considerable challenges in controlling and working Microgrids (MG's) configured in DC and AC. Hybrid Micro-Grids (HMGs) are developed particularly for overcoming the effective power regulation difficulties encountered in standalone MGs by combining the advantages of individual AC and DC configurations. Since microgrids are equipped with power electronic interfaces, unlike the conventional system, maintaining voltage stability, frequency stability, and optimal power management is challenging and requires a different approach. This paper attempts to analyze various stability issues in existing systems and the control methods employed in prior works for a better understanding and management of HMG systems. It also presents a comparative study of related works in terms of their control techniques and achieved performance. The paper further discusses various research challenges prevailing in this field thereby providing an insight into the development of better control methods and techniques for resolving various stability issues in HMG for better management and supporting future applications. [ABSTRACT FROM AUTHOR]

The article concerns the energy security of a wastewater treatment process caused by unforeseen situations related to the risk of electrical power outages. In this case, renewable energy sources based on distributed generation power systems can solve this problem in each wastewater treatment plant. The article highlights e related challenges and proposes the direction of solutions in this regard based on Czech conditions. The first part of the paper deals with the consequences of long-term outage of wastewater treatment plants on the population and the environment. There are several solutions presented for blackout conditions, and model calculations are made based on data from a Czech wastewater treatment plant. Diesel engine-generators, biogas as a cogeneration source of heat and electricity, solar panels with storage systems and combined biogas and solar systems were considered as approaches to provide energy autonomy during a blackout in a wastewater treatment plant. Special attention was paid to a combination of CHP units with solar panels and batteries. The results were evaluated for three different locations for this combination. It was concluded that biogas combustion in the CHP unit was the most profitable option, allowing the production of electricity independently of the grid for its own consumption and possibly for other operations. The last part of the paper deals with the transition to island operation, which must occur during a blackout. This transition is more difficult for both solar panels and cogeneration units if they were to supply electricity to the grid before a blackout. The transition to energy island operation could be ensured by frequency relay and processor devices to control the circuit breaker. Then, to maintain island operation, it would be necessary to have an automatic load shedding/application system. [ABSTRACT FROM AUTHOR]

Hybrid microgrid (HMG) control strategies reveal several critical research gaps that must be addressed. Current approaches often fall short in efficiency and reliability due to the inherent complexities of transitioning between grid-connected mode (GCM) and islanded mode (IM), resulting in increased losses and operational difficulties. Additionally, managing overloads, especially in IM, poses significant challenges for maintaining stable voltage and frequency regulation. This paper seeks to address these issues by introducing a novel universal control structure (UCS) for HMGs, which includes a frequency compensation unit (FCU) and a three-stage bidirectional AC/DC droop. It presents a streamlined yet robust solution for handling overloads, maintaining power balance, and ensuring precise voltage and frequency regulation while promising smooth maneuver in both GCM and IM. The proposed UCS provides flexible and reliable operation, allowing for the versatile placement of DC and AC sources and loads. This will reduce power transformation stages thereby lowering cost and increasing efficiency of system. Through experimental validation, this study demonstrates the effectiveness of the proposed control in addressing these critical research gaps and advancing the field of HMG control strategies. [ABSTRACT FROM AUTHOR]

The optimal operation of energy resources in smart distribution system (SDS) is one of the significant concerns that must be properly addressed and is of utmost importance. By optimal operation the operating point of distributed energy resources (DERs) and the strategy of energy exchange with the upstream network can be appropriately determined. Therefore, this work aims to investigate energy loss-constrained optimal operation of SDS. The SDS comprises of dispatchable distributed generations (DDGs), solar generation and electric vehicles (EVs). Participation of DDGs and EVs in both active and reactive power is considered in this paper. The proposed operation of SDS aims at minimizing the total operating cost of SDS. Moreover, to improve the technical efficiency of SDS, energy loss is added as one of the constraints in the optimization problem. The operational problem of SDS with reactive power support from EVs is modeled as a mixed integer second-order cone programming problem and solved using MOSEK solver. Different case studies are framed and compared to investigate the effect of considering energy loss constraint and reactive power from EVs. Simulation results verify the efficacy of proposed model in optimally coordinating different DERs in SDS. [ABSTRACT FROM AUTHOR]

Recent advancements in renewable energy technologies, alongside changes in utility infrastructure and progressive government policies, have bolstered the integration of renewable-based distributed generation units within distribution systems. This paper introduces the Energy Valley Optimizer, a novel tool designed for the strategic placement of distributed generation units and capacitor banks. This placement is crucial not only for optimizing energy loss and enhancing bus voltage stability but also for promoting sustainable energy use and reducing environmental impact over the long term. By minimizing energy loss and voltage fluctuations, the optimizer contributes to a more sustainable and resilient energy system. It achieves this through the optimal allocation of resources across various load patterns within a 24 h period and is tested on the ALG-AB-Hassi-Sida 157-bus distribution network in South Algeria. Comparative analysis with existing algorithms—such as the Liver Cancer Algorithm, Walrus Optimization Algorithm, and Zebra Optimization Algorithm—demonstrates the superior performance of the Energy Valley Optimizer. It not only enhances technical and economic efficiencies but also significantly lowers the total cost of energy over 24 years, thus supporting sustainable development goals in energy management. [ABSTRACT FROM AUTHOR]

Stabilizing the power flow distribution in distribution networks and determining the connection locations and capacities of distributed generation are crucial issues in optimizing the operation of distribution networks with distributed generation. This paper proposes an energy storage scheduling and optimization model based on deep reinforcement learning （deep RL） to match the relationship between distributed energy resource allocation and electricity load demand， thereby stabilizing power flow distribution in distribution networks with high penetration rates. Using line losses and voltage fluctuations as the loss functions， the paper proposes a decision-making model for placement and sizing of distributed generation based on multi-objective genetic algorithm. Testing is conducted on the IEEE 14-bus system， and the results indicate that the algorithm can effectively select the optimal connection locations and capacities for distributed generation， reducing overall line losses while ensuring voltage amplitude remains stable.

Most microgrid protection schemes found in published literature suffer from a lack of generality in that they work well for the assumed topology, including type and placement of sources. Other generic protection schemes tend to be too complicated, too expensive, or both. To overcome these drawbacks, a topology-agnostic, scalable, and cost-aware protection based on fundamental principles that work in the presence of high penetration of inverter-based resources (IBRs) is developed and tested in this paper. The protection system also implements stable automatic reconfiguration of the healthy sections of the system after clearance of fault, thus increasing resilience by self-healing. To achieve this ambitious goal, stable inverter models are developed that operate in unbalanced networks in grid-connected and islanded modes, even with 100% IBRs, share power without conflicting controls, and can ride through faults while limiting fault currents. The scheme is tested for primary and backup protection and reconfiguration on the IEEE 123-node feeder in grid-connected and islanded modes with 15 IBRs connected to the system. [ABSTRACT FROM AUTHOR]

The advancements in smart grid technologies had brought forth the prospect of self-healing distribution grid through intentional islanding, aided by the steadily rising penetration of inverter-based distributed generations (IBDGs). Adaptive protection is the key enabler for this resilient grid architecture. For cost-effectiveness, overcurrent relays (OCRs) with adaptive features had been proposed, often with the sensitivity problem due to low short-circuit current magnitude from the IBDG taken into consideration and largely addressed. However, apart from this widely discussed sensitivity problem, there is an underlying issue on selectivity of the OCR which is frequently disregarded when designing an adaptive overcurrent protection scheme for IBDG dominated microgrid. This selectivity problem is mainly caused by the current diversion to load during fault, which is often disregarded when performing OCR grading for a conventional grid. In this paper, this selectivity problem of the OCR is discussed in depth through a comparative study of conventional grid and a modern IBDG dominated grid. The coordination time interval margin violations problems are demonstrated through theoretical calculations and real-time hardware-in-the-loop experiments. This research aims to provide better insights into the selectivity problem as a step towards achieving a cost-effective yet reliable overcurrent-based adaptive protection for IBDG dominated microgrid. [ABSTRACT FROM AUTHOR]

nature inspired Harris Hawk optimization algorithm for position and rating of distributed generating units in distribution system is proposed in this paper. By installing DGs nearby consumer load centers, line losses can be reduced and voltage profile improves. But penetration of DGs at unsuitable location with unmatched rating will have large impact on distribution systems. This will affect reliability of distribution network, will lessen voltage quality and rises harmonics. Hence there is a requirement of optimization of position and rating DGs before installing in distribution systems. Voltage profile and DG capacity limitation are considered while optimizing DGs. IEEE 33 bus radial distribution system is considered for allocation. Harris Hawk Optimization Algorithm is implemented to optimize position and rating because of its global convergence and reduced calculation liability. Minimization of main objective function is carried out by considering total losses, voltage profile and capacity of DGs. The recommended process is verified on IEEE 33 bus radial distribution system in MATLAB environment and results show the effectiveness of proposed algorithm. [ABSTRACT FROM AUTHOR]

To seamlessly transition a microgrid (MG) from islanded to grid-connected mode, it is necessary to synchronize the magnitude, frequency, and phase of the MG voltage to the voltage of the main grid. In this paper, we propose a distributed control strategy to achieve synchronized operation of an islanded MG supported by multiple controllable distributed generators (DGs). The proposed method utilizes a pinning-based consensus algorithm to ensure explicit coordination between magnitude, frequency, and phase angle regulation while ensuring proportional power sharing. System frequency is regulated by all the DGs in proportion to their capacity, while a selected DG eliminates the phase and magnitude regulation errors. Controller design criteria is based on small-signal stability analysis. The proposed control strategy is implemented in hardware controllers and its effectiveness is demonstrated using a real-time hardware-in-the-loop MG testbed. [ABSTRACT FROM AUTHOR]

Due to the uncertainty of feeder impedance, conventional droop control-based power sharing scheme presents poor reactive power sharing accuracy in microgrid. As microgrid configuration becomes more and more complicated, reactive power sharing between various distributed generation (DG) equipment is very challenging. To achieve proper power sharing with a simple control method in microgrid, a new structure and power sharing method is proposed in this paper. Instead of using complicated reactive power sharing scheme, this paper proposes separated energy server (ES) units to provide reactive power. Then, active power supplying and reactive power supplying can be achieved separately by energy routers (ERs) and ESs, respectively. With the introduction of ES, the power sharing between DG units can be easily achieved without any supplementary communications or control algorithms. In addition, to reduce costs,a hybrid reactive power compensation configuration with capacitor banks and ESs is provided. Operation principle and power control strategy for DG units and ESs are explained and analyzed in this paper. In order to properly select the coefficients of the power controllers, sensitivity and stability of the system are investigated. Simulation and experimental results are presented to prove the validity of the proposed power sharing method, showing that ERs can effectively share the active power and ESs can effectively share the reactive power according to their capacity. [ABSTRACT FROM AUTHOR]

The sharing of nonlinear loads among different distributed generation units (DGs) is always a tradeoff between accuracy and voltage quality. This paper proposes a virtual harmonic conductance for each harmonic as a family of droop characteristics in terms of conductance versus current. Assigning a variable conductance for each harmonic current improves the DG controllability, thus offering accurate nonlinear load sharing, which is crucial at the near-rated loading and enhanced voltage quality. This paper also unveils a tuning methodology for the droop characteristics that sets a maximum permissible value for each individual harmonic to comply with international standards. Lastly, a hybrid voltage and current control system is suggested to accurately track the DG harmonic conductance designated by the proposed droop characteristics. While the proposed algorithm is capable of accurately distributing common nonlinear loads among DGs, it also enjoys the advantage of supplying local nonlinear loads by their dedicated DGs. A comprehensive performance evaluation assures the effectiveness of the proposed control strategy. [ABSTRACT FROM AUTHOR]

This paper presents an algorithm for detection, classification, and characterization of voltage sags and swells in electricity networks using three-phase voltage ellipse parameters. The proposed method employs the instantaneous magnitude of three-phase voltage signals in three axes, which are separated from each other by 120 ^\circ . Thus, the resultant rotating vector, namely, the three-phase voltage vector, traces an ellipse. Then, the parameters of the ellipse, which include minor axis, major axis, and inclination angle, are used to develop the proposed algorithm for classification and characterization of voltage sags and swells. The proposed method is validated using real data of the IEEE working group and some measured real data of the Belgian transmission grid. The method is further tested for the sags and swells generated due to balanced and unbalanced faults at different buses, in test distribution networks (radial and mesh type) embedded with distributed generation and in a practical distribution network of Australia. This paper also demonstrates the proposed algorithm as a real-time sag/swell monitoring tool. [ABSTRACT FROM PUBLISHER]

In this paper, an economic dispatch (ED) problem for a community microgrid is studied. In this microgrid, each agent pursues an ED for its personal resources. In addition, each agent is capable of trading electricity with other agents through a local energy market. In this paper, an energy market operating in the presence of the grid is introduced. The proposed market is mainly developed for an experimental community microgrid at the Missouri University of Science and Technology, Rolla, MO, USA, and can be applied to other distribution level microgrids. To develop the algorithm, first, the microgrid is modeled and a dynamic ED algorithm for each agent is developed. Afterwards, an algorithm for handling the market is introduced. Lastly, simulation results are provided to demonstrate the proposed community market, and show the effectiveness of the market in reducing the operation costs of passive and active agents. [ABSTRACT FROM PUBLISHER]

The optimal integration of renewable-based distributed generations (DGs) in distribution system offers several techno-economic and environmental benefits. The demand response (DR) can further augment the benefits associated with DGs. This paper investigates the impact of DR on joint allocation of wind-based and solar-based DGs in distribution system. The integration of renewable-based DGs in coordination with the DR becomes a multi-constraints complex optimization problem. Therefore, in this paper a new methodology is proposed for optimal accommodation of renewable-based DGs in coordination with DR. The optimization problem is formulated as mixed-integer second-order cone programming (MISOCP) problem to minimize energy loss. The solvers which can solve MISOCP problem are commercially available and the optimal solution obtained using such solvers is guaranteed to be global. The proposed framework is investigated on standard 33-bus distribution system under different case studies to evaluate the impact of integrating DR on the allocation of DGs. [ABSTRACT FROM AUTHOR]

Summary The power grid constructed with electric power router (EPR) will have the ability of flexibly controlling the voltage and power flow on each line of the grid, which will be helpful to maximize the integration of the renewable distributed generation to the grid. Most of the current methods for transmitting energy depend on storage unit or large scale calculation, which are relatively difficult. To avoid these disadvantages, this paper proposed a two‐step routing strategy based on the improved shortest path method for DC power grid with EPRs. The improved shortest path method combines Shortest Path Faster Algorithm (SPFA) with depth first search (DFS) algorithm, which could handle the negative weights and the negative cycle issue in the graph of the power flow paths. The increase of the transmission line power loss and the EPR's power loss are taken as the weight for the path search method to evaluate the cost of the path. Applying the proposed method to each power demand and supply finally helps to obtain the current distribution of the whole grid. By analysis of typical scenarios, compared with the power flow distribution of traditional DC power grid, the one produced by the proposed strategy could improve the power transmission capability as well as reduce the maximum voltage drop in the network. Besides, this strategy introduces less power loss, than many other ways do, in power routing. The effectiveness of the rioting strategy is related to the configuration of the network. [ABSTRACT FROM AUTHOR]

A key motivator for wider deployment of microgrids (small electric networks with distributed generation connected that operate either connected at low and medium voltage levels or isolated mode) is to bring about the decentralization of the generation. This goal is because microgrids use renewable power sources and storage energy systems. However, the microgrids operation represents various challenges for grid-connected microgrids about the power interchanges with the distribution network. If the operation is performed under optimal conditions, there are benefits for microgrid investment. This paper proposes a detailed formulation to operate microgrids with photovoltaic systems and storage. The model can be used with multiple microgrids interconnected considering electricity prices and tariffs. The model corresponds to an optimal power flow approach for microgrids considering some energy storage systems. The mathematical model considers explicitly electricity tariffs. Illustrative results indicate the optimal operation of microgrids considering a load curve; specifically, the microgrid is designed to operate at different operational circumstances. A case includes multiple microgrids interconnected at different electricity prices. The electricity tariffs determine the power interchanges between the distribution network and the microgrid. Such insights about the optimal operation of microgrids provide a wide range of applications, particularly in operation and feasibility of projects. [ABSTRACT FROM AUTHOR]

Due to its effective contribution to resolve many problems and its positive impact on distribution systems, great attention has been paid to DG during the last decade. In this paper, an efficient approach based on a newly developed metaheuristic that is the Water Cycle Algorithm (WCA) is adopted for the Optimal Incorporation of Distributed Generation (OIDG) in radial distribution systems (RDSs) for real power loss reduction, voltage stability enhancement and voltage profile improvement. Various case studies containing up to two different objective functions are investigated. The methodology adopted in this paper is carried out on the standard 33-bus, 69-bus and 85-bus distribution test systems. Some interesting results are also discussed in this paper. [ABSTRACT FROM AUTHOR]

There is a growing focus on exploring direct current (DC) microgrids in traditional power grids. A key challenge in operating these microgrids is ensuring proper current distribution among converters. While conventional droop control has been used to address this issue, it requires compensating for voltage deviations in the DC bus. This paper introduces an innovative distributed secondary control approach that effectively addresses both voltage restoration and current sharing challenges within a standalone DC microgrid. The distributed secondary control proposed in this study is integrated into the microgrid's cyber layer, enabling information sharing between controllers. This distributed approach ensures reliability, even in the event of partial communication connection failures. The controller employs a fuzzy logic control approach to dynamically determine the parameters of the secondary control, resulting in an enhanced control response. Additionally, the proposed approach can handle constant power and resistive loads without specific requirements. Employing the Lyapunov method, we have derived adequate stability conditions for the proposed controller. The performance of the controller has been assessed using MATLAB/Simulink® models and validated with real-time experimental testing performed with a SpeedgoatTM real-time machine, considering five different test cases. The results indicated that the proposed control system is robust in achieving its control objectives within a DC microgrid, exhibiting fast response and minimal oscillations. [ABSTRACT FROM AUTHOR]

The wireless sensor network (WSN) is an essential technology of the Internet of Things (IoT) but has the problem of low coverage due to the uneven distribution of sensor nodes. This paper proposes a novel enhanced whale optimization algorithm (WOA), incorporating Lévy flight and a genetic algorithm optimization mechanism (WOA-LFGA). The Lévy flight technique bolsters the global search ability and convergence speed of the WOA, while the genetic optimization mechanism enhances its local search and random search capabilities. WOA-LFGA is tested with 29 mathematical optimization problems and a WSN coverage optimization model. Simulation results demonstrate that the improved algorithm is highly competitive compared with mainstream algorithms. Moreover, the practicality and the effectiveness of the improved algorithm in optimizing wireless sensor network coverage are confirmed. [ABSTRACT FROM AUTHOR]