Smart Grid and Intelligent Micro Grid

This paper presents a output tracking design for regulating the load voltage of the electric power system. Based on a model of electric power system proposed by Dobson and Chiang (1988), the saddle-node bifurcation and Hopf bifurcations were observed (Wang, et al, 1994) by treating the reactive power as system parameter. Those bifurcations were found to lead to the appearance of the dynamic or the static voltage collapses of the power systems. In construct to the state feedback design at the bifurcation point via the tuning of the Static Var Compensator as proposed in (Saad, et al, 2005), a sliding mode control (SMC) scheme using SVC was employed in this study to construct a load voltage tracking design control law for regulating the load voltage and hence providing the stability of electric power systems. The numerical simulations demonstrated that the proposed control scheme not only could provide the regulation of the load voltage but also prevent and/or delay the appearance of bifurcation phenomena and chaotic behavior.

Smart grid implementations rely on the real-time monitoring and controlling of the electric power grid. To achieve real time there is need for a messaging system with minimum delays. After mentioning latest implementations and their delays we analyze the role of the different communication protocols needed within smart grids and we describe key factors to a message's delay. Taking into consideration a packet's speed constraints we then calculate a radius, within which, the ETSI communication requirements for smart grids are satisfied.

The smart meter offered exceptional chances to well comprehend energy consumption manners in which quantity of data being generated. One request was the separation of energy load-profiles into clusters of related conduct. The Research measured the resemblance between groups them together and load-profiles into clusters by k-means clustering algorithm. The cluster met, also called “Gender (Male/Female), House (Rented/Owned) and customers status (Satisfied/Unsatisfied)” display methods of consuming energy. It provided value information aimed at utilities to generate specific electricity charges and healthier aim energy efficiency programs. The results show that 43% extremely dissatisfied of energy customer is achieved by using energy consumption.

A smart city constructed through the Internet of Things is a great and best medium nowadays. In our study, we have designed an advanced and automated device that can identify overloaded polluted drainage, which is responsible for water-borne disease and unexpected floods. We are using a smart ultrasonic sensor with an Ethernet shield integrated Arduino UNO. This proposed model’s most vital side is the remote data access system using IP address and the webserver. This research is adequate for city corporations to advance their city, Develop their city to be more delighter, and reduce their fund used for extra human resources of city corporations cleaner. For data access methods, we are using the city Wi-Fi router and a monitoring station. We also proposed a separate web page designed to show the report. Materials used here are very uncomplicated and inexpensive but adequate to make an advanced automation intelligence system. In this modern scientific era, to lead a comfortable life, ...

We are simply running out of fossil fuel. So in near or far future we must move to the use of renewable energy. Bangladesh is an agricultural country. A large amount of cattle dung, agricultural residue, poultry dropping, water hyacinth, rice husk etc. are available in Bangladesh which are used for power generation [1]. Biomass gasification, a new and promising technology of power generation in Bangladesh. Electricity generated from biomass gasification can be used for the purpose of rural electrification, one of the crying need of Bangladesh. Already some private organizations are producing power from the biomass. This paper includes availability, proper selection and quality of biomass throughout the country and utilization of by-product released by the plant. In this paper, a case study is incorporated on biomass gasification in Bangladesh to generate power from rice husk.

— An Intelligent grid is a modern electric system. It uses communication, Automation and computer to improve the flexibility, security, reliability, efficiency and safety of electrical system. An Intelligent grid is a modern electric system. It uses communications, sensors, automation and computers to improve the flexibility, security, reliability, efficiency, and safety of the electricity system. In short, it brings all elements of the electricity system production, delivery and consumption closer together to improve overall system operation for the benefit of consumers and the environment. In the nutshell, the project tackles issues such as Theft Monitoring, Load Shedding and even provides features such as Line Status Monitoring, Intelligent Monitoring and Automatic Generation Selection that can make the grid shrewder.

Cloud computing is a collection of resources and services offered through the Internet. It is an Internet-based computing, where common resources, software and information are delivered to devices and computers on-demand. Common example of cloud services is Google apps, by Google and Microsoft SharePoint. Cloud computing is receiving a good deal of attention lately because of the implications for better flexibility and availability at very minor cost. Public cloud computing is one of the several deployment models. A public cloud is a cloud computing environment where infrastructure is available to the general public on the internet. Since cloud computing share distributed resources via the network in the open environment, security problems becomes more important to develop the secure cloud computing application. In this paper, we pay attention to the key security issues and challenges in public cloud computing environment which will aware both end users and vendors to get the information about the key security issues associated with cloud computing. We also discuss the precautions taken for mitigate the security issues.

In this work, we address the problem of providing fast and on-line households appliance load detection in a non-intrusive way from aggregate electric energy consumption data. Enabling on-line load detection is a relevant research problem as it can unlock new grid services such as demand-side management and raises interactivity in energy awareness possibly leading to more green behaviours. To this purpose, we propose an On-line-NILM (Non-Intrusive Load Monitoring) machine learning algorithm combining two methodologies: i) Unsupervised event-based profiling and ii) Markov chain appliance load modelling. The event-based part performs event detection through contiguous and transient data segments, events clustering and matching. The resulting features are used to build household-specific appliance models from generic appliance models. Disaggregation is then performed on-line using an Additive Factorial Hidden Markov Model from the generated appliance model parameters. Our solution is implemented on the cloud and tested with public benchmark datasets. Accuracy results are presented and compared with literature solutions, showing that the proposed solution achieves on-line detection with comparable detection performance with respect to non on-line approaches.

Although Internet of Things (IoT) brings significant advantages over traditional communication technologies for smart grid and smart home applications, these implementations are still very rare. Relying on a comprehensive literature review, this paper aims to contribute towards narrowing the gap between the existing state-of-the-art smart home applications and the prospect of their integration into an IoT enabled environment. We propose a holistic framework which incorporates different components from IoT architectures/frameworks proposed in the literature, in order to efficiently integrate smart home objects in a cloud-centric IoT based solution. We identify a smart home management model for the proposed framework and the main tasks that should be performed at each level. We additionally discuss practical design challenges with emphasis on data processing, as well as smart home communication protocols and their interoperability. We believe that the holistic framework ascertained in this paper can be used as a solid base for the future developers of Internet of Things based smart home solutions.

Centralized communication-based control is one of the main methods that can be implemented to achieve autonomous advanced energy management capabilities in DC microgrids. However, its major limitation is the fact that communication bandwidth and computation resources are limited in practical applications. This can be often improved by avoiding redundant communications and complex computations. In this paper, an autonomous communication-based hybrid state/event driven control scheme is proposed. This control scheme is hierarchical and heuristic, such that on the primary control level, it encompasses state-driven local controllers, and on the secondary control level, an event-driven MG centralized controller (MGCC) is used. This heuristic hybrid control system aims at reducing the communication load and complexity, processor computations, and consequently system cost while maintaining reliable autonomous operation during all possible scenarios. A mathematical model for the proposed control scheme using Finite State Machines (FSM) has been developed and used to cover all the possible modes/sub-modes of operation, and assure seamless transitions among them during various events. Results of some case studies involving severe operational scenarios were presented and discussed. Results verify the validity and effectiveness of the proposed communication-based control scheme. Index Terms—Communication-based control, DC microgrids, finite state machine, hybrid state/event driven control.

The concept of feeding photovoltaic power to the grid has gained widespread acceptance in these days of renewable energy generation and distribution. In this work, all areas including standards and specifications of single-phase and three-phase grid-connected inverter, classification of inverter types, historical overview of inverter technologies, classifications of inverter topologies are to be covered. The information will include details not only on the topologies commercially available but also on the switching devices employed and the associated switching frequencies, efficiency etc. Also advantages & Disadvantages of various topologies are to be included in the thesis.  Finally being an M.Tech student of Renewable Energy Science & Technology, I am going to do my Master degree project on Study of Power conditioning Unit of Photovoltaic Power System & so this paper is being submitted as my Term Paper. This paper includes different types of solar PV system, standards, and specifications of single-phase grid-tied PV inverter, single-phase grid-tied PV inverter topologies, and development of various types of single-phase grid-tied PV inverters

The great challenge for designing and developing sustainable alternative energy infrastructure is in essence the same as for maintaining our present infrastructure: How can we best solve the problems of delivering energy when and where it is needed? This involves rethinking supply and demand, load balancing, and energy sourcing paradigms with a view toward local production utilizing next generation technologies. Exploiting distributed generation means designing hybrid systems based on site-specific conditions; using new technologies to leverage traditional energy sources; and minimizing transmission and distribution costs – particularly the losses associated with long-distance transmission. Load balancing in particular becomes far more tractable when viewed as a local problem of matching energy supply and demand. Looking at modern network technologies as the models for creating a new generation of energy delivery systems provides  insights into how local energy production systems can be scaled up to internetworked production systems that leverage alternative energy generation based on local and sustainable resources together with traditional large scale generation. As smart grid development advances, network theory and technology provides a new model for energy systems based on a multi-dimensional energy production network rather than the outmoded single-direction, source-to-consumption model we now have.

With the continuous development of science and technology, the intelligent development of community system becomes a trend. Meanwhile, smart mobile devices and cloud computing technology are increasingly used in intelligent information systems; however, smart mobile devices such as smartphone and smart pad, also known as thin clients, limited by either their capacities (CPU, memory or battery) or their network resources, do not always meet users' satisfaction in using mobile services. Mobile cloud computing, in which resource-rich virtual machines of smart mobile device are provided to a customer as a service, can be terrific solution for expanding the limitation of real smart mobile device, but the resources utilization rate is low and the information cannot be shared easily. To address the problems above, this paper proposes an information system for intelligent community, which is composed of thin clients, wide band network and cloud computing servers. On one hand, the thin clients with the characteristics of energy efficiency, high robustness and high computing capacity can efficiently avoid the problems encountered in the PC architecture and mobile devices. On the other hand, the cloud computing servers in the proposed information system solve the problems of resource sharing barriers. Finally, the system is built in real environments to evaluate the performance. We deploy the proposed system in a community with more than 2000 residents, and it is demonstrated that the proposed system is robust and efficient.

Electrical energy consumption has been increasing in recent years and the technology moves towards On-Site power generation for mainly to reducing the transmission losses and gaining some benefits such as high reliability, modularity, high power quality. But unfortunately due to uncontrolled use of individual DG units can cause various problems thereby compromising their benefits. To improve performance the micro grids in integrated with main grid or standalone operations by using an efficient controllers and with high efficient converters/inverters. The paper introduces a residential micro grid with a new topology. These paper proposes i) a DC-DC converter along with regenerative clamping circuit, ii) Constant current controller for grid integrated power generation, iii) Constant voltage current controller standalone DG units. The residential grid performance is evaluated under grid connected and islanding conditions and performance is evaluated by using MATLAB tool.

Knowledge Management is the process of collecting information which supports to create disseminate and utilize the knowledge between the individuals, groups within an organization or independent organization. The process of knowledge management involves various steps such as identifying, collecting, storing, sharing, applying, creating and selling knowledge. Agents are autonomous intelligent computer programs that perform tasks on behalf of the user or user-initiated process by using its knowledge base. Agents are designed and developed in such a way that they are goal-oriented, adaptive, reactive and mobile. Agents incorporated in the process of knowledge management should be capable of communicating with other agents by using its common characteristics namely cooperate, coordinate and collaborate. These common characteristics will improve the performance of knowledge management process by helping the agents to discover the knowledge from it. Agent uses its learning characteristics to update its knowledge base whenever it encounters new information from the organization. Agent’s uses its dynamic characteristics for knowledge sharing among users in an organization. Knowledge sharing is done both at work group and at company level. During this process agent roles associated with the knowledge management and knowledge discovery are identified. This paper aims at describing such agents and their roles.

Abstract: A high penetration level of renewable energy sources such as wind power turbines and solar photovoltaic generation, in micro-grid systems causes some problems to micro-grid operator, e.g., lack in primary reserve. Recently, many countries around the world decided to increase their electric vehicles in the near future which provide a good chance to use them as a battery energy storage system (BESS). This paper proposes a new scheme to provide necessary primary reserve from electric vehicles by using multi-agent control of each individual vehicle. The proposed scheme determines the primary reserve based on vehicle’s information such as initial state of charge (SOC), the required SOC for the next trip, and the vehicle’s departure time. The effectiveness of the proposed scheme is shown by the simulation study in a micro-grid with several generation units such as diesel engine generator (DEG), flywheel, fuel cell, renewable energy resources, and electric vehicles.


Keywords: electric vehicle, primary frequency control, multi-agent control, renewable energies.

The biggest challenge for the large scale commercialization of the electric car is creating an infrastructure that can support it, mainly a smart grid with adequate charging stations. The Pacific Northwest National Laboratory (PNNL) estimates that the United States will invest nearly $500 billion in traditional electric infrastructure over the next 20 years. According to the Electric Power Research Institute, "Energy companies currently lose $150 billion each year from power outages and disturbances". Major investments decisions like these ought include the consideration of additional marginal investments to modernize, improve the grid. It is argued that utilities must correct and update customer and other infrastructure data before a smart grid can be implemented effectively (ESRI study), to which it can be argued there are opportunities for coinciding development.

Innovations in technologies, economic benefits, quality requirements and environmental concerns are changing the face of the existing power system. Centralized generating facilities are giving way to smaller, more distributed generation partially due to the loss of traditional economies of scale. The need of an intelligent grid, better known as Micro grid at the distribution end, has been recognized to accommodate distributed energy resources (DERs) and renewable energy technologies on large scale. Micro grids can provide improved electric service reliability and better power quality to end customers and can also benefit local utilities by providing dispatch able load for use during peak power conditions or allowing system repairs without effecting customer loads. This report highlights the concept, benefits and features of Micro Grids. In this paper a single phase high frequency micro grid is shown as a solution for better utilization of micro grid. 1-Φ 500 Hz buses are used to combine renewable sources with loads and grid. Proposed system utilizes an active filter called unified power quality conditioner .Also a unified power flow conditioner is used to control the power flow from/to grid. Both unified power quality conditioner and unified power flow conditioner consist of series and shunt active filters that use instantaneous ‘p-q’ theory to calculate compensating voltage and current, which then are synthesized using pulse width modulation in voltage source inverter (VSI).

—This paper proposes a solution to voltage rise and/or sag in single-phase unbalanced distribution systems using photovoltaic (PV) arrays with reactive power capability. The PV is controlled to inject maximum power using Maximum Power Point Tracker (MPPT) to supply local loads when the solar power is available. The reactive power capability of the PV inverters regulates the bus voltages in transient conditions due to irradiance variations or load changes to be within standard limits. A combined control algorithm of dq-current control with hysteresis current control (HCC) capability regulates the inverter current at different power factors according to the voltage value. The inverter reactive power supplied/consumed to/from the grid is calculated using fuzzy logic control (FLC) function. The control algorithm dq/FLC/HCC is tested with a 10-node unbalanced distribution system under various case-studies of solar irradiance variations and step-change of system loads. The obtained results clearly justify the proposed control in maintaining the bus voltages within standard limits in both transient and steady-state conditions. Index Terms—Photovoltaic (PV) generators, dq-current control, FLC, voltage change, reactive power support.

Smart grid is the process of applying ICT in order to optimize energy consumption and decrease energy loses. This paper presents a three tier Internet of Thing based hierarchical framework for the smart home, as a reflection to the present lack of intelligent solutions that do not fully use the advantages of Internet of Thing technologies. Our framework aims to extend the smart home to microgrid level, in order to integrate all renewable distributed energy sources from the microgrid and to achieve better energy optimization. As an extension to the traditional data processing, we define fog computing approach for smart home. Through simulation on real smart meter dataset, we showed that fog computing based on predictive filters can reduce the number of transmissions and minimize smart home network traffic.

—In this paper, a smart wireless wristband is proposed. The potential of innovative gesture based interactivity with connected lighting solutions is reviewed. The solution is intended to offer numerous benefits, in terms of ease of use, and enhanced dynamic interactive functionality. A comparative analysis will be carried out between this work and existing solutions. The evolution of lighting and gesture controls will be discussed and an overview of alternative applications will be provided, as part of the critical analysis.

La diffusione sempre maggiore di unità di generazione diffusa è favorita dall’utilizzo di fonti rinnovabili come irraggiamento solare e vento e grazie alle potenzialità della micro cogenerazione (produzione combinata di energia termica ed elettrica) resa una scelta vincente proprio dal fatto che la generazione diffusa è posta dentro ai centri abitati, diversamente ai tradizionali impianti di produzione di grandi dimensioni.
La tesi analizza inizialmente come la rete elettrica attuale sia inadatta a garantire l’adeguata penetrazione di unità di generazione diffusa e introduce il concetto di smart grid , che rappresenta la sfida più promettente degli anni a venire nell’ambito della progettazione di reti di distribuzione dell’energia elettrica.
Successivamente viene analizzata più approfonditamente la micro grid, una tipologia di rete intelligente le cui enormi potenzialità sono attualmente oggetto di numerosi studi da parte di prestigiose università e centri di ricerca situati in tutto il mondo. La micro grid viene analizzata nella varie architetture possibili e nei suoi componenti principali. Vengono poi elencati alcune modalità di controllo per la micro grid. Infatti la novità più sensibile introdotta da questo approccio alla distribuzione è rappresentata dal fatto che regolazione e controllo possono essere effettuate localmente e questo rende la micro grid in grado di lavorare in servizio isolato. Questa facoltà permetterà di elevare sensibilmente l’affidabilità del servizio elettrico in quanto il 90% dei guasti avvengono a livello di distribuzione MT e BT. Sarà anche possibile elettrificare zone finora non coperte dalla rete tradizionale grazie all’elevata integrabilità della generazione diffusa nella micro grid.
Vengono poi approfondite quelle che sono le problematiche che sorgono nel momento della disconnessione dalla rete a monte e durante il servizio isolato; in particolare la regolazione di frequenza, la regolazione di tensione e le difficoltà legate alla sicurezza per la difficoltà di porre il neutro della rete a terra nella fase di servizio isolato.
Infine alcune considerazioni sul ruolo che potrà ricoprire la micro grid nella distribuzione di energia elettrica nel prossimo futuro. Per la sua proprietà di poter essere declinata e progettata in modo da rispondere specificatamente alle esigenze dell’area di copertura, a seconda delle diverse condizioni ambientali ed economiche del territorio, sarà in grado di portare diversi benefici e sarà un importante (se non il più importante) strumento alla ricerca di un equilibrio energetico che il pianeta non ha ancora evidentemente trovato e non potrà certamente trovare perseverando con l’attuale sistema centralizzato di distribuzione dell’energia.

Over-current protection is principally intended to counteract excessive current in power systems. In distribution systems in Malaysia, non-directional over-current protection is adopted because of the radial nature of the power system used. Relay typically used in distribution network are designed to cater for current flow in one direction, i.e., from transmission network to load. However, with the forecasted increase in generation from renewable sources, it is important that adequate codes are in place with regards to their integration to sub-transmission/distribution network. Distribution network dynamically changes from "passive" to "active" network. With distributed generation connected to distribution network, power flows bi-directionally. Hence, directional over-current protection is adopted along the line between the transmission grid and the distributed generation. The bi-directional flow of power also complicates the earth fault protection. This is due to the presence of the distributed generation that will cause the line near the delta side of the transformer to be still energized after the operation of earth fault relay during single-phase-to-ground-fault. This paper investigates the directional over-current and earth fault protections used to protect the microgrid (biomass generator) in Malaysia. In this study, under-voltage relays are adopted at the delta side of the transformer to fully clear the single-line-to-ground fault, which cannot be cleared by earth fault relay. Three-phase-balanced fault and single-line-to-ground-fault at all possible locations in the network have been simulated. Simulation shows good coordination and discrimination between over-current relays. © 2013 Elsevier Ltd. All rights reserved.

http://www.sciencedirect.com/science/article/pii/S0142061513004201

Due to the increasing penetration of distributed generation, storage, electric vehicles and new ICT technologies, distribution networks are evolving towards the Smart Grid paradigm. For this reason, new control strategies, algorithms and technologies need to be tested and validated before their actual field implementation. In this paper we present a novel modular distributed infrastructure, based on real-time simulation, for multipurpose Smart Grid studies. The different components of the infrastructure are described and the system is applied to a case study based on a real urban district located in northern Italy. The presented infrastructure is shown to be flexible and useful for different and multidisciplinary Smart Grid studies.

La cogenerazione è ormai ben radicata nel sistema energetico italiano: nata ufficialmente nel 2002, si avvia ormai verso i vent'anni di "età". Tempo di bilanci, dunque. Quali tecnologie si sono dimostrate più adatte alla cogenerazione? Quali meritano, per il futuro, l'attenzione di tecnici e legislatori? Per rispondere, non c'è che da osservare il funzionamento degli impianti negli anni trascorsi. Si potrebbe sospettare che la normativa sulla Cogenerazione ad Alto Rendimento (CAR), comparsa nel 2011, abbia influenzato il comportamento degli operatori, favorendo magari tecnologie che prima di allora non sarebbero risultate convenienti. Non è così: le prestazioni delle varie tecnologie sono rimaste sostanzialmente invariate nel tempo. Lo dimostra un confronto tra il periodo 2003-2008 e quello 2011-2012. Per ciascuno di tali periodi, abbiamo analizzato un ampio campione di impianti, calcolando, come medie ponderali, alcuni indicatori di efficienza. La mole di dati esaminati è stata tale da impedire, finora, di estendere l'analisi ad anni più recenti; si può tuttavia affermare che le conclusioni raggiunte, basate su ben sette anni di esercizio, non dipendono da circostanze contingenti, e verrebbero confermate da auspicabili analisi ulteriori. Il numero di ore di funzionamento ed il fattore di carico Dapprima abbiamo calcolato, per ciascuna unità, il numero equivalente di ore di funzionamento (H eq). E' questo il rapporto tra l'energia elettrica prodotta annualmente e la potenza dell'unità, pari al numero di ore durante le quali l'unità avrebbe funzionato se avesse prodotto costantemente la massima potenza. Il valore H eq è stato poi diviso per il numero effettivo (H eff) di ore di funzionamento nell'anno. Si è così ottenuto il "fattore di carico" F c , sempre inferiore o uguale ad uno. eff eq c H H F  H eq è un indice di regolarità del funzionamento: un valore elevato suggerisce che l'unità sia esercìta in prossimità della massima potenza e con un limitato numero di avviamenti e di arresti. Sono, queste, condizioni di funzionamento favorevoli, perché prossime a quelle di progetto; le prestazioni dell'impianto (i rendimenti, in particolare) sono elevate. Viceversa, un basso H eq fa ritenere che avviamenti ed arresti siano numerosi. E' difficile, infatti, pensare ad un impianto che funzioni ininterrottamente per pochi mesi, e trascorra in fermata tutto il resto dell'anno. Più realistico immaginare un alternarsi frequente di periodi di funzionamento e di fermata. Un basso valore di H eq , tuttavia, non fornisce alcuna indicazione riguardo alla durata dei periodi di funzionamento: non consente, cioè, di distinguere se l'impianto funzioni poche ore alla piena potenza, oppure più a lungo ma con potenza ridotta. Maggiori lumi offre, in tal caso, F c. Se esso è prossimo all'unità, l'impianto si mantiene vicino alla piena potenza, indipendentemente dalla durata complessiva di funzionamento. Un F c elevato indica che gli avviamenti e gli arresti-numerosi, per le ragioni già viste-sono brevi. Quale influenza abbiano poi tali transitori sulle prestazioni dell'impianto è facile comprendere. Durante tali fasi, il fluido vettore del calore (vapore, ad esempio) non ha ancora raggiunto, oppure

This paper presents a new under-frequency load
shedding technique based on the combination of random and
fixed priority of loads. It has been observed that placing all of
the loads in the distribution system with fixed priority results
in un-optimum load shedding. On the other hand, designing the
load priority with a combination of random and fixed priority
provides the technique with some sort of flexibility in achieving the
optimal load shedding. The validation of the proposed scheme on
different scenarios proves that the proposed technique is capable
of achieving the optimal load shedding and recovering frequency
to nominal value without any overshoot.

Electrical networks are composed of stages of generation, transmission, and distribution of energy. Distribution networks (RD) are an important element of the electricity grid because it provides the effective delivery of energy to end-users. The RD’s are subject to failure and their optimization is of fundamental importance in the context of Smart Grids, where it is sought a greater efficiency of the processes involved between the production and distribution of energy. The distribution networks (RD) have topologies and loads of various types. This dissertation proposes a method and algorithm for the reconfiguration of the electrical network using machine learning with linear regression and a branch exchange algorithm aiming at the optimization of RD operation. The method and algorithm proposed to do maneuvers in the RD as transfer and load balancing and aiming to increase its level of reliability. The proposal is validated in a test network of IEEE (IEEEbus14) using simulation and testing environment implemented in “R” language and using the Newton Raphson method to calculate the power flow. The solution developed show satisfactory in supporting the decision-making for three reconfigurations of distribution networks in the context of the Smart Grid.

Smart grid is an advancement of the existing electrical grid. The key feature of the future smart grid is the decentralization of the main power grid into number of smaller grids (known as micro grids). Interconnection of the distributed generating (DG) sources is required with the existing electrical grid to enhance the reliability of the power system. Extensive integration of DG sources within a smart grid causes failure of a successful implementation of smart grid due to the presence of enormous fault current. Superconducting Fault Current Limiter (SFCL) has the capability to reduce the fault current level within the first cycle of the fault current resulting in an increased transient stability of the power system. In this paper an application of a resistive type SFCL, designed in Simulink / SimPower System has been proposed to limit the fault current that occurs in an interconnected power system. A resistive type SFCL model has been developed in Simulink and the performance of SFCL at different locations has been analysed in the proposed system considering wind farm (10 MVA) as a distributed generating (DG) source with the conventional power plant, to reduce the fault current in micro grids. The feasible location of the SFCL having no negative effect on the DG source has been evaluated in three phase and single line to ground faults at various positions in the smart grid. Index Terms-conventional power plant, wind farm, micro grid, smart grid, superconducting fault current limiter, fault current.

Distributed electricity-based generators (DGs) play a major role in the generation of electricity, with the increase in global temperature. The generation distributed through the use of wind, solar energy, biomass, mini-hydro and the use of fuel cells and microturbines will provide a vital boost in the near future. Benefits such as environmental friendliness, flexibility and flexibility have enabled distribution to be distributed, supported by a variety of non-renewable and non-conventional micro source resources, an attractive option for modern electric grid preparation. The microgrid consists of a combination of loads and distributed generators that serve as one win-win system. As an integrated energy delivery system Microgrids can operate in parallel or separate from the main power grid. The Microgrid concept introduces the reduction of multiple transformers into a single AC or DC grid and helps connect various AC and DC renewable sources and loads to power systems. DG connectivity for use / grid through electrical converters has increased in concern about safe operation and equipment protection. For customers a microgrid can be designed to meet their specific needs; for example, improvements in local reliability, reduction in food service loss, support for local voltages, increased utilization of waste heat, adjustment of voltage sag or uninterrupted power transmission. In the present work the performance of the hybrid AC / DC microgrid system is analyzed in grid-bound mode. Here the photovoltaic system, wind turbine generator and battery are used for microgrid development. Control systems were also developed to enable converters to integrate the AC grid into the DC sub grid. Results are available in MATLAB / SIMULINK environment.

The objective of this work is to formulate the optimal power flow problem for isolated micro-grids and solve it using the Particle Swarm Optimization (PSO). The implementation is done on a 34-bus radial distribution system where the power flow solution is obtained using the solution of quadratic equation in the Backward-Forward Sweep technique. This power flow algorithm includes the model of load, power generated from the renewables such as wind and solar photovoltaic systems to calculate the amount of power required from the diesel generators for optimal operation. A realistic data profile is provided to these models considering for a period of over 24-hour duration for loads, solar photovoltaic systems and wind profile. The solution of this optimization problem is obtained by varying different system parameters of the PSO such as number of particles, inertia and acceleration factor.

The accurate monitoring of distribution grids is essential to enable the intelligent management and control of future Smart Grids. Several challenges prevent an easy development of the state estimation tools needed to assess the operating conditions of distribution networks. The lack of a suitable measurement infrastructure is one of the most challenging aspects to face. However, in last years, several utilities started a massive deployment of smart meters in their networks. The proper use of these measurements is key to enhance the performance of distribution system state estimators. This paper presents a two-level approach conceived to efficiently include smart meter measurements in low voltage grid state estimation. The proposed solution relies on a cloud-based smart metering architecture, which allows scalability and interoperability among different off-the-shelf meters. Moreover, a suitable design of the estimation algorithm, using the uncertainty propagation theory, is proposed in order to maximize the accuracy of the estimation results. Tests performed on a sample low voltage network show the performance and the main features of the proposed state estimation solution.

With the introduction of micro grid, the major threat to this amalgamation of power grid and information technology is the security of its components such as digital computers, software from hackers. It is known that there is a bidirectional flow of power as well as information, hence, security becomes a key factor for its successful operation as it is more reliable because of its higher efficiency. Hence, there must be proper security for its successful operation. In this paper, an over view of the cyber security i.e. why it is needed and its defence against cyber-attacks are presented