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Journal ArticleDOI

Adaptive Protection System for Microgrids: Protection practices of a functional microgrid system.

TL;DR: In this article, the authors proposed a distributed energy resources (DER) integration to reduce transmission losses and enhance the operation reliability of distribution systems, where DER penetrations representing bidirectional power flows and topology-dependent fault currents could affect protection devices, cause danger to the maintenance personnel, and result in uncontrollable undervoltage and frequency.
Abstract: Distributed energy resources (DERs) offer on-site generation at consumption points, which are expected to change the conventional concept of central power generation. DER integration reduces transmission losses and enhances the operation reliability of distribution systems. However, distribution systems are traditionally designed as passive networks in which large DER penetrations representing bidirectional power flows and topology-dependent fault currents could affect protection devices, cause danger to the maintenance personnel, and result in uncontrollable under-/overvoltage and frequency. IEEE Standard 1547 requires DER units to stop energizing the distribution system when the system is de-energized due to faults.
Citations
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Journal ArticleDOI
TL;DR: This paper presents a review of issues concerning microgrid issues and provides an account of research in areas related to microgrids, including distributed generation, microgrid value propositions, applications of power electronics, economic issues, micro grid operation and control, micro grids clusters, and protection and communications issues.
Abstract: The significant benefits associated with microgrids have led to vast efforts to expand their penetration in electric power systems. Although their deployment is rapidly growing, there are still many challenges to efficiently design, control, and operate microgrids when connected to the grid, and also when in islanded mode, where extensive research activities are underway to tackle these issues. It is necessary to have an across-the-board view of the microgrid integration in power systems. This paper presents a review of issues concerning microgrids and provides an account of research in areas related to microgrids, including distributed generation, microgrid value propositions, applications of power electronics, economic issues, microgrid operation and control, microgrid clusters, and protection and communications issues.

875 citations

Journal ArticleDOI
09 May 2017
TL;DR: It is concluded that networked microgrids in particular provide a universal solution for improving the resilience against extreme events in Smart Cities.
Abstract: This paper focuses on the role of networked microgrids as distributed systems for enhancing the power system resilience against extreme events. Resilience is an intrinsically complex property which requires deep understanding of microgrid operation in order to respond effectively in emergency conditions. The paper first introduces the definition and offers a generic framework for analyzing the power system resilience. The notion that large power systems can achieve a higher level of resilience through the deployment of networked microgrids is discussed in detail. In particular, the management of networked microgrids for riding through extreme events is analyzed. In addition, the merits of advanced information and communication technologies (ICTs) in microgrid-based distributed systems that can support the power system resilience are presented. The paper also points out the challenges for expanding the role of distributed systems and concludes that networked microgrids in particular provide a universal solution for improving the resilience against extreme events in Smart Cities.

393 citations

Journal ArticleDOI
TL;DR: Protection schemes for renewable integrated power networks which includes distribution, transmission and microgrid systems are presented, which are experiencing dynamic fault currents and frequent changing network topologies.
Abstract: Among different sources of alternate energy, wind and solar are two prominent and promising alternatives to meet the future electricity needs for mankind. Generally, these sources are integrated at the distribution utilities to supply the local distribution customers. If the power generated by these sources is bulk, then they are either integrated at the distribution/transmission level or may be operated in an island mode if feasible. The integration of these renewables in the power network will change the fault level and network topologies. These fault levels are intermittent in nature and existing protection schemes may fail to operate because of their pre-set condition. Therefore, the design and selection of a proper protection scheme is very much essential for reliable control and operation of renewable integrated power systems. Depending upon the level of infeed and location of the renewable integration, the protection requirements are different. For low renewable infeed at the distribution level, the existing relay settings are immune from any small change in the network fault current from new incoming renewables. However, bulk renewable infeed requires modification in the existing protection schemes to accommodate the fault current variation from the incoming renewables. For bulk penetration of the renewable, the requirement of modified/additional protection schemes is unavoidable. Adaptive relaying and non-adaptive relaying schemes are discussed in the literature for protection of power networks, which are experiencing dynamic fault currents and frequent changing network topologies. This article presents a detailed review of protection schemes for renewable integrated power networks which includes distribution, transmission and microgrid systems. The merits and demerits of these protection schemes are also identified in this article for the added interest of the readers. The visible scope of advance protection schemes which may be suitable for providing reliable protection for dynamic fault current networks is also explored.

348 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present a detailed technical overview of microgrid and smart grid in light of present development and future trend, including existing technical challenges, communication features, policies and regulation, etc.
Abstract: The modern electric power systems are going through a revolutionary change because of increasing demand of electric power worldwide, developing political pressure and public awareness of reducing carbon emission, incorporating large scale renewable power penetration, and blending information and communication technologies with power system operation. These issues initiated in establishing microgrid concept which has gone through major development and changes in last decade, and recently got a boost in its growth after being blessed by smart grid technologies. The objective of this paper is to presents a detailed technical overview of microgrid and smart grid in light of present development and future trend. First, it discusses microgrid architecture and functions. Then, smart features are added to the microgrid to demonstrate the recent architecture of smart grid. Finally, existing technical challenges, communication features, policies and regulation, etc. are discussed from where the future smart grid architecture can be visualized.

343 citations

Journal ArticleDOI
TL;DR: The simulation results verify that the proposed hierarchical coordination strategy is an effective and efficient way for coordinating microgrid flows in an islanded community microgrid, while maintaining the rated frequency and voltage with each microgrid.
Abstract: In this paper, a community microgrid with multiple ac and dc microgrids is introduced and analyzed. Individual microgrids with different frequency and voltage requirements would operate as self-controlled entities, which could also cooperate with neighboring microgrids for providing back-up operations in the community microgrid. A hierarchical coordination strategy with primary, secondary, and tertiary coordination is proposed for the economic operation of an islanded community microgrid. The hierarchical strategy is also applied to a grid-connected community microgrid and the results are discussed. The simulation results verify that the proposed hierarchical coordination strategy is an effective and efficient way for coordinating microgrid flows in an islanded community microgrid, while maintaining the rated frequency and voltage with each microgrid. The simulation results also demonstrate the economic operation of a grid-connected community microgrid in which individual microgrids operate as autonomous agents, while satisfying the community objectives.

304 citations


Cites background from "Adaptive Protection System for Micr..."

  • ...Droop-based hierarchical strategy which includes primary, secondary, and tertiary control is introduced to facilitate flexible and efficient operations of ac microgrids [8]–[10] and dc microgrids [11], [12]....

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References
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Journal ArticleDOI
TL;DR: Reliability indices based on frequency and duration of outages are measured at the microgrid level and the load point level, and the potential system enhancements are discussed for improving the economic operation of the IIT microgrid.
Abstract: In this paper, the application of high reliability distribution system (HRDS) in the economic operation of a microgrid is studied. HRDS, which offers higher operation reliability and fewer outages in microgrids, is applied to looped networks in distribution systems. The microgrid model in this study is composed of distributed energy resources (DER) including distributed generation (DG), controllable loads, and storage. The microgrid would utilize the local DER as well as the main grid for supplying its hourly load economically which is subject to power quality and reliability requirements. The HRDS implemented at Illinois Institute of Technology (IIT) is used as a case study along with the local DER to increase the load point reliability and decrease the operation cost of the IIT microgrid. The availability of distribution lines, main grid supply, and microgrid generation is considered using the Markov chain Monte Carlo simulation in the microgrid scenarios. The reliability indices based on frequency and duration of outages are measured at the microgrid level and the load point level, and the potential system enhancements are discussed for improving the economic operation of the IIT microgrid.

229 citations

Journal ArticleDOI
TL;DR: In this paper, the authors discuss microgrid objectives and present options for microgrid operations and their monitoring and control in the context of a functional system at the illinois institute of technology (iit) in Chicago.
Abstract: in this article, we discuss microgrid objectives and present options for microgrid operations and their monitoring and control in the context of a functional system at the illinois institute of technology (iit) in Chicago. the microgrid represents a multitier hierarchical control of self-sustaining energy infrastructure with islanding and resynchronization, self-healing, and demand response capabilities. the intelligent high-reliability distribution system (HRDS) at iit is equipped with phasor measurement units (PMUs) for real-time monitoring, nondispatchable renewable energy production, as well as conventional and dispatchable energy resources.

96 citations

Proceedings ArticleDOI
22 Jul 2012
TL;DR: The role of high reliability distribution system (HRDS) in microgrid operations is evaluated in this article, where the HRDS implemented at Illinois Institute of Technology (IIT) is used as a case study along with DER to increase the load point reliability and decrease the operation cost of the microgrid.
Abstract: Campus microgrid is composed of distributed energy resources (DER) including distributed generation (DG), controllable loads, and storage. In this paper, the role of high reliability distribution system (HRDS) in microgrid operations is evaluated. The HRDS implemented at Illinois Institute of Technology (IIT) is used as a case study along with DER to increase the load point reliability and decrease the operation cost of the microgrid.

11 citations