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Internet-of-Things concepts are evolving the power systems to the Energy Internet paradigm. Microgrids (MGs), as the basic element in an Energy Internet, are expected to be controlled in a cooperative and flexible manner. This article proposes a novel distributed control scheme for multiagent systems (MASs) governed MGs in future Energy Internet. The control objectives are frequency/voltage restoration and proportional power sharing. The proposed control scheme considers both intra- and inter-MASs interactions, which offers group plug-and-play capability of distributed generators. The stability and communication delay issues in the control framework are analysed. A multisite implementation framework is presented to explain the agent architecture as well as data exchange in local area networks and the cloud server. Then a cyber hardware-in-the-loop experiment is conducted to validate the proposed control method with multisite implementation. The experimental results prove the effectiveness and application potentials of the proposed approach. [ABSTRACT FROM AUTHOR]

The electric energy demand will increase in the future, and the will to exploit larger amounts of generation from renewable resources requires the development of new strategies to manage a more complex electrical system. Different techniques allow the smart management of distribution networks such as load shifting, peak shaving, and short-term optimization. This work aims to test, in a real low-voltage (LV) active network (LV test facility of Strathclyde University of Glasgow), a Microgrid Smart Energy Management System, which adopts a two-stage strategy. The two levels of the proposed energy control system are composed of: 1) midterm controller that, according to weather, load, and generation forecasts, computes the profile of the controllable resources (generation, load, and storage), the dispatch problem is then solved through an optimization process; and through 2) short-term controller, which controls the power absorption of the active network. This procedure is hierarchically designed to dispatch the resources/loads, according to priority signals with the objective to contain the energy consumption below predetermined thresholds. The scalability and effectiveness of the architecture, which is validated in a real test bed, demonstrates the feasibility of implementing such a type of controller directly connected to the LV breakers, delivering a part of a real smart grid. [ABSTRACT FROM PUBLISHER]

Inverter-dominated microgrids impose significant challenges on the distribution network, as inverters are well known for their limited contribution to fault current, undermining the performance of traditional overcurrent protection schemes. This paper introduces a new protection scheme based on the initial current traveling wave utilizing an improved mathematical morphology (MM) technology, with simplified polarity detection and new logics introduced for meshed networks and feeders with single-end measurement. The proposed protection scheme provides ultrafast response and can be adapted to varied system operational modes, topologies, fault conditions, and load conditions. Only low-bandwidth communication is required to achieve high-speed operation and adequate discrimination level in meshed networks. Simulation in PSCAD/EMTDC verifies both the sensitivity and stability of the proposed protection scheme under different microgrid operational scenarios. [ABSTRACT FROM PUBLISHER]

Communications is becoming increasingly important to the operation of protection and control schemes. Although offering many benefits, using standards-based communications, particularly IEC 61850, in the course of the research and development of novel schemes can be complex. This paper describes an open-source platform which enables the rapid prototyping of communications-enhanced schemes. The platform automatically generates the data model and communications code required for an intelligent electronic device to implement a publisher-subscriber generic object-oriented substation event and sampled-value messaging. The generated code is tailored to a particular system configuration description (SCD) file, and is therefore extremely efficient at runtime. It is shown here how a model-centric tool, such as the open-source Eclipse Modeling Framework, can be used to manage the complexity of the IEC 61850 standard, by providing a framework for validating SCD files and by automating parts of the code generation process. The flexibility and convenience of the platform are demonstrated through a prototype of a real-time, fast-acting load-shedding scheme for a low-voltage microgrid network. The platform is the first open-source implementation of IEC 61850 which is suitable for real-time applications, such as protection, and is therefore readily available for research and education. [ABSTRACT FROM PUBLISHER]

Distributed control and optimization strategies are a promising alternative approach to centralized control within microgrids. In this paper, a multi-agent system is developed to deal with the distributed secondary control of islanded microgrids. Two main challenges are identified in the coordination of a microgrid: (i) interoperability among equipment from different vendors; and (ii) online re-configuration of the network in the case of alteration of topology. To cope with these challenges, the agents are designed to communicate with physical devices via the industrial standard IEC 61850 and incorporate a plug and play feature. This allows interoperability within a microgrid at agent layer as well as allows for online re-configuration upon topology alteration. A test case of distributed frequency control of islanded microgrid with various scenarios was conducted to validate the operation of proposed approach under controller and power hardware-in-the-loop environment, comprising prototypical hardware agent systems and realistic communications network. [ABSTRACT FROM AUTHOR]