Microgrid (MG) is a cyber-physical system with coupled power and communication networks. The centralized secondary control of MGs with periodical communications restricts system efficiency and resilience. This paper proposes a distributed event-triggered secondary control scheme in islanded MGs with its cyber-physical implementation. The proposed control scheme operates with reduced frequency of communications depending on the MG states change 'events' (e.g. load variations and communication failures). Besides, the secondary control objectives, including frequency/voltage regulation and accurate real/reactive power sharing, are decoupled into two timescales. Instead of designing eventtriggering conditions (ETCs) for each secondary control functions, only ETCs for power sharing control in slower timescale are designed. Thus, the communication burden is significantly reduced since communications among neighbour controllers are only needed at the event-triggered time. The proposed controller has been tested on a hardware-in-the-loop (HIL) platform, where the physical system is modelled in OPAL-RT and the cyber system is realized in Raspberry Pis. The control effectiveness is validated by the HIL results. 1 Index Terms-distributed event-triggered control, cyberphysical systems, microgrids, hardware-in-the-loop, raspberry pi.

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 corporative and flexible manner. This paper proposes a novel distributed control scheme for multi-agent 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 (DGs). The stability and communication delay issues in the control framework are analysed. A multi-site 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 (C-HiL) experiment is conducted to validate the proposed control method with multi-site implementation. The experimental results prove the effectiveness and application potentials of the proposed approach. 1

Smart grid systems are characterized by high complexity due to interactions between a traditional passive network and active power electronic components, coupled using communication links. Additionally, automation and information technology plays an important role in order to operate and optimize such cyber-physical energy systems with a high(er) penetration of fluctuating renewable generation and controllable loads. As a result of these developments the validation on the system level becomes much more important during the whole engineering and deployment process, today. In earlier development stages and for larger system configurations laboratory-based testing is not always an option. Due to recent developments, simulation-based approaches are now an appropriate tool to support the development, implementation, and rollout of smart grid solutions. This paper discusses the current state of simulation-based approaches and outlines the necessary future research and development directions in the domain of power and energy systems.

In the context of smart grid development, this paper considers the problem of interoperability of micro-grid platforms, particularly among research institutions. Various levels of interoperability are introduced with the respective requirements. The primary aim of the paper is to propose a suitable private hybrid cloud based SCADA architecture satisfying various necessities in the framework of interoperability of micro-grid platforms while maintaining security restriction conditions. Due to the limited time restriction of critical SCADA functions in the electrical grid (protection, real time control, etc.), only selected non-critical SCADA functions (back-up, data historian, etc.) are accessible to partners from the private cloud. The critical SCADA tasks functionality remains under control of local server, thus, a hybrid cloud architecture. Common Information Model (IEC 61970 and IEC 61968, CIM/XML/RDF) is proposed to be used as model for information exchange. The communication model is based on PaaS delivery model and OPC Unified Architecture (OPC UA) specifications are considered. OPC gateway is proposed as conversion between the old OPC Distributed Common Object Model (DCOM) protocol and the Simple Object Access Protocol (SOAP) for cloud.