The Smart Grid Simulation Framework: Model-Driven Engineering Applied to Cyber-Physical Systems

Guest Editorial

Smart grid is a cyber-physical system with a high level of complexity due to its decentralized infrastructure. IEC 61850 and IEC 61499 are two industrial standards that can address the challenges introduced by the smart grid on the substation automation level. Development of smart grid automation software is a very time-consuming process due to the need to address many requirements and a high degree of customization in every new substation, which limits the adoption of such smart grid technologies in digital substations. This article aims at addressing this limitation by applying a semiformal boilerplates (BPs) model of functional requirements originally presented in informal natural language. The BPs are then modeled formally in an ontology for model-driven engineering (MDE) model transformation. The contribution of this article is the development of the semiformal and formal BP representation in the form of ontology to formulate smart grid requirements and demonstrating how functional requirements can be translated to IEC 61499 control codes using MDE to autogenerate an IEC 61499 protection and control system with structure and control flow. The MDE framework augmented with the requirement models is illustrated in a case study from the International Council on Large Electric Systems representing different stages of modeling in the proposed framework.

Analysis of information flow security in cyber–physical systems

A survey on applications of Alternating Direction Method of Multipliers in smart power grids

Smart grids are electric networks that employ advanced monitoring, control, and communication technologies to deliver reliable and secure energy supply, enhance operation efficiency for generators and distributors, and provide flexible choices for prosumers. Smart grids are a combination of complex physical network systems and cyber systems that face many technological challenges. In this paper, we will first present an overview of these challenges in the context of cyber-physical systems. We will then outline potential contributions that cyber-physical systems can make to smart grids, as well as the challenges that smart grids present to cyber-physical systems. Finally, implications of current technological advances to smart grids are outlined.

Smart grids are electric grids that utilize advanced technologies of monitoring, control, and communication to supply reliable and secure energy, improve the efficiency of the system, and provide flexibility to the prosumers. The beginning of the smart grid era and the development in modern infrastructures of metering, communication, and energy storage have revolutionized the power grid. Smart grids are developed with complex physical networks and cyber systems thus enabling smart grids for the Internet of Energy (IoE). IoE is the cloud where sources of power generation and loads of power consumption are embedded with intelligence. Modern electric power grids are integrated with sensors used to provide measurements. The sensor measurements and the complex applications of various sensors cause a need for Cyber-Physical System (CPS). CPS is a class of systems that integrates physical process, computation, and networking. The CPS model of the smart grid helps in modeling and simulation for evaluation of the system performance and characteristics. The CPS model of the smart grid must enable the smart grid to be robust, 2allow future extensions, and compatible with web service technologies. The power generation sources and loads such as smart buildings are the physical layers, the sensors used for measurements form the cyber-physical integration and the data storage and processing using IOE forms the cyber layer of the smart grid. The CPS model of the smart grid helps in the integration of intelligent devices and allied information and communication technologies for robust and reliable operation in smart grids. In the smart grid paradigm, the energy management system has a vital role to increase the efficiency and reliability of the system. This chapter presents a CPS model for smart grid and the challenges associated with the development of the CPS model. In addition, this chapter describes the energy management system model of the smart grid.

The improvement of renewable energy sources exploitation is a central topic of the present studies in the energetic field. One of the main obstacles to the renewable energy increase in the global energetic mix is represented by the fluctuating nature of renewable power sources. The power fluctuations are cause of stress for the electric grid to which the individual nodes are connected. A wider exploitation of renewable power is possible through the implementation of a “smart grid”, constituted by an interconnection of several smart nodes consisting in a user and a renewable source. To reduce the stochastic effects of the renewable energy source it is possible to introduce in the nodes composing the smart grid an energy storage, finalized to smooth the power peaks, rending the node itself less disturbing for the electric grid. This paper presents a simulation model of a smart node, consisting in a user power profile, a photovoltaic panel, an electric vehicle and a battery. Through the simulation model it is possible to evaluate the node effect on the electric grid, with a quantitative approach. Tests were worked out in different node configurations: basic (the only user power profile), basic with photovoltaic panel, basic with storage, basic with panel and storage and finally the complete configuration including also the electric vehicle. The tests were repeated for a domestic and an industrial user to evaluate the size influence over the parameters of interest

Smart grid and distributed generation should be the solution of the global climate change and the crisis energy of the main source of electrical power generation which is fossil fuel. In order to meet the rising electrical power demand and increasing service quality demands, as well as reduce pollution, the existing power grid infrastructure should be developed into a smart grid and distributed power generation which provide a great opportunity to address issues related to energy efficiency, energy security, power quality and aging infrastructure systems. The conventional of the existing distributed generation system is an AC grid while for a renewable resources requires a DC grid system. This paper explores the model of smart DC grid by introducing a model of smart DC grid with the stable power generation give a minimal and compressed circuitry that can be implemented very cost-effectively with simple components. The PC based application software for controlling was developed to show the condition of the grid and to control the grid become ‘smart’. The model is then subjected to a severe system perturbation, such as incremental change in loads to test the performance of the system again stability. It is concluded that the system able to detect and controlled the voltage stability which indicating the ability of power system to maintain steady voltage within permissible rangers in normal condition.

Securing cyber-physical systems (CPS) like the Smart Grid against cyber attacks is making it imperative for the system defenders to plan for investing in the cybersecurity resources of cyber-physical critical infrastructure. Given the constraint of limited resources that can be invested in the cyber layer of the cyber-physical smart grid, optimal allocation of these resources has become a priority for the defenders of the grid. This paper proposes a methdology for optimizing the allocation of resources for the cybersecurity infrastructure in a smart grid using attack-defense trees and game theory. The proposed methodology uses attack-defense trees (ADTs) for analysing the cyber-attack paths (attacker strategies) within the grid and possible defense strategies to prevent those attacks. The attack-defense strategy space (ADSS) provides a comprehensive list of interactions between the attacker and the defender of the grid. The proposed methodology uses the ADSS from the ADT analysis for a game-theoretic formulation (GTF) of attacker-defender interaction. The GTF allows us to obtain strategies for the defender in order to optimize cybersecurity resource allocation in the smart grid. The implementation of the proposed methodology is validated using a synthetic smart grid model equipped with cyber and physical components depicting the feasibility of the methodology for real-world implementation.

Cyber-physical systems (CPS) are aimed at combining the physical system with the cyber ones to provide a better control and improve the management of physical systems around us. Recently, the CPS and its applications, e.g., health-care and smart grid, have gained attention of the research community. In this paper, we consider the privacy aspect of users in a CPS, particularly in smart grid system as our use-case, and provide a mechanism that utilizes the advances in network coding to maintain data privacy. We address privacy issues associated with gathering metering information of clients in a smart grid system. In smart grid systems, wireless multi-hop communications are mainly used to gather metering information through exchanging data and control messages between smart meters and the utility. We argue that any communication paradigm used in a smart grid should support all aspects of privacy such as anonymity, unlinkability, unobservablity, and undetectablity. We propose innovative schemes for traffic routing and encryption that benefit from the enhanced network coding technology. Our analysis shows that our schemes maintain privacy of users despite the possibility of detecting metering data by an adversary. In addition, our scheme has extra favorable features such as less computation complexity, reliable, and robust communication.

Energy problem is the important basis of sustainable development and it also relates to state security. To speed up the development of energy construction and to safeguard the supply of energy is one of the most important goals of construction and development of economy in China. As the problem of energy becomes more and more serious, renewable energy has caused high attention by our country and the world which has also become one of the key development strategies in China. At present the use ratio of renewable energy will become higher as fossil energy dry up gradually. Before significant breakthrough in energy utilization technology renewable energy will take place of fossil fuels gradually and becomes the important energy to support human lives. Micro grid is one of the ways to make use of distributed renewable sources and will be the key technology for smart grid construction in the future. How to make planning for smart gird including micro grid scientifically and reasonably is the challenging task for grid planning personnel.

Cyber-Physical Systems (CPS) are infrastructures with capabilities of perception, networking, and computation. They consist of physical and virtual components that interact with their environment. Their main goal is to monitor the physical system in real-time to have its behavior under control. Some of these infrastructures require well-defined security measures due to their critical processing capabilities. Digital Twins are defined as virtual structures emulating the physical components in various systems. They enable the deployment of isolated simulation environments to test changes and specify the security issues of a CPS. One of the main applications of CPS is smart grids. Microservices allow us to create fine-grained operations on automation systems. Using small, well-defined, modular processes, we can observe the states of smart grid infrastructure in many stages. In this work, we aim to design a framework that can create a reliable environment for smart grids compliant with existing industrial standards. We propose a service-oriented digital twins framework consisting of entities such as power meters, data aggregators, and system parameters for providing a scalable and highly available platform for complex energy systems.

As a result of the old-style electric grid's inability to handle the extensive incorporation of renewable energy resources and distributed renewable energy resources into the electric grid. In the twenty-first century, smart grid technology has entered the picture. Because smart grids operate on two-way communication, communication and information technology are critical to the smart grid's effective operation. The advanced version of the smart grid structure is presented in this article. Furthermore, this article discusses existing and advanced communication and information technology. Finally, the manuscript discusses future research advancements in communication and the most crucial information technologies, such as the Internet of Things (IoT), cloud computing, fog and edge computing, and blockchain in the smart grid. So, the smart grid can manage the massive integration of renewable energy resources while providing customers with efficient, sustainable, and reliable power.KeywordsIoT-Internet of ThingICT-Information and Communication TechnologyCC: Cloud Computing

Explainability can help cyber-physical systems alleviating risk in automating decisions that are affecting our life. Building an explainable cyber-physical system requires deriving explanations from system events and causality between the system elements. Cyber-physical energy systems such as smart grids involve cyber and physical aspects of energy systems and other elements, namely social and economic. Moreover, a smart-grid scale can range from a small village to a large region across countries. Therefore, integrating these varieties of data and knowledge is a fundamental challenge to build an explainable cyber-physical energy system. This paper aims to use knowledge graph based framework to solve this challenge. The framework consists of an ontology to model and link data from various sources and graph-based algorithm to derive explanations from the events. A simulated demand response scenario covering the above aspects further demonstrates the applicability of this framework.

Cyber physical systems (CPSs) utilised in many of the critical infrastructures including the smart grid. The operational activities of smart grid's CPS use different industrial solution such as industrial control systems (ICS) for monitoring and controlling the physical architecture of smart grid. Therefore, it is quite essential to keep these industrial control systems secure and safe from potential hazards and cyber world as it may be harmful for human safety, strategic infrastructure of a country and also for the economy. The study gathered the scattered guidelines, best practices and policies available from various organisations such as National Institute of Standards and Technology (NIST), ISO, and North American Electric Reliability Corporation (NERC) for the purpose of developing safe and secure ICS security systems and also the knowledge about the issues involved in ICS security and protection. A conceptual framework is proposed and developed to address the shortcomings in-order to protect the ICS systems in a smart grid environment. The proposed framework was developed by reviewing related studies, standards and utilising IT security working experience. This framework will not only expand the horizon of knowledge but also provides pathway for the development of existing activities of CPS applications such as smart grid.