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Virtualization has emerged as a promising technological solution for electrical substations, driven by the convergence of information and operational technologies and the new requirements of cost efficiency and adaptability. Virtualization employs software to emulate hardware-level functionalities by means of an equivalent computing system. However, despite the promising potential that virtualization offers in driving cost efficiencies and enabling operational flexibility, there is a scarcity of techno-economic studies assessing its financial and societal impact. This paper proposes a novel, open-source cost-benefit assessment model based on net present value analysis (NPV) and system dynamics tailored to the case of protection, automation and control systems (PACs) in electrical substations. The model explores the capital expenditures (CAPEX) and operational expenditures (OPEX) of two alternatives: 1) traditional substations based on intelligent electronic devices (IEDs) and 2) virtualized PAC functions based on hardware-independent implementations deployed in virtual machines or containers. The economic model is evaluated for a 30-year simulation through comprehensive, optimistic and pessimistic scenarios of virtualization adoption as well as sensitivity analyses of relevant functional cases covering reliability, redundancy, initial costs, and virtualization roll-outs. The findings indicate that virtualization presents a promising technology for substations, leading to reductions in both CAPEX and update costs of approximately 20% and 60%, respectively, compared to traditional substations. Similarly, from a societal perspective, virtualization can offer positive key performance indicators associated with system downtime reductions and savings in power consumption and, consequently, in carbon footprint. However, the technology maturity, roll-out strategy, software licensing, and maintenance schemes can hinder the overall cost savings and affect payback periods.

This article implements and validates the performance of a virtual intelligent electronic device (vIED) framework for digital substations using a real-time (RT) simulation environment. The work looks toward the future design of protection, automation, and control systems, an evolution of the digital substation design based on IEC 61850 and virtualization technology. An RT simulation setup was developed to speed up and enhance the deployment and maintenance of vIEDs with a novel well-defined test methodology. Several scenarios were tested by varying the number of vIEDs and relevant (communication, scalability, and functionality) configuration criteria. In addition, we assessed the efficiency of a software-defined communication network for the vIED framework and its adaptability to dynamic scaling of the network under transient data traffic loads. The tests demonstrated the efficient performance of vIEDs across various system configurations, particularly for requirements on the response time and network transfer latency. The findings showcase the significance of proper design and testing methodology that can be benchmarked against other virtualization platforms for substation systems.

In the quest of an efficient smart energy management system that can fulfill the power demand of consumers, researchers are focusing on smart power system which can integrate both conventional and renewable energy resources as well as production of clean energy. As a result, the concept of Internet of Energy (IoE) is developed which is similar to the perception of Internet of Things (IoT), which supports both energy and information flow. In this study, a systematic review of the current state-of-the-art of IoE and IEC 61850 has been presented, and it has identified the research gaps and opportunities for future development. The discussion unfolds by illuminating the evolution of smart grids and IoE, shedding light on the benefits and challenges inherent in employing IEC 61850 as a communication standard for IoE. Moreover, the potential application of IEC 61850 standard for enabling IoE in smart grids has been explored. Besides reviewing the trends and challenges of IoE and its key technologies, such as energy routers, power generation equipment, and energy storage devices; it also discussed how the IEC 61850 standard can facilitate the communication and interoperability among these technologies and provide a robust and flexible platform for the IoE. The outcome of this study show that IEC 61850 has a wide range of applicability and suitability for IoE, as it can support various functions and features of IoE, such as information modeling, data exchange, plug-and-play, fault detection, and intelligent control. This study also presents some examples of IEC 61850 based IoE systems, such as energy routers, wind and solar power plants, battery storage systems, and vehicle-to-grid systems. The comparison of this study with the equivalent studies shows that this study provides a comprehensive and up-to-date overview of IoE and IEC 61850, and covers a wide range of topics and aspects of IoE and IEC 61850. This study also provides a critical evaluation of the strengths and weaknesses of IEC 61850 for IoE, and proposes some directions for future research and development.

This paper introduces an innovative adaptive scheme for detecting and locating faults in DC-zonal shipboard microgrids (SBMGs). This scheme relies on the estimation of high-frequency impedance. The proposed scheme is implemented in an intelligent electronic device (IED) in which the Fast Fourier Transform is applied to obtain the high-frequency components of the current and voltage at each node. Then, these components are exchanged between the two IEDs that protect the same line by using IEC 61850 GOOSE-based communication system. The estimated high-frequency impedance of the line is calculated and compared to the prescribed settings to detect and locate the fault. After fault detection and localization, communication signals are exchanged between the two IEDs positioned at each end of the line. This exchange precedes the transmission of tripping signals to the relevant circuit breakers for the accurate isolation of the faulty line. The proposed protection scheme is tested through MATLAB/Simulink Ⓡ environment. The scheme can detect and locate the fault under different uncertainty conditions, such as fault impedances, various system configurations, changes in system loads and generations, multi-faults’ existence, contingency conditions, and the presence of noise on the communication signals. The results proved its efficient performance and superiority. The scheme can detect and locate the faults quickly and accurately within 0.125 ms.

Smart grid technology drives economic and social development but raises vulnerability to cyber threats due to digital substations’ growing reliance. To counter these risks, recent updates to communication standards, including encryption and authentication processes, have been integrated into the infrastructure. Notably, adhering to the IEC 62351 standard governing the GOOSE protocol for substation communication faces practical challenges due to conflicting time requirements with traditional security procedures. In this paper, we present an innovative geometric approach for GOOSE message authentication and encryption. Utilizing vector coordinate shifts, our method exhibits efficiency and speed of implementation, ensuring compliance with the protocol’s stringent time constraints. Importantly, unlike other approaches in the literature, our technique has the potential to be easily applicable and effective for a wide range of infrastructures without requiring the use or addition of specific hardware components or changes to the GOOSE message format, while guaranteeing high performances and computational simplicity. The paper is complemented by a simulation campaign on a digital substation model, assessing the approach’s performance and its efficacy in countering cyber threats.

The existing Overcurrent Protection Function (OCPF) of distribution systems can be coordinated for all fault current values involving single feeders. However, it is vulnerable to Multiple Feeder Faults (MFF), which involve at least two feeders simultaneously, leading to the incoming feeder relay trip faster than the faulted feeder relays. In this case, all feeders connected to the power transformer are de-energized, even the healthy ones, directly impacting the network reliability, service quality and availability of the electricity utilities and ultimately leading to outage costs for the customers. In light of this, an IEC 61850-based OCPF scheme with the directional element is proposed to support existing OCPF to deal with MFF and encompass the integration of distributed generation, and can be directly implemented in the digital substations without requiring further equipment installation. Moreover, a hardware-in-the-loop platform is developed for testing the interoperability of the proposed scheme with multi-vendor protection relays, which can also assist electricity utilities in the validation of their protection and control schemes based on their requirements before the field implementation. Test cases are specifically elaborated to study the interoperability of the proposed scheme with three real devices—whose configuration details are also provided to aid protection engineers—in a real distribution system under different conditions such as switching operations, MFF types, resistance, location, and integration of distributed generation. The results show that the proposed scheme manages to enhance the selectivity and reliability of the digital substation protection system, hence representing a valuable complement to existing OCPF schemes.

The trend of transforming substations into smart automated facilities has led to their swift digitalization and automation. To facilitate data exchange among equipment within these substations, the IEC 61850 standard has become the predominant standard. However, this standardization has inadvertently made these substations more susceptible to cyberattacks, which is a significant concern given the confidential information that is transmitted. As a result, cybersecurity in substations is becoming an increasingly critical topic. IEC 62351 standard provides guidelines and considerations for securing the IEC 61850 messages to mitigate their vulnerabilities. While securing Generic Object-Oriented Substation Event (GOOSE) messages has received considerable attention in literature, the same level of scrutiny has not been applied to Sampled Value (SV) messages despite their susceptibility to cyberattacks and similar frame format. This paper presents the impact of replay and masquerade attacks on SV messages. It also develops a scheme for securing SV messages against these attacks. Due to high sampling rate and time critical nature of SV messages, the time complexity of security scheme is critical for its applicability to SV messages. Hence, in this work, SV emulators have been developed in order to send these modified secure SV messages and investigate their timing performance. The results show that the proposed scheme can mitigate replay and masquerade attacks on SV messages while providing the necessary high sampling rate and stringent timing requirements.

Data centres are becoming an increasingly important part of our society’s infrastructure. The number of data centres is growing constantly, making growing the gross level of electrical energy consumption. At the same time, the rapid spread of sophisticated electrical devices as well as other automation systems in general produces an opportunity for making data centres an attractive player in the constantly designing energy market. But for this, new advanced technologies must be applied to solve the problems of complexity and heterogeneity in various types of data centre design. A new concept, which is based on the automated generation of a digital twin (DT) system, directly from its schematic representation is presented in this paper. A DT is a virtual version of an object or system, designed to aid decision-making and virtual commissioning through simulation, machine learning, and reasoning. In the scope of current work, the IEC 61850 standard is chosen as a starting point for a multi-step generation of the DT combining simulation model and decentralized control logic. As a result, the designed DT “clone” of an electrical system consists of the SIMULINK model of the electrical system plus the automatically generated control application (based on the IEC 61499 standard).

The wide propagation of electric vehicle (EV) charging infrastructure integrated into the energy distribution network poses numerous challenges for the engineering and control of the latter: the load dynamic characteristics become more unsteady, requiring more advanced control, predictions, and virtual commissioning. One step toward the automation of the design and simulation of new charging stations can be reached through the integration of the EV-specific standards and protocols with other widely spread electrical standards and, thereby, improving the compatibility between standards, increasing the reuse of the intelligent work results, and promoting the development of EVs’ infrastructure. A method for virtual commissioning of electrical charging stations is proposed, implemented, and tested in a form of a software tool in which the electrical system description from the widely used IEC 61850 standard is used as an input. The designed tool builds a digital twin of the charging station that consists of its Simulink model as well as two automatically generated communication code primitives using the open charge point protocol for control and management purposes over the autogenerated model. The generated digital twin can be used for virtual commissioning purposes. The application of the method is illustrated in a case study.

Programmable Logic Controllers (PLCs) are essential components for enabling remote monitoring and automated control in industrial control systems. Recently PLCs are often utilized in a modernized power grid system for implementing an additional layer of automated control, such as operation of circuit breakers under specific conditions. Thus, in order to create a software-based smart grid testbed (or ‘cyber range’ for cyber security experiments); emulation of the PLC is imperative. OpenPLC is a software widely used for emulating PLCs, but unfortunately it does not support IEC 61850 standard, which is the globally adopted standard for substation automation in smart power grid systems. Thus, in this paper, the enhancement of OpenPLC to support IEC 61850 protocol and information models is discussed. The performance of the implementation has been validated to corroborate its application for use cases in the smart grid paradigm. Subsequently, the implementation is demonstrated in a smart grid cyber range to evaluate the impacts of attacks and thereby, the effectiveness of security measures and robustness of PLC control logic. The implementation, named ‘OpenPLC61850’, is made available as an open-source project for the wider research and industry community.

The state-of-the-art digital signatures incur undesirable delays, hence are impractical for time-stringent Industrial Control Systems (ICSs). The recent revision to IEC 62351–6 standard stepped back from digital signatures in favor of symmetric key based solutions, thereby sacrificing key properties, e.g., scaling well for multiple destinations, easy key distribution and management, public verifiability, and non-repudiation. Inspired by the Online/Offline signatures, this paper presents a new digital signature model to provide the key properties of digital signatures within the delay requirements, hinting that this step back can be avoided. The Online/Offline signatures concept divides the signature generation into two phases; offline (before the message is given), online (using the outputs of the former for faster signing after the message is given). The conventional solutions following this concept potentially reduce the delay, yet do not meet IEC 61850 delay requirements as they still involve expensive operations in the online phase, and their offline phase hinders throughput. This paper introduces Less-online/More-offline Signatures (LoMoS) to enable minimal end-to-end delay and high message throughput. LoMoS entails avoiding expensive operations entirely during the online phase. We present a construction that converts any digital signature scheme into LoMoS, retains its properties, and unlike existing solutions, benefits from shorter messages. [ABSTRACT FROM AUTHOR]

According to the IEC 62351-7 standard, data collection using network and system management (NSM) can be used to support the security monitoring of the smart grid. In this article, an NSM security monitoring platform for a realistic IEC 61850 substation model is developed using the specifications provided in IEC 62351-7. In the developed model, grid measurements are ready to take operative decisions, whereas collected NSM data are leveraged to detect cyberattacks and/or identify anomalies. The model includes power components (e.g., transformers, lines, and generators), controllers (e.g., voltage control), protection devices (e.g., overcurrent, distance, differential, and under/overvoltage), communication protocols (e.g., sampled value and generic object-oriented substation event), and NSM (e.g., agents and managers) applications. Moreover, a two-step deep learning framework is proposed for anomaly detection and cyberattack identification with enhanced accuracy. The first step can apply long short-term memory, recurrent neural network, and gated recurrent units, each in combination with an autoencoder. Then, the ensemble learning technique is used in the second step to augment the outputs of these deep learning models. To evaluate the effectiveness of the proposed cyberattack and anomaly detection framework, we detail and simulate potential cyberattacks targeting the performance of the IEEE 9-bus system. The proposed anomaly detection scheme can identify these threats using NSM data in a hardware-in-the-loop testbed. Finally, based on our assessment results, recommendations are provided for cybersecurity guidelines concerning IEC 62351-7. [ABSTRACT FROM AUTHOR]

Information and Communications Technology (ICT) supports the development of novel control and communication functions for monitoring, operation, and control of power systems. However, the high-level deployment of ICT also increases the risk of cyber intrusions for Supervisory Control And Data Acquisition (SCADA) systems. Attackers can gain access to the protected infrastructures of the grid and launch attacks to manipulate measurements at the substations. The fabricated measurements can mislead the operators in the control center to take undesirable actions. The Intrusion Detection System (IDS) proposed in this paper is deployed in IEC 61850 based substations. The proposed IDS identifies falsified measurements in Manufacturing Messaging Specification (MMS) messages. By cross-checking the consistency of electric circuit relationships at the substation level in a distributed manner, the falsified measurements can be detected and discarded before the malicious packets are sent out of the substations through DNP3 communication. A cyber-physical system testbed is used to validate the performance of the proposed IDS. Using the IEEE 39-bus test system, simulation results demonstrate high accuracy of the proposed substation-based intrusion detection system.

Sensing and monitoring electrical signals and power device parameters within the smart grid network infrastructure plays a fundamental role in assessing the smart devices’ proper functioning. Nevertheless, a key challenge for academic teaching and researching purposes is the elevated cost of real electronic devices, such as current and potential transformers, or even intelligent electronic devices. Therefore, traffic emulators are a valuable solution for the evaluation of new smart grid communication proposals. In this work, we propose TITAN, a tool to support the evaluation of automation systems’ communication networks. TITAN enables the emulation of IEC 61850 communication, ranging from data sensing to data acquisition, thus supporting extensive research and development on this fundamental smart grid domain. This tool can interact and communicate with real elements, such as intelligent electronic devices. It enables the emulation of voltage and current data sensing communication, as well as the implementation of different data acquisition schemes by an emulated supervisory system. Our main contributions are: (i) TITAN, a tool with a distributed microservices architecture to execute communication traffic generation tasks; (ii) a user-friendly interface to integrate and manage all components; and (iii) a proof of concept testbed using TITAN and real teleprotection devices. Real case studies using TITAN reveal its feasibility in supporting low-cost testbeds for research, teaching, and testing purposes in sensing and acquisition for automation systems.

International Electrotechnical Commission (IEC) 62351-6 standard specifies the security mechanisms to protect real-time communications based on IEC 61850. Generic Object Oriented Substation Events (GOOSE) and Sampled Value (SV) messages must be generated, transmitted and processed in less than 3 ms, which challenges the introduction of IEC 62351-6. After evaluating the security threats to IEC 61850 communications and the state of the art in GOOSE and SV security, this work presents a novel architecture based on wire-speed processing able to provide message authentication and confidentiality. This architecture has been implemented and tested to evaluate its performance, resource usage, and the latency introduced. Other proposals in the scientific literature do not support real-time traffic, so they are not suitable for GOOSE and SV messages. Whereas the others exceed the target latency of 3 ms or do not comply with the standards, our design authenticates and encrypts real-time IEC 61850 data in less than 7 $\mu$ s—predictable latency—, and complies with IEC 62351:2020.

Smart grid refers to the advancement of the current electric grid with the help of information and communication technologies. In such scenarios, an efficient and secure smart grid communication system is essential. Accordingly, Software-Defined Networks (SDN) have been gaining more prominence for smart grids in recent years, as this paradigm allows monitoring and managing these communication networks efficiently. An example is the Autonomic and Resilient Framework for Smart Grids (ARES). ARES allows integration between the supervisory system and the SDN controller, allowing for better energy applications. Although ARES emphasizes the need for security as a premise for its implementation, it does not provide a concrete implementation of this aspect. In this work, we provide an extensive review of the related literature about Authentication, Authorization, and Accountability (AAA) for smart grids, classifying approaches according to several relevant characteristics. We further propose 3AS, extending the ARES framework with a security component based on the IEEE 802.1X standard. 3AS has been implemented on the Ryu SDN controller and evaluated in an emulated environment. Results indicate 3AS successfully provides authentication, authorization, and accountability with low control load and delay, thus being suitable for diverse smart grid scenarios.

Modernisation of substations using digital-based Substation Communication Networks (SCN) enables the automation of substations, allowing effective and efficient monitoring of substation equipment and implementing complex control and protection schemes. The IEC 61850 standard for SCN’s objective is to integrate substation devices from different vendors, enabling peer-to-peer communication between the devices. The reliability investigation of the IEC 61850 based SCN architecture continues since it is left to the system designer to determine based on the network’s applications and functions. In all endeavours to designing highly available SCN architectures, redundant systems are employed in mission-critical applications. In this paper, the impact of Common Cause Failures (CCF) and the quality of repairs on the reliability performance of IEC 61850 based architecture are investigated using the Markov process and Linear Dynamical Systems, where the diagnostic coverage level of the system is based on the ISO 13849-1. The results of the case studies indicate that common engineering design and coupling factors have a negative impact on the system reliability performance, notably for systems with high diagnostic coverage. The results also indicate that the factors have less impact when the system diagnostic coverage is low, specifically at low repair efficiency levels. However, the impact becomes more pronounced as the repair efficiency increases, as observed from the responses of the transition probability matrix’s eigenvalue magnitudes. Thus, it is critical to ensure the minimum impact of common engineering design and coupling factors by diversifying the system’s subsystems to ensure a high independence level.

With the deployment of advanced information and communication technologies (ICT) the legacy power grid is being transformed as smart grid. However, the extensive use of ICT makes it vulnerable to cyberattacks. Standardization of power system communication with interoperable protocols has many benefits and at the same time the standardized semantics makes it much more vulnerable to cyberattacks. IEC has published a new standard IEC 62351 which provides the security guidelines for securing power system communication against cyber-attacks. In this paper, the cybersecurity considerations for IEC 61850 Manufacturing Message Specification (MMS) messages as per the IEC 62351-4 standard are discussed in detail. Further, the implementation of IEC 62351-4 security specifications for MMS messages are demonstrated through experiments in lab.

Communication-assisted protection and self-healing control (CAPSC) is perceived as a new alternative to ensure reliable operation of distribution networks (DNs) because of its prominent advantages of information sharing. Although the application of CAPSC based on IEC 61850 has been verified in substations, it has not yet been effectively promoted in DNs. To fully exert its advantages in DNs, a novel scheme of IEC 61850-based CAPSC is proposed in this paper. The proposed scheme enable samplings to be synchronized by propagation delay compensation without external clocks. Adaptive execution algorithms of protection and self-healing control are introduced considering changeable topology and configuration conditions. The coordination between protection and self-healing control in this scheme is simplified by component state descriptions instead of event signals. The scheme proposed in this paper has been incorporated in an engineering field application. A closed-loop test has been conducted on a real-time digital simulator (RTDS) according to the field connections and parameters to verify the rationality and effectiveness of the proposed scheme.

Integration of distributed renewable energy sources in microgrids presents many challenges to grid such as voltage, stability and power management issues. In literature different control strategies to improve the performance of microgrids integrated with renewable energy sources proposed. FACTS based controller such as Unified Power Flow Controller (UPFC) has also been employed in microgrids to improve the power management and transient stability. Coordinated control strategies between UPFC controller and DERs have been developed. However, the underlying communication for realizing these strategies has not been discussed. This paper presents IEC 61850 and XMPP based communication for coordinating UPFC and DERs in microgrid for its stable operation. IEC 61850 information model for UPFC controller is developed. Furthermore, the XMPP protocol is utilized to provide the scalability for communication network in microgrids with high penetration of DERs. Additionally, XMPP also provides improved security along with the scalability. IEC 61850 message exchanges over XMPP communication between different components of microgrid for power management is demonstrated.

As the number of electric vehicles and PhotoVoltaic (PV) panels per household increases, the need for a coordination between these active components becomes more imminent. Home energy management systems (HEMS) have been proposed to increase efficiency, renewable energy capture and reduce costs for the owners. However, renewable energy is intermittent and time dependent. To increase the capture of this source, an integrated control with Electric Vehicle (EVs) is required to store excessive solar energy. Furthermore, coordination with the load profile enables storage for use at a later time or selling the excess energy to the grid. This requires the use of a Home Energy Management System (HEMS) that can coordinate all these components with the grid. Operation of these controllers need to be validated before actual deployment. In this paper, a standardized communication modeling based on IEC 61850 is developed for a HEMS controller. An integrated emulation platform using network simulator and IEC 61850 Intelligent Electronic Devices (IEDs) emulator is set up and the operation of HEMS is demonstrated with proper message exchanges. Such validation is crucial to project's success before on-site deployment.

Smart parking lots are smart places capable of supporting both parking and charging services for electric vehicles (EVs). In order to manage EV charging, the parking lot local controller (PLLC) requires data exchange with EV charging stations (EVCSs) through communication infrastructures. However, data losses and communication delays are unavoidable and may significantly degrade the system performance. This work aims to investigate the underlying communication networks for remote monitoring of EVCSs in a smart campus parking lot. The communication network consists of two subnetworks: parking area network (PAN) and campus area network (CAN). PAN covers communication among EVs, charging stations and PLLC, while CAN enables dedicated communication between PLLCs and a global controller of the university. As one of the major obstacles in EV system is the lack of unified communication architecture to integrate EVCS in the power grid, we develope communication models for the in-vehicle system and EVCSs based on logical node concept of IEC 61850 standard. Furthermore, we implement network models for EVCSs using OPNET modeler. Different communication technologies and configurations are considered in modeling and simulations, and end-to-end delay is evaluated and discussed.

A significant component in electrical power systems are substations, in which the substation communication network is essential. Due to the evolving nature of communication protocols, and the introduction of the IEC 61 850 standard, substation communication networks can provide fast and reliable information transmission. Such improvements in transmission allow for improved protection and control of the power system network. A well-designed substation communication network can be achieved with the use of appropriate modeling, and as a result, this paper aims the review the methods in which parts of, or the entire substation communication network can be modeled. Modeling methods aim to determine various parameters of a substation communication network design, which include the traffic load distribution, and various message delays under different network conditions that may be experienced. In order for modeling to be carried out, a general structure of a substation communication network must be defined, which is laid out by the IEC 61 850 standard. The findings of the review in this paper show that there are various methods in which a substation communication network can be modeled, which include analytical modeling, software-based modeling, hardware/experimental modeling, and time-series based modeling. However, each method enables for different parameters to be found, with some of the methods having drawbacks including a limited network model size, and inability to find certain necessary parameters. The methods reviewed in this paper can be used and expanded on to create useful and accurate models of a substation communication network.

Emerging power system protection and control applications require faster-responding measurements and more accurate knowledge of the actual latency of the measurement and communications systems. A new method for accurately determining the reporting latency of a phasor measurement unit (PMU) has been developed and demonstrated. This method operates in real-time, works passively for any existing PMU without requiring changes to the PMU hardware or software, and it is very accurate-providing a measurement uncertainty of

With the integration of Distributed Energy Resources (DERs) into the distribution networks, the Active Distribution Network Management is becoming quite challenging. The DERs are integrated into the distribution networks through distribution substations. For achieving greater control and ease of operation substations are being automated by employing substation communication network based on standardized communication. IEC 61850 standard has emerged as the most popular standard due to its object-oriented modeling and interoperability features. To ensure smooth and efficient operation of substation automation system, the performance requirements for intra substation communication needs to be evaluated. This paper presents modelling of data traffic in the substation according to IEC 61850 and provides validation through simulation as well as through experimental setup. In the experimental setup, a real bay is replicated in the laboratory for performance validation. The scheme has been validated for VLAN and priority tagging implementation with the obtained simulation results.

There is growing awareness towards cybersecurity threats in power systems. IEC 61850 standard facilitates communication between different Intelligent Electronic devices (IEDs) and eases interoperable operation with set data and message structures. An unwanted consequence of this standardized communication over ethernet is increased viability to cyber threats. The IEC 62351-6 standard stipulates the use of digital signatures for ensuring integrity in IEC 61850 message exchanges. However, the digital signatures result in higher computational times which makes it very difficult to use for Generic Object-Oriented Substation Events (GOOSE) messages. This short communication article proposes implementation of the Message Authentication Code (MAC) algorithms, such as Hash-based Message Authentication Code (HMAC) and Advanced Encryption Standard-Galois Message Authentication Code (AES-GMAC), for GOOSE message integrity. Lab tests are run to observe their timing performances and feasibility for GOOSE.

There is growing awareness towards cybersecurity threats in power systems. Deployment of more intelligent electronic devices (IEDs) and the communication lines increase the probability of such attacks. IEC 61850 standard facilitates communication between different IEDs and eases interoperable operation with set data and message structures. An unwanted consequence of this standardized communication over ethernet is increased viability to cyber threats. Replay and masquerade attacks are, especially, of concern due to their imminent impact on the operation. While detecting replay attacks is easier, since the original messages are used for the attack, masquerade attack messages may be difficult to distinguish from original ones. Furthermore, inadequate mitigation approaches may be tricked by the hackers and the system starts the attacker as the authentic sender and discards original messages from authentic sources. It is vital to develop an approach that incorporates message authentication. In this fashion, when the hackers modify the message contents to by-pass security systems, the tampering can be detected, and the messages will be discarded. This paper analyses replay and masquerade attacks on IEC 61850 GOOSE messages and develops a solution to mitigates both of those. To detect modified messages, two distinct authentication mechanisms are utilized: RSA since it is the algorithm stipulated in IEC 62351-6 and Elliptic Curve Digital Signature Algorithm (ECDSA) due to its widespread use in smartgrid cybersecurity solutions. A full solution to mitigate GOOSE replay and masquerade attacks is developed based on the proposed framework in IEC 62351 standard. Full implementation is tested in the lab and results are included to show the viability of the solution.

Multi-agent-based smart grid applications have gained much attention in recent times. At the same time, information and communication technology (ICT) has become a crucial part of the smart grid infrastructure. The key intention of this work is to present a comprehensive review of the literature and technological frameworks for the application of multi-agent system (MAS) and ICT infrastructure usages in smart grid implementations. In the smart grid, agents are defined as intelligent entities with the ability to take decisions and acting flexibly and autonomously according to their built-in intelligence utilizing previous experiences. Whereas, ICT enables conventional grid turned into the smart grid through data and information exchange. This paper summarizes the multi-agent concept of smart grid highlighting their applications through a detailed and extensive literature survey on the related topics. In addition to the above, a particular focus has been put on the ICT standards, including IEC 61850 incorporating ICT with MAS. Finally, a laboratory framework concepts have been added highlighting the implementation of IEC 61850.

Distribution lines are generally protected by overcurrent relays. With the integration of an inverter-interfaced solar photovoltaic (PV) plant having a current-limiting feature, the fault current seen by the relay on the PV side of that feeder becomes comparable to the load current. The conventional overcurrent relaying principle is not suitable for distribution line protection. Distance relay may be a viable option for protection of distribution lines connecting the solar PV plant. However, positive- and negative-sequence source impedances of the PV plant depend on an inverter controller, which results in limited performance of fixed setting distance relay. This article proposes an adaptive distance relay setting to protect distribution line connecting the PV plant, using prefault voltage and current data at the relaying point. The method calculates positive- and negative-sequence PV source impedances for boundary setting of distance relay at the PV side. The proposed trip boundary is modified adaptively with the change in prefault conditions of the PV plant. Performance of the proposed method is tested for different control strategies and operating capacities of the PV plant and variation in the grid source impedance on a 34-bus distribution system. Real-time application of the proposed method is validated in hardware-in-the-loop using OPAL-RT simulators with IEC 61850 as the communication protocol and found to be accurate. [ABSTRACT FROM AUTHOR]

This paper proposes an original Smart-Grid test bed aimed at teaching the IEC 61850 standard to students and professionals. It includes emulation of medium voltage loads and generators, with a supervisory control and data acquisition system. With this test bed, lab classes focused on the setup and configuration of protection relays using semantics of xml language are proposed. For this, GOOSE services and their functionalities are taught and tested with experiments involving real cases. The presented lab classes are part of a dedicated complete pedagogic module comprising lectures and experiments. Through the development, the test and the deployment of their own solutions in an actual distribution grid, the students learn by integrating theory and practice through the complete chain of Smart-Grid solutions: from the electrical to the communication layers. [ABSTRACT FROM AUTHOR]

HVDC technologies are widely acknowledged as one of solutions for the interconnection of renewable energy resources with the main electric power grid. The application of the latest modular multi-level converter (MMC) makes power conversion much more efficient. Due to the relatively low impedance in a DC system, DC fault currents may rise to an extremely high level in a short period of time, which can be very dangerous for HVDC converters. To improve the sustainability and security of electricity transmission, protection solutions for HVDC systems are being developed. Nevertheless, they have various drawbacks on fault signal detection and timely clearance. This paper proposes a protection method that provides a fast and reliable solution addressing those drawbacks. A protection algorithm based on travelling wave simulation and analysis is proposed to detect abrupt transient signals. The algorithm shows high efficiency, reliability, selectivity and has low sampling frequency requirements. The proposed protection method has been validated through a cyber-physical simulation platform, developed using a real-time digital simulator (RTDS) and IEC 61850 communication links. The obtained results show that the proposed method has good potential for practical applications. [ABSTRACT FROM AUTHOR]

Accurate fault location reduces operating cost and outage time. This paper proposes a time-domain method to accurately locate faults in transmission lines, which only requires a very short data window (several milli-seconds) during faults. First, the voltage distribution through the line during faults is accurately obtained by solving the matrix form partial differential equations using the proposed numerical scheme. The proposed numerical scheme is mathematically validated for the transmission line fault location problem, with the optimal selection of time and distance intervals to ensure stability and minimum solution error. Afterwards, the fault location is obtained via the extremum value of the voltage distribution. The method fully considers distributed parameters as well as asymmetry of the line. Extensive numerical experiments validated that (a) the proposed numerical scheme demonstrates advantages towards other numerical schemes; (b) the proposed method presents higher fault location accuracy compared to the existing method, independent of fault types, locations and impedances; and (c) the fault location accuracy is not sensitive towards fault inception angles, loading conditions, measurement errors and parameter errors. The proposed method works with relatively low sampling rates (80 samples per cycle) and is compatible with IEC 61850 standard in present digital substations. [ABSTRACT FROM AUTHOR]

In this paper, we use hyper-network methods to identify the critical elements of a cyber-physical system (CPS) under data attack according to IEC 61850. The related works are introduced first, such as cyber offensive tools, procedures, and data attack models. Some definitions of a hypergraph are presented. Then, considering the functional attributes of logical nodes, a hyper-network model of substation auto system (SAS) is proposed using hyper-graph theory. On this basis, a CPS model that takes into account the functional influence after data attack is established. In addition, combined with the analysis of the network model, the efficiency indexes are given to evaluate the effectiveness of the CPS under data attack. The reasons why we choose these indexes in network and hyper-network model are also explained. Finally, the analysis in the case study illustrates that the method proposed is helpful for identifying critical elements of the CPS, which provides a new avenue for future vulnerability analysis research.

The future energy networks are envisioned to be green and clean with high penetration of renewable energy-based generators. The most promising type is solar energy which has immense potential around the globe. Solar home systems (SHSs) with rooftop solar panels are proliferating in urban cities as well as in distant rural areas. Possible interaction of SHS with utility grid will result in dynamic power flow which is a huge challenge for power utility authorities and consumers. The smart meters (SMs) are being deployed to make this possible through bi-directional energy and information exchange. In order to address this need, this paper develops the communication models of SHS and SM based on the IEC 61850 standard. These models provide standardized approach to these technologies and facilitate a series of functionalities, such as power flow control, demand response, and other ancillary services, using configured message exchange. The detailed models, their use cases and the messages are studied in detail. Furthermore, extensive simulations are run with riverbed modeler to investigate the dynamic performance. IEC 61850-based models of SHS and SM are implemented, message frames are developed according to use cases, and the functionalities mentioned earlier are run as scenarios. Finally, the performances of different communication technologies have been analyzed to estimate their adequacy for smart grid implementations.

Electric vehicles (EVs) can act as flexible resources in grid due to their bidirectional power transfer capabilities. In microgrids, the bidirectional power transfer capability of EVs through proper scheduling can be utilized to improve reliability, security, and quality of supply. Optimal scheduling of EVs is generally managed and controlled through the energy management system of microgrid. Since microgrid energy management (EM)-based scheduling of EVs is data driven, an effective communication between different actors of EM is required. This paper presents a IEC 61850 communication-based EM in microgrids with integrated EVs. Furthermore, augmentation of existing IEC 61850-90-8 logical nodes of EV and its related equipment with new data objects to include information exchanges for discharging operation of EVs have been proposed. Finally, in this paper, XMPP-based communication approach and its mapping to the service models for EM problem has been demonstrated.

Smart grid is the nexus of advanced information and communication technologies and legacy power systems. With increasing awareness on the vulnerabilities of smart grids to cyberattacks, cybersecurity is becoming a prime concern. Earlier, it was assumed that the power system communication protocols are very specialized and different, so the “security by obscurity” approach would be sufficient. However, with the standardization of communication protocols for power utilities and the emergence of the power market, this approach is no longer valid. IEC 62351 Standard has been published to provide security recommendations for different power system communication protocols including IEC 61850. IEC 61850 is emerging as the most promising and popular power system communication standard. Therefore, in this article, a detailed analysis of security threats, possible attacks, and security requirements for IEC 61850 communication is presented. Building on this, the security considerations presented in IEC 62351 for securing different IEC 61850 messages, such as generic object-oriented substation events (GOOSE), sampled values (SV), routable-GOOSE, routable-SV, and manufacturing message specification messages have been presented in great detail. [ABSTRACT FROM AUTHOR]

Automation in power generation, distribution and transmission has advanced from a semi-automated to fully autonomous approach. This work presents some of the implementations of a transmission and distribution transformer monitoring model for the creation of a management system of these assets, whose topology was elaborated based on IEC 61850. The implementation incorporates the creation of two new LN ' s,: (B) - Diagnosis of the Degradation of the Isolation System of Transformers; (E) - Life Expectancy of the Isolation System of Transformers, post asset recovery action. In order to subsidize the structure of the new LN's Groups, a pilot asset management system was implemented for two transformers from Copel Transmissão e Distribuição (Pilarzinho Substation in Curitiba, Paraná). In this work two new LN's were proposed for groups (B) and (E) respectively: "Degradation of the Transformer Isolation System (paper-oil) - BIOP", and "Remaining Utility Life of the Transformer Insulation System - ELTR ". These LNs were used in the experimental electronic area (IEDs) of the pilot project area, using the Hadrom Xtorm Remote Terminal Unit (ALTUS, IEC 61850 compatible) and evaluated and validated in the field. [ABSTRACT FROM AUTHOR]

In electrical power systems, the overcurrent relays (ANSI/IEEE 50/51) are widely used for protection, and it is one of the main alternatives for identifying system faults. In radial systems supplied by a single source, protection and selectivity can be achieved using the traditional techniques based on time-current curves coordination. However, in a system with multiple sources and operational conditions, traditional techniques are not sufficient to obtain selectivity. This paper presents an adaptative protection system which, based on IEC 61850, adjusts the protection to changes in the power system. The proposal uses a communication network to change the overcurrent settings according to the sources in operation. The performance of the proposed system was evaluated in a case study. The system is composed of five independent power supplies, a utility and four cogeneration units with different rated power; thus 15 combinations of sources are possible during islanding conditions. The results demonstrate that the proposal can provide the selectivity of the system in any operational condition. [ABSTRACT FROM AUTHOR]

This paper presents a power swing detection algorithm in multi-machine power systems, which uses wide-area synchrophasor measurements and is based on Zubov’s stability boundaries. Zubov’s boundary method, an approximation of the famous Lyapunov function, is very common for numerical analyses of power system stability. This work extends the concept of Zubov’s approximation boundaries to online protection applications. First, the proposed protection algorithm constructs a series of Zubov’s stability boundaries on power angle–frequency ($\delta$ – $\omega$) plane for generators based on real-time measurements from phasor measurement units/merging units. Then, it tracks the trajectory of each generator in the $\delta$ – $\omega$ plane after the disturbance to differentiate out-of-step (OOS) conditions from stable swings. The proposed approach is suitable for online applications, which is a significant improvement over the existing methods for swing detection since it does not require offline studies and network reduction. Effectiveness of the proposed method is shown using a single-machine infinite bus and New-England 10-machine 39-bus systems. The proposed method is also implemented in a hardware-in-the-loop setup with a customized IEC 61850-based OOS relay, and performance is compared with a commercially available relay. [ABSTRACT FROM AUTHOR]

Combined real-time hardware-in-the-loop simulations and modeling of communication networks (co-simulation platforms) is a powerful testbed for development and validation of relay protection schemes utilizing communication links especially for applications in Smart Grids. This paper introduces laboratory tests in such environment of a new protection scheme for medium voltage networks with distributed generation. It is based on impedance measurements with compensation of remote infeed currents and high fault resistances. Since the scheme utilizes multi-terminal measurements, a communication network emulator has been developed to model Ethernet network impairments. The test method uses Monte-Carlo approach for evaluation of protection dependability. The results demonstrate enhancement of impedance relay performance compared to the conventional protection. Moreover, fault location capability is preserved with sufficient accuracy. Nevertheless, communication network imperfections, such as jitters and data loss, deteriorate scheme functionality. [ABSTRACT FROM AUTHOR]

IEC 61850 is poised to be the communication standard of the future power networks. Due to its historical evolution, it focuses on substation automation and modeling its entities. There have been recent extensions in the standard's modeling to include other grid equipment as well as distributed generators. However, the configuration of the communication network, as it is outlined in IEC 61850-6, is very substation-focused and cannot be used for microgrids. The microgrid network is a wide-area network with multiple distributed generations (DGs) cannot be configured in a manner similar to a substation communication network detailed in IEC 61850-6. This is because the enhanced system configuration description language (SCL) files cannot be exchanged with each DG while this is not an issue for substation modeling. Also, this would result in multiple copies of enhanced SCL files and is not feasible to implement. Thus, there is a need to develop a process for configuring IEC 61850 based communication networks at the microgrid level. This paper proposes a central configurator and a step-by-step configuration procedure for modeling microgrids according to IEC 61850. Such a configurator assists in connecting IEDs in different locations and updates the system with the new deployment. The process is shown with a centralized microgrid protection scheme by employing a microgrid-level system configurator. [ABSTRACT FROM AUTHOR]

Contrary to reliability analysis in power systems with the main mission on safely and securely withstanding credible contingencies in day-to-day operations, resilience assessments are centered on high-impact low probability (HILP) events in the grid. This paper proposes an autonomous load restoration architecture founded on IEC 61850-8-1 GOOSE communication protocol to engender an enhanced feeder-level resilience in active power distribution grids. Different from the past research on outage management solutions, most of which 1) are not resilience-driven; 2) are reactive solutions to local single-fault events; and 3) do not address both network built-in flexibilities and flexible resources. The proposed solution harnesses 1) the imported power and flexibility from the neighboring networks; 2) distributed energy resources; and 3) vehicle to grid capacity of electric vehicles aggregations to enhance the feeder-level resourcefulness for agile response and recovery. Through real-time self-reconfiguration strategies, the suggested solution is capable of coping both single and subsequent outage events, and will engender a heightened resilience before and during the contingency period. Moreover, a resilience evaluation framework, which quantifies the contribution of all resources involved in service restoration, is developed. Real-time performance of the designed architecture is evaluated on a real-world power distribution grid using a real-time hardware-in-the-loop platform. Numerical case studies through a number of diverse scenarios demonstrate the efficacy of the proposed restoration solution in practicing an enhanced resilience in power distribution systems in response to HILP scenarios. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This article presents a communications test rig based on a customized intelligent electronic device (IED) for its use in a laboratory-scale microgrid. The laboratory setup for this article uses the following three types of subsystems: distributed energy resources DERs (solar, wind), energy storage (batteries), and loads (active, reactive, linear, and nonlinear). A Raspberry Pi computer, using the Linux operating system, allows programming the algorithms needed by the communications platform. The protocol employed for data exchange, between the different subsystems and the central supervisor module, is the IEC 61850 standard. Three experimental test cases serve to show the proposed IEDs performance. The first test transfers data between a solar source and a client station. The second test transfers data, in distributed mode, between four nodes associated to different generation sources. The last test shows a secondary control using two experimental inverters operating in parallel connection. The IEDs communicate the compensating values for regulating frequency and voltage in the system composed of a master and one or more slave inverters. [ABSTRACT FROM AUTHOR]

Recent developments in renewable energy and information technology (IT) fields made it easier to set up power systems at a smaller scale. This proved to be a turning point for developing first-access electricity systems for the underserved locations around the world. However, there are planning and operation challenges due to lack of past data on such places. Deployment of Internet-of-Things (IoT) devices and proliferation of smart infrastructures with additional sensors will lead to tremendous opportunities for gathering very useful data. For different stakeholders to access and manage these data, trusted and standardized mechanisms need to be in place. Storing proper data in a well-structured common format allows for collaborative research across disciplines, large-scale analytics, and sharing of algorithms and methodologies, in addition to improved customer service. Data standardization plays a more vital role in the context of electricity access in the underdeveloped countries, where there is no past data on generation or consumption as in utility grids. Data collected in a standard structure, being it for a short period of time, facilitate learning from the past experiences, monitoring the current projects, and delivering better results in the future endeavors. It will result in ways to better assist consumers and help the industry operate more efficiently by sharing data with different stakeholders. It can also enhance competition, thus making electricity accessible faster and to more people. The focus of this article is data standardization for first-access electricity systems, in general, and renewable energy-based microgrids, in particular. Different data sources and ways that the corresponding data can be exploited, technological and capacity constraints for storage of data, political and governance implications, as well as data security and privacy issues, are examined. This article is relevant to different stakeholders, such as investors, public utilities, nongovernmental organizations (NGOs), and communities. Using the data standardization approach developed here, it is possible to create a much-needed first-access electricity system database. This will provide an important resource for project developers and energy companies to assess the potential of a certain unelectrified site, estimating its demand growth in time and establishing universal control systems that can seamlessly communicate with different components. [ABSTRACT FROM AUTHOR]

Microgrid protection schemes require a fast, reliable, and a robust communication system, to adjust relay settings for the appropriate current levels according to the microgrid's operation mode. However, risks of communication link failures and cyber security threats are major challenges for the implementation of protection scheme. This paper presents a co-simulation platform for microgrid based on multiagent system (MAS) when the communication is available in the system. IEC 61850 is used to emulate the proposed protection scheme. The data distribution service (DDS) middleware is used to link between the hardware and software environments. During islanded mode, the system is capable of riding-through communication failures by the aid of a lithium-ion battery. When the communication is attacked, the battery plays an important role and contribute to the fault current for helping the circuit breaker to trip during islanded mode. The design of the control algorithm for the battery's ac/dc converter is developed with single mode operation to eliminate the reliance on communicated control command signals to shift the controller between different modes. [ABSTRACT FROM AUTHOR]

Electrical substations play a crucial role in power grids. A number of international standards, such as IEC 60870 and 61850, have emerged to modernize substations for efficient and timely control. However, owing to insufficient security consideration and implementation, the digitization of a large number of connected substations could dramatically increase the scale of damage on power grids caused by cyber attacks. In this paper, we discuss the practical design, implementation, and deployment of active command mediation defense (A*CMD), a distributed cybersecurity solution to counter attacks injecting malicious remote control commands. A*CMD takes advantage of artificial command-delaying to realize an additional layer of security for each substation in an autonomous, decentralized manner. In particular, for grid operators to make appropriate delay configuration, the procedure to find tolerable delay for a power grid model of interest is formulated and demonstrated with multiple power grid models of different sizes. We further show practical deployment options of A*CMD along with proof-of-concept implementations, whose performance and stability are evaluated with a software-based smart-grid testbed. [ABSTRACT FROM AUTHOR]

Intermittency of renewable energy resources makes reactive power management a challenge in microgrids. Since standards do not recommend the use of distributed energy resources (DERs) for voltage regulation and reactive power management in microgrids, therefore, traditionally, locally controlled Distribution STATic COMpensators (DSTATCOM) are widely used. The management of reactive power requirement in microgrids can be improved through communication-based coordinated operation of DERs and DSTATCOM. To make this communication standardized and interoperable, this paper presents modeling of DSTATCOM as per IEC 61850 and an eXtensible Message Presence Protocol (XMPP) for providing scalability and information security. The mapping of IEC 61850 Abstract Communication Service Interface services over MMS ASN.1 XER (XMPP—web protocol) to transform the basic MMS type message into an XML message for their use in XMPP communication is also demonstrated. [ABSTRACT FROM AUTHOR]

IEC 62351-6 standard stipulates the use of digital signatures for ensuring integrity and authenticity in IEC 61850 Generic Object-Oriented Substation Events (GOOSE) message exchanges. Yet, it does not specify any method for ensuring confidentiality in GOOSE messages. With rapid growth of IEC 61850 from substation automation to power management domain, sensitive data that requires privacy is carried over GOOSE messages. In this letter, a novel method employing Authenticated Encryption with Associated Data (AEAD) algorithms is proposed to achieve both confidentiality and integrity of GOOSE messages. Further, lab tests are run to observe the timing performance and applicability of these algorithms to GOOSE messages with strict timing requirements. [ABSTRACT FROM AUTHOR]

The smart grid (SG) approach is based on a strong interaction between the network communication infrastructure and the power grid. Usually the management of the infrastructure is done by the distribution system operators (DSOs) that are worried about the increasing managing complexity due to the presence of increasing number of distributed energy resources and electrical vehicles. The use of software-defined networking (SDN) may simplify the network configuration and management for DSO, as highlighted from previous research works. The objective of this paper is to introduce and characterize an internet protocol (IP)-based communication architecture with specialized SDN bridges operating also over narrowband power line communication (PLC) to reach the last mile applications (e.g., smart meters and inverters). The feasibility of this approach depends on the communication performance of the supervisory level used to dynamically configure the SDN bridges. The characterization of this level is done using the following performance indicators: the round trip time (RTT), the packet loss (PL) ratio, and the actual IP throughput. The experimental results show the feasibility of the proposed architecture, since the limitations are given only by the physical implementation of the PLC modem. In detail, results of the case study show that the minimum RTT is on the order of 30 ms, the PL ratio is always less than 1.7% and the maximum throughput is of 95 Mbit/s, fully compatible with the requirements of the applications. [ABSTRACT FROM AUTHOR]