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This study emphasizes the urgent need for systems that monitor the operational states of primary electrical equipment, particularly power transformers. The rapid digitalization of and increasing data volumes from substations, coupled with the inability to retrofit outdated equipment with modern sensors, underscore the necessity for algorithms that analyze the operational parameters of digital substations based on key power system metrics such as current and voltage. This research focuses on digital substations with Architecture III and aims to develop an algorithm for processing digital substation data through an appropriate mathematical tool for time-series analysis. For this purpose, the fast discrete wavelet transform was chosen as the most suitable method. Within the framework of the research, possible transformer faults were divided into two categories by the nature of their manifestation. A mathematical model for two internal transformer fault categories was built. The most effective parameters from the point of view of the possibility of identifying an internal fault were selected. The proposed algorithm shows its effectiveness in the compact representation of the signal and compression of the time series of the parameter to be monitored. [ABSTRACT FROM AUTHOR]

The paper raises a variant of architecture of realization of logical line protection on the basis of implementation of modern technologies. The idea of development and implementation of digital substations, the core of which is the application of IEC 61850 standard, has been developing at a great pace in the world. The appearance of this standard in substations opens new ways of realization of protection of electrical installations. In this article we consider the method of construction of line protection using the method of logical selectivity, and as the main terminals are considered Sepam devices series 1000+, as one of the most widely distributed devices in the electric power industry of the Russian Federation, the basic support for the standard IEC 61850.

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.

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.

Industrial Control Systems (ICS) are increasingly integrated with Information Technology (IT) systems, blending Operational Technology (OT) and IT components. This evolution introduces new cyber-attack risks, necessitating specialized security measures like Intrusion Detection Systems (IDS). This paper presents our work on both developing an experimental protocol and conducting tests of various IDS types in a digital substation hardware in the loop (HIL) testbed, offering insights into their performance in realistic scenarios. Our findings reveal significant variations in IDS effectiveness against industrial-specific cyber-attacks, with IT-specific IDSs struggling to detect certain attacks and changing testlab conditions affecting the assessment of ICS-specific IDSs. The challenges faced in creating valid and reliable evaluation metrics underscore the complexities of replicating operational ICS conditions. This research enhances our understanding of IDS effectiveness in ICS settings and underscores the importance of further experimental research in HIL testlab environments. [ABSTRACT FROM AUTHOR]

This study emphasizes the urgent need for systems that monitor the operational states of primary electrical equipment, particularly power transformers. The rapid digitalization of and increasing data volumes from substations, coupled with the inability to retrofit outdated equipment with modern sensors, underscore the necessity for algorithms that analyze the operational parameters of digital substations based on key power system metrics such as current and voltage. This research focuses on digital substations with Architecture III and aims to develop an algorithm for processing digital substation data through an appropriate mathematical tool for time-series analysis. For this purpose, the fast discrete wavelet transform was chosen as the most suitable method. Within the framework of the research, possible transformer faults were divided into two categories by the nature of their manifestation. A mathematical model for two internal transformer fault categories was built. The most effective parameters from the point of view of the possibility of identifying an internal fault were selected. The proposed algorithm shows its effectiveness in the compact representation of the signal and compression of the time series of the parameter to be monitored.

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RELEVANCE. Recently, along with the initial scope of synchronized vector measurements (synchrophasor) technology associated with Wide Area Measurement System (WAMS), more and more attention is paid to expanding the scope of this technology. Digital substations are one of the places for generating synchrophasor signals, at the same time, synchrophasor data are proposed to be used for the purposes of relay protection and automation at the digital substations itself, which will facilitate the construction of centralized relay protection systems at the substation. THE PURPOSE. Consider the use of synchrophasor technologies at a digital substation of the fourth type, as a replacement for Sampled Values (SV) signals. Consider additions to the standard set of synchrophasor signals necessary for the operation of various relay protections at a digital substation. Perform an analysis of the accuracy of calculating the synchrophasor when the frequency of the controlled current and voltage changes relative to the nominal value, when higher harmonics appear in the measured signal. Develop a pre-computation technique for relay protection algorithms. METHODS. When solving the problem, the method of calculating the total measurement error of the synchrophasor TVE (Total Vector Error) was used - a value that characterizes the deviation of the amplitude and phase of the measured vector from their specified values. CONCLUSION. The use of synchrophasor signals with the necessary additions for the operation of relay protection reduces the load on the digital network of the digital substation, simplifies the operation of relay protection algorithms. Calculations have shown that the measurement errors of synchrophasor do not go beyond the specified parameters. The proposed methods of precomputation allow to speed up the work of relay protection algorithms.

The development of modern power systems is directly related to changes in the traditional principles of management, planning, and monitoring of electrical modes. The mass introduction of renewable energy sources and control devices based on power electronics components contributes to changing the nature of the flow of transient and quasi-established electrical modes. In this area, the problem arises of conducting a more accurate and rapid assessment of the parameters of the electrical regime using synchronized vector measurement devices. The paper presents an extensive meta-analysis of the modern applications of phasor measurement units (PMUs) for monitoring, emergency management and protection of power systems. As a result, promising research directions, the advantages and disadvantages of the existing approaches to emergency management, condition assessment, and relay protection based on PMUs are identified. [ABSTRACT FROM AUTHOR]

Modern power systems are rapidly transitioning towards a fully digital substation paradigm. Based on the IEC 61850, a common communication protocol between the different intelligent electronic devices (IEDs) promises a significant enhancement in terms of efficiency and interoperability. In this context, synchronization represents a crucial aspect as it allows us to rigorously compare measurements taken at the same time in different locations. In this paper, we consider a measurement chain for synchrophasor estimation based on digital inputs: an instrument transformer, a stand-alone merging unit (SAMU) and a phasor measurement unit (PMU). Both the SAMU and the PMU are equipped with independent synchronization sources. In case the SAMU loses its synchronization, the final measurement result would be considered invalid until a complete restoration of the SAMU synchronization status. In view of a longer continuity of operation, this paper proposes an alternative approach to evaluate the PMU Time Quality in real-time. This approach allows for continuing crucial monitoring and control operations, such as state estimation and fault detection, even in the presence of temporary loss of synchronization. A characterization, in both simulated and experimental conditions, proves the potential and reliability of the proposed approach. In the considered test case, the come-back within a sufficient time quality is correctly detected in less than 200 s, while waiting for the full restoration of the SAMU time reference would cost several minutes.

The issues of introduction of electrical digital substations in the Russian Federation are considered. An existing criteria analysis for assessing the modern relay protection devices efficiency is carried out and an assessment of their sufficiency is made. A mathematical model development of the digital substations relay protection complexes operation has been developed using the queuing theory, the graphs theory and Markov chains. The failure-free operation probability calculated value of the relay protection complexes corresponds to the long-term analysis data. This indicates that the mathematical model is correct. The proposed mathematical model makes it possible to take into account the impact of the maintenance quality on the digital substation relay protection complexes efficiency.

In various domains such as energy, manufacturing, and maritime, cyber–physical systems (CPSs) have seen increased interest. Both academia and industry have focused on the cybersecurity aspects of such systems. The assessment of cyber risks in a CPS is a popular research area with many existing approaches that aim to suggest relevant methods and practices. However, few works have addressed the extensive and objective evaluation of the proposed approaches. In this paper, a standard-aligned evaluation methodology is presented and empirically conducted to evaluate a newly proposed cyber risk assessment approach for CPSs. The approach, which is called FMECA-ATT&CK is based on failure mode, effects and criticality analysis (FMECA) risk assessment process and enriched with the semantics and encoded knowledge in the Adversarial Tactics, Techniques, and Common Knowledge framework (ATT&CK). Several experts were involved in conducting two risk assessment processes, FMECA-ATT&CK and Bow-Tie, against two use cases in different application domains, particularly an autonomous passenger ship (APS) as a maritime-use case and a digital substation as an energy-use case. This allows for the evaluation of the approach based on a group of characteristics, namely, applicability, feasibility, accuracy, comprehensiveness, adaptability, scalability, and usability. The results highlight the positive utility of FMECA-ATT&CK in model-based, design-level, and component-level cyber risk assessment of CPSs with several identified directions for improvements. Moreover, the standard-aligned evaluation method and the evaluation characteristics have been demonstrated as enablers for the thorough evaluation of cyber risk assessment methods. [ABSTRACT FROM AUTHOR]

Link for citation: Sushkov V.V., Sukhachev I.S., Sidorov S.V. Development of a comprehensive approach to diagnosing the overhead line faults location in single-phase ground faults based on a digital substation data processing algorithm. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 7, рр. 66-77. In Rus. Relevance. Emergency of electric complex of outgoing transmission lines is associated with the occurrence of damage to the line isolation and the resulting transients, marked by the presence of higher harmonic components of currents and voltage, which reduce the reliability and energy efficiency of electrical equipment of oil and gas companies: degrade the mechanical characteristics and efficiency of electric motors, accelerate aging of their isolation, disrupt the operation of control systems and emergency automatics, fault diagnostics systems. One of the reasons of high-level emergency situations, outages and emergency repairs in electric complexes of outgoing transmission lines of oil and gas companies is appearance of phase-to-ground faults. A large number of changing factors are known to influence the reliability of phase-to-ground fault location methods: parameters of transmission line operating mode, its structural and electrical parameters, fault type, transient resistance value, ground resistance and others. Inclusion in the transmission line fault location algorithms of averaged values of a number of the factors listed above independent of changes of humidity of soil and air, its temperature and other factors causes an error of methods of fault location up to 30 %. Accordingly, the research to develop a fault location method for overhead transmission lines with isolated neutral points during phase-to-ground faults based on a digital substation data processing algorithm, accounting for tower parameters and natural-climatic factors, is relevant. Objective: improving the reliability of power grids and providing consumers with power of the required standard by applying a digital fault location system to the outgoing transmission lines electrical complex. Methods: mathematical analysis of a power transmission line, taking into account its design features and natural-climatic factors on the basis of the method of mirror images; mathematical analysis of steady-state and transient modes of transmission line operation considering self and mutual parameters terms of wires; transmission line currents and voltages Fourier analysis; validation of developed method of phase-to-ground fault location in power grid of Tyumen region energy company. Results. The authors have developed the phase-to-ground faults location method for transmission lines in power grids with isolated neutral points, which differs in the following – first the faulty overhead line feeder branch is identified by correspondences between the negative sequence voltage values of the phase voltages at the transformer substation inputs, and then the distance to the location of the single-phase ground fault is determined along the branch line based on the resonant frequencies of the line taking into account its design features and natural and climatic factors.

Modern power systems are rapidly transitioning towards a fully digital substation paradigm. Based on the IEC 61850, a common communication protocol between the different intelligent electronic devices (IEDs) promises a significant enhancement in terms of efficiency and interoperability. In this context, synchronization represents a crucial aspect as it allows us to rigorously compare measurements taken at the same time in different locations. In this paper, we consider a measurement chain for synchrophasor estimation based on digital inputs: an instrument transformer, a stand-alone merging unit (SAMU) and a phasor measurement unit (PMU). Both the SAMU and the PMU are equipped with independent synchronization sources. In case the SAMU loses its synchronization, the final measurement result would be considered invalid until a complete restoration of the SAMU synchronization status. In view of a longer continuity of operation, this paper proposes an alternative approach to evaluate the PMU Time Quality in real-time. This approach allows for continuing crucial monitoring and control operations, such as state estimation and fault detection, even in the presence of temporary loss of synchronization. A characterization, in both simulated and experimental conditions, proves the potential and reliability of the proposed approach. In the considered test case, the come-back within a sufficient time quality is correctly detected in less than 200 s, while waiting for the full restoration of the SAMU time reference would cost several minutes. [ABSTRACT FROM AUTHOR]

Network human operators’ decision-making during grid outages requires significant attention and the ability to perceive real-time feedback from multiple information sources to minimize the number of control actions required to restore service, while maintaining the system and people safety. Data-driven event and alarm management have the potential to reduce human operator cognitive burden. However, the high complexity of events, the data semantics, and the large variety of equipment and technologies are key barriers for the application of Artificial Intelligence (AI) to raw SCADA data. In this context, this paper proposes a methodology to convert a large volume of alarm events into data mining terminology, creating the conditions for the application of modern AI techniques to alarm data. Moreover, this work also proposes two novel data-driven applications based on SCADA data: (i) identification of anomalous behaviors regarding the performance of the protection relays of primary substations, during circuit breaker tripping alarms in High Voltage (HV) and Medium Voltage (MV) lines; (ii) unsupervised learning to cluster similar events in HV line panels, classify new event logs based on the obtained clusters and membership grade with a control parameter that helps to identify rare events. Important aspects associated with data handling and pre-processing are also covered. The results for real data from a Distribution System Operator (DSO) showed: (i) that the proposed method can detect unexpected relay pickup events, e.g., one substation with nearly 41% of the circuit breaker alarms had an ‘atypical’ event in their context (revealed an overlooked problem on the electrification of a protection relay); (ii) capability to automatically detect and group issues into specific clusters, e.g., SF6 low-pressure alarms and blocks with abnormal profiles caused by event time-delay problems.

In this paper, we provide an approach for analyzing cyber security threats and attacks in digital substations, which is based on several steps we performed within our work on two Research Council of Norway (RCN) projects. In the literature, there are various separate or theoretical concepts to understand and follow a security analysis of smart grids in general, but none is focused specifically on digital substations. Moreover, none is showing real applicability on an existing use case, making the implementation difficult. The approach we propose here is a result of our attempts to create a comprehensive overview of the individual steps we have been taking to do the analysis. For that reason, firstly, we start with defining and explaining a digital substation and its concepts, and the security challenges related to digital substations. Afterwards, we present the main steps of the security analysis for digital substation. The first step is the security pyramid. The following steps are threat analysis, threat modeling, risk assessment and the simulation impact analysis, which are another contribution from our group presented in this paper. Considering that the main goal of a security analysis is to create awareness for the stakeholders of digital substations, such an impact simulation provides a flexible way for stakeholders to see and to understand the consequences of security threats and attacks. We summarize the paper with an illustration of the steps we are taking in the form of the approach for digital substation. [ABSTRACT FROM AUTHOR]

The development of modern power systems is directly related to changes in the traditional principles of management, planning, and monitoring of electrical modes. The mass introduction of renewable energy sources and control devices based on power electronics components contributes to changing the nature of the flow of transient and quasi-established electrical modes. In this area, the problem arises of conducting a more accurate and rapid assessment of the parameters of the electrical regime using synchronized vector measurement devices. The paper presents an extensive meta-analysis of the modern applications of phasor measurement units (PMUs) for monitoring, emergency management and protection of power systems. As a result, promising research directions, the advantages and disadvantages of the existing approaches to emergency management, condition assessment, and relay protection based on PMUs are identified.

The digitization of electrical substations brings great challenges for the commissioning of electrical protections, and interoperability tests must be performed with different equipment. Therefore, this work evaluates the response time of an electrical protection relay operating with sampled values in a digital substation with a process bus. A test scheme is proposed to emulate the process bus based on analyzing the main components in a digital substation with multi-vendor device interoperability. In addition, the delay times of the protection relay with the process bus are measured, considering interoperable infrastructure as a fundamental factor in the system performance. The results are compared with the response times of a conventional relay that operates with analog signals to identify the impact of the digitalization of signals in electrical substations with a process bus. Each relay has an instantaneous overcurrent function adjusted to operate with the same pickup currents at different fault current levels. The results show that tripping times are admissible for the operation of the protection relays, considering three-time measuring points in the test scheme. The time delays found are related to high data traffic in the communication network and the traffic saturation according to the time measuring point. Other delays related to processing SVs in an MU do not represent a risk for the protection scheme. For the industry, the methods presented in the research are useful for configuring and testing electrical substations with different equipment and topologies. In addition, the results presented here seek to generate confidence in companies and engineering teams when migrating to systems with digital substations. [ABSTRACT FROM AUTHOR]

The electric power industry digital transformation features and the intelligent electronic devices (IEDs) introduction in the low-voltage circuits of power stations and substations are considered. The analysis of normative documents and standards is carried out. The features of scheduled maintenance of relay protection and automation devices are determined, the possibilities and prospects of organizing condition-based maintenance are considered. The mandatory steps required for any type of maintenance are defined. A method for checking the electrical and time characteristics of the overcurrent protection of an intelligent electronic device is proposed. The device is designed in accordance with the IEC-61850 standard and operates in the local area network of a digital substation of architecture III.

The digital transformation of electrical substations relies on the communication protocols introduced in the IEC Std 61850. In particular, the Sampled Value data format is expected to be employed in an ever-increasing number of measurement applications and devices. In this context, National Metrological Institutes are required to develop calibration infrastructures capable of dealing with synchronous analog and digital input and output channels. In this paper, we characterize the performance of the METAS calibrator in terms of transmission latency and publishing rate stability. In particular, we discuss the feasibility of meeting the stringent requirements of meterological applications even in a non real-time operating system. To this end, an enhanced software library and measurement procedure are introduced. The proposed results confirm the quasi-deterministic behavior of the calibrator and proves its refined precision and stability with respect to commercial devices. [ABSTRACT FROM AUTHOR]

This work presents a novel use case with Time-Sensitive Networks (TSN) for implementing a deterministic system allowing the joint transmission of all substation communications over the same Ethernet-based infrastructure. This approach streamlines the transition to Smart Grid by simplifying the typically complex architecture of electrical substations, characterized by multiple field buses and bridging devices. Thus, Smart Grid represents a disruptive innovation advancing substations to an “all-digital” environment with a uniform interface to access, manage, and update their communications and variables. TSN can serve as its underlying foundation as it is based on open, interoperable standards and enhancements for Ethernet that can establish deterministic communications with bounded end-to-end latency. This is shown with a TSN Proof of Concept (PoC) in a real-life substation that can integrate its most usual signals: digitized analog triggers for critical events or interlocks, GOOSE signaling (IEC 61850), and Best-Effort “Internet-like” traffic. This TSN PoC is shown to be versatile enough to propagate digitized critical events around 160 μs earlier than legacy substation equipment while preserving the integrity of background traffic. Furthermore, its flexibility was characterized in-depth in controlled laboratory tests, thereby confirming TSN as a viable alternative for supporting Smart Grid so long as the appropriate configuration is supplied.

The article describes the digital relay protection devices features for electric power equipment. A technical description is given and the main conclusions of the test operation of the Digital Substation software and hardware complex are presented. A method for simulation modeling of a decentralized relay protection system with digital protocol communication is proposed. The presented model takes into account the layout of the real complex of protection. The model can be used when checking the correctness of the functioning of existing devices. The method can be used to build new digital protection algorithms that comply with IEC 61850.

The article discusses an economical way to deploy diagnostic monitoring systems for high-voltage electrical units through a combination of passive fiber-optic systems for collecting and transmitting technological information of SCADA with diagnostic information transmission systems of systems for continuous technical diagnostics in them. The usage of existing communication network of SCADA will increase economy and expand the scope of continuous diagnostic systems.

The digital transformation of electrical substations relies on the communication protocols introduced in the IEC Std 61850. In particular, the Sampled Value data format is expected to be employed in an ever-increasing number of measurement applications and devices. In this context, National Metrological Institutes are required to develop calibration infrastructures capable of dealing with synchronous analog and digital input and output channels. In this paper, we characterize the performance of the METAS calibrator in terms of transmission latency and publishing rate stability. In particular, we discuss the feasibility of meeting the stringent requirements of meterological applications even in a non real-time operating system. To this end, an enhanced software library and measurement procedure are introduced. The proposed results confirm the quasi-deterministic behavior of the calibrator and proves its refined precision and stability with respect to commercial devices.

• Digital substation. • Centralized protection and control (CPC). • Protection functions implemented in a generic hardware platform. • Multicriteria Faulted Phase Selection algorithm. • Improved protection algorithm operation under renewables and conventional scenarios. The integration of devices based on renewable energies and power electronics makes it necessary to rethink some of the methods used for protection and control in distribution and transmission grids. The difference between short circuit current contributions from renewable and conventional generators may affect protection system operation. Fault phase selection is one of the elements to be analyzed under renewable generation scenarios due to its importance in protection functions such as distance protection. The digitization of substations presents new opportunities in control and protection systems, such as functionality increase, reliability improvement, cost reduction of the installation and capacity for remote maintenance. This paper proposes a multi-criteria fault phase selection algorithm developed to be implemented in digital substations. The proposed faulted phase algorithm combines the results provided by four independent protection algorithms and has been designed to be applied in transmission power systems. Depending on the electrical variables measured in each event, quality criteria are defined to consider the strengths and weaknesses of each independent algorithm. The proposed algorithm has been implemented and tested on the centralized protection and control platform called EPICS, obtaining very satisfactory results. [ABSTRACT FROM AUTHOR]

Abstract Digital substations are mostly important in the future of the electric power industry which makes their testing a critical process to ensure the required reliability and security of the grid. The paper introduces the definition of a digital substation and efficient testing, as well as the requirements for isolation during testing. It later describes testing related features in IEC 61850 Edition 2 and testing methods that can be used in digital substations. Maintenance testing examples and testing tools requirements are also presented. And remote testing principles are described at the end of the paper. The proposed remote testing by controlling the test system in a remote substation from the convenience of the engineering office brings significant benefits by improving efficiency and safety, as well as reducing outage times.

The importance of the work is conditioned by the need to analyze the requirements of IEC 61850-9-2 for transmission of measured sampled values from the non-conventional current and voltage transformers to units of relay protection and automation, control and electric power fiscal accounting. These requirements should be also taken into account when developing both software and hardware for emulation of transmission of measured instantaneous values of electric energy. The main aim of the study: to identify the features of the sampled values transmission from non-conventional current and voltage transformers in accordance with IEC 61850-9-2 and to develop software to emulate this process. The methods used in the study: modeling of systems and data. The results: The paper introduces the developed software for emulating transmission of sampled values at 80 or 256 samples per period for phase and neutral line sinusoidal currents and voltages in accordance with IEC 61850-9-2 and IEC 61850-9-2LE and the results of verification of the software operation using two independent programs. The authors have described the protocol of IEC 61850-9-2 and appropriate data fields that can be used to develop the software of digital substations.

Smart Grids employ intelligent control applications that require high quality data: fast, secure, and error free. Several researchers have focused on providing techniques for low latency and secured data links for these applications. Bad data detection is however generally provided only at the central level due to limitations in legacy technologies employed in many substations. With the introduction of IEC61850 data sharing within the substation becomes more flexible and transparent allowing more sophisticated management of data quality. Hence, this paper proposes a substation level bad data detection algorithm to facilitate also these types of requirements from applications. The algorithm is based on automatically detecting the substation topology by parsing standard substation description files and online state of circuit breakers and disconnectors. By applying linear weighted least square based state estimation algorithm, bad data from failing current transformers (CT) can be detected. By conducting the verification of different types of bad data, the results show the output of bad data detection algorithm provides higher accuracy than output from both measurement and protective CT in both static and faulty situations. [ABSTRACT FROM PUBLISHER]

Visions of energy transition focus on activating end users, meaning that numerous flexible-distribution network-level devices become active participants in power-system operations. This implies a fast, reliable, and secure exchange of data, enabling the distribution-system operators to maintain, or even improve, the quality and delivery of service. With the introduction of the International Electrotechnical Commission (IEC) 61850 standard, the path is set for a single communication topology covering all substation levels. The standard has the potential to change the way substations are designed, built, tested, and maintained. This means that the key segment of the substation, its protection system, will go through a transition period with the end goal of having a digitized substation where all information exchange is performed over an Ethernet communication bus. This paper analyzes the performance impact of the IEC 61850-9-2LE on the protection system. To do this, a laboratory hardware-in-the-loop test setup was developed representing traditional-, hybrid-, and digital-substation topology. The setup serves to simulate faults and create transient waveforms in an extended IEEE 123-node test system, which is then used to detect the reaction times of protection relay devices. To verify the results, a significant number of tests was performed clearly showing the benefits of digitalizing the distribution system.

The paper presents the approach for solving the task of development of technology of high accuracy measurement digital information transmission via communication system from remote terminal unit on the base of adaptive digital combined current and voltage transformer (ADCCVT) to SCADA-system. We showed the design and technical characteristics of the said transformer, ADCCVT–SCADA communication system structure and also the programming model of data exchange between ADCCVT and SCADA-system. We analysed transformer design features determining the technology and means of data transmission. Discussed an opportunity of using the universal SCADA-systems and OPC-servers for control digital substations under IEC 61850 standard. Presented the modelling results. [ABSTRACT FROM AUTHOR]

A flood of alarm messages in an automatic digital substation makes the monitoring task a significant challenge for the operators in a remote control center, especially under fault scenarios. An online intelligent alarm-processing system is developed based on the architecture of the digital substation. First, real-time alarms are classified according to the IEC 61850 standard in order to provide synthesized and organized alarms for the alarm-processing procedure in the next step. Then, a new and systematic alarm-processing approach for digital substations is developed. Two modules (i.e., the generation of candidate hypotheses and the truth evaluation for the hypotheses) are included in the developed approach, and these two modules are operating in parallel in online implementation. This approach could not only determine the fault/disturbance cause but also the missing or false alarms as well as the causes of the false alarms. According to actual application requirements, an online intelligent alarm-processing system is developed and applied in the Xingguo substation—the first digital substation in Jiangxi Province, China. Finally, an actual alarm-processing scenario serves to demonstrate the presented alarm-processing method as well as the developed software system. [ABSTRACT FROM AUTHOR]