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The digital transformation process of power systems towards smart grids is resulting in improved reliability, efficiency and situational awareness at the expense of increased cybersecurity vulnerabilities. Given the availability of large volumes of smart grid data, machine learning-based methods are considered an effective way to improve cybersecurity posture. Despite the unquestionable merits of machine learning approaches for cybersecurity enhancement, they represent a component of the cyberattack surface that is vulnerable, in particular, to adversarial attacks. In this paper, we examine the robustness of autoencoder-based cyberattack detection systems in smart grids to adversarial attacks. A novel iterative-based method is first proposed to craft adversarial attack samples. Then, it is demonstrated that an attacker with white-box access to the autoencoder-based cyberattack detection systems can successfully craft evasive samples using the proposed method. The results indicate that naive initial adversarial seeds cannot be employed to craft successful adversarial attacks shedding insight on the complexity of designing adversarial attacks against autoencoder-based cyberattack detection systems in smart grids.

Abstract Fault indicators (FI) and remotely controlled switches (RCS) can reduce the power outage time in distribution network (DN) by finding and isolating the faulty area. Therefore, they play an important role in reducing the power outage cost and increasing the reliability of the DN. In DN, there may be high‐priority loads. One of the goals of improving and updating the DN is to increase the reliability of all network buses, especially buses feeding such loads. Here, the placement of FI and RCS, as the distribution system automation devices, is designed and modelled to increase the reliability of the buses supplying high‐priority loads. For the placement problem, two goals of cost and reliability have been considered. But the problem is not defined as a multi‐objective optimization. Rather, it is modelled as a one‐objective optimization (i.e. network cost) and constrained to a certain level of reliability in predetermined locations and buses. The IEEE‐33bus network is used as the sample network and different scenarios are simulated. The number of FI and RCS and the optimization cost of simulated scenarios are compared to evaluate the efficiency of the proposed model. The obtained results show the adequacy of the modelling.

In order to use the existing hardware sources to improve the line selection performance of single-phase grounding fault of small resistance grounding systems， a method for line selection of single-phase grounding fault based on the global steady-state monitoring information of the substation automation system is investigated. The zero-sequence voltage of the busbar and the zero-sequence current of each line in the case of single-phase grounding faults are deduced. The ratio of zero-sequence current of lines with single-phase grounding faults to that of non-fault lines under extreme conditions is analyzed. Moreover， the line selection method of single-phase grounding fault is proposed. The zero-sequence current is used as the starting criterion for line selection of single-phase grounding fault， and the setting principle of zero-sequence principle is introduced to calculate the maximum transition resistance that can be started under the setting value of zero-sequence current. An example is given to illustrate the proposed method， and the results show that the steady-state monitoring information of the substation automation system can remarkably improved the detection performance of single-phase grounding fault of small resistance grounding systems.

5G network slicing is promising in prioritizing time‐critical protection communication in wireless networks of smart grids. However, network slicing offered by telecommunication providers encompasses all smart grid applications, lacking granularity. Smart grid automation standards provide recommendations on prioritization of protection communication to improve reliability but only for wired connections. Therefore, this paper investigates hierarchical token bucket (HTB) traffic shaping and uplink (UL) bitrate adaptation of a live video stream for prioritizing protection communication within a 5G slice. An experimental setup combines controller‐hardware‐in‐the‐loop (CHIL) with a quality of service (QoS) measurement system for validation. The system under test consists of commercial 5G networks, intelligent electronic devices (IEDs), and merging units for validation with three smart grid applications: fault location, line differential, and intertrip protection. HTB traffic shaping improves protected faults by 47.57% in congested and 1.16% in non‐congested scenarios. UL bitrate of the video stream adaptation by 2 Mbps increases protected faults by 3.69%. HTB traffic shaping even improves prioritization with a wired connection without introducing additional delays. HTB traffic shaping must be deployed in routers to maintain good QoS for critical applications. Collaboration between utilities and telecommunication providers is essential to effectively deploy 5G network slicing on smart grids. [ABSTRACT FROM AUTHOR]

The lack of annotated semantic segmentation datasets for electrical substations in the literature poses a significant problem for machine learning tasks; before training a model, a dataset is needed. This paper presents a new dataset of electric substations with 1660 images annotated with 15 classes, including insulators, disconnect switches, transformers and other equipment commonly found in substation environments. The images were captured using a combination of human, fixed and AGV-mounted cameras at different times of the day, providing a diverse set of training and testing data for algorithm development. In total, 50,705 annotations were created by a team of experienced annotators, using a standardized process to ensure accuracy across the dataset. The resulting dataset provides a valuable resource for researchers and practitioners working in the fields of substation automation, substation monitoring and computer vision. Its availability has the potential to advance the state of the art in this important area. Dataset:  https://zenodo.org/record/7884270. Dataset License: CC-BY [ABSTRACT FROM AUTHOR]

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.

Fault indicators (FI) and remotely controlled switches (RCS) can reduce the power outage time in distribution network (DN) by finding and isolating the faulty area. Therefore, they play an important role in reducing the power outage cost and increasing the reliability of the DN. In DN, there may be high‐priority loads. One of the goals of improving and updating the DN is to increase the reliability of all network buses, especially buses feeding such loads. Here, the placement of FI and RCS, as the distribution system automation devices, is designed and modelled to increase the reliability of the buses supplying high‐priority loads. For the placement problem, two goals of cost and reliability have been considered. But the problem is not defined as a multi‐objective optimization. Rather, it is modelled as a one‐objective optimization (i.e. network cost) and constrained to a certain level of reliability in predetermined locations and buses. The IEEE‐33bus network is used as the sample network and different scenarios are simulated. The number of FI and RCS and the optimization cost of simulated scenarios are compared to evaluate the efficiency of the proposed model. The obtained results show the adequacy of the modelling. [ABSTRACT FROM AUTHOR]

Abstract 5G network slicing is promising in prioritizing time‐critical protection communication in wireless networks of smart grids. However, network slicing offered by telecommunication providers encompasses all smart grid applications, lacking granularity. Smart grid automation standards provide recommendations on prioritization of protection communication to improve reliability but only for wired connections. Therefore, this paper investigates hierarchical token bucket (HTB) traffic shaping and uplink (UL) bitrate adaptation of a live video stream for prioritizing protection communication within a 5G slice. An experimental setup combines controller‐hardware‐in‐the‐loop (CHIL) with a quality of service (QoS) measurement system for validation. The system under test consists of commercial 5G networks, intelligent electronic devices (IEDs), and merging units for validation with three smart grid applications: fault location, line differential, and intertrip protection. HTB traffic shaping improves protected faults by 47.57% in congested and 1.16% in non‐congested scenarios. UL bitrate of the video stream adaptation by 2 Mbps increases protected faults by 3.69%. HTB traffic shaping even improves prioritization with a wired connection without introducing additional delays. HTB traffic shaping must be deployed in routers to maintain good QoS for critical applications. Collaboration between utilities and telecommunication providers is essential to effectively deploy 5G network slicing on smart grids.

The lack of annotated semantic segmentation datasets for electrical substations in the literature poses a significant problem for machine learning tasks; before training a model, a dataset is needed. This paper presents a new dataset of electric substations with 1660 images annotated with 15 classes, including insulators, disconnect switches, transformers and other equipment commonly found in substation environments. The images were captured using a combination of human, fixed and AGV-mounted cameras at different times of the day, providing a diverse set of training and testing data for algorithm development. In total, 50,705 annotations were created by a team of experienced annotators, using a standardized process to ensure accuracy across the dataset. The resulting dataset provides a valuable resource for researchers and practitioners working in the fields of substation automation, substation monitoring and computer vision. Its availability has the potential to advance the state of the art in this important area.

Maintaining proper operation of adaptive protection schemes is one of the main challenges that must be considered for smart grid deployment. The use of reliable cyber detection and protection systems boosts the preparedness potential of the network as required by National Infrastructure Protection Plans (NIPPS). In an effort to enhance grid cyber-physical resilience, this paper proposes a tool to enable attack detection in protective relays to tackle the problem of compromising their online settings by cyber attackers. Implementing the tool first involves an offline phase in which Monte Carlo simulation is used to generate a training dataset. Using rough set classification, a set of If-Then rules is obtained for each relay and loaded to the relays at the initialization stage. The second phase occurs during online operation, with each updated setting checked by the corresponding relay's built-in tool to determine whether the settings received are genuine or compromised. A test dataset was generated to assess tool performance using the modified IEEE 34-bus test feeder. Several assessment measures have been used for performance evaluation and their results demonstrate the tool's superior ability to classify settings efficiently using physical properties only. [ABSTRACT FROM AUTHOR]

IEC61850 is the mainstream of the development for substation automation. This paper presents a practical consideration and analysis for implementing a secure sampled measured value (SeSV) message in substation automation system. Due to the lack of security features in the standard, IEC Working Group 15 of Technical Committee 57 published IEC62351 on security for IEC61850 profiles. However, the use of authentication methods for SV based on IEC62351 standards are still not integrated, and computational capabilities and performance are not validated and tested with commercial grade equipment. Hence, this paper shows the performance of security feature enabled SeSV packets transmitted between protection and control devices by appending a message authentication code (MAC) to the extended IEC61850 packets. A prototype implementation on a low cost commodity embedded system has proved that the MAC-enabled SV message can fully secure the process bus communication in the digital substation with negligible time delay. [ABSTRACT FROM AUTHOR]

Travelling wave based protection functions require significantly higher sampling rates than protection functions based on time-domain superimposed quantities or fundamental frequency phasors. Integrating these high sampling rates in digital substations leads to a significant increase of the communication load of process-level networks and causes high computational cost for centralized protection systems. This paper builds on a distributed signal processing approach, which allocates the filtering operations among standalone merging units (SAMU). In particular, the paper presents a decimation filter design to integrate signals with high sampling rates at the process-level. Thereby, signal sequences with high, medium and low sampling rates are provided according to the requirements of the respective protection function. The decimation filter structure is optimized with respect to time delay by the Remez exchange algorithm and with respect to computational cost by a multistage approach and a sparse filter design algorithm. In addition, the filter response is verified against the accuracy constraints defined in IEC 61869-6 and IEC 61869-13. The paper shows that it is feasible to distribute the filtering operations among SAMUs, while keeping the time delay below the maximum allowable processing delay of 2 ms. [ABSTRACT FROM AUTHOR]

The thermography camera is widely used to inspect electrical equipment. The existing defect assessment indicators are mainly the hot spot temperature and the relative temperature difference (RTD), and the analyzing process used to calculate the indicators is usually off-site. A smart thermography camera is designed and its application in the diagnosis of electrical equipment is investigated in this article. For the camera, the regional RTD is calculated automatically based on equipment detection and image registration algorithms, and the defects can be judged according to the existing criteria. Firstly, the regional RTD and its implementation method are proposed to reduce the error when the hot spot is unmeasurable. Then the object detection method based on the convolutional neural network (CNN) is modified dedicated to infrared (IR) images. Over 12 000 historical images and 18 000 labels are used for training and tests. The modified model can identify 16 classes of substation equipment with 86.4% mAP. With low latency, the inference speed of this on-site smart camera reaches 30 frames/s. The test results show that the similarity of diagnosis result between our method and the criteria is 92.2%. [ABSTRACT FROM AUTHOR]

• The paper presents a new method to detect cyberattacks from power quality disturbances in smart digital substations • The method uses wavelets as the signal processing tool and the deep learning to extract the salient features of the cyberattacks • The method uses only three features among the physical and the network features to detect the cyberattacks after representing them in the time-frequency domain • The proposed approach was applied on two publicly available dataset from an SDS • The results have shown that the proposed approach was effective to detect and classify cyberattacks from power quality disturbances with 100% detection accuracy • Furthermore, the proposed approach has been experimentally tested in real-time using OPAL-RT. Smart Digital Substations use communication networks to exchange the information among its components to perform monitoring and control, which makes such components prone to cyber-security threats. The presence of power quality disturbances may add complexity to the problem of detecting such cyberattacks as some of these power quality disturbances behave in a similar manner to some attacks. In this paper, a novel approach that detects cyberattacks from power quality disturbances and normal operation is developed. The proposed approach uses only three out of the twenty-nine features to detect such cyberattacks. The proposed approach uses the continuous wavelet transform to represent such features in the time-frequency scalograms, which are then fed to a convolution neural network for detecting cyber-attacks and power disturbances in IEC-61850 substation systems. The proposed approach has been tested on three datasets from substation test systems as well as in real-time using OPAL-RT. The results have shown that the proposed approach was effective in detecting the cyberattacks from power disturbance and normal operation with a detection accuracy of 100% in simulation environment and 99.45% in real-time using OPAL-RT. [ABSTRACT FROM AUTHOR]

Maintaining proper operation of adaptive protection schemes is one of the main challenges that must be considered for smart grid deployment. The use of reliable cyber detection and protection systems boosts the preparedness potential of the network as required by National Infrastructure Protection Plans (NIPPS). In an effort to enhance grid cyber-physical resilience, this paper proposes a tool to enable attack detection in protective relays to tackle the problem of compromising their online settings by cyber attackers. Implementing the tool first involves an offline phase in which Monte Carlo simulation is used to generate a training dataset. Using rough set classification, a set of If-Then rules is obtained for each relay and loaded to the relays at the initialization stage. The second phase occurs during online operation, with each updated setting checked by the corresponding relay’s built-in tool to determine whether the settings received are genuine or compromised. A test dataset was generated to assess tool performance using the modified IEEE 34-bus test feeder. Several assessment measures have been used for performance evaluation and their results demonstrate the tool’s superior ability to classify settings efficiently using physical properties only.

Penetrating distributed generation units into the radial distribution networks has been making the protection schemes become ever so complex. The microgrid modes of operation have also increased this complexity. Moreover, the 'loop‐based microgrid' concept has made it extremely difficult or even impossible to utilise the available radial protection schemes. Although redesigning a new protection structure solves the problem, there should be an affordable way for surviving today's protection systems; accordingly, this study equips the ordinary overcurrent relays with intelligent electronic devices to act as an agent within a multi‐agent framework. Given these devices are equipped with an efficient communication infrastructure for industrial applications, named IEC 61850 standard, the proposed approach uses a communication‐based strategy, named token, to securely protect the system without any conflict in relays' operation. The simulation results prove the effectiveness of the proposed method for any DG's penetration, network configuration and fault location. This kind of flexible strategies can affordably differ the expensive protection system replacement in the future revolutionary network upgrades. [ABSTRACT FROM AUTHOR]

As an onsite condition monitoring method, an infrared inspection can help to discover and analyze abnormal temperature increases in power equipment. For improving the efficiency of the onsite diagnosis of insulators in substations, this article proposes an automatic diagnosis method using instance segmentation and temperature analysis of infrared insulator images. For developing this method, thousands of infrared images from field inspection databases were collected to establish an annotated data set of insulator images. With the aid of the Mask R-convolutional neural network (CNN), it was possible to extract multiple insulators automatically in the infrared images. Transfer learning, as well as the dynamic learning rate algorithm, were then employed to realize the training process of Mask R-CNN with the annotated image data set. The result of the testing experiment showed that the mean Average Precision (mAP) of the model is 0.77, and the frame per second (FPS) is 5.07, which indicated great identification accuracy and computing speed of the proposed model. Next, function fitting was realized to extract the temperature distribution of each insulator. Finally, to evaluate the condition of each insulator, rules, which are based on the related standards, were established using machine language. This is the first time that the machine could independently realize fault analysis of multiple insulators in the infrared images, which is a great attempt to adapt the development of the Internet of Things and the tendency of predictive maintenance. Moreover, because of the universality of the model algorithm used, automatic infrared fault diagnosis for other power equipment could also be performed in a similar manner, which has significant potential applicability in the area of power equipment diagnosis. [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]

The new grid operation constraints, allied to the substation automation and intelligence, require the state estimation (SE) to work even more efficiently, with reliability and accuracy. The proposed method for optimally allocating existing phasor measurement unit (PMU) channels and their resources at substations ensures reliability in the SE process even in cases of equipment malfunctioning, and guarantees the quality improvement of the SE. The proposed algorithm has two stages. In the first stage, a genetic algorithm optimally allocates the PMUs. In the second stage, a heuristic method optimises measurement and channel allocation. Equipment failure, missing data, observability issues, methods to reduce critical sets in SE results to preserve the system's observability, are also discussed. [ABSTRACT FROM AUTHOR]

Generic Object Oriented Substation Event (GOOSE) message reflects the transmission of information between many intelligent electronic devices, which is more reliable as original data. The communication Ethernet opaque also leads to a big problem of information extraction analysis, limiting the development of state maintenance and other techniques. This study describes the process equipment and the network transmission technology of the intelligent substation and analyses the specified message format of IEC61850. The study then compares it with the characteristics of the typical intelligent substation message and gives the analysis method and the meaning of each byte in the actual message frame, making the communication network in the process layer more transparent and giving a clear direction of information acquisitions and analysis. It also provides some reference meanings to the intelligent substation communication and the equipment status analysis. [ABSTRACT FROM AUTHOR]

Generic Object Oriented Substation Event (GOOSE) message reflects the transmission of information between many intelligent electronic devices, which is more reliable as original data. The communication Ethernet opaque also leads to a big problem of information extraction analysis, limiting the development of state maintenance and other techniques. This study describes the process equipment and the network transmission technology of the intelligent substation and analyses the specified message format of IEC61850. The study then compares it with the characteristics of the typical intelligent substation message and gives the analysis method and the meaning of each byte in the actual message frame, making the communication network in the process layer more transparent and giving a clear direction of information acquisitions and analysis. It also provides some reference meanings to the intelligent substation communication and the equipment status analysis.

Multi-terminal DC (MTDC) grids based on voltage source converters (VSCs) are a promising option to integrate the increasing share of generation from the distributed energy resources (DERs) both in the transmission and distribution grids. However, with the broader use of VSCs for the transmission and distribution grid, there is an absence of a standardised data model for the VSC. In this work, the authors propose an IEC 61850 based data model for VSCs and an existing IEC 61850 model is extended for the dual-active bridge (DAB) converter as an interlink between various DC terminals and the modular multilevel converter (MMC). Furthermore, a generic data modelling guideline is proposed for intelligent electronic devices (IEDs), which are responsible for the interoperability among converters in the MTDC grid. The implementation of the real-time monitoring system of a hybrid AC-DC MTDC grid with the proposed IED is presented as an exemplary case. Through experimental tests of this MTDC grid, it is shown that the proposed IED meets the latency requirements for P2 through P6 class of monitoring, protection, and control applications according to the IEC 61850 standard. The automation architecture presented in this work is also validated for interoperability within the MTDC grid.

Highlights • Real time assessment of IEEE 1588 with multi-protocol traffic interactions. • Combined GNSS and IEEE 1588 systems offer a more reliable timing performance. • Manufactures have vendor-specific interpretations of IEEE 1588 messages. • IEEE 1588 satisfies the ±1 μs accuracy requirement in transmission substations. • Use capture card and impairment simulator to identify performance boundary. Abstract Accurate timestamping with 1 µs precision is required by power system monitoring and control equipment, including: Phase Measurement Units (PMUs) for real-time measurement and control; travelling wave detectors for fault location, protection and control; and sample value measurement techniques associated with the IEC 61850 process bus. The conventional way of achieving this is to transmit 1-PPS or IRIG-B timing signals using dedicated cables but such an approach is expensive and difficult to update as secondary control systems evolve. IEEE 1588 precision time protocol (PTP) allows the transmission of time information with sub-microsecond accuracy in an Ethernet network. However, a comprehensive study is required to enhance the confidence of the power industry in using PTP in present and future IEC 61850 based substations. This paper delivers a design and experimental validation of the real-time time synchronisation characteristics achievable with IEEE 1588. Several factors which can potentially affect the synchronisation accuracy in delivering a time reference from the master clocks to the end devices during both steady-state and transient changes were investigated. The objective is to increase the understanding of the real-time performance of a complete IEEE 1588 timing system applied in transmission substations, and identify the limitations of commercially-available devices. [ABSTRACT FROM AUTHOR]

Abstract Development of smart grid has progressively transformed traditional power system into a Cyber-Physical Power System (CPPS), however relying on the Information and Communication Technologies (ICTs) may bring more serious Cyber-induced Dependent Failures (CDFs) as well. This paper focuses on developing a comprehensive model to evaluate the impacts of Cyber-Physical Integration (CPI) on distribution system reliability. The vulnerability to CPI from distribution feeders and upstream substation are incorporated in sequential Monte Carlo simulations (MCS) along with several main wiring forms of substation are investigated to decrease the impact of CDF. CDF with various modes are evaluated in terms of the fault scope and impacts on reliability indices. The scope of CDF is considered by defining a cyber-state set, while their impacts on reliability indices are calculated by zone partitioning and the minimal path method. Conclusions were drawn and verified by the IEC 61850-based test system, including the modified Roy Billinton Test System (RBTS) with upstream substation. This work provided help reference for smart distribution system planning and the CPPS research as well. [ABSTRACT FROM AUTHOR]

This paper proposes the new concept of intelligent electronic devices (IEDs) with built-in distributed intrusion detection systems. The proposed IEDs have the capabilities to monitor and detect anomalies and abnormal behaviors of the host system of IED and IEC 61850-based messages, e.g., sampled values and generic object oriented substation event. The proposed IEDs collaborate with neighboring IEDs to make an accurate decision and find the origin of cyber attacks. The commodity embedded system has been used to verify the performance of the proposed intrusion detection system with power system protection functions of IEDs. The results show that the proposed mitigation methods work accurately and efficiently with protection functions, e.g., overcurrent and distance protections, on the embedded board. [ABSTRACT FROM AUTHOR]

Remote inspection is critical for smart factories, power systems and undersea and space exploration, among other domains. However, these applications have conflicting requirements: operators should experience high situation-awareness, implying a considerable amount of data to be presented, while having a minimal sensory load, not to compromise the time to make decisions. Recent research suggests computer vision inspection and the adoption of virtual reality (VR) as an alternative to traditional SCADA interfaces. Nevertheless, although VR may provide a good representation of a substation’s state, it lacks some real-time information, available from online field cameras and microphones. This work discusses a method to augment virtual environments of power substations with field images, enabling operators to promptly see a virtual representation of the inspected area’s surroundings. In addition, the system interacts with a SCADA database, continuously comparing the equipment states against the ones inferred by processing the field images. Whenever a discrepancy is found, a virtual camera can be teleported to the affected region, speeding up system reestablishment. Our results concern the registration accuracy and performance impact for a simple scenario. The collected metrics suggest good registration levels and low impact on real-time rendering performance.

The IEC 61850 communication standard is getting popular for application in electric power substation automation. This paper focuses on the potential application of the IEC 61850 generic object-oriented substation event (GOOSE) protocol in the AC microgrid for adaptive protection. The focus of the paper is to utilize the existing low-voltage ride through characteristic of distributed generators (DGs) with a reactive power supply during faults and communication between intelligent electronic devices (IEDs) at different locations for adaptive overcurrent protection. The adaptive overcurrent IEDs detect the faults with two different preplanned settings groups: lower settings for the islanded mode and higher settings for the grid-connected mode considering limited fault contributions from the converter-based DGs. Setting groups are changed to lower values quickly using the circuit breaker status signal (XCBR) after loss-of-mains, loss-of-DG or islanding is detected. The methods of fault detection and isolation for two different kinds of communication-based IEDs (adaptive/nonadaptive) are explained for three-phase faults at two different locations. The communication-based IEDs take decisions in a decentralized manner, using information about the circuit breaker status, fault detection and current magnitude comparison signals obtained from other IEDs. However, the developed algorithm can also be implemented with the centralized system. An adaptive overcurrent protection algorithm was evaluated with PSCAD (Power Systems Computer Aided Design) simulations, and results were found to be effective for the considered fault cases.

Industrial automation has been widely used in electric power substations. In this context, the IEC 61850 standard provides for the utilisation of redundancy in the data link layer to increase frame reception probability. This study aims to evaluate the availability of two power substation automation architectures based on the IEC 62439‐3 standard, which describes two redundancy protocols named parallel redundancy protocol (PRP) and high‐availability seamless redundancy (HSR). The authors evaluate both architectures using either PRP or HSR protocol against using no redundancy protocols. The reliability block diagram method has been used, and afterwards, the mean time to failure and availability have been calculated. Results show that the utilisation of redundancy protocols allied to the repair during the mission allows classifying the architectures in the higher availability class according to CEI IEC 870‐4. [ABSTRACT FROM AUTHOR]

This paper examines the development and implementation of a communication structure for battery energy storage systems based on the standard IEC 61850 to ensure efficient and reliable operation. It explores this standard’s capability to define suitable data exchange with battery energy storage systems and the feasibility of implementation in the field. It also analyzes the extent to which standard IEC 61850′s information model and defined interfaces suffice to ensure communication that enables full integration of a battery energy storage system in an electrical (smart) grid. A data model compliant with the standard is developed and subsequently tested in prototype implementation among a control center, photovoltaic system and battery energy storage system. [ABSTRACT FROM AUTHOR]

The increase of cyber-attacks on industrial and power systems in the recent years make the cybersecurity of supervisory control and data acquisition and substation automation systemsa high important engineering issue. This paper proposes a defense in depth cybersecurity solution for smart substations in different layers of the substation automation system. In fact, it presents possible vulnerabilities in the substation automation system and propose a multiple layer solution based on best practice in cyber security such as the hardening ofdevices, whitelisting, network configuration, network segmentation, role-based account management and cyber security management and deployement. [ABSTRACT FROM AUTHOR]

Distance protection is the most widely used protection technique for transmission line protection due to its enhanced selectivity towards fault, fast response, and availability of various relay programming algorithms. However, when faults are detected in zone 2 of a relay, instantaneous tripping is not possible and are cleared after an inherent time delay. Sometimes, this increased disturbance duration may lead to system instability, power quality problems, or may result in increased plant damage. To address this issue, communication‐assisted accelerated distance protection has been employed. To have this communication for tele‐protection through standardised and interoperable means, an IEC 61850 GOOSE‐based communication‐assisted distance protection scheme is employed. This IEC 61850 GOOSE‐based accelerated scheme must meet the stringent performance requirements. Thus, this study presents the experimental validation and performance evaluation of IEC 61850 GOOSE‐based accelerated protection scheme by transporting GOOOSE messages through tunnelling in inter‐substation for accelerated distance protection scheme. A system‐in‐the‐loop platform has been developed to analyse the end‐to‐end delay performances of GOOSE messages under different WAN scenarios here. It has been found that for worst‐case scenario, there is a significant operating time saving in the proposed scheme. [ABSTRACT FROM AUTHOR]

This study presents a method for discriminative detection of direct current (DC) faults on voltage source converter‐powered multi‐terminal high‐voltage direct current transmission systems using two fundamental guiding principles, namely instantaneous current‐differential and travelling waves. The proposed algorithm utilises local voltage and current measurements from all transmission lines connected to a DC busbar, and current measurement from the DC side of the converter. The scheme operates at a sampling frequency of 96 kHz, which conforms with IEC 61869‐9. No long distance communication is involved while measurements and signal exchange within DC substations are enabled by the utilisation of IEC 61850. Performance is assessed firstly through detailed transient simulation, using verified models of modular multi‐level converters, hybrid DC circuit breakers and inductive DC‐line terminations. Furthermore, practical performance and feasibility of the scheme are evaluated through laboratory testing, using the real‐time Opal‐RT hardware prototyping platform. Simulation and experimental results demonstrate that the proposed protection algorithm can effectively, and within a very short period of time (i.e. <1 ms), discriminate between busbar and line faults (internal faults), while remaining stable during external faults. Additionally, it has been demonstrated that IEC 61869‐9 is suitable for enabling fast DC protection schemes incorporating travelling waves. [ABSTRACT FROM AUTHOR]

The medium-voltage grid is often planned in loops, but operated in a radial structure to allow a robust protection scheme. This allows the reconfiguration of the grid. This paper focuses on reconfiguration after a fault to re-establish the service, also referred to as self-healing. It includes the localization of faults and finds new grid configurations based on the actual status of the grid. The solving of the reconfiguration problem is nonpolynomial difficult. Finding an acceptable solution to resupply nonfaulted grid parts under tight time limits is difficult. The innovative contribution of this paper is an approach that finds new configurations as local as possible to the faulty area, evolvingly increasing the search space. New configurations are generated based on a heuristic method relying on graph theory. An aggregated fitness function is used to evaluate the solutions. For the realization, a distributed control architecture in the form of an advanced substation automation is proposed. [ABSTRACT FROM PUBLISHER]

With the rapid development of China's economy, smart grid has been built in an all-round way. As an important basic node of smart grid, the technical complexity of smart substation automation system is getting higher and higher. Once a fault occurs, if not handled in time, it will seriously affect the safety and stability of the power grid, which poses a great loss to economic production activities. The traditional mode of local maintenance has the drawbacks of high time consuming, low efficiency, and heavy workload. To solve these problems, a remote maintenance technology for substation automation equipment based on general service protocol (GSP) is first proposed in this paper, and the brand new system architecture is designed which involves the service management center, the maintenance center, and substations. The standardized interaction mechanism, integrated deep security protection methods, and flow control strategy are adopted to ensure the standardization, security, and reliability of the remote maintenance system. Finally, the effectiveness of the proposed methods is successfully demonstrated, and the comprehensive performance of the remote maintenance system is evaluated by comparing with the traditional local maintenance mode. [ABSTRACT FROM PUBLISHER]

A radial distribution system consists of 33/11 kV substation, 11kV feeders, distribution transformers, service mains and load points. The reliability of the radial distribution system has a significant influence on overall power system reliability. One of the method to improve the reliability of distribution system is automating both the substation and feeders. The automation process will reduce the restoration time after occurrence of fault and hence the annual average outage duration of load points decreases. In this paper (i) the effect of centralized star and redundant star automation schemes on load points of one and half breaker substation, (ii) the reliability indices of 11 kV radial feeder for non-automated and iii) automated scheme are evaluated. Further, the reliability indices of the complete distribution system for the above said cases are evaluated. Reliability of substation is evaluated using cut-set method and reliability of feeder is evaluated using Failure Mode and Effective Analysis Method (FMEA). Results obtained shows that redundant star automation scheme is better over the centralized star automation scheme. It is also concluded from the results that redundant star substation and feeder automation have more effective impact on distribution reliability. [ABSTRACT FROM AUTHOR]

The recent trend of decreasing reliability of the existing power grid due to various kinds of equipment failures at the transmission and distribution level, has led the researchers to develop advanced protection techniques. In distribution systems, the conventional substations are getting transformed to digital substations in the light of upcoming advanced technologies. The key component of such a digital substation is substation monitoring control center (SMCC). This study proposes a novel algorithm for the real‐time condition monitoring of substation equipment using thermal images obtained from thermal cameras. The processing of these is done at the remote terminal unit by extracting the speeded‐up robust features and passing the same through trained adaptive neuro fuzzy inference system (ANFIS) and support vector machine (SVM) classifier. The information based on the output at the SVM/ANFIS classifier is sent to the SMCC where appropriate actions are taken by the substation engineer. This novel real‐time monitoring of substation equipment overcomes the drawbacks of the conventional methodology of manual inspection done at a periodic interval thereby preventing the electrical assets from failure before any catastrophe would happen. Also, a comparative study establishes the superiority of SVM over ANFIS in identifying the critical fault conditions using thermal imaging. [ABSTRACT FROM AUTHOR]

The aim of this study is to design and implement an accurate virtual model of a basic feeder protection relay. This paper focuses on certain sets of ANSI functions and COMTRADE (Std C37.111) to interact with an online simulation subjects to different fault scenarios. The proposed methodology includes robust synchronization between power system simulations and the response of the virtual relay. The results validation integrates a distribution system simulation software running with remote control for time-based simulation, then it reproduces voltage and current signals with the virtual relay operation. The performance is assessed in three cases of study comparing real protection equipment and the operation of the virtual relay at the same fault scenarios. This paper is the next step of the attempt to reach a versatile test engine for substation automation systems, including multiple protective virtual devices, which reduces costs and allows to assess critical protection schemes. [ABSTRACT FROM AUTHOR]

Today's power utilities, around the world, own multiple substations that are connected together to form a complex energy network. The functions within and between these substations are being automated according to globally accepted power utility automation standard IEC 61850. This automation results in efficient operation and enhanced protection of power network with the aid of the communication system. Implementing the protection schemes modeled using communication configurations of standardized information exchange will lead to digital power grid. Designing an IEC-61850-based protection scheme to take care of the faults outside the substations is a challenge, as the typical local-area-network-based generic-object-oriented substation events and sampled-value messages need to be transmitted over a wide-area network. This paper presents communication configuration for line current differential protection schemes applied between two automated substations. It presents the simulation results of communication configuration network between two substations. Its performance is evaluated using a network simulator tool. This study intends to guide the development of a robust protection scheme with IEC-61850-based communication configuration. [ABSTRACT FROM PUBLISHER]

This paper proposes an algorithm, including a multiagent-based system architecture, for distributed inference of power grid topologies. The core algorithm is based on processing measurement time series, or fingerprints, using statistical correlation to determine the connectivity between nodes. Notably, the method and proposed system architecture is completely distributed. The solution has been developed with contemporary IEC 61850 compliant substation automation systems in mind. This paper includes a presentation of the theoretical foundation for the distributed topology inference algorithm as well as the proposed system architecture. A case study utilizing the RBTS bus 4 model is included to demonstrate the capabilities of the method under static as well as transient situations. Furthermore, the results and analysis of the performance and scalability of the algorithm are presented. The main contribution of this paper is an application to infer the electrical connectivity of power grids without central functionality. [ABSTRACT FROM PUBLISHER]

This study introduces a laboratory test set up developed to evaluate the functionality of a novel decentralised distribution automation architecture. The demonstration system consists of a simulated distribution network in real‐time simulation environment including simulated monitoring and control devices as well as physical devices interfaced with the simulator as hardware‐in‐the‐loop test devices. System involves also substation automation units for real‐time monitoring and control that are interfaced with the simulator and physical devices. The operating principle of the system is demonstrated with an example simulation case. The main goal for this system was to test the functionality of the decentralised distribution automation architecture and track out any potential interfacing issues of automation system before implementing the concept to actual field demonstrations. Based on the tests executed with the system described in this study, the proper functionality of all the features of the automation architecture was verified and successfully deployed at the field test sites. [ABSTRACT FROM AUTHOR]

Accurate timing is often required for the intelligent electronic devices (IEDs) used in transmission substations. A common method of achieving this is direct connection of a device to a local global positioning system (GPS) receiver and the use of its one-pulse-per-second synchronizing signal and the IRIG-B coded message. However, concerns about GPS reliability are encouraging the use of timing systems less dependent on the direct use of local GPS receivers. The IEEE 1588 protocol is a network-based time synchronization technique designed to coexist with IEC 61850 applications and deliver sub microsecond timing accuracy. Many utilities are now considering the adoption of IEEE 1588, but they need confidence in the reliability of this technology before it can be rolled out to real substations. Hence, comprehensive tests were undertaken on an IEEE 1588 timing system, to help gain insight into the limitations of the system. This paper presents a procedure to assess the performance of a timing system based on distributed GPS receivers and one based on a mixture of GPS receivers and IEEE 1588 devices. Test results indicate whichever system is selected, high quality devices and systems, with appropriate installation and engineering, are essential to satisfy the stringent \pm 1\, \mu \texts accuracy requirements needed by critical IED applications. [ABSTRACT FROM AUTHOR]

The Purpose of the IDE4L project was to define, design, and demonstrate the ideal grid for all, with an active distribution network that integrates renewable energy sources (RESs) and new loads and guarantees the reliability of classical distribution networks. The active distribution network consists of the infrastructure of power delivery, active resources, and active network management (ANM) and combines passive infrastructure with active resources, ANM functionalities, and distribution automation information and communication technology infrastructure. Active distributed energy resources (DERs) include distributed generation (DG), demand, response, and storage. The concept of a commercial aggregator offering flexibility services is also integrated in an ANM. [ABSTRACT FROM PUBLISHER]