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Occupational Health and Safety (OHS), represent a very wide field of interdisciplinarity and multidisciplinarity in the following domains: technical, medical, military and security, because of the multiple of sources of elements of instability (risks, dangers, threats) to the workers, in order to discover the best optimal methods, actions of prevention and protection and ensuring the workplace's working in maximum safety conditions, without disturbing the industry and the national economy's wellbeing. The most effective way to protect the workesr health and safety is to remove the generators of risks, supplied that a methodology is available to identify how to treat these generators of risks. The assessment is carried out using the National Research and Development Institute of Occupational Safety - NRDIOS Bucharest method, in order to establish the risk/safety levels in a quantitative manner, based on a systemic analysis and on the assessment of risks of accidents and professional diseases. The role of OHS for power substation high voltage (critical power infrastructures) is to generate the national economy electricity, well-being, and safety work and health environment, workers and workplaces secured, and security of industrial and power process, in order to optimally operate the national economy and ensure energy security. [ABSTRACT FROM AUTHOR]

In order to ensure energy security the state must ensure access to electricity to all domestic and industrial consumers, which are made through power substations, which are very dangerous workplaces by the fact that the voltage are very high. For this reson role of Occupational Health and Safety (OHS) is to ensure secure workplaces in an ergonomic and healthy working environment for personnel. In many unfortunate cases, OHS activity is subordinate to production or service activity and risk assessments and audits are also made formally by non-specialized personnel, leading to undesirable events with an unstable effect, and the need for auditing with legal and other provisions is intended to verify compliance with OHS rules and principles and to limit or stop work accidents. This paper addresses the verification of OHS, by "INCDPM Bucharest method" - Auditing of conformity with legal and other provisions" - to an 400/220/110/20 kV power substation, for the purpose of verifying knowledge and conformity with legal and other provisions at the workplaces level and assessing the efficiency or failure of the OHS management system of the analyzed economic entity management, and after implementation it will serve as a tool to verify the functioning of the system. The auditing of the OHS shows that the power substation under consideration has an overall level of security close to maximum and a low overall risk level, which means that OHS rules are met and the auditing has had a positive effect. [ABSTRACT FROM AUTHOR]

The most effective way to ensure safety and protect the health of workers at work is to eliminate sources of danger. It is an action whose effects are maximal if carried out in the design and construction of work systems, but which is also beneficial afterwards, but with one condition: a methodology is in place to allow analysis, identification and determination of the treatment of these sources. The development of theory and applications in the field of systems security has provided a scientific basis and useful tools for the work of preventing professional risks. All methods designed to achieve system security have been taken over and adapted to determine with their help the possibilities of protecting the safety and health of workers. The development, implementation and promotion of an integrated, proactive approach to OSH management in high and very high voltage power substations has long been supported by policies and practices established at international, european and national level, including strategies, legal provisions, standards, guidelines, programs and campaigns initiated and undertaken by various stakeholders, such as international organizations, EU bodies, governments, trade unions and employers asociations, labor inspectorates and insurance institutions. [ABSTRACT FROM AUTHOR]

In recent decades, as a consequence of accelerated economic development, the issue of industrial and occupational risks, as well as the degree of diversification of real risks, have become increasingly important. The experience gained with accidents at work, damage and other categories of undesirable events highlights the need to understand and control risks "upstream", i.e. before the accident occurs. At the same time, awareness of populations at risk has resulted in a significant decrease in the risk acceptability threshold. In response to these social phenomena, public institutions, economic agents in the industry, researchers in the disciplines involved have proposed methods of risk forecasting, aimed at developing prevention and protection systems that improve the risk management process. Prevention of occupational risks is the only way to improve the safety and health conditions of the participants in the work process, as well as a reliable source for reducing costs, increasing labor productivity, quality of production and, finally, quality of social life. Risk management facilitates a structured and systematic approach to decision-making. The value and strength of the managerial approach to risk lies in the fact that it combines various valuation and consultation techniques, uniting them into an ensemble that gives consistency to the decision-making process. Risk management gives any organization the ability to better understand how operations are carried out and the ability to respond more effectively to changes in internal and external circumstances. [ABSTRACT FROM AUTHOR]

Despite the continuous advancement of intelligent power substations, the terminal block components within equipment cabinet inspection work still often require loads of personnel. The repetitive documentary works not only lack efficiency but are also susceptible to inaccuracies introduced by substation personnel. To resolve the problem of lengthy, time-consuming inspections, a terminal block component detection and identification method is presented in this paper. The identification method is a multi-stage system that incorporates a streamlined version of You Only Look Once version 7 (YOLOv7), a fusion of YOLOv7 and differential binarization (DB), and the utilization of PaddleOCR. Firstly, the YOLOv7 Area-Oriented (YOLOv7-AO) model is developed to precisely locate the complete region of terminal blocks within substation scene images. The compact area extraction model rapidly cuts out the valid proportion of the input image. Furthermore, the DB segmentation head is integrated into the YOLOv7 model to effectively handle the densely arranged, irregularly shaped block components. To detect all the components within a target electrical cabinet of substation equipment, the YOLOv7 model with a differential binarization attention head (YOLOv7-DBAH) is proposed, integrating spatial and channel attention mechanisms. Finally, a general OCR algorithm is applied to the cropped-out instances after image distortion to match and record the component's identity information. The experimental results show that the YOLOv7-AO model reaches high detection accuracy with good portability, gaining 4.45 times faster running speed. Moreover, the terminal block component detection results show that the YOLOv7-DBAH model achieves the highest evaluation metrics, increasing the F1-score from 0.83 to 0.89 and boosting the precision to over 0.91. The proposed method achieves the goal of terminal block component identification and can be applied in practical situations. [ABSTRACT FROM AUTHOR]

Infrared thermography is a predictive maintenance tool used in substations to identify a disturbance in electrical equipment that could lead to poor operation and potential failure in the future. According to Joule's law, the temperature of electrical equipment is proportional to the current flowing through it. Other external factors, such as solar incidence, air humidity, wind speed, and air temperature, can interfere with its operating temperatures. Based on this premise, this article aims to analyze the influence of atmospheric and load conditions on the operational cycle of thermography-monitored equipment in order to describe the operating temperature of the object using only external data and to show the impacts of external influences on the final temperature reached by the object. Five multivariate time series regression models were developed to describe the maximum equipment temperature. The final model achieved the best fit between the measured and model temperature based on the Akaike information criterion (AIC) metric, where all external variables were used to compose the model. The proposed model shows the impacts of each external factor on equipment temperature and could be used to create a predictive maintenance strategy for power substations to avoid failure. [ABSTRACT FROM AUTHOR]

Ensuring high-quality and uninterrupted power supply to consumers is one of the main problems of creating reliable power systems of a new generation. It is associated with the implementation of an integral assessment of the technical state of equipment of the power stations and substations, based on technical diagnostics data. Integral assessment involves the choice of ranges of the set of parameters of the technical state for groups of constituent elements of equipment, as well as the determination of their weight coefficients. Currently, the problem is solved with the help of expert assessments, arbitrarily in each specific case, which may lead to an incorrect integral assessment of the state of the equipment. The principle of decomposition makes it possible to determine the individual performance characteristics of each of them. At the same time, their subsequent aggregation ensures that the emergent properties of the system are taken into account. Such an approach was used in this work to evaluate individual types of equipment and their constituent elements. The algorithm for constructing a tree with a minimum random weight, proposed in this paper, makes it possible to increase the validity of decisions. They are made at various stages of designing complex technical systems and include tasks with an integral assessment of the technical state of equipment of power plants and substations. In the proposed algorithm, as a result of using the tree of variants, a matroid is formed, on which, using the "greedy" algorithm, the optimal solution can be determined. [ABSTRACT FROM AUTHOR]

The calculations of permanent regimes of high and very high voltage power substations are performed to predetermine the optimal operation of the analyzed power substation and the energy system from a technical point of view and economic. This paper presents the behavior of the 220/110/20 kV Sardanesti power substation for the current operating conditions, if the electricity consumption increases or decreases, checking the stability of the system in the Oltenia area and developing a strategy on the safety and security of the National Energy System. [ABSTRACT FROM AUTHOR]

The calculation of defects represents the analysis of the behavior of the energy system in short-circuits and/or phase outages, and the purpose of performing these calculations is to determine the current circulations and the values of the residual voltages in the nodes. This paper presents the behavior of the 220/110/20 kV power substation Sardanesti to certain types of short-circuits in order to verify the stability of the system in the Oltenia area and to develop a strategy on the safety and security of the National Energy System. [ABSTRACT FROM AUTHOR]

Phase synchronization can aid in understanding the dynamics of underlying systems. In an electric substation, disconnect, failures mostly occur due to overheating. In this work using the Hilbert transform to assess the phase synchrony of a disconnect temperature and its relationship with meteorological variables and disconnect current can be helpful in understanding temperature influences and composition. Statistical methodologies, including entropy analysis, correlation, Kalman filter, Fast Fourier Transform, Augmented Dickey–Fuller test, and Kwiatkowski–Phillips–Schmidt–Shin test, were employed. One of the differentials of this study is the use of the median filter, which was able to access the phase synchrony of the variables with disconnect temperature. An important result is that current is not the most correlated variable with disconnect temperature, instead, air temperature exhibits the highest correlation, and the highest phase synchronization is only obtained when disconnect current and air temperatures are combined. This study contributes to the advancement of power substation operations, advocating for continuous monitoring and analysis to ensure a reliable electricity supply obtaining better predictive maintenance. [Display omitted] • The median filter facilitates access to phase synchronization information. • The combination of air temperature and current demonstrates the highest level of synchronization information. in the disconnect temperature. • Solar incidence decreases synchrony. • The disconnect temperature, disconnect current, and air temperature share the same frequency modules. • Night-time phase synchrony is higher. [ABSTRACT FROM AUTHOR]

Despite the continuous advancement of intelligent power substations, the terminal block components within equipment cabinet inspection work still often require loads of personnel. The repetitive documentary works not only lack efficiency but are also susceptible to inaccuracies introduced by substation personnel. To resolve the problem of lengthy, time-consuming inspections, a terminal block component detection and identification method is presented in this paper. The identification method is a multi-stage system that incorporates a streamlined version of You Only Look Once version 7 (YOLOv7), a fusion of YOLOv7 and differential binarization (DB), and the utilization of PaddleOCR. Firstly, the YOLOv7 Area-Oriented (YOLOv7-AO) model is developed to precisely locate the complete region of terminal blocks within substation scene images. The compact area extraction model rapidly cuts out the valid proportion of the input image. Furthermore, the DB segmentation head is integrated into the YOLOv7 model to effectively handle the densely arranged, irregularly shaped block components. To detect all the components within a target electrical cabinet of substation equipment, the YOLOv7 model with a differential binarization attention head (YOLOv7-DBAH) is proposed, integrating spatial and channel attention mechanisms. Finally, a general OCR algorithm is applied to the cropped-out instances after image distortion to match and record the component’s identity information. The experimental results show that the YOLOv7-AO model reaches high detection accuracy with good portability, gaining 4.45 times faster running speed. Moreover, the terminal block component detection results show that the YOLOv7-DBAH model achieves the highest evaluation metrics, increasing the F1-score from 0.83 to 0.89 and boosting the precision to over 0.91. The proposed method achieves the goal of terminal block component identification and can be applied in practical situations.

Infrared thermography is a predictive maintenance tool used in substations to identify a disturbance in electrical equipment that could lead to poor operation and potential failure in the future. According to Joule’s law, the temperature of electrical equipment is proportional to the current flowing through it. Other external factors, such as solar incidence, air humidity, wind speed, and air temperature, can interfere with its operating temperatures. Based on this premise, this article aims to analyze the influence of atmospheric and load conditions on the operational cycle of thermography-monitored equipment in order to describe the operating temperature of the object using only external data and to show the impacts of external influences on the final temperature reached by the object. Five multivariate time series regression models were developed to describe the maximum equipment temperature. The final model achieved the best fit between the measured and model temperature based on the Akaike information criterion (AIC) metric, where all external variables were used to compose the model. The proposed model shows the impacts of each external factor on equipment temperature and could be used to create a predictive maintenance strategy for power substations to avoid failure.

Wearing personal safety protective equipment (PSPE) plays a key role in reducing electrical injuries to electrical workers. However, substation employees often ignore this regulation due to lack of safety awareness and discomfortable feeling of wearing PSPE. Therefore, it is necessary to develop a detection algorithm for PSPE and workers to build real-time video surveillance systems in power substations. In this paper, a wear-enhanced YOLOv3 method for real-time detection of PSPE and substation workers is proposed. The gamma correction is first applied as the preprocessing method to highlight the details of the operators and data augmentation is performed. Next, K-means++ algorithm replaces K-means in wear-enhanced YOLOv3 method to derive the most suitable prior bounding box size and lift the detection speed. Then, the proposed method can be quickly and effectively trained based on transfer learning. Finally, extensive experiments are carried out on a dataset of images about usage of safety helmets, insulating gloves and boots. Using the proposed method, the mean average precision is improved by over 2% and the frames per second is the highest compared with other typical object detection methods, which illustrates the effectiveness of the wear-enhanced YOLOv3 method for PSPE and workers detection.

Ensuring high-quality and uninterrupted power supply to consumers is one of the main problems of creating reliable power systems of a new generation. It is associated with the implementation of an integral assessment of the technical state of equipment of the power stations and substations, based on technical diagnostics data. Integral assessment involves the choice of ranges of the set of parameters of the technical state for groups of constituent elements of equipment, as well as the determination of their weight coefficients. Currently, the problem is solved with the help of expert assessments, arbitrarily in each specific case, which may lead to an incorrect integral assessment of the state of the equipment. The principle of decomposition makes it possible to determine the individual performance characteristics of each of them. At the same time, their subsequent aggregation ensures that the emergent properties of the system are taken into account. Such an approach was used in this work to evaluate individual types of equipment and their constituent elements. The algorithm for constructing a tree with a minimum random weight, proposed in this paper, makes it possible to increase the validity of decisions. They are made at various stages of designing complex technical systems and include tasks with an integral assessment of the technical state of equipment of power plants and substations. In the proposed algorithm, as a result of using the tree of variants, a matroid is formed, on which, using the “greedy” algorithm, the optimal solution can be determined.

Monitoring of electromagnetic field (EMF) near power distribution facilities, both in the low- and the high-frequency ranges, has become highly demanded in recent years. The reason lies in the accumulated concerns on public health, which is mostly caused by the evolution of electric power and communication infrastructure, in and around the power substations, as well as their closeness to residential areas. In this paper, the initial comparative analysis of the EMF monitoring results of three one-day campaigns, in 2015, 2018 and 2020, performed in the vicinity of the Serbian highpower distribution substation "Novi Sad 7", is presented. The overall EMF levels in all campaigns comply with the reference levels prescribed by the Serbian legislation, including some new EMF sources which were detected in 2018 and 2020. Likewise, the used continuous monitoring has demonstrated suitability to systematically address EMF fluctuation on daily basis, as well as corresponding concerns on EMF exposure. [ABSTRACT FROM AUTHOR]

Featured Application: Integrated sound system tuned to mask audible noises generated by the operation of electrical substations, aiming to comply with legal requirements. Low-frequency audible noise generated by the magnetostriction effect inherent to the operation of power transformers has become a major drawback, especially in cases where the electrical substation is located in urban areas subject to strict environmental regulations that impose noise limits, differing for day and night periods. Such regulations apply a +5 dB penalty if a tonal component of noise is present, which is clearly the case of magnetostriction noise, typically concentrated at twice the industrial frequency (50 Hz or 60 Hz, depending on the country). The strategy used to eliminate the tonal characteristics, therefore contributing to establish compliance with the applicable regulation and to alleviate the discomfort it causes to the human ear, consisted in superimposing to the substation noise a masking sound synthesized from "sounds of nature" with suitable intensities, to flatten the noise spectrum while enhancing the soundscape. The masking system (heavy-duty speakers powered by a microprocessor platform) was validated at an already judicialized urban scenario. Measurement results confirmed that the masking solution was capable of flattening the tonal frequencies, whose beneficial effect yielded the cancellation of the public civil action filed by the neighbors. The proposed solution is ready to be replicated in other scenarios. [ABSTRACT FROM AUTHOR]

The IEC 61850 standard has contributed significantly to the substation management and automation process by incorporating the advantages of communications networks into the operation of power substations. However, this modernization process also involves new challenges in other areas. For example, in the field of security, several academic works have shown that the same attacks used in computer networks (DoS, Sniffing, Tampering, Spoffing among others), can also compromise the operation of a substation. This article evaluates the applicability of hierarchical clustering algorithms and statistical type descriptors (averages), in the identification of anomalous patterns of traffic in communication networks for power substations based on the IEC 61850 standard. The results obtained show that, using a hierarchical algorithm with Euclidean distance proximity criterion and simple link grouping method, a correct classification is achieved in the following operation scenarios: 1) Normal traffic, 2) IED disconnection, 3) Network discovery attack, 4) DoS attack, 5) IED spoofing attack and 6) Failure on the high voltage line. In addition, the descriptors used for the classification proved equally effective with other unsupervised clustering techniques such as K-means (partitional-type clustering), or LAMDA (diffuse-type clustering).

With the world facing the urgency of energy transition, the development of efficient and quiet electrical infrastructures is of topical importance in the construction of the environment of the future. The problem of noise from power distribution systems is often underestimated, although several works in the literature underline the effect of disturbance on the population, especially concerning the low frequency range. This paper overviews the issue of the low-frequency noise generated by electrical substations, from the experimental characterization of the source to the possible mitigation measures at the source, along the propagation path and at the receiver. Alongside the general presentation, a case study serves as a practical demonstration of the proposed methodological approach. It was found that in the investigated situation the main disturbance comes from the transformer at two low-frequency harmonics of twice the networking frequency. A traditional noise barrier is designed taking into account the strict size constraints imposed by technical compatibility with the electrical infrastructure, which limits its efficacy at low frequency. Noise masking with broadband signals can be a complementary solution to further reduce noise disturbance and contain it within prescribed limits. The evaluation of subjective response of the receivers to different mitigation solutions is made possible by the availability of the impulse response. [ABSTRACT FROM AUTHOR]

Low-frequency audible noise generated by the magnetostriction effect inherent to the operation of power transformers has become a major drawback, especially in cases where the electrical substation is located in urban areas subject to strict environmental regulations that impose noise limits, differing for day and night periods. Such regulations apply a +5 dB penalty if a tonal component of noise is present, which is clearly the case of magnetostriction noise, typically concentrated at twice the industrial frequency (50 Hz or 60 Hz, depending on the country). The strategy used to eliminate the tonal characteristics, therefore contributing to establish compliance with the applicable regulation and to alleviate the discomfort it causes to the human ear, consisted in superimposing to the substation noise a masking sound synthesized from “sounds of nature” with suitable intensities, to flatten the noise spectrum while enhancing the soundscape. The masking system (heavy-duty speakers powered by a microprocessor platform) was validated at an already judicialized urban scenario. Measurement results confirmed that the masking solution was capable of flattening the tonal frequencies, whose beneficial effect yielded the cancellation of the public civil action filed by the neighbors. The proposed solution is ready to be replicated in other scenarios.

Power networks are among the most important infrastructures that without them, industrial, economic and social procedures will halt. Therefore, they should be planned for the most difficult conditions to provide services with minimum disruption. Power substations are of great importance to a power network, because any disruption in their components can produce extensive problems through the network and result in power failure in a large area. Hence, vulnerability assessment of power substations and planning for reducing their vulnerability is fairly essential. Earthquake can inflict serious damages to power substations. Due to inappropriate anchors, most of the power substation components in Iran are vulnerable to earthquake. There are several methods for seismic vulnerability assessment of substations such as ALA as a qualitative procedure and HAZUS and RISK-UE as quantitative methods. In this paper, seismic vulnerability of the Qazvin 1 and Minoodar substations, located in the city of Qazvin-Iran, is assessed using ALA, HAZUS and RISK-UE methods and the probable damages of earthquake to power substation components are discussed considering two earthquake scenarios. Initially, the target performance and assessment metrics of the mentioned substations are studied with ALA and the necessity of quantitative analysis is determined. Then the quantitative analyses are conducted with HAZUS and RISK-UE methods and the results are compared. Finally, direct economic consequences are determined and risk analyses are performed and the reduction in the risk due to hardening based on implementation of proper seismic anchorage is determined. The results show that the implementation of seismic anchorage reduces the seismic risk about 41.4 and 34.2 percent for Qazvin 1 and Minoodar substations respectively. The effects of seismic risk reduction in the studied substations could be more emphasized considering the indirect tangible and intangible losses that are resulted from power outage and interdependency between infrastructures. The study may also be an example of a range of qualitative to quantitative investigations of lifelines for seismic risk reduction studies.

This paper introduces the concept of a battery energy storage system as an emergency power supply for a separated power network, with the possibility of island operation for a power substation with one-side supply. This system, with an appropriately sized energy storage capacity, allows improvement in the continuity of the power supply and increases the reliability of the separated network at a specified time during the limitation of power transmission as a result of damage or disconnection of the main power line. This paper presents and describes a specific method of energy storage system dimensioning based on real measurement data. Based on the obtained parameters, an analysis of the reliability improvement of the considered network was performed. The implementation of the battery energy storage system will contribute to a more than 5-fold reduction in the occurrence of power outages in the time interval from 3 min to 1.5 h, which will clearly reduce the System Average Interruption Frequency Index and System Average Interruption Duration Index factors. In this paper, the network conditions for operational normality and failure are presented and the cost for implementation of an energy storage system (about EUR 1 million) is compared with the possible implementation of an additional power line (about EUR 5 million) to a specific power substation.

This work presents a new methodology for reliability assessment of power substations. The proposed methodology is based on a combination of two different techniques for reliability studies, which are fault tree and Monte Carlo Simulation. Usually, these techniques are individually used for reliability evaluation purposes, but the solution here presented shows the advantages of combining both of them. Results reveal that by using a new procedure, based on these well-understood techniques, vulnerable points can be identified in power substations, thus being a useful tool for deciding on new investments allocation. Firstly, the presented methodology is evaluated by using a system analytically solved, confirming its accuracy. Secondly, the proposed methodology is compared to a conventional method for reliability studies, showing its practical applicability, since both of them show the same expected results. [ABSTRACT FROM AUTHOR]

Abstract Introduction: With ever improving technology and increasing the use of high voltage power in industrial environments, concerns about the destructive effects of electromagnetic waves on human health have increased. Thus the present study aims to evaluate the effects of electromagnetic waves on the general health of Zahedan gas power plant personnel. Materials & Method: The present case-control study investigated the health of people at one point of time and their amount of exposure to electromagnetic waves at the same time. The data collection tool in this study was 28-item general health questionnaire (GHQ-28). After measuring the electromagnetic waves at distances of 1, 1.5 and 3 meters at high voltage power substations and data extraction, the data were entered to SPSS software and analyzed by descriptive statistics, t-test and chi-square. Results: In this study, the age and experience variables were not significantly different in two groups (p> 0.05). The highest magnetic fields in high voltage power substations was at a distance of 1 meter in the substation 607 (28/1 mG) and in precision tool work units (7.03 mG). The results showed that the depressive and general health symptoms were significantly different between the exposed and unexposed groups (p = 0.04), however the difference was not significant in terms of physical performance, anxiety and social performance (p> 0.05). Conclusion: although the level of exposure was lower than standard level determined in Iran, the significant difference of the general health and depression between the two groups, explains the necessity of conducting more studies in this regard. Also by reducing the exposure time and increasing people’s awareness it is possible to take important steps to reduce exposure and complications.

This study discusses a numerical study that was developed to optimize the ventilation system in a power substation prior to its installation. We established a multiobjective particle swarm optimizer to identify the best approach for simultaneously improving, first, the ventilation performance considering the most appropriate inlet size and outlet openings and second, the reduction of the synthetic noise of the ventilation and power consumption from the exhaust fan equipment and its operation. The study used building information modeling to construct indoor and outdoor models of the substation building and verified the overall performance using ANSYS FLUENT 18.0 software to simulate the air velocity and air temperature distribution within the building. Results show that the exhaust fan of the B1F cable finishing room and the 23 kV gas insulated switchgear (GIS) room optimize the reduction of horsepower by approximately 1 Hp and 0.5 Hp. The combined noise is reduced by 4 dBA and 2 dBA; the exhaust fan runs for 30 min, and the two equipment rooms can cool down by 2.9 °C and 1.7 °C, respectively. Therefore, it is confirmed that the MOPSO algorithm provides a more energy-efficient and environmentally friendly building ventilation environment.

With the world facing the urgency of energy transition, the development of efficient and quiet electrical infrastructures is of topical importance in the construction of the environment of the future. The problem of noise from power distribution systems is often underestimated, although several works in the literature underline the effect of disturbance on the population, especially concerning the low frequency range. This paper overviews the issue of the low-frequency noise generated by electrical substations, from the experimental characterization of the source to the possible mitigation measures at the source, along the propagation path and at the receiver. Alongside the general presentation, a case study serves as a practical demonstration of the proposed methodological approach. It was found that in the investigated situation the main disturbance comes from the transformer at two low-frequency harmonics of twice the networking frequency. A traditional noise barrier is designed taking into account the strict size constraints imposed by technical compatibility with the electrical infrastructure, which limits its efficacy at low frequency. Noise masking with broadband signals can be a complementary solution to further reduce noise disturbance and contain it within prescribed limits. The evaluation of subjective response of the receivers to different mitigation solutions is made possible by the availability of the impulse response.

The objective of this paper is to measure magnetic flux density and electric field intensity due to selected power substations in the city of Tehran to evaluate the difference between the measured parameters and threshold levels specified in relevant standards. Hence, three types of power substations of 63, 230 and 400 kV were randomly selected. Based on confidence level of 95% (α =0.05), 250 measurements were made at various distances from power substations. It is found that the results of data analysis were well below the recommendations in ICNIRP (2010) while, a previous study by Nassiri et al. (2012) with regard to electromagnetic field due to power substations in the city of Tehran revealed that most of the studied population (64.8%) was suspected to have mental disorders. Therefore, to study electromagnetic field due to power substation in urban environment, the adverse effect of electromagnetic field on human beings must be investigated rather than just environmental measurement of electromagnetic field. [ABSTRACT FROM AUTHOR]

Exposure to low-frequency electromagnetic fields (EMF) has become an issue considering a number of high-power low-frequency EMF sources installed in residential environment. Therefore, the EMF monitoring and appropriate exposure assessment are highly important regarding the safety, since residents can spend considerable time in the vicinity of such high-power objects. This short paper brings the case study related to the broadband continuous monitoring of the low-frequency magnetic field in the vicinity of the outdoor power substation, as a particularly important and interesting EMF source. Moreover, the exposure assessment of the general population, performed by a newly proposed adaptive boundary exposure approach, is presented. This approach assesses the upper and lower daily exposure boundaries, offering the range where real exposure is positioned. The reduction of difference between boundaries can be attained by frequency spectrum analysis, while in this case study the initial boundary difference was reduced from 99.6% to 33.3%. [ABSTRACT FROM AUTHOR]

Recent earthquakes have shown that Electrical Power Substations apparatuses are seismically vulnerable. This causes to disrupt the power supply in many cases, and therefore their seismic evaluation with high reliability is significantly important. Using fragility curves is a common practice for assessing seismic vulnerability. In general, fragility curves are based on only one intensity measure (IM), such as peak ground acceleration (PGA). This study has attempted to propose multivariate fragility analysis. One of the major advantages of this developed multivariate fragility analysis is to more reliably determine the seismic vulnerability of a region. A 420 kV circuit breaker (CB) was modeled and analyzed by using finite element technique. The results show that by adding another IM as peak ground velocity (PGV) the dispersion of the created data decreases to a great extent and therefore, the developed fragility surfaces helps conducting the seismic risk evaluation of electric power system components with higher level of reliability. Based on the obtained numerical results it can be expressed that for moderate damage state the fragility values are not much dependent on the PGV variation, while for severe damage state the dependence of fragility values on PGV is noticeable, particularly for PGA values in range of 0.1–0.7 g. [ABSTRACT FROM AUTHOR]

This paper examines the role of gravel in the heating process of substation environments. The choice of the material applied to the electric energy substation surface level can influence temperature changes in equipment. Ambient temperature is an important parameter used to define how many years a transformer will last when subjected to a load curve, under normal and emergency operation conditions. This paper shows that the ambient temperature of 30 °C, suggested in IEEE C 57.91 standard for calculating transformer's loading depending on the desired equipment life span is underestimated. There are differences in ambient temperature on surfaces when applying different rocks on the soil surface substations. In terms of the resistivity, some rocks have higher values than others when the drain systems fail to drain all the rainwater to the soil. Two field tests were performed, one in the 345 kV/138 kV Jacarepagua Substation in Rio de Janeiro, and the other in the Substation of Foz do Iguaçu in the state of Paraná, where measurements were performed at three locations: switchyard of 600 kV direct current – DC, 500 kV and 750 kV alternating current – AC. Laboratory tests of thermal and electrical properties of rocks typically used to cover the ground of substations were also performed. This paper presents some consideration of drainage properties. [ABSTRACT FROM AUTHOR]

Electronic elements of a substation control system have been recognized as critical cyberassets due to the increased complexity of the automation system that is further integrated with physical facilities. Since this can be executed by unauthorized users, the security investment of cybersystems remains one of the most important factors for substation planning and maintenance. As a result of these integrated systems, intrusion attacks can impact operations. This work systematically investigates the intrusion resilience of the ten architectures between a substation network and others. In this paper, two network architectures comparing computer-based boundary protection and firewall-dedicated virtual local-area networks are detailed, that is, architectures one and ten. A comparison on the remaining eight architecture models was performed. Mean time to compromise is used to determine the system operational period. Simulation cases have been set up with the metrics based on different levels of attackers’ strength. These results as well as sensitivity analysis show that implementing certain architectures would enhance substation network security. [ABSTRACT FROM AUTHOR]

In this study, the Highway N Substation in Missouri was studied with finite element method for its vulnerability under seismic loading. The component of the substation system was modeled with due considerations of mass, stiffness and geometries. Full-scale shake table experiments were carried out on three electric switches to partially validate the finite element model (FEM). After a systematical modal analysis based on the FEM, response spectrum analyses were performed to characterize the dynamic behavior of 'rigid' buses and switches of the structure. In time-history analysis, two methods were employed to generate the seismic motions: 1) site-specific synthetic ground motion and 2) spectrum compatible ground motion. The results from both ground motions were analyzed and the magnitude and location of the maximum moments in each case were identified. The effect of slip joints on switches was examined and the maximum relative displacement under the seismic loads was identified. [ABSTRACT FROM AUTHOR]

A proposal of a fault location technique for power distribution systems considering distributed generation (DG) and uncertainties associated to the fault resistance, load magnitude and model, fault type and faulted node is presented in this study. The approach presented here uses only single end measurements at the main power substation and at the DG source. To demonstrate the good performance of the proposed approach, tests on the 24.9 kV IEEE 34 nodes test feeder, which includes three‐phase and single‐phase laterals, are performed. According to the results, a high performance is obtained in the fault distance estimation, considering the shunt faults and the uncertainties in the proposed test scenarios. Finally, it is demonstrated that the proposed approach helps to maintain high continuity indexes by speeding up the fault location task in modern power distribution utilities. [ABSTRACT FROM AUTHOR]

Frequency instability, voltage instability or a combination of both have been the cause of several power system breakdowns throughout the world in the recent decades. Occurrence of a super‐component contingency (SCC) that refers to multiple and simultaneous outages of grid facilities like a power plant or substation may lead to blackout if no remedial action schemes (RAS) are implemented. This study proposes a new event‐based RAS to overcome the frequency and voltage instabilities caused by SCCs through optimal load shedding. To do this, a new multi‐objective framework is presented simultaneously optimising the competing objective functions of long‐term voltage stability margin, steady‐state frequency deviation, maximum transient frequency deviation and load shed amount. A modified system frequency response model is also proposed for frequency stability assessment. Multi‐objective decision making (MODM) is performed using a combination of analytical hierarchy process, modified augmented ε‐constraint method and technique for order preference by similarity to ideal solution. The effectiveness of both the proposed model and MODM solution approach is extensively illustrated on a simulated model of Iran's power system in 2012. [ABSTRACT FROM AUTHOR]

In power substations, switching operations of circuit breakers and disconnect switches generate transient electromagnetic emissions, which may interfere with the normal operations of electronic equipments. This study introduces the design of a novel wireless transient measurement system for measuring or monitoring transient electromagnetic emissions in power substations. Unlike traditional transient measurement systems that use several standalone waveform recording equipment, the presented system, adopting novel network measurement concept, works as a truly automatically controlled interactive data acquisition multi‐node network, and has the ability to provide time‐correlated data from numerous sensors. The accuracy of time correlation is smaller than 1.4 μs. As a result, it provides excellent scalability and is well suited for the measurement of analogue signals spread over a large physical space with time synchronisation. Another major difference is that the new system uses wireless links and programmable devices to replace cables and data acquisition equipment of currently available systems, thus making the new measurement system more compact, flexible and much more powerful. The designed measurement units could do both time‐domain measurement and real time spectrum analysis. [ABSTRACT FROM AUTHOR]

Abstract: It is very difficult to build load model for every substation since there are numerous substations in large area power grid. A practical method is to classify the substations into several classes, pick out a typical substation from each class and build its load model, then generalize it to other substations of the same class. In this paper, a new method based on SOM (Self-Organization Map) neural network is presented for load characteristics classification and synthesis of substations in large area power grid. SOM neural network is a clustering method with self-organizing characteristics and mapping capability that can classify different input patterns automatically. Besides, the trained SOM neural network can discriminate the new input pattern conveniently without retraining. Therefore, the new substations can be discriminated with the existing classification result unchanged. The effectiveness of the proposed method is verified by a simulation of 183220kV substations in Shandong power grid using MATLAB Neural Network Toolbox. At first, the load composition rate in each substation is chosen as the feature vector, then SOM neural network is introduced to the classification and synthesis of the load characteristics of substations. At last, the synthetic load characteristic of each class is derived from the cluster center. The result is satisfactory since the method not only decreases the randomness and subjectivity of the load characteristic classification and synthesis of substations, but also improves the effectiveness and efficiency of load modeling. The method offers a new way for practical load modeling. [Copyright &y& Elsevier]

With the increasing depletion of fossil fuels and growing environmental pressure, the mankind has got known the need to vigorously develop the renewable energy and the energy-saving technology. The high Tc superconducting (HTS) power technology will be very helpful to enhance the stability, reliability, and efficiency and transmission capacity of the power grid which would be dominated by the renewable energy. In this paper, we will report the installation and operation of a 10 kV HTS power substation which includes a 75 m/1.5 kA HTS power cable, a 10 kV/1.5 kA HTS fault current limiter, a 1 MJ/0.5 MVA high Tc SMES and a 630 kVA/10 kV/0.4 kV HTS power transformer. [ABSTRACT FROM PUBLISHER]

Abstract: A PCEUDO finite element method of transient analysis of multi-conductors transmission lines (MTL) in a reference is pointed out and proved to be the finite difference time domain (FDTD) method. Based on the explicit/implicit method, a time domain finite element method of transient analysis of MTLs is presented. And the method is validated with one numerical examples making comparison with the FDTD method. [Copyright &y& Elsevier]

• Analysis of delay attacks on Precision Time Protocol, PTP, in power substations. • A new method for detecting delay attacks on Sync messages as well as attacks on transparent clocks. • No need for an external reference clock to detect delay attacks. • Possibility to detect simultaneous attacks on the substation network. • Mathematical analysis and simulation of proposed attack detection algorithm. • Low average attack detection time and very low overhead network traffic. Time synchronization is one of the main issues for guaranteeing the correctness of actions depending on the time of measured data or detected events by electronic devices across industrial networks. According to the accuracy needed in different applications and networks, several synchronization protocols or algorithms have been proposed so far. The Precision Time Protocol, PTP, is one of the most accurate synchronization protocols introduced for automation applications. It has also been used in power grids and digital substations. However, due to the variety of cyber-attacks in electrical power systems in recent years, its security should be considered and evaluated as other substation components. This paper introduces a new PTP attack detection algorithm. The proposed algorithm can detect delay attacks on Sync messages as well as attacks on transparent clocks and simultaneous attacks on the network. The efficiency and advantages of the proposed algorithm over other methods are verified through mathematical analysis as well as several simulations. [ABSTRACT FROM AUTHOR]

The effects are studied of the material for leveling spread over and of installation channels led through substation site upon the safety risk associated with grounding. The main ground grid performances in case of ground faults are analyzed for various ratios of overlaid material and surrounding soil resistivities and horizontal dimensions and thickness of the overlaid material. Also, the effects of the installation channels dug along various routes upon the potential distribution on the ground surface and step voltages are considered. It was shown that the mentioned local nonuniformities can substantially affect the safety performances of the ground grid and that they should be carefully taken into consideration. The local soil irregularities considered have been modeled by applying the method of finite elements. [ABSTRACT FROM AUTHOR]

A power substation is susceptible to intrusions of foreign objects. The intrusions can likely result in failures of power supplies. Therefore, recognizing foreign objects becomes important to ensure constant and stable power supplies. However, existing object recognition methods fail to achieve acceptable accuracy and performance. In this paper, we propose an efficient Foreign Objects Detection Network for Power Substation (FODN4PS) to improve the recognition accuracy with less time. FODN4PS consists of a Moving Object Region Extraction Network (MORE Net) and a classification network, where the MORE Net can get the position of foreign objects, and the classification network can recognize the category of foreign objects. Experimental results show that FODN4PS is faster and more accurate in object recognition than the Fast R-CNN and Mask R-CNN. [ABSTRACT FROM AUTHOR]

This paper introduces the concept of a battery energy storage system as an emergency power supply for a separated power network, with the possibility of island operation for a power substation with one-side supply. This system, with an appropriately sized energy storage capacity, allows improvement in the continuity of the power supply and increases the reliability of the separated network at a specified time during the limitation of power transmission as a result of damage or disconnection of the main power line. This paper presents and describes a specific method of energy storage system dimensioning based on real measurement data. Based on the obtained parameters, an analysis of the reliability improvement of the considered network was performed. The implementation of the battery energy storage system will contribute to a more than 5-fold reduction in the occurrence of power outages in the time interval from 3 min to 1.5 h, which will clearly reduce the System Average Interruption Frequency Index and System Average Interruption Duration Index factors. In this paper, the network conditions for operational normality and failure are presented and the cost for implementation of an energy storage system (about EUR 1 million) is compared with the possible implementation of an additional power line (about EUR 5 million) to a specific power substation. [ABSTRACT FROM AUTHOR]

This study discusses a numerical study that was developed to optimize the ventilation system in a power substation prior to its installation. We established a multiobjective particle swarm optimizer to identify the best approach for simultaneously improving, first, the ventilation performance considering the most appropriate inlet size and outlet openings and second, the reduction of the synthetic noise of the ventilation and power consumption from the exhaust fan equipment and its operation. The study used building information modeling to construct indoor and outdoor models of the substation building and verified the overall performance using ANSYS FLUENT 18.0 software to simulate the air velocity and air temperature distribution within the building. Results show that the exhaust fan of the B1F cable finishing room and the 23 kV gas insulated switchgear (GIS) room optimize the reduction of horsepower by approximately 1 Hp and 0.5 Hp. The combined noise is reduced by 4 dBA and 2 dBA; the exhaust fan runs for 30 min, and the two equipment rooms can cool down by 2.9 °C and 1.7 °C, respectively. Therefore, it is confirmed that the MOPSO algorithm provides a more energy-efficient and environmentally friendly building ventilation environment. [ABSTRACT FROM AUTHOR]