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3D reconstruction of a large-scale electrical substation scene (ESS) is fundamental to navigation, information inquiry, and supervisory control of 3D scenes. However, automatic reconstruction of ESS from a raw LiDAR point cloud is challenging due to its incompleteness, noise and anisotropy in density. We propose an automatic and efficient approach to reconstruct ESSs, by mapping raw LiDAR data to our well-established electrical device database (EDD). We derive a flexible and hierarchical representation of the ESS automatically by exploring the internal topology of the corresponding LiDAR data, followed by extracting various devices from the ESS. For each device, a quality mesh model is retrieved in the EDD, based on the proposed object descriptor that can balance descriptiveness, robustness and efficiency. With the high-level representation of the ESS, we map all retrieved models into raw data to achieve a high-fidelity scene reconstruction. Extensive experiments on large and complex ESSs modeling demonstrate the efficiency and accuracy of the proposed method. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a novel detection device for deteriorated zinc‐oxide (ZnO) surge arresters. It is necessary to understand the state of ZnO surge arresters for AC traction substations under operation. The waveform distortion of leakage currents can be detected through an increase in multiple harmonic currents; therefore, this effect was employed to develop a device for diagnosing damage to the surge arrester. By adopting a Rogowski coil and band‐pass filters, we can obtain more output of the 5th–15th order harmonic currents in comparison with conventional devices. If the threshold value of harmonic elements is exceeded, the lights on the device may light up to indicate the deterioration. The validity of the device was verified by artificial deterioration tests using damaged ZnO elements and a capacitor. This developed device could indicate the soundness of the surge arresters that are in proper working order while being under the influence of feeding voltages, which include harmonic voltages. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive set of steady-state models to be included in power flow simulation studies of dc railway networks. This simulation framework covers all important aspects and features of each element of modern dc railways. The proposed models are simplified to achieve the maximum simulation speed while keeping the required accuracy. Not only nonreversible, controlled, and uncontrolled reversible substations are considered, but also onboard and offboard accumulation systems. The train model can consider the low network receptivity (overvoltage protection for trains equipped with regenerative braking) and overcurrent protection. It is also possible to include in the simulation dc/dc links between nodes of the railway network at the same or different voltage. To date, there is no other work able to conjugate all the mentioned models in a complex multitrain scenario. [ABSTRACT FROM AUTHOR]

Electricity companies have been under a great pressure to improve their technical and financial performances in order to survive and thrive in the deregulated environment. Therefore, these companies are seeking for innovative approaches to take the most out of the restricted resources. These approaches inherently concentrate the available budgets to the most critical components. In this regard, prioritizing the system components and identifying the most critical ones play a vital role in the planning and operation of the system. This paper presents a novel approach to prioritize power transmission system components. In the proposed methodology, a criticality factor is defined and implemented to rank the components based on their impacts on the operation of the power system. Furthermore, a complete model of substations including misoperation of circuit breakers and protection systems is, for the first time, taken into account in the critical component identification process. The proposed approach is used to identify the vulnerable parts of the system and assist the decision makers to manage the limited resources. The proposed methodology is, then, applied to the IEEE 24-bus Reliability Test System, and components are prioritized accordingly. [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]

When designing utility substations, it is necessary to consider all directional components of the electromagnetic reaction forces during short-circuit faults to properly account for their effects on substation equipment. IEEE 605 assumes straight long parallel conductors in its two-dimensional (2-D) force calculations while ignoring any bends and 3-D placement of conductors. CIGRE's Brochure 105 provides practical information on the mechanical effects of short-circuit currents in HV and EHV open air, conventional substations. Although these computational methods are easy to implement, they have several limitations and are sometimes too conservative. Previously published papers address such conservatism using dynamic analysis approaches that provide more accurate results when compared to experimental data. This paper provides two extensions to IEEE 605 and CIGRE 105 for calculating fault current reaction forces. A closed-form equation defining the simplified 2-D short-circuit force time history during a fault based on CIGRE 105 and a computationally inexpensive numerical 3-D force calculation technique are presented. [ABSTRACT FROM PUBLISHER]

This article presents a method supporting the decision-making process for implementation of a regenerative inverter in a 3 kV DC traction system. The method in question consists of two steps. The first one is based on the solution of power flow (PF) problem in the novel model of DC power supply system with the limited overhead contact system (OCS) receptivity. The second step consists in execution of an optimization-oriented procedure. The optimization criteria are defined as follows: net energy drawn from a traction substation, cost of inverter implementation and energy loss in a supplying medium voltage grid. The optimized variables are rated power of the inverter and its location as well as other parameters of the inverter, which may be selected optionally. The optimization procedure is based on a genetic algorithm (GA), the results are presented as Pareto-fronts. Among the Pareto-optimized solutions, the single solution is chosen based on the criteria of a payback period. [ABSTRACT FROM AUTHOR]

Very fast transient overvoltages (VFTO) generated in a gas insulated substation (GIS) during disconnector switching operations are one of the major concerns in insulation design of the GIS. Such over voltages can cause malfunctioning of the protection and control circuits in addition to initiating faults inside the gas insulated bus ducts especially in the presence of metallic particles. In this paper, VFTOs have been estimated at various locations using EMTP in a 1100 kV rated GIS during disconnector switching operations. For the substation studied, the maximum computed overvoltage is 1.76 p.u without considering the trapped charge on the bus bar and it reaches 2.54 p.u with a trapped charge of −1 p.u. Major frequency components in the computed VFTO lie in the range of 800 kHz to 15 MHz. Studies on mitigation of VFTO by the use of damping resistors in the disconnector showed that a resistance close to 500 Ω gives the best results. For the bus sections with trapped charge, increasing the resistance value above 500 Ω results in a negative peaking of VFTO. Transient radiated fields through the bushings of the GIS are also studied for electro magnetic compatibility (EMC) design of the substation. [ABSTRACT FROM AUTHOR]

This paper presents a detailed investigation of the lateral characteristics of cold-formed steel truss structures used in electric power substations. Five full-scale specimens were tested, and their responses were recorded under monotonic and cyclic loading regimes. Of particular interest were the specimens' maximum lateral load capacities and deformation behaviours. A rational estimation of the seismic response modification factor, R, of the truss structures is also provided. In addition, different types of stiffened sections were employed in order to examine the impact of the presence of stiffeners and lips on seismic behaviour, as well as on the lateral resistance of the structure. Detailed comparisons between relevant code methods, finite element modelling and an experimental study were then conducted to suggest an appropriate value for the R factor. A financial evaluation was also performed, to highlight the advantages of employing cold-formed steel trusses in the electric power substation industry. The results show that the cold-formed steel structural system is a reasonable alternative to the currently used hot-rolled steel structures, and that its use decreases the cost of the structures by almost 50%. [ABSTRACT FROM AUTHOR]

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]

In recent times, real-time simulation has been used to validate the testing and design of protection, control, and communications systems prior to their commissioning in the field, which has improved the reliability and security of the commissioning processes for electrical systems. This paper reviews the state-of-the-art and future trends in protection, control, and communications testing of electrical grids using real-time simulation. In addition, a summary is presented in which all the works and technologies mentioned are listed with the purpose of identifying new challenges in the proposed topic. Finally, future trends related to the use of real-time simulation for evaluating protection, control, and communications schemes are presented. Real-time simulation is very useful due to the increasing complexity of modern electrical power systems, therefore, it is necessary to use this kind of tool to facilitate field testing, avoid unnecessary work, and reduce costs for clients. [ABSTRACT FROM AUTHOR]

Knowledge of the currents is a key foundation for smart grid applications. However, knowledge of low voltage currents is generally poor. The new information streams from advanced metering infrastructure (AMI)/smart meters and the monitoring of distribution substations offer the opportunity of rectifying this. Unfortunately, often not all the smart meter readings will be available in real-time. For example, this situation will arise when older (non-compliant) smart meters do not have real-time reporting capabilities. This paper investigates how knowledge of the substation currents can be combined with the available real-time AMI/smart meter readings and the historical readings from the non-real-time meters, to estimate these missing values. It is found that the k-nearest neighbor weighted average approach performs best but that the gains over using simpler methods are relatively modest. [ABSTRACT FROM AUTHOR]

The paper presents an original analytical procedure developed for the determination of the part of ground fault current dissipated through the substation grounding system (electrode) into the surrounding earth in the cases when a specific measure has been taken to reduce it. The practical realization of this measure is simple and consists of burying one bare copper wire of a sufficient length together with the feeding cable line. The presented method enables a quick, and, for practical purposes reasonably accurate determination of the copper wire length providing the required safety conditions in the considered HV distribution substation and its vicinity. The developed analytical procedure is simplified by introducing an equivalent neutral conductor substituting all three cable line metal sheaths as well as all surrounding metal installations. The presented quantitative analysis shows that the effects achieved by this measure are significant. [ABSTRACT FROM AUTHOR]

In this study, an approach is presented for external network modeling of power systems in the absence of required data involving all of transmission lines and equipment in all of the substations. In the proposed approach which is based on multi-port networks, the studied power system is divided into two parts of surface layer and deep region. The surface layer should be modeled high accuracy, thorough details and frequency dependent. The deep region should be modeled by a multi-port equivalent network. This multi-port equivalent network is achievable using a steady state model of the power system which is under the study. In order to investigate the performance of the proposed approach, numerical studies are performed for a typical network. Results show the high precision of the modeled network in comparison to the complete network. Effectiveness of the presented approach in electromagnetic transient studies of large-scale power systems has been indicated in this paper. [ABSTRACT FROM AUTHOR]

The Cryogenic Underground Observatory for Rare Events (CUORE) experiment at Gran Sasso National Laboratory of INFN searches for neutrinoless double beta decay using TeO 2 crystals as cryogenic bolometers. The sensitivity of the measurement heavily depends on the energy resolution of the detector, therefore the success of the experiment stands on the capability to provide an extremely low noise environment. One of the most relevant sources of noise are the mechanical vibrations induced by the five Pulse Tube cryocoolers used on the cryogenic system which houses the detectors. To address this problem, we developed a system to control the relative phases of the pulse tube pressure oscillations, in order to achieve coherent superposition of the mechanical vibrations transmitted to the detectors. In the following, we describe this method and report on the results in applying it to the CUORE system. [ABSTRACT FROM AUTHOR]

This paper concentrates on the LCL filter with damping resistance intended to connect the shunt active power filter of an active dc-traction substation to the point of common coupling with the transmission grid. In order to find design conditions and conceive a design algorithm, attention is directed to the transfer functions related to currents and the associated frequency response. The mathematical foundation of the design method is based on meeting the requirements related to the significant attenuation of the high-frequency switching current, concurrently with the unalterated flow of the current that needs to be compensated by active filtering. It is pointed out that there are practical limitations and a compromise must be made between the two requirements. To quantify the extent to which the harmonics to be compensated are influenced by imposing the magnitude response at both highest harmonic frequency to be compensated and switching frequency, a performance indicator is defined. As an additional design criterion, the damping power losses are taken into consideration. The validity and effectiveness of the proposed method are proved by simulation results and experimental tests on a laboratory test bench at small scale reproducing the specific conditions of a dc-traction substation with six-pulse diode rectifier. [ABSTRACT FROM AUTHOR]

Critical process loads need to be safeguarded against power system disturbances and erroneous operations caused by human factors. During such events, a fast synchronism-supervised transfer scheme is required to ensure continuous operation. This paper discusses the implementation of a fast motor bus transfer scheme using existing protective relays. The scheme is designed to respond to local and remote (upstream) events in the substation. This makes possible an attempt to initiate a fast transfer for events that are remote to the motor bus. On a failure to achieve a fast transfer, the scheme resorts to an in-phase transfer and, if that fails, finally a residual transfer. Real-time dynamic modeling was performed to simulate motor bus decay and reacceleration. This paper provides the results of the simulations and the response of the transfer scheme. [ABSTRACT FROM AUTHOR]

Engineers and planners have realized that equipment grounding is a necessary part of installation process in Electrical power substations. Over years, grounding or earthing has been carried out primarily through preparation of Earth Mat which is interconnected with several Earth-rods buried around the equipment under consideration. This approach takes several efforts to have an acceptable and reliable result. However, this paper presents a more flexible, economical and results oriented approach. A flow chart which describes the procedures of carrying out the proposed method of earthing is developed. This was applied to two case studies: a proposed Power transformer substation and distribution Transformer substation located within the same geographical domain. On the two cases, the measured earth resistances are presented and discussed. The results from the case study indicates that the earth resistance values obtained from this new approach are reliable and in compliance with IEEE Standards 80,142, 81 and 1100. [ABSTRACT FROM AUTHOR]

Power systems are experiencing drastic changes with the introduction of renewables and customer owned resources. These changes introduce new challenges in protection, control, and operation of power systems. In protection, it is necessary to develop new methods that are immune to the new characteristics and they avoid relay misoperations. In particular, any protection system is vulnerable to hidden failures. This paper introduces a new dynamic state estimation-based centralized protection scheme (DSEBCPS) at a substation level. The system supplements dynamic state estimation-based protection for individual zones known as “setting-less relays” to secure their operation against hidden failures. The DSEBCPS communicates with the setting-less relays via the station bus and obtains essential information from each protection zone, such as phasor quantities and breakers/disconnects status. This information is processed by the DSEBCPS to estimate substation topology and states. Specifically, the DSEBCPS performs dynamic state estimation in the quasi dynamic domain once per cycle to detect any abnormality within the substation. Upon detecting abnormalities, the DSEBCPS performs hypothesis testing to identify the source of the abnormality, that is, a fault or a hidden failure. Upon detecting a hidden failure, the DSEBCPS identifies the compromised data, replaces this data with estimated values by using the substation estimated states and model. The corrected data are used by the setting-less relays, enabling self-healing characteristics. The proposed capability to detect hidden failures and correct the effects of these failures in real time makes the setting-less relays secure against misoperations and bridges a critical gap in protection systems. This capability is demonstrated through numerical experiments that include several scenarios of hidden failures. The integration of the proposed scheme with the individual protection zone relays form a resilient protection and control system, which is self-immunized against hidden failures. [ABSTRACT FROM AUTHOR]

On August 17th, 2012, a diode rectifier at Nagano Traction Substation was broken. The broken rectifier was dismantled and investigated in detail and, as a result, it was estimated that the overvoltage caused by the lightning flash caused the dielectric breakdown in the rectifier. To confirm the assumption of the broken process, the field measurement at Nagano Traction Substation and FDTD (finite-difference time-domain) calculation analysis at Nagoya Institute of Technology were carried out. As a result, it was indicated that the direct lightning to the elevated bridge over the substation caused the transient overvoltage of the grounding system of the substation and resulted in the breakdown within the rectifier. Because the concrete bridge pier is located adjacent to the substation, the surge voltage from the elevated bridge is able to influence the potential of the substation mesh. In this paper, the investigation process to determine the cause of the trouble will be shown in detail. [ABSTRACT FROM AUTHOR]

This paper presents a novel multi-objective model of active distribution network planning based on stochastic programming and uncertain random network (URN) theory. The planning model is proposed to find the final scheme with optimal alternative, location, size and operational strategy for the candidate distribution lines, transformer substations (TSs), distribution generations (DGs), static var compensators (SVCs) and on-load tap changers (OLTCs). Firstly, a scenario-based approach is developed to analyse the uncertainties in network system, such as the demand and intermittency of renewable sources. Since the impact of multiple uncertain factors on network cannot be ignored, a network frame is then modelled by uncertain and random weights of spanning tree (ST) instead of fixed value. In order to achieve the minimization of total cost, and further the selection of a minimum spanning tree (MST) with the uncertain and random weight, a 3-dimensional uncertain space is constructed based on the combination of the previous two targets. In addition, a second-order cone programming (SOCP) is applied to cope with the multi-objective, mixed-integer nonlinear nature of the proposed planning model. Simulation is performed on a modified Pacific Gas and Electric Company (PG&E) 69-bus distribution system, and the results demonstrate the effectiveness of the proposed model. [ABSTRACT FROM AUTHOR]

A cable splice failure in one of the cables associated with one of the 6 MVAR capacitor banks in an electrical substation at a manufacturing plant in South America caused a fire in the 88/4.16kV electrical substation. The fire caused the plant to stop production for approximately 29 days while temporary repairs were made. Operating two shifts per day/seven days a week, and stopping for maintenance once a year, the manufacturing production generates approximately $750,000 in revenue per day. The cable splice failure caused an electrical short circuit in the substation 4.16kV distribution system for approximately 120 seconds. The cable splice failure ignited the adjacent cables in the cable tray, causing damage to various sections of the 4.16kV cables, three 88kV disconnect switches, and four 88kV -- 4.16kV transformers. The cable fire in the electrical substation resulted in property damages and business interruption losses with an estimated value of $20 million. The four 88kV -- 4.16kV transformers that were in service at the time of the substation fire were exposed to voltage transients and electromagnetic forces produced by the short-circuit currents for approximately 120 seconds. [ABSTRACT FROM AUTHOR]

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This work presents an alternative solution for autonomous inspections in electrical substations. The autonomous system is a robot that moves on rails, collects infrared and visible images of selected targets, also processes the data and predicts the components lifetime. The robot moves on rails to overcome difficulties found in not paved substations commonly encountered in Brazil. We take advantage of using rails to convey the data by them, minimizing the electromagnetic interference, and at the same time transmitting electrical energy to feed the autonomous system. As part of the quality control process, we compared thermographic inspections made by the robot with inspections made by a trained thermographer using a scientific camera Flir® SC660. The results have shown that the robot achieved satisfactory results, identifying components and measuring temperature accurately. The embodied routine considers the weather changes along the day, providing a standard result of the components thermal response, also gives the uncertainty of temperature measurement, contributing to the quality in the decision making process. [ABSTRACT FROM AUTHOR]

Uneven load allocations and random load behaviors are two major causes for three-phase power imbalance. The former mainly cause systematic imbalance, which can be addressed by low-cost phase swapping; the latter contribute to random imbalance, which requires relatively costly demand-side managements. To reveal the maximum potential of phase swapping and the minimum need for demand-side managements, this paper first proposes a novel a priori judgment to classify any set of three-phase power series into one of four scenarios, depending on whether there is a definite maximum phase, a definite minimum phase, or both. Then, this paper proposes a new method to decompose three-phase power series into a systematic imbalance component and a random imbalance component as the closed-form solutions of quadratic optimization models that minimize random imbalance. A degree of power imbalance is calculated based on the systematic imbalance component to guide phase swapping. Case studies demonstrate that 72.8% of 782 low-voltage substations have systematic imbalance components. The degree of power imbalance results reveal the maximum need for phase swapping, and the random imbalance components reveal the minimum need for demand-side management, if the three phases are to be fully rebalanced. [ABSTRACT FROM PUBLISHER]

High distributed generation (DG) penetration can lead to significant changes in the operation of high voltage transmission systems. In this paper, a methodology is proposed, which can optimally allocate synchronous DG (SDG) units to sub-transmission substations based on defining an SDG planning model for maximizing the profit of regional transmission system operators under the conditions existing in the Iranian system by taking into account their relevant costs and revenues. The constraints include the network and the DG capacity constraints. The formulated problem is executed by a heuristic approach comprising three main parts. The algorithm starts with determining the maximum DG capacity at each bus by short-circuit studies in order to satisfy short-circuit-level constraints. In the second part, the SDG planning problem is tackled by the Tabu search algorithm. The final stage is to investigate the constraints of protection blinding and false tripping for the solution of the second part. The proposed model, in different scenarios, was put to test in Isfahan Regional Electricity Company network in Iran. According to the results, significant profit related to the transmission and sub-transmission systems was achieved by the proposed model. [ABSTRACT FROM PUBLISHER]

In this research, the objective is introducing the fundamentals of reliability analysis, it has been applied to the planning and design of Series Capacitor (SC) Bank, applied for power lines. It considers the cost of power outages, the decision process for new and existing power equipment in several systems, as well as the ability to make quantitative analysis “Cost – Vs. - Reliability” trade-off studies. The lack of credible data concerning equipment reliability and the cost of power outages has hindered engineers in making such studies. The study case considers a Reliability, Availability, and Maintainability (RAM) calculations, it has been performed for the series capacitor banks to be located at Cotaruse 220 kV, 4500 m over sea level (mosl) in a substation, located in Peru. The calculations are divided into forced and scheduled outages. A crew delay (for example: travel time) of 2 h, as well as 1 h for switching, have been included in calculations. The results are divided into forced and scheduled outages with a reliability calculation and spare parts are listed in this research. [ABSTRACT FROM AUTHOR]

To mirror an important aspect of ultra-high voltage network development, the remarkable amount of energy cost and carbon emissions of a typical ultra-high voltage transformer substation in China is revealed, in light of the hybrid method as the integration of input-output analysis and process analysis. By inclusively inventorying all the input items as products of the economy, the study differs from previous studies that simply treat the input items as some primary materials. The results show that the total energy cost and carbon emissions of 1000 kV transformer substation are 6.82E+09 MJ and 7.12E+05 t CO 2 eq., respectively. Equipment purchasing contributes more than 80% to the overall energy cost and carbon emissions, followed by construction engineering, additional service and installation engineering. From the sectoral perspective, Manufacture of equipment for power transmission and distribution and control sector (Sector 78) dominates the energy cost and carbon emissions induced by 1000 kV transformer substation, followed by Construction industry (Sector 95). The comparison and analysis between current research and previous studies in different countries and different voltages is clearly discussed. This study not only enhances our understanding about the impact of ultra-high voltage network on energy and environment, but also provides insights for energy conservation and low carbon development. [ABSTRACT FROM AUTHOR]

For substations in large-area district heating systems, the primary network supply water can be used as a driving force to realize heat transfer between the primary and secondary networks under an absorption heat-exchanger technique. An absorption heat-exchanger comprises an absorption heat pump (driven by hot water) and a conventional water-water heat exchanger. Generally, the return water of the secondary network is divided into two parts: one part is sent into the water-water heat exchanger, which is heated by the primary network; the other part is heated in the absorption heat pump. Finally, the water from each part is mixed and transmitted to the end user. The flow distribution of the secondary network affects the return water temperature of the primary network. This paper presents a theoretical analysis of the flow distribution principle for the secondary network. Here, an entransy analysis is adopted as an optimization method for the heat exchange process. The absorption heat-exchanger model is simplified and the mathematical representations of each entransy dissipation part are provided. The optimal flow distribution principle is obtained by calculating the minimum value of the total entransy dissipation. The principle provides a reference for optimized design and operation of the absorption heat exchanger. [ABSTRACT FROM AUTHOR]

In this paper, a decision-making model for the appropriate implementation of the reward and penalty scheme (RPS) for electricity distribution companies (EDCs) is presented to be used to update the parameters of the RPS in each regulatory period and also to improve the efficiency of this scheme. In this regard, an objective function is considered in order to optimize investment costs, imposed costs, and the amounts of reward and penalty for the distribution company. This optimization is based on the failure rate of equipment and is formulated as a non-linear programming (NLP) Problem. In the optimized objective function, all existing equipment in the distribution network is divided into three categories medium-voltage, low-voltage, and substation equipment and the imposed cost on the distribution company is modeled using the Markov process. The proposed model has been applied to an electricity distribution company in Iran. Finally, the optimized values of costs incurred by the distribution company from outage, cost of investment aimed at outage reduction, and failure rates in the three named categories are obtained and can be used to determine the new parameters of the RPS in the subsequent regulatory period. [ABSTRACT FROM AUTHOR]

In the modern electrical grid, accuracy and speed of fault clearance are the major challenges which need to be addressed. This paper covers a case study of fault location techniques in electrical transmission network, using numeric relay and offline fault locator. Healthiness of electrical transmission line is ensured using line signature analyzer. Comparative study of online and offline fault location in electrical transmission network has been carried out and the inferences are drawn. On the basis data available it can be said that the frequency of occurrence of single line to ground fault is maximum (about 75%) among various types of faults. Data at 220 kV and 132 kV substations has been collected and analyzed, keeping focus on single line to ground fault. Architecture of Substation Automation System (SAS) using single communication technology based on IEC 61850-8 and IEC 61850-9 is explained. Proposed architecture consisting of numeric meter with Java Compilation Unit (JCU) and Ethernet switch standardized as per IEC 61850 is demonstrated. The Java source code to send indications to output port of numeric meter is included. [ABSTRACT FROM AUTHOR]

Modern cyber-physical smart power grids are becoming increasingly dependent on the associated cyber networks for performing various monitoring and control functions, which inevitably leads to increased cyber vulnerabilities. It is thus a pressing task to develop effective methods for comprehensively evaluating the overall adequacy of power systems considering the probable cyber vulnerabilities. This paper is focused on quantifying the impact of substation cyber vulnerabilities on power supply adequacy. The temporal occurrence pattern of cyber attacks is statistically analyzed based on the human dynamics theory. Also, the attack/defense interactions of intelligent attackers and defenders are modeled by static and Markov games in different attack scenarios. A novel power system adequacy evaluation framework is proposed by incorporating both physical failures and cybersecurity risks. Simulation studies are performed on a typical IEEE reliability test system, and the influences of critical factors related to cybersecurity are carefully investigated. These quantitative studies show that implementing effective cyber security measures and making informed decisions about the allocation of limited resources are beneficial to enhancing the overall adequacy of contemporary cyber-physical power systems. [ABSTRACT FROM AUTHOR]

This paper presents a useful model to determine the washing periods and to indicate the pollution levels of electrical insulators. The behavior of leakage current, which is one indicator of the presence of pollutants on the insulator surfaces, was characterized through a regression model. We quantitatively examine the behavior of leakage current and the way electrical components are polluted. The data for environmental variables and leakage current in an electrical substation are analyzed and a model is identified that well represents the leakage current behavior on the insulators. Through this model, some predictions of the pollution effect can be made using analysis tools that enable the identification of the effects of leakage current on the entire network. This method can be used to obtain leakage current models on electrical substations located in highly polluted zones. [ABSTRACT FROM AUTHOR]

Composite insulators are widely used in modern power systems to provide electrical insulation and mechanical support for transmission lines and substations. However, the insulation strength will decrease greatly under the combined conditions of ice-covering and contamination, and icing flashovers may take place under these serious conditions. In this paper, AC flashover tests of different artificially ice-covered 220 kV composite insulators were carried out in a multi-function artificial climate chamber under energized ice accumulation conditions. The test results indicate that, with the increasing of ice thickness, the flashover voltages decrease and tend to saturation. The icing flashover voltages can be increased by adding booster sheds, but excessive booster sheds can lead to lower flashover voltages under heavy icing conditions. The voltage distributions of the iced insulators were measured using experimental methods. The results show that, the air gaps withstand most of the applied voltage. The zinc oxide (ZnO) resistors that are contained in the insulators can influence the voltage distributions of the iced insulators, but have little affect on the icing flashover voltages. The work done in this paper can provide reference for the design and type selection of outdoor composite insulators in cold climate regions. [ABSTRACT FROM AUTHOR]

Most electrical substations are remotely monitored and controlled by using Supervisory Control and Data Acquisition (SCADA) applications. Current SCADA systems have been significantly enhanced by utilizing standardized communication protocols and the most prominent is the IEC 61850 international standard. These enhancements enable improvements in different domains of SCADA systems such as communication engineering, data management and visualization of automation process data in SCADA applications. Process data visualization is usually achieved through Human Machine Interface (HMI) screens in substation control centres. However, this visualization method sometimes makes supervision, control and maintenance procedures executed by engineers slow and error-prone because it separates equipment from its automation data. Augmented reality (AR) and mixed reality (MR) visualization techniques have matured enough to provide new possibilities of displaying relevant data wherever needed. This paper presents a novel methodology for visualizing process related SCADA data to enhance and facilitate human-centric activities in substations such as regular equipment maintenance. The proposed solution utilizes AR visualization techniques together with standards-based communication protocols used in substations. The developed proof-of-concept AR application that enables displaying SCADA data on the corresponding substation equipment with the help of AR markers demonstrates originality and benefits of the proposed visualization method. Additionally, the application enables displaying widgets and 3D models of substation equipment to make the visualization more user-friendly and intuitive. The visualized SCADA data needs to be refreshed considering soft real-time data delivery restrictions. Therefore, the proposed solution is thoroughly tested to demonstrate the applicability of proposed methodology in real substations. [ABSTRACT FROM AUTHOR]