Power Substations Research Articles

A Prioritised Automatic Switching Algorithm for Load Shedding Using Labview

Load shedding is employed at the Ghana Grid Company (GRIDCo) Tarkwa power substation to ensure a balance between power demand and available power. This involves taking off loads from the power transmission network when demand exceeds available power. Such loads are later reintroduced when available power is adequate to supply applied loads. The traditional technique of load shedding employed at the GRIDCo power substation in Tarkwa requires dropping electrical loads based on frequency variations. This may lead to dropping load of entire sections without consideration of essential loads. Research into prioritised load shedding algorithm using semi adaptive load shedding approach can continuously monitor and switch loads at the study area which is a transmission substation located in the Western Region of Ghana. Electrical Transient Analysis Program (ETAP) software version 2019 was used to simulate the single line system of the GRIDCo substation to determine the rate of change of frequency against varying loads. The implementation of the proposed technique was achieved with Laboratory Virtual Instrument Engineering Workbench (LabVIEW) software version 2019. Using typical load shedding data from the GRIDCo Tarkwa power substation, the proposed design was tested and found to be effective in carrying out load shedding.

PROBLEMS OF RELIABLE HEAT SUPPLY PROVIDING IN THE CONDITIONS OF NON-GUARANTEED ELECTRICITY SUPPLY TO HEAT-GENERATING ENTERPRISES

The paper analyzes the current state of centralized heat supply systems. Considered problems that arise when the power supply is turned off for a longer period of time. For example, due to natural disasters or the destruction of power stations, substations and networks. An analysis of the consequences of long-term shutdowns of centralized heat supply sources in the winter period at extremely low temperatures, which leads to the failure of the main and auxiliary equipment, heat networks and domestic heating systems, was carried out. Considered several real options for reservation or full self-sufficiency of boiler room heat supply needs in power supply for the most common types of boiler room. Namely, with water heating boilers and direct connection to the heating network and with steam boilers and steam water boilers. It is proposed to introduce elements of own power generation on a permanent basis, as part of the technological process of the heat supply system or a separate boiler house of medium and large capacity, which, with their rational combination, can lead to a significant economic effect. It is shown that the most promising is the redundancy due to the built-in heat generation scheme, the electricity generation system, i.e. full or partial cogeneration. It was found that when gas turbines are used in the cogeneration system of heat and electricity, it is advisable to use units with a low temperature of up to 800°C and a gas pressure before the turbine of up to 0.8 MPa, which are characterized by high reliability, low cost and provide the greatest release of utilized heat. Keywords: centralized heat supply systems, reliability of power equipment, power supply of boiler houses

Solid-State Power Substations for Future Power Grids

Solid-State Power Substations for Future Power Grids

Perception and early warning technology of power substation safety construction operation based on multi-dimensional information fusion

Perception and early warning technology of power substation safety construction operation based on multi-dimensional information fusion

Perception and early warning technology of power substation safety construction operation based on multi-dimensional information fusion

Perception and early warning technology of power substation safety construction operation based on multi-dimensional information fusion

Simulation Analysis and Steady-state Operation Tests of Magneto-biased Superconducting Fault Current Limiter on a 66kV Power Substation in China

Simulation Analysis and Steady-state Operation Tests of Magneto-biased Superconducting Fault Current Limiter on a 66kV Power Substation in China

Investment efficiency evaluation of electric power substation projects by stages using the EWM-DEA model

Investment efficiency evaluation of electric power substation projects by stages using the EWM-DEA model

TECHNO-ENVIRONMENTAL ASSESSMENT OF ELECTRIFIED ROAD IN LAEM CHABANG PORT, THAILAND

Increased awareness of decarbonization and high fuel prices have induced a need for a wider deployment of alternative energy sources. Battery-powered electric trucks using an electrified road system offer a promising solution. This paper aims to evaluate the fuel consumption and environmental benefits of a 6 km road in Laem Chabang Port, Thailand, with a prototype system based on conductive charging from below. Battery capacity penetrations were designed for 1258 trucks traveling on weekdays. The annual electricity demand reached 1.608 TWh, and the flexible demand reached 1.65 TWh. The input was Thailand's standard electricity, with one 50 kVA power substation per 0.0016 km<sup>2</sup> and a 22 kV/400-230 V voltage system. Penetration required a capacity of 525 kWh. The findings indicate that fuel consumption was 592.43 TWh, and CO<sub>2</sub> emissions were 51.63 MtCO<sub>2</sub> annually. The electrified road system was evaluated with time series, fixed-effect, and tobit regressions. The time series analysis revealed that CO<sub>2</sub> emissions would be nearly zero by 2060, with an annual 4% increase in Laem Chabang's gross domestic product. A fixed-effect analysis signified the findings with Thailand's recent potential, whereas the tobit regression represented the influence of possible changes. These regressions demonstrated that variations in revenue, oil resources, openness to the sea, and political stability significantly affected CO<sub>2</sub> emissions, although there was no change in the implementation of the electrified road system.

Load flow, short circuit and motor starting studies in electrical power substations

Load flow, short circuit and motor starting studies in electrical power substations

Analysis of the Timetable Impact on Energy Consumption of a Subway Line

This paper analyzes the timetable impact on the energy consumption of a subway line. In most timetable studies, simplified models are used and can lead to misestimation of the braking energy and thus the energy transfer between braking vehicles and accelerating vehicles. In this paper, specific attention is paid to the models of the vehicles, the traction power substation, and the rail supply network to enable an accurate estimation of the energy consumption. The energetic macroscopic representation formalism is used to organize the models of the subsystems so they have the right interactions. The developed model is validated by experimental tests on a real subway line. The error on the global energy consumption is lower than 2.2%. The model is then employed to examine the influence of the vehicle time interval on energy consumption. A 10-second adjustment in this time interval can result in a substantial 22% decrease in energy consumption for the analyzed real subway line.

Two-Stage Distributionally Robust Optimization for Infrastructure Resilience Enhancement: A Case Study of 220 kV Power Substations Under Earthquake Disasters

Two-Stage Distributionally Robust Optimization for Infrastructure Resilience Enhancement: A Case Study of 220 kV Power Substations Under Earthquake Disasters

Seismic Vulnerability Curves for Non-reinforced Asymmetric Masonry Buildings Retrofitted with External Shotcrete: A Case Study on Control and Switchgear Room of Power Substations

Seismic Vulnerability Curves for Non-reinforced Asymmetric Masonry Buildings Retrofitted with External Shotcrete: A Case Study on Control and Switchgear Room of Power Substations

DEVELOPMENT OF THE CALCULATION PROCEDURE ALGORITHM FOR THE CALCULATION OF LIGHTNING RODS PROTECTION ZONES ACCORDING TO THE INTERNATIONAL STANDARD IEC 62305

A series of publications on the problem of lightning protection in power stations and substations, especially in the conditions of decreasing stability of the functioning of the energy system of Ukraine is continued. In addition, the relevance of the work is substantiated by the increase in thunderstorm activity on the planet as a whole and by the data of the national energy company in Ukraine, which leads to emergency shutdowns on power transmission lines. The system of algorithms for the computational procedure for calculating the protection zones of the system, which consists of numerous rod and cable lightning conductors and protective nets, using the rolling sphere method is developed. It is noted, that the majority of strategic energy facilities in Ukraine have lightning protection systems built according to outdated standards, therefore, their inspection and modernization is necessary taking into account current regulatory documents. A generalized algorithm for constructing a protection zone using the Delaunay algorithm and previously obtained mathematical expressions has been developed, which in turn consists of sub-algorithms: constructing a polygonal grid based on the points of the coordinates of the lightning conductors, finding the areas of contact with the sphere of the vertices of the polygonal grid, constructing a grid of nodes of the analysis points, finding the height coordinates for of each analysis point, construction of the protection surface based on the grid coordinates of the analysis point nodes. The software implementation was carried out and an example of the application of algorithms was shown when calculating the protection of an operating substation with a voltage class of 150 kV. The general features of software implementation in the LiGro software complex are given. The developed software product found its application in the modernization of existing lightning protection systems of operating power facilities of Ukraine with a voltage class of 35-750 kV.

APLICAÇÃO DA LOGICA FUZZY PARA PRIORIZAÇÃO DA MANUTENÇÃO DE DISJUNTORES DE SUBESTAÇÃO DE ENERCIA ELÉTRICA

In electric power supply, in order for electric power substations to continue to operate, the maintenance of the electrical equipment present is of utmost importance. Currently there are several forms of preventive maintenance scheduling, where each power supply company adopts an existing method or develops a new method. To perform this work, we used the methodology of fuzzy logic that enables the calculation of reliability among the uncertainties, in order to classify the degree of criticality in the maintenance of circuit breakers that may present technical problems, performed a preventive maintenance, comparing with the method already used by the distribution company. The results found demonstrate greater accuracy than the model currently presented by the distributor. Although the results obtained are satisfactory, its use is only indicated as a support tool for teams and specialists. Since its factors still need to be adjusted, for a better predictability rate, where some samples the maintenance date is very close to the breaker failure date.

ОБРАТИМЫЙ ПРЕОБРАЗОВАТЕЛЬ ЭНЕРГИИ С МАХОВИЧНЫМ НАКОПИТЕЛЕМ В СИСТЕМАХ ЭЛЕКТРОСНАБЖЕНИЯ

The problem of voltage unbalance and the need to power factor correction remain a relevant objective for electric power engineering. A variable load profile reduces the operating efficiency of electric power plants and leads to an overestimation of the power of transformer substations and the wire size of supply lines. Thus residential buildings power equipment remains underloaded for a significant part of the time. The decrease of power-frequency characteristic is becoming increasingly noticeable. This situation is not a problem yet, but in the future it may complicate the task of frequency stabilization. Finding solutions to existing and predicted problems is an important topic of research. To solve the problems posed, the work proposes the concept of a reversible energy converter, that is an electrotechnical complex with a flywheel energy storage and a two-section frequency converter based on two reversible voltage converters (active front end). The planning area of application of a reversible energy converter is transformer substations of residential and public buildings of urban power supply systems. The reversible energy converter is designed to solve such problems as load leveling, reactive power compensation (power factor correction), balancing voltages and power-frequency characteristic control. The work presents a connection scheme a reversible energy converter to the supply system and provides an expression for the phase load voltage.

КОНЦЕПЦІЯ ПІДВИЩЕННЯ БЕЗПЕКИ ВУЗЛІВ РОЗПОДІЛЬНОЇ ЕНЕРГЕТИЧНОЇ ІНФРАСТРУКТУРИ УКРАЇНИ

The issue of one of the problems that arose in the energy infrastructure of Ukraine as a result of the regular destruction of its facilities during the war is considered. It concerns ways of increasing the security of nodes of the distribution system of the energy infrastructure of Ukraine during its further restoration and modernization. An overview of the relevant issues that arise when using different methods to achieve the set goal is made. The importance of the problem of protection of electrical substations of the energy distribution infrastructure and the need for appropriate research and development to create an optimal method of protection are indicated. The urgency of developing a method and means of protection of an important element of substations (power transformer) is noted. One of the variants of the optimal concept of the corresponding protection is described. It provides for the location of transformers in an earthen niche, accordingly formed and decorated with auxiliary elements. This option is simple, technological and economically beneficial. This method of protecting transformers should protect them from fragments of explosive devices and blast waves. The proposed concept has room for improvement. Ref. 4, fig. 2. Keywords: power grid, transformer, safety, shelter, concept.

Neglected frequencies analysis on switching operations in extra-high voltage electrical power substations

Neglected frequencies analysis on switching operations in extra-high voltage electrical power substations

Dispatching Method of Distributed Energy Storage Resources in Substation Based on Peak-shaving Compensation Response Model

The conventional distributed energy storage resource scheduling method is mainly based on automatic load demand response scheduling, and the load response gap between peak hours and low hours is large, which affects the economic benefits of energy storage resource scheduling. Therefore, a distributed energy storage resource scheduling method based on a peak shaving compensation response model is designed. The cluster scheduling characteristics of distributed energy storage resources are extracted, and the distributed energy storage resources are charged and discharged synchronously at the same scheduling node. Combined with the resource scheduling strategy of the substation, the scheduling load of energy storage resources is limited so that the scheduling impact on the substation power grid is reduced. Based on the peak-shaving compensation response model, the dispatching objective function of distributed energy storage resources in the substation is optimized, the dispatching of distributed energy storage resources in the substation is optimized from the perspective of safe and economic operation, and the stochastic error of distributed energy storage resource scheduling is avoided in the form of a compensation response constraint to meet the resource scheduling requirements. Comparative experiments show that this method is more economical and can be applied to real life.

Attentive multi-scale aggregation based action recognition and its application in power substation operation training

With the rapid development of the power system and increasing demand for intelligence, substation operation training has received more attention. Action recognition is a monitoring and analysis system based on computer vision and artificial intelligence technology that can automatically identify and track personnel actions in video frames. The system accurately identifies abnormal behaviors such as illegal operations and provides real-time feedback to trainers or surveillance systems. The commonly adopted strategy for action recognition is to first extract human skeletons from videos and then recognize the skeleton sequences. Although graph convolutional networks (GCN)-based skeleton-based recognition methods have achieved impressive performance, they operate in spatial dimensions and cannot accurately describe the dependence between different time intervals in the temporal dimension. Additionally, existing methods typically handle the temporal and spatial dimensions separately, lacking effective communication between them. To address these issues, we propose a skeleton-based method that aggregates convolutional information of different scales in the time dimension to form a new scale dimension. We also introduce a space-time-scale attention module that enables effective communication and weight generation between the three dimensions for prediction. Our proposed method is validated on public datasets NTU60 and NTU120, with experimental results verifying its effectiveness. For substation operation training, we built a real-time recognition system based on our proposed method. We collected over 400 videos for evaluation, including 5 categories of actions, and achieved an accuracy of over 98%.

Modeling and Energy-Optimal Control for Freight Trains based on Data-Driven Approaches

This paper focuses on the energy optimization problem of traction substations. The paper addresses the difficulty of considering time-varying parameters and environmental characteristics of freight train in mechanism modeling. In response, a new optimization method called “Modeling and Energy-Optimal Control for Freight Trains based on Data-Driven Approaches” is proposed. Firstly, a data-driven model considering the “Train-Track-Power grid” (TTP) is constructed based on recorded data. The energy optimization problem is regarded as a finite Markov decision process. A dynamic programming (DP) algorithm is utilized to optimize the train’s control force. The data-driven model is then used to solve for the train’s speed curve, traction substation power, and contact network voltage. Secondly, a multi-input multi-output self-organizing fuzzy neural network (MIMO-SOFNN) model is designed during the modeling process, and an Levenberg–Marquardt algorithm with self-adaption damping factor (SA-LM) is proposed for model parameter learning. Finally, experimental analysis is conducted to validate the high accuracy of the MIMO-SOFNN model compared to five other models. The effectiveness of the SA-LM algorithm is also verified through a comparison with five other algorithms. In the energy optimization experiments, when compared with the actual operation data of a freight railway company in China, the proposed energy optimization method in this paper reduces the energy consumption of the traction substation by 34.8%.