Добірка наукової літератури з теми "Generalized Substation design"

With the continuous progress of intelligent power system technology, in order to meet the needs of substation operation and maintenance, a target detection algorithm is applied to identify the status of equipment switches. YOLOv7, as the latest achievement of YOLO (You Only Look Once) series algorithms, has good speed and accuracy in target detection tasks. However, when the generalized network is applied in a specific scenario, its advantages are not obvious due to its high weight and poor portability. In this paper, an improved GF-YOLOv7 network model is proposed to apply in the recognition of the status of bounce locks in a substation. The MobileViT module is used to improve the feature extraction ability of the backbone network. Referring to the CBAM feature attention mechanism, the channel attention module and the spatial attention module are used to design a more lightweight feature fusion network. The experimental results in the test set show that the proposed network can significantly reduce the network weight and improve the detection accuracy on the basis of a small reduction in the detection speed, and the accuracy reaches 97.8%, which can meet the needs of the detection task of substation bounce locks.

Relevance The calculation of electrical loads is the basis for choosing the carrying capacity of all elements of the electrical network. An increase in rated loads compared to the necessary ones leads to cost overruns on power transmission lines and an increase in power of transformers, and a decrease in rated loads leads to increased power dissipation in networks, increased heating of conductors and transformers and increased thermal deterioration of their insulation. The reliability of the calculation of electrical loads depends both on the reliability of the calculation coefficients used and on the correctness of the methods used. Therefore, the research and improvement of the calculation of electrical loads in the design of power supply systems is an actual problem. Aim of research To investigate the determination of rated loads of transformer substations, methods of accounting for power dissipation in different modes of operation of the power supply system and methods for determining rated currents of cable lines to transformer substations. To consider the correctness of the use of standard forms for determining electrical loads recommended by regulatory documents. To develop a generalized form of performing calculations of electrical loads of transformer substations, combining the calculation of loads on the side of lower and higher voltages. Research methods To solve the tasks, the definition of electrical loads according to standard forms of regulatory documents is investigated. The methods of accounting for power dissipation in transformers under different operating modes of the power supply system and the determination of rated currents along cable lines to transformer substations are considered. Results The shortcomings of the execution and design of the calculation of electrical loads according to standard forms are revealed: standard forms do not contain information at which values of the heating time constant calculations are performed to determine the rated power of the electrical power load on the side of the lower and higher voltages of transformer substations, do not contain the definition of power dissipation in transformers. Ways of improving the calculation of electrical loads of transformer substations are proposed. A generalized form of execution and design of calculations of electrical loads of transformer substations have been developed, which include the values of time constants when calculating electrical power loads, the type and passport data of the selected transformer, calculations of power dissipation in transformers in two modes and calculations of the load current of cable lines to transformer substations.

The parameters of complex power supply schemes of tram lines, which are required for simulation modeling, were studied: statistical characteristics of traction loads of feeders and voltage on the tires of traction substations. It was established that the distribution function of the feeder feeding the tram depot corresponds to the logarithmic normal law, the distribution function of the modules of the idle voltage deviation and the angles between the idle voltages of adjacent traction substations to the truncated normal law. It is proposed to modernize the information bases of electric traction network parameters with complex power schemes to increase the efficiency of modeling the modes of operation of sections of urban electric transport. A method of calculating instantaneous schemes has been developed, which allows to create algorithms that do not depend on the degree of complexity of the scheme. A method of simulation modeling of complex power supply systems of electric transport based on the synthesis of the matrix method of calculating instantaneous circuits and the method of statistical tests for modeling the organization of traffic of trams and trolleybuses is proposed. Algorithms and simulation models of traction power supply systems of urban electric transport have been developed, taking into account the modes of operation of power systems. A single simulation complex has been created that takes into account the traffic schedules of trams and trolleybuses, power flows in power supply systems, which makes it possible to obtain generalized dependences of power flows and energy losses, and to increase the accuracy of calculations of electrical parameters to 5–7%. Adequacy of the simulation model to the real process was verified by experimental data on a number of two-track, single-track sections of electric traction networks and complex power supply schemes of traction substations. The error in determining the integral indicators of costs and energy losses does not exceed 5%, and the rms currents – 3%. The use of simulation modeling in the design of traction power supply systems allows to improve the quality of electrical engineering calculations of complex power supply schemes and to propose energy-efficient power supply modes.

One of the important components of the passenger transportation system in many domestic cities is trolleybus transport, as one of the types of environmentally friendly urban passenger vehicles for public use. Since the beginning of the 2000s, in many countries of the world, its intensive development has been taking place at a new level thanks to the use of trolleybuses with autonomous running, capable of transporting passengers on sections of routes not equipped with a contact electrical network. The purpose of this study is to analyze the economic and social aspects of the development and use of trolleybuses with autonomous running in Ukraine. Based on the analysis of the main design parameters of trolleybuses with autonomous running, the effect of autonomous mileage on reducing the nominal passenger capacity without increasing the permissible gross weight regulated for classic trolleybuses and buses was assessed. The market value of new modern models of trolleybuses of Ukrainian and Belarusian manufacturers, equipped with various autonomous sources of electricity, in particular traction batteries and supercapacitors, was analyzed. The inadequacy of the market value of trolleybuses with autonomous running is shown, which is much higher than classic trolleybuses. A generalized evaluation indicator of the technical excellence of trolleybuses with autonomous running is proposed, which takes into account the total structural weight, nominal passenger capacity and autonomous mileage. Two options for the development of trolleybus transport and its integration into urban transport systems are considered, related either to the existing trolleybus electric networks or, in the near future, to the reconstruction and construction of more powerful electric substations for faster charging of autonomous sources of electric energy. Their implementation will ensure a significant increase in the autonomous mileage of trolleybuses without a significant increase in the capacity of autonomous sources of electricity. Proposed measures to ensure the active development of urban and suburban passenger transport systems based on the use of trolleybuses with autonomous running.

Insulation coordination models are an essential part of power system studies and are used to determine the performance of a transmission line or substation. This paper generalizes the guidelines and parameters to be used in modelling the substation and in performing the analysis on the prediction of the transformer damage. Modelling parameters and the substation layout design are based and adapted from 132/11 kV Simpang Renggam – Ayer Hitam substation in Johor Baharu, Malaysia, courtesy of the Tenaga Nasional Berhad (TNB). The model is based on the single phase line model, as was suggested by the IEEE, to be adequate to represent the substation in transient analysis simulation. Extensive analyses on the placement of the surge arresters at the substation and a prediction of the transformer damage are also presented. The results obtained from this analysis are then compared with the suggested Basic Lightning Insulation Level (BIL) by the TNB, according to the standards, for assessing the percentage of transformer damage and optimizing the substation performance in terms of its reliability and cost effectiveness.