Study on Main Electrical Connection of 500kV Smart Terminal Substation

2014 ◽  
Vol 945-949 ◽  
pp. 2850-2853
Author(s):  
Yang Qi Huang ◽  
Nian Liu ◽  
Jian Hua Zhang

With the rapid development of city construction, contradiction between power supply and demand becomes more marked, so the idea of building 500kV terminal substation is put forward. This paper analyzes the design principle of main electrical connection of 500kV terminal substation, introduces several typical main electrical connection forms and compares the reliability and economy of referred forms between traditional schemes with circuit breakers and disconnecting switches and new schemes with disconnecting circuit breakers (DCB). The new scheme of transformer line block connection with disconnecting circuit breaker is recommended as the prior of 500kV main electrical connection in 500kV smart terminal substation.

Author(s):  
Adrian Plesca ◽  
Alina Scintee

Busbar technology is more and more used to realize connections within power supply systems in answer to the need of compactness. The integrated problem on heat conduction and radiation-convective heat exchange describes the temperature regime in current conductors and current carrying busbars of power electrical apparatus such as circuit breakers or high breaking capacity fuses. Beside steady-state conditions, the transient thermal regime of busbar has an important influence upon whole power supply system from thermal behaviour point of view. Hence, a 3D thermal analysis of a power system including fuse, low voltage circuit breaker and busbars connections, using a specific software package based on Finite Element Method, has been done. From 3D thermal modelling and simulations, the thermal transient impedance for the busbar has been computed. This allows a better correlation between protection characteristics of the fuse and circuit breaker and busbar design.


2020 ◽  
Vol 34 (3) ◽  
pp. 43-48
Author(s):  
Wan-Su Ko ◽  
Chung-Seog Choi

The purpose of this study is to develop an earth leakage alarm circuit breaker, equipped with a leakage alarming function (JER-E2S, ETECKOREA Co., Korea), and to analyze its characteristics. The developed mechanism is exclusively used for single-phase and 220 V circuits, with a rated current of 32 A, 20 A, 20 A (for restrooms), 16 A, etc. It satisfies all characteristics of existing earth leakage circuit breakers (ELB). If a fire current, which is a resistive leakage current (Igr), flows through an electric line, the device detects the leakage current in real time and warns against the leakage through a blinking LED lamp. Since the developed device displays a tolerance to a capacitative leakage current (Igc) that inevitably occurs in LED lamps, communication devices, etc., it ensures a stable power supply. In addition, the earth leakage alarm circuit breaker protects against power failure due to a momentary ground fault. Therefore, it can supply power without the risk of the circuit breaker malfunctioning due to a momentary ground fault caused by water droplets, leaves, etc. Moreover, with a standby power of less than 0.1 W, the developed earth leakage alarm circuit breaker exhibits a power saving performance that is 3~8 times greater than that of other ELBs. Installation of approximately 10 earth leakage alarm circuit breakers in one apartment household, with an area of 120 m2, can save 2~5 kWh per month. Therefore, the developed earth leakage alarm breaker not only satisfies the characteristics of existing earth leakage breakers, but also exhibits outstanding power supply quality since it has the functions of electric fire prevention and malfunction prevention. Therefore, this device can innovatively contribute to electric fire prevention.


2019 ◽  
Vol 124 ◽  
pp. 01042 ◽  
Author(s):  
I. Fomin ◽  
R. Belikov ◽  
V. Zelyukin ◽  
E.V. Mikhailova

An important direction in improving the technical and economic level of technologies and agricultural production machinery is to ensure high reliability of power supply. Power interruptions cause damage to both agricultural consumers and power supply organizations. Therefore, obtaining on-line information about the occurrence of emergency operating conditions, and, therefore, minimizing the time for making operational decisions on their elimination, is an urgent task. Known methods and technical control means are complex, expensive and not effective enough. At the same time, they have both advantages and disadvantages. In this respect, it is very important to work out efficient technical means of remote control of power line sectionalizing circuit-breakers of the agro-industrial complex on the basis of innovative methods of monitoring. The proposed control method is implemented in a device for remote control of the overhead line circuit-breaker operation based on an analog-to-digital converter, with subsequent software-based processing of the received data on a computer. This method implementation of circuit breaker opening remote control will improve power supply reliability of agricultural consumers.


Author(s):  
Vitaliy Sivokobylenko ◽  
Dmitriy Kuzmenko

Searching the Damaged Outgoing Feeder in Networks with Insulated Neutral by Phase-to-ground FaultThe method of searching the damaged feeder was improved by alternate disconnecting of feeder circuit-breakers, which allow to enlarge reliability of the systems of power supply by diminishing the number of multiple earth fault in electric network. Diminishing the number of multiple earth faults is attained by exception of switching overvoltage, because commutations of feeder circuit-breakers are carrying out when shunting circuit breaker is closed. The detection of damage in the feeder, when this method is used, is produced on the change of phase of current in the circuit of shunting circuit breaker after disconnecting of circuit-breaker of this feeder.


Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1204
Author(s):  
Gul Ahmad Ludin ◽  
Mohammad Amin Amin ◽  
Hidehito Matayoshi ◽  
Shriram S. Rangarajan ◽  
Ashraf M. Hemeida ◽  
...  

This paper proposes a new and surge-less solid-state direct current (DC) circuit breaker in a high-voltage direct current (HVDC) transmission system to clear the short-circuit fault. The main purpose is the fast interruption and surge-voltage and over-current suppression capability analysis of the breaker during the fault. The breaker is equipped with series insulated-gate bipolar transistor (IGBT) switches to mitigate the stress of high voltage on the switches. Instead of conventional metal oxide varistor (MOV), the resistance–capacitance freewheeling diodes branch is used to bypass the high fault current and repress the over-voltage across the circuit breaker. The topology and different operation modes of the proposed breaker are discussed. In addition, to verify the effectiveness of the proposed circuit breaker, it is compared with two other types of surge-less solid-state DC circuit breakers in terms of surge-voltage and over-current suppression. For this purpose, MATLAB Simulink simulation software is used. The system is designed for the transmission of 20 MW power over a 120 km distance where the voltage of the transmission line is 220 kV. The results show that the fault current is interrupted in a very short time and the surge-voltage and over-current across the proposed breaker are considerably reduced compared to other topologies.


2021 ◽  
Vol 13 (2) ◽  
pp. 444
Author(s):  
Xucai Zhang ◽  
Yeran Sun ◽  
Ting On Chan ◽  
Ying Huang ◽  
Anyao Zheng ◽  
...  

Urban vibrancy contributes towards a successful city and high-quality life for people as one of its vital elements. Therefore, the association between service facilities and vibrancy is crucial for urban managers to understand and improve city construction. Moreover, the rapid development of information and communications technology (ICT) allows researchers to easily and quickly collect a large volume of real-time data generated by people in daily life. In this study, against the background of emerging multi-source big data, we utilized Tencent location data as a proxy for 24-h vibrancy and adopted point-of-interest (POI) data to represent service facilities. An analysis framework integrated with ordinary least squares (OLS) and geographically and temporally weighted regression (GTWR) models is proposed to explore the spatiotemporal relationships between urban vibrancy and POI-based variables. Empirical results show that (1) spatiotemporal variations exist in the impact of service facilities on urban vibrancy across Guangzhou, China; and (2) GTWR models exhibit a higher degree of explanatory capacity on vibrancy than the OLS models. In addition, our results can assist urban planners to understand spatiotemporal patterns of urban vibrancy in a refined resolution, and to optimize the resource allocation and functional configuration of the city.


2018 ◽  
Vol 10 (12) ◽  
pp. 4580 ◽  
Author(s):  
Li Wang ◽  
Huan Shi ◽  
Lu Gan

With rapid development of the healthcare network, the location-allocation problems of public facilities under increased integration and aggregation needs have been widely researched in China’s developing cites. Since strategic formulation involves multiple conflicting objectives and stakeholders, this paper presents a practicable hierarchical location-allocation model from the perspective of supply and demand to characterize the trade-off between social, economical and environmental factors. Due to the difficulties of rationally describing and the efficient calculation of location-allocation problems as a typical Non-deterministic Polynomial-Hard (NP-hard) problem with uncertainty, there are three crucial challenges for this study: (1) combining continuous location model with discrete potential positions; (2) introducing reasonable multiple conflicting objectives; (3) adapting and modifying appropriate meta-heuristic algorithms. First, we set up a hierarchical programming model, which incorporates four objective functions based on the actual backgrounds. Second, a bi-level multi-objective particle swarm optimization (BLMOPSO) algorithm is designed to deal with the binary location decision and capacity adjustment simultaneously. Finally, a realistic case study contains sixteen patient points with maximum of six open treatment units is tested to validate the availability and applicability of the whole approach. The results demonstrate that the proposed model is suitable to be applied as an extensive planning tool for decision makers (DMs) to generate policies and strategies in healthcare and design other facility projects.


2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Xudong He ◽  
Jian Wang ◽  
Jiqiang Liu ◽  
Enze Yuan ◽  
Kailun Wang ◽  
...  

The rapid development of the smart grid brings convenience to human beings. It enables users to know the real-time power supply capacity, the power quality, and the electricity price fluctuation of the grid. However, there are still some threats in the smart grid, which increase all kinds of expenses in the grid and cause great trouble to energy distribution. Among them, the man-made nontechnical loss (NTL) problem is particularly prominent. Recently, there are also some NTL detection programs. However, most of the schemes need huge amounts of supporting data and high labor costs. As a result, the NTL problem has not been well solved. In order to better avoid these risks, problems such as tampering of smart meter energy data, bypassing the smart meter directly connected to the grid, and imbalance between revenue and expenditure of the smart grid are tackled, and the threat scene of NTL is constructed. A hierarchical grid gateway blockchain is proposed and designed, and a new decentralized management MDMS system is constructed. The intelligent contract combined with the elliptic curve encryption technology is used to detect the storage and the acquisition of power data, and the detection of NTL problems is realized. At the same time, it has a certain ability to resist attacks such as replay, monitoring, and tampering. We tested the time consumption and throughput of this method on Hyperledger Fabric. At the same time, eight indexes of other methods proposed in the literature are compared. This method has a good effect.


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