Operation and Maintenance of High and Low Voltage Transformer and Distribution Equipment

2021 ◽  
Author(s):  
A N Sarwade ◽  
P K Katti ◽  
J G Ghodekar

Current and voltage signals recieved from conventional iron core Current Transformer (CT) and Voltage Transformer plays very important role for correct operation of Distance Distance Relay (DDR). Increase in secondary burden connected to CT causes it to saturate at earlier stage. The saturated CT produces distorted secondary current, causing DDR to under reach and to operate by certain time delay. Rogowski Coils (RCs) are attaining increased acceptance and use in electrical power system due to their inherent linearity, greater accuracy and wide operating current range. This paper presents use of RC as an advanced measurement device suitable for DDR. Case study for validation of use of RC is carried out on low voltage system. The simulation results of Distance protection scheme used for protection of part of 220kV AC system shows excellent performance of RC over CT under abnormal conditions.


Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 125 ◽  
Author(s):  
Lurian Pires Klein ◽  
Aleksandra Krivoglazova ◽  
Luisa Matos ◽  
Jorge Landeck ◽  
Manuel de Azevedo

The co-evolution of techno-economic, societal, environmental and political-institutional systems towards sustainable energy transitions is largely influencing the disruptive reconfiguration of the energy sector across the globe. At the heart of this disruption is the peer-to-peer energy sharing concept. Nonetheless, peer-to-peer energy sharing business models are yet very little put into practice due to the rigid energy market structures and lagging regulatory frameworks across the globe. In view of this, this paper presents a novel peer-to-peer energy sharing business model developed specifically for the context of the Portuguese energy market, which was successfully trialed in three pilot projects in Portugal under real market conditions. All things considered, the novelty of this paper lies on an innovative approach for the collaborative use of the surplus electricity generation from photovoltaic systems between end-users under the same low voltage/medium voltage transformer substation, which resulted in direct financial benefits to them. While absent deregulation obstructs the implementation of effective peer-to-peer energy sharing markets in Portugal, such demonstration projects are essential to challenge restrictive regulatory frameworks that do not keep pace with techno-economic and societal innovations, thus helping to build the emerging consumer-centric energy regime and disrupt the old one.


2017 ◽  
Vol 66 (6) ◽  
pp. 1405-1410 ◽  
Author(s):  
Huanghui Zhang ◽  
Haiming Shao ◽  
Jiafu Wang ◽  
Wei Wang ◽  
Feipeng Lin ◽  
...  

Weed Science ◽  
1983 ◽  
Vol 31 (2) ◽  
pp. 159-162 ◽  
Author(s):  
Dennis L. Bucholtz ◽  
F. Dan Hess

The combustion apparatus described provides a rapid and inexpensive alternative for measurement of radioisotopes in plant parts. The apparatus utilized a nickel-chromium resistance wire connected to a low-voltage transformer to generate the heat required to ignite the plant tissue. The nickel-chromium wire also served as the sample holder. Combustion was performed in an O2-flushed liquid scintillation vial, and the combustion gases containing either 14CO2 or 3H2O were trapped in situ, scintillant was added, and the vials assayed for radioactivity. The percentage of the radioactivity recovered after combustion was 96.0 for 14C and 93.4 for 3H with standard deviations of 6.8 and 3.0%, respectively.


2021 ◽  
Vol 1972 (1) ◽  
pp. 012049
Author(s):  
Han Liu ◽  
Xian Huizhu ◽  
Duan Dapeng ◽  
Lv Fengming ◽  
Sun Jian ◽  
...  

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