Results 11 to 20 of about 536 (252)

Energy limit of oil‐immersed transformers: A concept and its application in different climate conditions

IET Generation, Transmission & Distribution, 2021
The reality of modern power grids requires the use of flexibilities from generation, load and storage. These flexibilities allow system operators to modify a transformer loading in a smart way. Therefore, power constraints of transformers can be overcome
Ildar Daminov, Anton Prokhorov, Raphael Caire, Marie‐Cécile Alvarez‐Herault   +3 more
doaj   +1 more source

DC breakdown characteristics and charges accumulation behaviour of thermally upgraded paper aged in natural ester

IET Science, Measurement & Technology, 2021
Considering that the working temperature is much higher in high‐voltage direct‐current (HVDC) convert transformers than in conventional AC transformers, the combination of thermally upgraded paper and natural ester might be a better choice to withstand ...
Runhao Zou, Jian Hao, Yanqing Li, Ruijin Liao, Wenping Li   +4 more
doaj   +1 more source

Analysis of hybrid polarization frequency domain spectrum characteristics of oil‐paper insulation transformers

IET Science, Measurement & Technology, 2021
This paper utilizes a hybrid Debye model to accurately simulate the relaxation response process of the oil‐paper insulation of a transformer to explore the application of frequency domain dielectric spectroscopy (FDS) in nondestructive diagnosis of the ...
Yang Zou, Jin He, Qianlin He, Mengqi Wang   +3 more
doaj   +1 more source

Ageing of DC conduction in thermally aged oil‐impregnated pressboard

IET Science, Measurement & Technology, 2021
Ageing of the conduction process in a dielectric allows a better understanding of the phenomena. Available literature shows that the DC conductivity of oil impregnated pressboard increases with applied electric stress, particularly above 40 °C.
Nasirul Haque, Sovan Dalai, Biswendu Chatterjee, Sivaji Chakravorti   +3 more
doaj   +1 more source

Partial discharge observation of a complex insulation structure model and residual space charge characteristics investigation under repeated lightning impulses

IET Science, Measurement & Technology, 2021
In this research, the authors concentrated on a rarely studied part in the power transformer's insulation structure: the connection part of radial and axial spacers. An experimental model was constructed to simulate this part.
Li Lu, Satoshi Ichimura, Toshiaki Rokunohe   +2 more
doaj   +1 more source

Prevention of the current transformer saturation by using negative resistance

IET Generation, Transmission & Distribution, 2021
In the power grid, various conditions may occur that saturate the core of a current transformer. Saturation of the protection core of the current transformers can cause a malfunction in the protection relays.
Saeed Sanati, Yousef Alinejad‐Beromi
doaj   +1 more source

Experimental investigations using quadratic‐tripping characteristics based on alienation/coherence coefficients of voltage and current signals for synchronous generators protection

IET Generation, Transmission & Distribution, 2021
A protection scheme is proposed using alienation method derived from coherence model which is a backup protection method for the differential overcurrent protection of synchronous generators.
Ragab A. Mahmoud, Ehab S. Elwakil
doaj   +1 more source

Air‐core dry‐type shunt reactor protection based on an alternative current alpha plane

IET Generation, Transmission & Distribution, 2021
This paper proposes an alternative current alpha plane protection for shunt reactors, which is able to identify internal faults, including turn‐to‐turn faults.
Maria Leonor Silva de Almeida, Larissa Marques Peres, Guilherme Gomes dos Santos   +2 more
doaj   +1 more source

A soft‐switching inverting high step‐down converter with a pair of coupled inductors and self‐driven synchronous rectifier

IET Power Electronics, 2021
In this paper, a non‐isolated coupled‐inductor high step‐down converter with extended duty cycle is proposed, which operates under discontinuous conduction mode.
Farzad Hosseinabadi, Behzad Soleymani, Ehsan Adib, Md. Rabiul Islam, Hosein Farzanehfard, Abbas Z. Kouzani, M. A. Parvez Mahmud   +6 more
doaj   +1 more source

Variable Reactance Criteria to Mitigate Voltage Deviations in Power Transformers in Light- and Over-Load Conditions

Machines, 2023
In this paper, variable reactance (VR) criteria are proposed to mitigate voltage deviations in power transformers under light-load inductive and capacitive conditions, as well as for over-load conditions.
Marta Haro-Larrode
doaj   +1 more source