Investigation of turn-turn short circuit model of YyD transformers based on symmetrical component and field-circuit coupling method

Author(s):  
Y. Yuan ◽  
J. Yang ◽  
W. Li ◽  
J. Diao
2019 ◽  
Vol 34 (5) ◽  
pp. 1998-2007 ◽  
Author(s):  
Thomas Kauffmann ◽  
Ulas Karaagac ◽  
Ilhan Kocar ◽  
Simon Jensen ◽  
Evangelos Farantatos ◽  
...  

2011 ◽  
Vol 219-220 ◽  
pp. 648-651
Author(s):  
Hong Zhang ◽  
Xu Hui Ma ◽  
Xiu Ye Yin

With the development of technology, the power system of offshore facilities (for short: power system) is increasingly complex, short-circuit current calculation process also becomes more complex. The simple recursive algorithm can not meet the requirements of short-circuit current calculation in complex power system. The paper, basing on the principle of short-circuit current calculation, taking modeling ideas, created an equivalent circuit model of power system for short-circuit current calculation. The equivalent circuit model can be used to simplify the progress of calculation and meet the needs of the power system development.


2022 ◽  
Vol 8 ◽  
pp. 1046-1055
Author(s):  
Fan Xiao ◽  
Yongjun Xia ◽  
Kanjun Zhang ◽  
Zhe Zhang ◽  
Xianggen Yin

Batteries ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 18 ◽  
Author(s):  
Sascha Koch ◽  
Alexander Fill ◽  
Katerina Kelesiadou ◽  
Kai Birke

The increasing need for high capacity batteries in plug-in hybrids and all-electric vehicles gives rise to the question of whether these batteries should be equipped with a few large capacity cells or rather many low capacity cells in parallel. This article demonstrates the possible benefits of smaller cells connected in parallel because of discharge effects. Measurements have been conducted proving the beneficial influence of a lower SoC on the thermal runaway behaviour of lithium-ion cells. A second test series examines the short circuit currents during an ongoing thermal propagation in parallel-connected cells. With the help of a developed equivalent circuit model and the results of the test series two major system parameters, the ohmic resistance of a cell during thermal runaway R tr and the resistance post thermal runaway R ptr are extracted for the test set-up. A further developed equivalent circuit model and its analytical description are presented and illustrate the great impact of R ptr on the overall discharged capacity. According to the model, cells with a capacity of no more than C cell = 10–15 Ah and a parallel-connection of 24 cells show the most potential to discharge a significant amount.


2011 ◽  
Vol 1327 ◽  
Author(s):  
Liyuan Han ◽  
Ashraful Islam

ABSTRACTThe present paper discusses the principle of dye-sensitized solar cells (DSCs) in terms of equivalent circuit model and the key issues to improve the device efficiency. Equivalent circuit model is proposed following analysis by electrochemical impedance spectroscopy of the voltage dependence of the internal resistance elements of DSCs. The influence of these elements upon cell performance in areas such as short circuit current density (Jsc), open circuit voltage (Voc), and fill factor (FF) was examined based on the equivalent circuit. Efficient sensitization of nanocrystalline TiO2 film was observed across the whole visible range and into the near-IR region as far as 1000 nm with a new panchromatic substituted β-diketonato Ru(II)-terpyridine dye (HIG1). Introduction of bulky alkyl substituent group in a β-diketonato Ru(II)-terpyridine dye (A3) suppress aggregate formation result in an improved performance of DSCs and the performance is independent of the additive added during the dye adsorption process. The haze factor of TiO2 electrodes is a useful index when fabricating light-confined TiO2 electrodes to improve Jsc. It was demonstrated that blocking of bare TiO2 surface with small molecules is an effective way of suppress interfacial charge recombination at the TiO2-dye/electrolyte interface and of improving shunt resistance and Voc. FF was also improved by reduction of the internal series resistance, which is composed of the following three elements: the redox reaction resistance at the platinum counter electrode, the resistance of carrier transport by ions in the electrolyte, and resistance due to the sheet resistance of the transparent conducting oxide. Finally, the highest efficiency scores of 10.4% and 11.1% (aperture illumination area 1.004cm2 and 0.219cm2, respectively) were confirmed by a public test center.


Author(s):  
Krzysztof Makowski ◽  
Aleksander Leicht

PurposeThe purpose of this paper is to present analysis of short-circuit transients in a single-phase self-excited induction generator (SP-SEIG) for different capacitor topologies.Design/methodology/approachThe paper presents field analysis of the short-circuit problem in the SP-SEIG on the base of two-dimensional field-circuit model of the generator.FindingsThe carried-out field computations of the tested SP-SEIG show that the self-excited induction generator is intrinsically protected from the results of sudden short-circuit, as output voltage and current drop rapidly to zero. Short-circuit is a problem when a series capacitor is used to improve output voltage regulation. Experimental results show that re-excitation of the generator is possible after the short-circuit is removed.Originality/valueThe originality of the paper is the presented analysis of short-circuit transients at terminals of SP-SEIG. A finite elements method-based field circuit model was used. The simulation results were validated by the measurements conducted on a laboratory test setup.


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