scholarly journals Impact Transient Characteristics and Selection Method of Voltage Transformer Fuse

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 737
Author(s):  
Ke Wang ◽  
Hongwen Liu ◽  
Qing Yang ◽  
Lu Yin ◽  
Jisheng Huang

In a neutral ungrounded system, the high voltage fuses used to protect voltage transformers (VTs) often abnormally blow out, causing unbalanced VT operation. Fuses also fail to blow out in time, resulting in further damage to the VT. This paper reported the results of steady-state current testing, breaking characteristics, X-ray measurements, fuse corona testing, and electromagnetic transient impact testing for VT fuses. This paper comprehensively examines and analyzes the quality and electrical performance of VT fuses and provides new guidance for the use of high voltage fuses in voltage transformers. This paper recommends that 35 and 10 kV systems use fuses rated for a current of 1 A based on a single fuse, which is not easily oxidized and has a wound skeleton composed of an Ag or Ni melt.

2019 ◽  
pp. 101-109 ◽  
Author(s):  
M. I. Aleutdinova ◽  
V. V. Fadin ◽  
Yu. P. Mironov

The possibility of creating a wear-resistant dry sliding electrical contact tungsten/steel was studied. It was shown that tungsten caused severe wear of the quenched steel counterbody due to unlimited plastic flow of its surface layer at a current density up to 150 A/cm2 . This indicated the impossibility of achieving satisfactory characteristics of such a contact. Low electrical conductivity and wear resistance of the contact tungsten/steel were presented in comparison with the known high copper/steel contact characteristics under the same conditions. X-ray phase analysis data of the steel sliding surfaces made it possible to state that the cause of the unsatisfactory sliding of tungsten was the absence of the necessary concentration of FeO oxide on the sliding surface of the steel. 


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2436
Author(s):  
Da-Won Lee ◽  
Achmad Yanuar Maulana ◽  
Chaeeun Lee ◽  
Jungwook Song ◽  
Cybelle M. Futalan ◽  
...  

Doping heteroatoms such as nitrogen (N) and boron (B) into the framework of carbon materials is one of the most efficient methods to improve the electrical performance of carbon-based electrodes. In this study, N-doped carbon has been facilely synthesized using a ZIF-8/polydopamine precursor. The polyhedral structure of ZIF-8 and the effective surface-coating capability of dopamine enabled the formation of N-doped carbon with a hollow structure. The ZIF-8 polyhedron served as a sacrificial template for hollow structures, and dopamine participated as a donor of the nitrogen element. When compared to ZIF-8-derived carbon, the HSNC electrode showed an improved reversible capacity of approximately 1398 mAh·g−1 after 100 cycles, with excellent cycling retention at a voltage range of 0.01 to 3.0 V using a current density of 0.1 A·g−1.


Author(s):  
Hao Liu ◽  
Feng Zhou ◽  
Lixue Chen ◽  
Min Lei ◽  
Xiaodong Yin ◽  
...  

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