scholarly journals Nickel oxide doping effects on electrical characteristics and microstructural phases of ZnO varistors with low residual voltage ratio

2011 ◽  
Vol 119 (1385) ◽  
pp. 43-47 ◽  
Author(s):  
Jinliang HE ◽  
Wangcheng LONG ◽  
Jun HU ◽  
Jun LIU
Keyword(s):  
Nickel Oxide ◽  
Electrical Characteristics ◽  
Residual Voltage ◽  
Voltage Ratio ◽  
Doping Effects ◽  
Zno Varistors

The Effects of Cu Dopant on the Microstructure and Non-Ohmic Electrical Properties of ZnO Varistors

2011 ◽  
Vol 343-344 ◽  
pp. 160-165 ◽  
Author(s):  
Ji Wei Fan ◽  
Xiao Peng Li ◽  
Zhen Guo Zhang ◽  
Zhi Qiang Jiao ◽  
Xiang Yang Liu ◽  
...  
Keyword(s):  
Electrical Property ◽  
Electrical Properties ◽  
Grain Boundary ◽  
Grain Growth ◽  
Electrical Characteristics ◽  
Doping Effects ◽  
Zno Varistors ◽  
Doped Zno ◽  
Cu Dopant ◽  
Good Agreement

The doping effects of Cu on the microstructure and non-ohmic electrical properties of ZnO varistors were studied. Addition of Cu2O can enhance the ZnO grain growth during sintering. The SEM and EDS results revealed that the added Cu mainly distributed in the grain boundary and spinel phases of ZnO varistors. The Cu2O addition increased the both of grain and grain boundary resistances. However it decreased the non-ohmic electrical characteristics of ZnO varistors, which is a good agreement with similar findings on Ag2O additions, but contrasts to the reports of good non-ohmic electrical property which found on binary Cu doped ZnO varistors.

The relation between residual voltage ratio and microstructural parameters of ZnO varistors

2005 ◽  
Vol 59 (2-3) ◽  
pp. 302-307 ◽  
Author(s):  
Shengtao Li ◽  
Feng Xie ◽  
Fuyi Liu ◽  
Jianying Li ◽  
Mohammad A. Alim
Keyword(s):  
Residual Voltage ◽  
Microstructural Parameters ◽  
Voltage Ratio ◽  
Zno Varistors

scholarly journals Computation of Energy Absorption and Residual Voltage in a Fourth Rail LRT Station Arresters in EMTP-RV: A Comparative Study

2021 ◽  
Author(s):  
Farah Asyikin Abd Rahman ◽  
Mohd Zainal Abidin Ab Kadir ◽  
Ungku Anisa Ungku Amirulddin ◽  
Miszaina Osman
Keyword(s):  
Electromagnetic Transients ◽  
Lightning Strike ◽  
Voltage Gradient ◽  
Urban Transit ◽  
Residual Voltage ◽  
Voltage Ratio ◽  
Lightning Channel ◽  
Breakdown Region ◽  
Current Region ◽  
Performance Results

AbstractThis paper presents a study on the performance of a fourth rail direct current (DC) urban transit affected by an indirect lightning strike. The indirect lightning strike was replicated and represented by a lightning-induced overvoltage by means of the Rusck model, with the sum of two Heidler functions as its lightning channel base current input, on a perfect conducting ground. This study aims to determine whether an indirect lightning strike has any influence with regard to the performance of the LRT Kelana Jaya line, a fourth rail DC urban transit station arrester. The simulations were carried out using the Electromagnetic Transients Program–Restructured Version (EMTP–RV), which includes the comparison performance results between the 3EB4-010 arrester and PDTA09 arrester when induced by a 90 kA (9/200 µs). The results demonstrated that the PDTA09 arrester showed better coordination with the insulated rail bracket of the fourth rail. It allowed a lower residual voltage and a more dynamic response, eventually resulting in better voltage gradient in the pre-breakdown region and decreased residual voltage ratio in the high current region.

Effect of Simultaneous Addition of Zr and Y on Electrical Characteristics of ZnO Varistors

2011 ◽  
Vol 485 ◽  
pp. 257-260 ◽  
Author(s):  
Takayuki Watanabe ◽  
Ai Fukumori ◽  
Yuji Akiyamna ◽  
Yuuki Sato ◽  
Shinzo Yoshikado
Keyword(s):  
Leakage Current ◽  
Nonlinear Coefficient ◽  
The Other ◽  
Electrical Characteristics ◽  
Simultaneous Addition ◽  
Zno Varistor ◽  
Low Leakage ◽  
Electrical Degradation ◽  
Low Leakage Current ◽  
Zno Varistors

The effect of simultaneously adding Zr and Y to Bi–Mn–Co–Sb–Si–Cr–Ni-added ZnO varistors (having the same composition as a commercial varistor) on the varistor voltage, leakage current, and resistance to electrical degradation were investigated. Varistor voltage increased with increasing amount of Y for addition of 0–2 mol % Zr. On the other hand, the nonlinear coefficient α prior to electrical degradation changed very little on the addition of both Y and Zr. With the addition of approximately 1 mol% Zr, the leakage current decreased with increasing amount of Y added. A ZnO varistor with a varistor voltage of approximately 600 V/m, a low leakage current, and excellent resistance to electrical degradation was fabricated by adding approximately 2 mol% Y and approximately 1 mol% Zr.

Voltage Response of ZnO Varistors to 8/20 µs Surge Current

2007 ◽  
Vol 280-283 ◽  
pp. 285-288 ◽  
Author(s):  
Zhen Ya Lu ◽  
Zhi Wu Chen ◽  
Feng Jin Yang
Keyword(s):  
Skin Effect ◽  
Voltage Response ◽  
Voltage Waveform ◽  
Residual Voltage ◽  
Zno Varistor ◽  
Rlc Circuit ◽  
Rear Part ◽  
Zno Varistors ◽  
Voltage Peak ◽  
Surge Current

The voltage response of ZnO varistors to 8/20 µs surge current was investigated. The observed frontal spikes on the residual voltage waveforms are caused by the ignition gap, and no frontal spike was observed when a thyristor was used as the discharge trigger. The rear part of the waveform is determined by the damping coefficient of the RLC-circuit. Near the critical point, the residual voltage waveform changes from non-oscillating attenuation modes to distinct across zero oscillating modes along with the increase of the peak current, but there will be no oscillation happen when a thyristor is used as the discharge trigger. The residual voltage peak is not synchronized with the current peak, and the voltage peak is leading, implying that the ZnO varistor appears to be inductive. According to the experiment results, it can be reasonably explained that the voltage peak leading phenomenon is attributed to the transient skin effect of the varistor materials.

Effects of cobalt doping on the electrical characteristics of Al-doped ZnO varistors

2010 ◽  
Vol 64 (9) ◽  
pp. 1081-1084 ◽  
Author(s):  
Wangcheng Long ◽  
Jun Hu ◽  
Jun Liu ◽  
Jinliang He
Keyword(s):  
Electrical Characteristics ◽  
Cobalt Doping ◽  
Zno Varistors ◽  
Doped Zno
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