scholarly journals Effect of Ionic Conductors on the Suppression of PTC and Carrier Emission of Semiconductive Composites

2020 ◽  
Vol 10 (8) ◽  
pp. 2915 ◽  
Author(s):  
Yingchao Cui ◽  
Hongxia Yin ◽  
Zhaoliang Xing ◽  
Xiangjin Guo ◽  
Shiyi Zhao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Space Charge ◽  
Current Method ◽  
Positive Temperature Coefficient ◽  
Ionic Conductor ◽  
Positive Temperature ◽  
Ionic Conductors ◽  
Ptc Effect ◽  
High Voltage Direct Current ◽  
Key Factor

The positive temperature coefficient (PTC) effect of the semiconductive layers of high-voltage direct current (HVDC) cables is a key factor limiting its usage when the temperature exceeds 70 °C. The conductivity of the ionic conductor increases with the increase in temperature. Based on the characteristics of the ionic conductor, the PTC effect of the composite can be weakened by doping the ionic conductor into the semiconductive materials. Thus, in this paper, the PCT effects of electrical resistivity in perovskite La0.6Sr0.4CoO3 (LSC) particle-dispersed semiconductive composites are discussed based on experimental results from scanning electron microscopy (SEM), transmission electron microscopy (TEM) and a semiconductive resistance test device. Semiconductive composites with different LSC contents of 0.5 wt%, 1 wt%, 3 wt%, and 5 wt% were prepared by hot pressing crosslinking. The results show that the PTC effect is weakened due to the addition of LSC. At the same time, the injection of space charge in the insulating sample is characterized by the pulsed electroacoustic method (PEA) and the thermally stimulated current method (TSC), and the results show that when the content of LSC is 1 wt%, the injection of space charge in the insulating layer can be significantly reduced.

Influence of the Semiconductive Composites Doped with Li4Ti5O12 on Space Charge Implantation in LDPE

2021 ◽  
Author(s):  
Hongxia Yin ◽  
Shiyi Zhao ◽  
Chuncheng Hao ◽  
Qingquan Lei
Keyword(s):  
Electric Field ◽  
Space Charge ◽  
High Voltage ◽  
Positive Temperature Coefficient ◽  
Positive Temperature ◽  
Conductive Network ◽  
Charge Accumulation ◽  
Insulation Layer ◽  
Injection Process ◽  
Key Factor

Abstract Space charge accumulation in the insulating layers of high-voltage directed current (HVDC) cables is the key factor that leads to their degradation and limits the operation safety. Hence, it is necessary to effectively inhibit carrier implantation to these layers. In this study, a new method is proposed to suppress the charge implantation to the cable insulation layer, a certain amount of Li4Ti5O12 nanopowder is doped in the semiconductive screen to enhance the internal conductive network and homogenize the electric field. The influences of Li4Ti5O12 particles in the semiconductive composite screen on the positive temperature coefficient effect and space charge injection process are explored. The obtained results reveal that the charge quantity in the insulation layer corresponding to the minimum peak resistivity is reduced by 49.7%, 58.9%, and 46.9% after the polarization at a Li4Ti5O12 content of 4 wt.% and electric field strengths of 10, 20, and 30 kV/mm, respectively.

Distinct positive temperature coefficient effect of polymer–carbon fiber composites evaluated in terms of polymer absorption on fiber surface

2016 ◽  
Vol 18 (11) ◽  
pp. 8081-8087 ◽  
Author(s):  
Xi Zhang ◽  
Shaodi Zheng ◽  
Xiaofang Zheng ◽  
Zhengying Liu ◽  
Wei Yang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Temperature Coefficient ◽  
High Density Polyethylene ◽  
Fiber Surface ◽  
Fiber Composites ◽  
Positive Temperature Coefficient ◽  
High Density ◽  
Carbon Fiber Composites ◽  
Positive Temperature ◽  
Ptc Effect

The positive temperature coefficient (PTC) effect for high-density polyethylene (HDPE)/carbon fiber (CF) composites was studied.

Influence of (Bi0.5M0.5)TiO3 (M=Li, Na, K, Rb) Addition on the Curie Temperature and PTC Effect of BaTiO3-Based Ceramics

2016 ◽  
Vol 697 ◽  
pp. 239-242 ◽  
Author(s):  
Meng Meng Yang ◽  
Zhi Jian Peng ◽  
Cheng Biao Wang ◽  
Xiu Li Fu
Keyword(s):  
Curie Temperature ◽  
Temperature Coefficient ◽  
Solid Solutions ◽  
High Purity ◽  
Positive Temperature Coefficient ◽  
Positive Temperature ◽  
Ptc Effect ◽  
Alkali Ions

In order to investigate the influence of (Bi0.5M0.5)TiO3 (M=Li, Na, K, Rb) addition on the Curie temperature (Tc) and positive temperature coefficient (PTC) effect of BaTiO3-based ceramics, BaTiO3-(Bi0.5M0.5)TiO3 (M=Li, Na, K, Rb) solid solutions were prepared by a conventional solid sintering reaction using high-purity reagents. It was found that the Tc of the samples would vary with (Bi0.5M0.5)TiO3 of different alkali ions, in which BT-BKT ceramics had the highest value (about 148 °C). Moreover, the incorporation of alkali ions would influence the PTC effect of the sample, which can be defined by the resistivity jump with the ratio of maximum to minimum resistivity (ρmax/ρmin). Under the present conditions, the ρmax/ρmin of BT-BRT and BT-BLT ceramics were almost equal and higher than those of BT-BNT and BT-BKT ceramics.

scholarly journals Synthesis of a Novel Semi-Conductive Composites Doping with La0.8Sr0.2MnO3 for Excellent Electric Performance for HVDC Cable

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 809 ◽  
Author(s):  
Hongxia Yin ◽  
Yingcao Cui ◽  
Yanhui Wei ◽  
Chuncheng Hao ◽  
Qingquan Lei
Keyword(s):  
Electric Field ◽  
Space Charge ◽  
Charge Injection ◽  
Inhibitory Effect ◽  
Uniform Electric Field ◽  
Positive Temperature ◽  
Ptc Effect ◽  
Suppression Effect ◽  
Conductive Composites ◽  
Conductive Particles

The semi-conductive layer located between the wire core and the insulation layer in high voltage direct current (HVDC) cable plays a vital role in uniform electric field and affecting space charges behaviors. In this work, the research idea of adding ionic conductive particles to semi-conductive materials to improve the conductive network and reduce the energy of the moving charge inside it and to suppress charge injection was proposed. Semi-conductive composites doped with different La0.8Sr0.2MnO3 (LSM) contents were prepared. Resistivity at different temperatures was measured to investigate the positive temperature coefficient (PTC) effect. Pulse electro-acoustic (PEA) method and thermal-stimulation depolarization currents (TSDC) tests of the insulation layers were carried out. From the results, space charge distribution and TSDC currents in the insulation samples were analyzed to evaluate the inhibitory effect on space charge injection. When LSM content is 6 wt. %, the experimental results show that the PTC effect of the specimen and charge injection are both being suppressed significantly. The maximum resistivity of it is decreased by 53.3% and the insulation sample has the smallest charge amount, 1.85 × 10−7 C under 10 kV/mm—decreased by 40%, 3.6 × 10−7 C under 20 kV/mm—decreased by 45%, and 6.42 × 10−7 C under 30 kV/mm—decreased by 26%. When the LSM content reaches 10 wt. %, the suppression effect on the PTC effect and the charge injection are both weakened, owing to the agglomeration of the conductive particles inside the composites which leads to the interface electric field distortion and results in charge injection enhancement.

scholarly journals Properties of Electrochromic Cell with WO3 and NiO: the Influence of Ionic Conductor

2015 ◽  
Vol 16 (3) ◽  
pp. 475-480
Author(s):  
T.N. Sabov ◽  
I.M. Hatsevych ◽  
O.I. Gudimenko ◽  
V.P. Melnyk ◽  
B.M. Romanyuk ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ionic Conductor ◽  
Ionic Conductors ◽  
X Ray ◽  
Coloration Efficiency ◽  
Tin Oxides ◽  
Electrochromic Cell ◽  
Different Types ◽  
Nio Films ◽  
Scanning Electron

The electrochromic WO3 and NiO films were deposited by magnetron sputtering on indium tin oxides coated glass. The structural properties of the films were investigated by scanning electron microscopy and X-ray diffractometery techniques. The electrochromic properties of the films were investigated by means cyclic voltammetry using different types of ionic conductors. The use of water electrolytes and electrolytes which are based on propylene carbonate leads to the destruction of electrochromic cells. The stable working electrochromic cell with WO3 and NiO films was obtained using ionic liquid as the ionic conductor. The coloration efficiency of electrochromic cell which is based on amorphous WO3 film and crystalline NiO film is 28.7 cm2/C.

Effects of Electroless Nickel Plating on Resistivity-temperature Characteristics of (Ba1-xPbx)TiO3thermistor

1997 ◽  
Vol 12 (4) ◽  
pp. 877-879 ◽  
Author(s):  
Chen Wanping ◽  
Li Longtu ◽  
Gui Zhilun
Keyword(s):  
Temperature Coefficient ◽  
Electroless Nickel ◽  
Positive Temperature Coefficient ◽  
Positive Temperature ◽  
Electroless Nickel Plating ◽  
Nickel Plating ◽  
Hydrogen Atoms ◽  
Temperature Characteristics ◽  
Ptc Effect ◽  
Plating Solution

Effects of electroless nickel plating on resistivity-temperature (R-T) characteristics of (Ba1-xPbx)TiO3 thermistor were studied. Comparison experiments showed that not only the permeation of plating solution, but also the reaction of electroless nickel plating influences the positive temperature coefficient (PTC) effect, and that the two effects are different in nature. It is first proposed in this paper that hydrogen atoms generated in electroless nickel plating may reduce components of PTC ceramics.

Sensing Characteristics of Improved Positive Temperature Coefficient Thermistors with Paint Forms

2021 ◽  
Vol 21 (7) ◽  
pp. 3891-3896
Author(s):  
Ju-Hun Ahn ◽  
Chang-Yull Lee
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Surface Temperature ◽  
Temperature Sensor ◽  
Positive Temperature Coefficient ◽  
Positive Temperature ◽  
Sensing Characteristics ◽  
Typical Temperature ◽  
Scanning Electron

The disadvantage of using a typical temperature sensor is limited depending on the shape of the model to be measured. If the shape is curved, it is not easy to check the surface temperature. A smart paint for temperature measurement is proposed to overcome this disadvantage. Polymer solutions were prepared with a dispersion of materials and viscosity with the properties of paint forms. The smart paints showed various sensing characteristics depending on the amount of materials. In addition, it was analyzed through the scanning electron microscopy (SEM) that sliver particles are disposed around the ceramic particles to have electrical conductivity. This study optimized the proportion of ceramics added to smart paints so that they could overcome the limitations of PTC thermistors that can only identify specific temperatures. Therefore, the developed paint-type temperature sensor makes it easy to measure the temperature of various models.

A new kind of shape-stabilized PCMs with positive temperature coefficient (PTC) effect

2014 ◽  
Vol 79 ◽  
pp. 470-476 ◽  
Author(s):  
Wen-long Cheng ◽  
Wan-fan Wu ◽  
Jia-liang Song ◽  
Yi Liu ◽  
Shuai Yuan ◽  
...  
Keyword(s):  
Temperature Coefficient ◽  
Positive Temperature Coefficient ◽  
Positive Temperature ◽  
Ptc Effect
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