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Preparation method for voltage-sensitive ceramics used for ultrahigh-voltage power transmission system and having excellent comprehensive electrical performance

A technology of power transmission system and electrical performance, applied in the field of material chemistry, can solve the problems of unstable aging characteristics of ZnO varistors, reduction of nonlinear coefficient, complicated production process, etc., and achieve the elimination of unstable aging performance and increase of nonlinear coefficient , The effect of stabilizing V-I characteristics

Inactive Publication Date: 2016-05-11
TSINGHUA UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In actual industrial production, Al ions are mostly used as donor ions to be added to ZnO varistor materials, but the addition of Al ions is often accompanied by an increase in leakage current, and at the same time leads to a decrease in the nonlinear coefficient, and the aging characteristics of ZnO varistors also become unstable
In industrial applications, there is also a method of pre-sintering ZnO and some auxiliary additives, so that part of the mixed raw materials are pre-reacted to improve the barrier and stability of the pressure-sensitive material. This method complicates the production process
At present, mainly by improving the uniformity of the crystal grains, the current can evenly flow through the entire varistor valve, thereby increasing the flow capacity of the ZnO varistor, but the uniformity of the grains is affected by the sintering process and the mixing and grinding process of raw materials, etc. The impact is greater, and it is more difficult to achieve uniformity of grains

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] (1) Slurry preparation

[0037] Auxiliary additives for ball milling:

[0038] Bi 2 o 3 (1.5mol%), MnO 2 (1mol%), Sb 2 o 3 (1mol%), Co 2 o 3 (1mol%), SiO 2 (1.5mol%) and Cr 2 o 3 (1mol%) was put into a ball mill jar of a star ball mill, an appropriate amount of deionized water was added, and ball milled for 300 min.

[0039] Add 90% mol of ZnO to the auxiliary mixing slurry after ball milling, add PVA, a dispersant and an appropriate amount of deionized water, and mix and ball mill all the mixing materials until they are uniformly dispersed.

[0040] Add aluminum and yttrium ions

[0041] In the uniformly mixed ZnO and auxiliary additives, add Al(NO3) 3 .9H 2 O (2mol%), Y (NO3) 3 .9H 2 O (2mol%), continue ball milling for 60min, after spray granulation, contain water.

[0042] (2) Molding

[0043] The powder obtained in the previous step is sprayed, and after automatically containing water, the tablet molding process is adopted. Using a hydraulic table...

Embodiment 2

[0054] (1) Slurry preparation

[0055] Auxiliary additives for ball milling:

[0056] Bi 2 o 3 (1.55mol%), MnO 2 (0.99mol%), Sb 2 o 3 (0.99mol%), Co 2 o 3 (1.01mol%), SiO 2 (1.48mol%) and Cr 2 o 3 (1mol%) was put into a ball mill jar of a star ball mill, an appropriate amount of deionized water was added, and ball milled for 300 min.

[0057] Add 92% mol of ZnO to the auxiliary mixing slurry after ball milling, add PVA, a dispersant and an appropriate amount of deionized water, and mix and ball mill all the mixing materials until they are uniformly dispersed.

[0058] Add aluminum and yttrium ions

[0059] In the uniformly mixed ZnO and auxiliary additives, add Al(NO3) 3 .9H 2 O (2.6mol%), Y (NO3) 3 .9H 2 O (2.1mol%), continue ball milling for 60min, after spray granulation, contain water.

[0060] (2) Molding

[0061] The powder obtained in the previous step is sprayed, and after automatically containing water, the tablet molding process is adopted. Using a ...

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PUM

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Abstract

A preparation method for voltage-sensitive ceramics used for an ultrahigh-voltage power transmission system and having excellent comprehensive electrical performance is provided. Preparation raw materials include zinc oxide ZnO, bismuth oxide Bi2O3, manganese dioxide MnO2, antimony trioxide Sb2O3, cobalt sesquioxide Co2O3, silica SiO2, alumina Al2O3, gallium oxide Ga2O3, and chromic oxide Cr2O3. The preparation method has the beneficial effects that leakage current is suppressed; combined addition of Al and Ga elements makes the aging performance of a ZnO voltage-sensitive resistor prepared by the formula more stable, and the shortcoming of unstable voltage-sensitive resistor aging performance brought by simple addition of Al ions is solved.

Description

technical field [0001] The invention relates to the field of material chemistry, in particular to a ceramic preparation method. Background technique [0002] ZnO varistors are made of ZnO as the main raw material, adding a small amount of Bi2O3, Sb2O3, MnO2, Cr2O3, Co2O3, and silver glass powder as auxiliary components, and are prepared by ceramic sintering process. Due to its good nonlinear performance and the advantages of large current capacity, since it was discovered in the 1870s, ZnO varistors have been widely used in power system lightning protection and overvoltage protection of power equipment as the core component of power system lightning arresters. [0003] With the continuous improvement of the transmission voltage level, especially in the UHV system, the problem of equipment insulation has become increasingly prominent, and it will pay a high price to comprehensively improve the equipment insulation. The surge arrester assembled with ZnO varistors with high gr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/453C04B35/622C04B35/626
CPCC04B35/453C04B35/622C04B35/62605C04B35/6261C04B2235/3241C04B2235/3267C04B2235/3275C04B2235/3294C04B2235/3298C04B2235/3418C04B2235/602C04B2235/6562C04B2235/6567
Inventor 何金良胡军赵洪峰曾嵘
Owner TSINGHUA UNIV
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