IMPROVEMENT OF THE ELECTRICAL PROPERTIES OF SYNTHETIC LIQUID DIELECTRIC FOR PULSE CAPACITORS

An increase in electricity generation is possible not only through the construction of power plants, but also through the creation of fundamentally new energy sources. One of the problems of modern electrical engineering is to ensure the reliability of the operation of capacitors at electric field strengths exceeding I50-200MV. In the domestic and foreign capacitor industry, for heavy pulse modes, castor oil (CO) is used as a liquid impregnation. The development of a method for producing a substitute for natural castor oil, which is a universal impregnating liquid in capacitors, is an urgent problem in the electrical industry. Thus, we have developed a method for the production of acetoxymethyl-w.hexyl-o-xylene, the electrophysical properties of which make it possible to use it as an environmentally friendly and promising substitute for natural castor oil. However, there was a problem of stabilization, since compounds of the ester type have (as impregnating liquids in capacitors) a disadvantage, which consists in their sensitivity to light hydrolysis and atmospheric effects. Ester exhibits high stability with respect to air up to 200 °С, therefore, inhibition by the addition of antioxidants is required is not new. In this work developed the basic electrophysical properties of the ester-acetoxymethyl-secondary hexyl-o-xyleole; methods for its purification and stabilization. There were chosen the adsorption method of thermo-oxidative stabilization to clean dielectric fluid from conductive impurities. As a result of the electrophysical characteristics of the acetoxymethyl-secondary hexyl-o-xyleole ester, as well as the method of its purification using alumina, and hydrogenation on a catalyst representing 0.2 % palladium on alumina and stabilization using additives NG-2246. As a result of the research, it was possible to obtain an ester with improved electrophysical parameters

The Influence of Particle Characteristic of Manganese Dioxide on Performance of Spinel Lithium Manganese Oxide

Several kinds of chemical manganese dioxide with different particle characteristic were prepared by redox reaction in liquid phase. Then, spinel lithium manganese oxide was synthesized by liquid impregnation. The result implied that the influence of particle characteristic on test result is important. The spinel lithium manganese oxide prepared by spherical MnO2 has better cycle performance than the spinel lithium manganese oxide prepared by MnO2 with irregular shape .The spinel lithium manganese oxide with little particle size has high initial specific capacity. The spinel lithium manganese oxide prepared by MnO2 with anemone shape has high specific capacity and stable cycle performance.