摘要：Recent increasing in industrial and economic development in the present world, demands theuse of more and more electrical energy which has to be transferred over long distances in largequantities efficiently. This is made possible by introducing the higher transmission voltage levelin the power system. Rapid growing this demand for use of higher voltage has given theopportunity to power engineers to develop the insulation of high quality for sustain high voltage(HV) tress over a long period. Presently, in high voltage electrical power system, variety ofmaterials (solid, liquid and gaseous) is used for insulation purpose to protect the incipientfailure in HV power equipment. The insulation design for such HV power equipment is one ofthe important challenging tasks to the power engineers as the HV equipments are involved withhuge cost. To protect such equipments different types of conducting electrodes having protectivegap are used widely throughout the world. Standard sphere electrodes are commonly used forthis purpose among those all electrodes configuration. Normally, air medium is widely use as aninsulating medium in different electrical power equipments as its breakdown strength is 30kV/cm. Therefore electrical breakdown characteristic of small air gap under the differentapplied voltage has its great significance for the designing of various air insulated HVequipment. In this study to simulate the air breakdown voltage experimentally in high voltagelaboratory, standard diameter of 25 cm spheres are used for measurement of air breakdownvoltages at NTP. In addition, the air breakdown voltage with insulation barrier and withoutinsulation barrier is investigated inside the high voltage test laboratory. The effects of thebreakdown voltage on paper insulation have been investigated in this work for qualityassessment. The comparison of microstructure before and after the breakdown test reveals theinformation about the effects of electrical stress on the insulating paper.
关键词：Breakdown voltage; electric field; standard sphere gaps; high voltage; dielectric strength.
