Analysis Of Main Insulation Electric Field Of Power Transform

Power transformer is an important part of the high voltage power transmission and transformation system. Since the reliability of the main power transformer insulation structure directly affects the safty and stablility of the transformer, the electric field analysis of the power transformer main insulation structure has important theoretical significance.In this paper, by using finite element analysis and the electric field analysis software Elecnet, I get the model of the main insulation structure of 240 MVA power transformer. Then I get the distribution law of the equipotential lines and the electric field intensity,find out the insulation weak links of the system. And on this basis I give the analysis of the reliability of the model Preliminarily.To better evaluate the reliability of power transformer, a dedicated software of analyzing power transformer main insulation electric field is developed. The software, basing on Visual Basic language and Elecnet, can evaluate the reliability of the power transformer main insulation electric by the whole-region power-line scanning method. Finally, the reliability of the model is given by using the software.Then I studied the factors that affect the reliability of the power transformer main insulation structure. Through the observation and its analysis result, it can be know that the electric field intensity value on upper left corner of coil and electrostatic ring is bigger. So the change of the maximum electric field intensity and the minimum insulation margin can be observed by changing the radius of coil and electrostatic ring.The software provided above is a simple and practical tool for the main insulation structure design and reliability analysis for power transformer. By comparing the calculation results of the models of different structure parameters, we can get an important reference for main insulation structure design and reliability analysis for power transformer.