負荷變化에 따른 3相 變壓器의 3次元 有限要素解析

Abstract

A transformer ideally changes one ac voltage level to another voltage level without affecting the actual power supplied. If a transformer steps up the voltage level of a circuit, it must decrease the current to keep the power into the device equal to the power out of it. Therefore, ac electric power can be generated at one central location, its voltage stepped up for transmission over long distances at very low losses, and its voltage stepped down again for final use. Because a transformer has series impedances within it, the output voltage of a transformer varies with the load even if the input voltage remains constant. This paper describes on the characteristic analysis of 3 phase transformer according to load variation. The 3D finite element analysis was used to find out the characteristics of voltage, current and magnetic flux density. It is shown that the magnitudes and the phases secondary voltages and the magnetic flux densities were unbalanced according to the load variation.