The investigation of magnetising current surges in power transformers

Abstract

The paper suggests a mathematical model for investigation of magnetising current surges at connection of power transformator to the network. It is shown, that calculative types of MCS can be exactly defined by using the parameters of the system and saturative transformer. This mathematical model allows to compare tuning out of different relay from MCS and calculate parameters of operation of protection according to the parameters of the system and transformer or characteristics of one-phase MCS. Program to calculate current in the phases of transformer was elaborated. This program allows to automate the process of transformer operation study at MCS and increase exactness operation and sensitivity of deferential protection of large power.