Selecting Power Transformers Based on Magnetic Path Parameters

Abstract

Present State of the Issue Considered: The authors considered the indicators, which qualitatively characterize the parameters and the magnetized inrush current value of the transformer's magnetic core and the induced transition processes in the high voltage electric main. Materials and methods: The indicators, evaluating the losses of energy of the magnetizing inrush current aperiodic component stored in the magnetic path inductance at transition processes; identification of magnetizing path parameters in a power transformer. The authors studied the following indicators: the tangent of the angle $\delta-$ describes the loss of energy in the active resistance of the magnetic path, merit factor Q - shows how many times the path reactive resistance exceeds the active one. Results: The indicators allow for the qualitatively assessment and comparison of transformers in terms of the minimal impact of the magnetizing inrush current aperiodic component on the electric system and setting the necessary properties to the manufacturer during the transformer manufacture. Conclusions: The indicators provide a quantitative and qualitative assessment of the duration and nature of the decay of the transition process in the electric main.