Operation Features Researching of Three-Phase Transformers Switched on to an Asymmetric Load

Abstract

Purpose: The article is dedicated to the various parameters influence investigation on the transient currents inrushes, flowing at the three-phase transformer loading.

Methodology: The authors examined of the electrical power system components, analyzed the features of the electrical power system and the level of electricity losses in each element during its operation, depending on the load parameters. The paper outlines the main ways to control the elements of the electrical power system, their advantages and disadvantages. The basis of the methodology of this article is the concept of calculating the inrush currents that occur during transients of the three-phase transformer inclusion on the load, due to the analysis of the load and transformer parameters influence using a transformer substation computer model.

Findings: Using the transformer station model and the authors were calculated and obtained dependences according to the magnitude of the inrush current on each phase of the transformer by: moment’s combinations of loads connection, load level changes and power factor of transformer loading, introducing a transformer asymmetric loading mode. The model calculation analysis data obtained follows that the value of the total minimum and maximum inrush currents when the load is connected to the transformer increases: proportional to the transformer load level rise; while reducing the load power factor; with an increase in the level of the transformer load asymmetry.

Conclusion: The findings may be used to create a control system, allowing to reduce energy losses when operating the elements of power supply system.