Stabilization characteristics of user load equipped with electric spring for various types of line impedance

In the last years, Renewable Energy Sources (RESs) have increasingly contributed to the power delivered by the grid. Despite the environmental benefits made by RESs, their unpredictable power production is responsible of variations in the voltage of the distribution lines that can be disruptive for the functioning of the supplied loads. Electric Spring (ES) is a device that faces such an issue by stabilizing the supply voltage of the critical load of a user in a simple but effective way. This paper is concerned with the stabilization characteristics of a user load supplied by a low-voltage distribution line and equipped with a reactive power-operated ES. After working out an ES model that facilitates the analysis of an ES-equipped user load, its stabilization characteristics are found for three types of line impedance, namely pure resistive, pure inductive and resistive-inductive. Comparison of the resultant characteristics shows the different performance of the ES-equipped user load under various types of line impedance.