Theoretical Study of the Steinmetz Circuit Design

Abstract

Abstract In several three-phase installations, such as electrothermal and traction systems, single-phase loads are sometimes delta connected with reactances to reduce voltage unbalances. This delta-connected set is called the Steinmetz circuit. This work studies the design of this circuit to balance line currents consumed by single-phase loads. In contrast to the simplified conditions considered in the conventional Steinmetz circuit design, the supply voltage unbalance and the resistance of the Steinmetz inductor are used to obtain more general analytical expressions. The differences between these expressions and those obtained from the simplified conditions are analyzed, and a numerical example based on PSpice simulations is provided to compare results. keywords: electric traction systemspower qualityenergy infrastructureunbalanced line currentsSteinmetz circuit