Detailed Investigation of the Residual and Non-Symmetry Active and Reactive Power Flow for No-Neutral Three-Phase Nonlinear Circuits

Abstract

The present study further investigates the harmful effects produced by nonlinear circuit elements components of the power grid by assessing the corresponding inflicted parasitic active and reactive power flows. A simplified no-neutral lumped elements circuit model is adopted comprising a three-phase linear balanced transmission line and two distorting loads, each containing a single nonlinear element. Their disparity in the distortive i-v characteristic, one being more distortive than the other, is under scrutiny from the unwanted active and reactive power circulation point of view, which allows to assess the associated dispatching, metering, and billing issues. The theoretical background this study relies on is the power theory developed by Professor Andrei Ţugulea in the mid-'80s, in total accordance with Budeanu’s power definitions. The power quantities designed to provide meaningful insight into the harmful distortive effects (residual-distorting and non-symmetry active and reactive power) are used and computed in the case of four illustrative case studies. The corresponding circuits are numerically solved, and the Ţugulea theory power quantities are evaluated. On that basis, comments and conclusions are presented, in view of further development of theoretical knowledge in the field.