Circuits with semi-periodic currents: Main features and power properties

Document Type


Publication Date



The active, reactive, scattered and unbalanced currents and powers, the RMS value and harmonic components are defined only for periodic quantities. Unfortunately, non-periodic variation of load parameters or their periodic variation but with a frequency different than the frequency of the voltage produced by power generators, causes non-periodic currents. Such non-periodic currents, however, are often much lower than periodic components and consequently, the entire current can be considered as semi-periodic. The notion of semi-periodic voltage has similar meaning. This paper discusses the main properties of semi-periodic currents, it provides their classification and introduces a concept of primary, secondary, coperiodic, non-coperiodic components as well as the concept of interharmonic noise and quasi-harmonics. The paper investigates how circuits with semi-periodic voltages and currents could be described in power terms.

Publication Source (Journal or Book title)

European Transactions on Electrical Power

First Page


Last Page


This document is currently not available here.