Electrical networks, and physical systems in general, are known to satisfy a power balance equation which states that the rate of change of the energy in time equals the power at the port of the network minus the power dissipated. However, when complex power is considered, there does not seem to exist a similar statement for the imaginary power, either in the timedomain or in the frequency-domain. Recently, in the context of electromagnetic fields, it has been shown by complexifying the time to t+js and interpreting s as reactive time, that it is possible to set up an imaginary power balance in terms of the rate of change of reactive energy in reactive time. Here these ideas are specialized to linear and time-invariant RLC networks. For non-sinusoidal waveforms it is shown that the rate of change of reactive energy in reactive time contains all the essential properties and features of the commonly accepted definition of reactive power under sinusoidal conditions. We believe that this provides an unambiguous and physically motivated resolution to the longstanding debate on how to generalize reactive power to non-sinusoidal waveforms.

Budeanu’s concept of reactive and distortion power for systems operating under nonsinusoidal conditions has been subject to criticism throughout the past decades, which finally led to its removal from the latest standards. Recently, some new results are presented that shed a different light on Budeanu’s reactive power and its compensation. In this paper, a further analysis is presented to reveal the possibility to endow Budeanu’s reactive and distortion powers with physical meaning. For linear and time-invariant systems it is shown that Budeanu’s reactive power is representing the mean value of the moving average of the difference between the total magnetic and the electric energy. Budeanu’s distortion power, after an appropriate decomposition, represents a measure of the power fluctuations around the active power and Budeanu’s reactive power.