Why we use the term non-active power, and how it can be measured under non-ideal power supply conditions

The paper identifies the difference between the terms reactive power and non-active power and describes them in terms of a general power theory that has been developed for m-wire systems in the instantaneous and average power domains. The differences between conventional measurements and the new approach are demonstrated using laboratory-scale three-phase transformers under conditions similar to those experienced on large power systems carrying geomagnetically induced currents, with harmonic distortion, unbalance and dc components. The implications affect all multi-wire systems under non-ideal conditions, including distorting loads and smart grid integration.