Working and reflected active powers of three-phase loads

Abstract

Unbalanced and/or harmonic generating loads have to be supplied with a working active power, which is higher than the active power measured at the load terminals. Consequently, energy providers of such loads are under paid for the energy delivered. The difference between the working active power and the common active power is referred to as the reflected active power. The reflected active power increases with the decline of the short circuit to load power ratio. Therefore, the reflected active power could be easily visible in weaker power systems, such as micro-grids in islanded mode or on terminals of very high power industrial loads, such as pulsing loads or arc furnaces. The load generated harmonics and/or load imbalance are the causes for the reflected active power. The paper presents results of studies on the dependence of the reflected active power on the relative short circuit power of the supply source.

Decomposition of the Voltages in a Three-Phase Asymmetrical Circuit with a Non-Sinusoidal Voltage Source

“…The scattered component u s in this example is equal to zero because, according to (12), there is no dispersion of the resistance R e(n) around the equivalent resistance R e for all harmonics and all phases.…”

“…The optimal solution here is to use the theory of Shepherd and Zakikhani [9], but one should remember the inaccuracies of this method. The CPC theory [10][11][12][13][14], whose evolution has accelerated in recent years, can be used to determine the compensator parameters more precisely. Further references can be found in [15][16][17][18][19][20].…”