Waves and complex power in transmission lines

Park approach belongs to the usual procedures specific of the modal analysis. Under this point of view, it can be therefore used in the analysis of three-phase static components, in particular in the study of transmission lines. In this case, the approach replaces the matrix formulation, specific of the modal analysis, with the space-vectors formulation. In this way, we obtain complex time-functions, similar to those obtained for the single-phase systems, that allow one to synthesize the whole logic modal processes in a straightforward and physically sound way, much more significant than the matrix formulation. For the same reason, the energetic approach appears more effective. Expressed in a complex form valid under any condition, it refers, in particular, to the imaginary power concept. This makes the computation possible, under the power quality point of view, of the effects due to the propagation of the harmonic and sequence instantaneous components along the line.