Evaluation of W. Quade's time-domain power theory for analysis applications in converter-dominated grids

Abstract:
In converter-dominated grids, the increased diversity of relevant consumer and infeed units requires new methods for grid analysis and load characterization to guarantee stable operation. Conventional methods focusing the fundamental oscillation do not suffice for complete system description. New methods have been proposed ranging from small to large signal analysis methods. However, the whole spectrum of relevant aspects is not yet covered. The active character of power electronic assets with a control depending, non-linear behaviour capable of mimicking various physical source or load structures results in a difficult challenge finding general and reliable load identification and stability analysis routines. This proposal contributes a period-based analysis quantity to this discussion by isolating an interpretation of the nonactive power calculation of the power theory published by W. Quade. While non-active power calculation is regulated through standards such as the DIN 40110 or IEEE 1459, this investigation reveals that the Quade concept performs a nonactive power decomposition into the time and conductor dimension of poly-phase circuits. This outlines a new analysis horizon and may constitute prospects for grid analysis and load characterization applications. A simple practical example will illustrates its implications on a practical load structure.