Ermittlung von Resonanzfaktoren zur Oberschwingungsbewertung nach VDE-AR-N 4110 basierend auf Netzimpedanzmessungen

Resonance factors are determined on various assumptions, which may lead to an overestimation of these factors and consequently misrepresent the electrical characteristic of the grid connection point. This may result in the denial for generation units to connect to the grid even when there is no factual basis for such action upon closer examination. This contribution demonstrates how practical assessments can be achieved by measuring the grid impedance at the point of interconnection. The harmonic assessment in the grid connection process is elucidated, and an adjusted evaluation based on a real case study is presented. Additionally, the resonance factors of further grid connection points are determined based on real measurements and compared. The results indicate that measurement-based resonance factors typically allow for higher harmonic current limit values.