Enhanced grid integration of renewable power plants by grid impedance measurement

This paper deals with the topic grid impedance measurement as an objective instrument to evaluate the grid integration of renewable power plants (RPP) e.g. wind-or pv-farms. Up to now the evaluation of grid integration is realized by using the calculated value of the grid impedance, which is normally provided by the grid owner. Since the grid impedance is a frequency and time dependent value calculated grid impedance does not reflect the real grid situation. This fact results to an incorrect and inefficient as well as uneconomic grid integration of RPP. In the following sections the problem of grid integration using calculated grid impedances is described and proposals are made for an enhanced grid integration of RPP by using realistic measured grid impedances.