A Correlation Index to Evaluate Impact of PV Installation on Joule Losses

This paper proposes a new correlation index, in order to connect the sizing and the siting of a PV unit with the respective impact on Joule losses of a radial distribution feeder. Randomly generated scenarios for PV units siting are investigated and based on the results the proposed index is formulated, corrected, and validated. The index incorporates factors such as: 1) the correlation coefficient between the installed PV capacity per node and the respective power rating of the distribution transformer, and 2) the size of a PV unit in relation to its distance from the feeding end. The importance of this index lies in the fact that it may be used from the DSO to evaluate the contribution of a new PV unit interconnection to the annual Joule losses of a line beforehand, and thus perform a better cost allocation.