Small-scale embedded generation effect on voltage profile: an analytical method

Nowadays, deep concern is focused on the introduction of small-scale embedded generation (SSEG) in LV networks, since some technologies have a natural inclination to be easily integrated into urban LV distribution networks. As a consequence, studies on the effects produced on LV distribution systems by SSEG are gaining more and more relevance. Some aspects regarding the quality of the power supplied to customers are dealt with, taking into consideration long-duration voltage variations in the presence of SSEG. In particular, the effect on the voltage profile in a LV distribution feeder is examined with reference to both distributed loads and lumped loads. Some analytical expressions are derived to determine the limit value of the power that can be injected into a single node of a distribution feeder without causing overvoltages. The expressions derived for distributed loads are compared to those for lumped loads in order to assess if the analytical evaluation of the current threshold can be performed by means of an equivalent model based on continuous quantities with a negligible error, since actually, the analysis of real cases implies dealing with lumped loads.