The increasing integration of controllable energy resources into distribution networks introduces novel challenges and opportunities in terms of distributed voltage control. As these devices are mainly controlling their active power injection, and do not provide voltage control capabilities, a regional coordinator has to determine favorable combinations of power injections and consumption with respect to the voltage profile of the particular network segment. The main challenge is to approximate voltage profiles from the complex nodal power balance of all nodes in a particular network. Standard algorithms calculate exact voltage profiles from combinations of complex nodal net power, but fail to provide information about the network conditions in the surrounding of this particular point of operation. In this paper we present a novel approach basing on the geometrical interpretation of a modified nodal admittance matrix. It allows for the determination of combinations of power injections in the surrounding of a point of operation that have a similar corresponding voltage profiles. Our approach takes into account reactive as well as active power injections.