Network creation and management

(To determine the topology of a network section (1) of an AC network (4) comprising a network connection point (3), at least outbound one of the Netanschlusspunkt (3) strand (5-9) having a plurality of power-consuming units (12, 13) and / or power generation units 14/15; 16/18; 17/19; 20/21) and at least one measuring point in the at least one strand (5-9) which are variations of subscriber lines of at least one of the plurality of power-consuming units (12, 13) and / or power generation units (14/15; 16/18; 17/19; 20/21) and variations of the mains voltage to the at least one measurement point of the mesh section (1) was measured. Then dependencies of the variations of the mains voltage to the at least one measurement point of the variations of the power ratings of at least some ones of the plurality of energy consumption units (12, 13) and / or power generation units (14/15; 16/18; 17/19; 20/21) certainly.