Determination and Limitation of Short-Circuit Currents in Low-Voltage Interconnected Networks.

With increasing load density, the short-circuit currents in meshed networks grow in value. Three-pole, two-pole and single-pole short-circuit crrrents in low-voltage model neworks were calculated as a function of load density. High short-circuit currents require the transfer of meshed networks into a different network form, e. g. a system fed by stations, or the strengthening of the low-voltage switching stations. An example is presented showing how a meshed network with high load density can be disconnected without difficulty and operated, when load-flow calculations have been used to gain data on the state of the network. The accuracy of the assumptions made for the load-flow calculation is verified by means of measurements.