Case study of Transient Regimes in Distribution Network With Distributed Generators

In this paper it was analyzed the influence of a distributed renewable sources of medium voltage power network of the various fault regimes. The real electrical network considered is complex and, depending on the operating scheme, it can contain up to four renewable sources. This real three-phase electrical network was implemented in the “ATP - Alternative Transients Program” software for which the electrical parameters of the model have been transmitted by the power network operator's staffs. It is well-know that for the analysis of the transient regimes an important factor is the connected modes and parameters of the neutral grounding of the power network. For the studied 20 kV network, the neutral can operate with Petersen coil and also with low impedance resistor. Simulations have been made in the ATP model of the network in the event of the occurrence of various types of faults, near the 20kV bus-bars of the substation and at a further point in the grid, near one of the renewable sources.