Impact of Photovoltaic Generators on the Three-Phase Short Circuit Operating Conditions

Distributed generation (DG) produces many benefits for the distribution systems, which, although traditionally designed under the assumption of passive networks, have become however active distribution systems. Then, new technical issues must be addressed, involving both normal and abnormal operating conditions such as short circuits. Photovoltaic systems (PVSs) are among the most diffuse DG and their contributions to the short-circuit operating conditions are depending on several factors, such as environmental conditions, PVS inverter control characteristics, self-protection systems, the location and the type of the fault. In this paper, an analytical model able to analyze quickly and accurately the three phase short-circuit operating conditions in a distribution system in presence of PVSs is presented. The model is applied to a typical North American MV network characterized by large penetration of PVSs investigating the influence of the aforementioned factors