Impact of distributed generation on weak distribution networks. study case on a Romanian microgrid

The trend of generating power at distribution voltage level, known as distributed generation, is thought to be the future of energy generation, as it is environmental friendly and brings many advantages especially for electricity consumers. The paper presents the study of a real Romanian weak distribution network; the microgrid, comprising a transformer and the associated feeders, supplies single- and 3-phase domestic customers and public lighting. Various penetration levels of photovoltaic generation are considered in order to understand the potential issues that could appear. Practically, single- and 3-phase PV panels of different rated power were placed at diverse locations, i.e. close to feeders' terminals, and transformer substation, respectively. The results showed that harmonic distortion and voltage profile are getting better, while voltage asymmetry is increasing but it remains in the allowed range; positive effects appear especially if the PV generators are located near the feeders' end, where the voltage level is quite low.