Simplified LV feeders model in presence of DG for MV network studies

The increasing presence of Distributed Generation (DG) at distribution level is worsening the network power quality with higher waveform distortion and voltage variations, and growing the cable and transformer loading level. Otherwise, DG can positively impact the network by increasing the voltage profile in those networks affected by voltage drops, reducing losses, helping Distribution Network Operators (DNO) fulfil regulator’s requirements and avoiding penalty by reducing the numbers of voltage drops and interruptions. In Medium Voltage (MV) network planning studies, LV networks are generally represented as aggregated loads at MV level but, in order to correctly evaluate the effectiveness of possible no network solutions as valuable alternatives to the traditional network reinforcements (identifying voltage constraints on LV networks and so defining the possible improvements), a more realistic model is needed. To this end, a simplified LV network model, that could be easily integrated in a probabilistic electrical simulation tool that simulates all the nodes of the MV network level (whilst having an aggregated view of maximum possible voltage rises and drops at the LV level), has been developed. The model is based on a matrix containing the main information of the LV network: number of feeders, lines parameters (resistance and reactance), load demand (active and reactive power), nominal power of the generators installed and their location in the network.