Limits to dispersed generation on Italian MV networks

Abstract

This paper describes a procedure developed by the authors with the aim to evaluate the capability of Medium Voltage (MV) busses to accept power injection from dispersed generators and to support the distribution system operators in facing the growing penetration of dispersed generation, especially due to Renewable Energy Sources (RES).\ud This simple procedure simulates an increasing power injection at every bus of the considered sample and checks the violation of operating limits in order to determine the maximum admissible nodal injection. The procedure is applied to a huge network data set, corresponding to real Italian MV grids and representing a significant subset (6%) of the system. Results presented in this paper could be a robust and statistically significant background for technical and economic considerations about the limits for\ud penetration of dispersed generation in the Italian system

Hosting Capacity Analysis: A Review and a New Evaluation Method in Case of Parameters Uncertainty and Multi-Generator

“…The authors of [12] proposed an approach to consider the maximum injection "equi v al ent " to the generators downstream the bus under examination. This method is useful for considering MGHC where the total injection is equal to the equivalent generator.…”

Smart grids: enabler for the energy transition

“…This may lead to limit the diffusion of generators, given the most valuable effects they could entail at both local and global levels: -Voltage variations: injection of active power increases the voltage profile in the neighbouring nodes. Voltage rise represents actually the main limitation to the penetration of DG in rural areas [5].…”

Monte Carlo simulation-based probabilistic assessment of DG penetration in medium voltage distribution networks

“…Additionally, in order to simulate the actual voltage regulation by the OLTC transformer of primary substation, our customized LF [14], [48] requires |V| of the MV busbar of the HV/MV transformer in primary substation to be equal to a fixed setpoint. This value, according to the practices adopted by DSOs, is determined in the condition of maximum load and no generation, in order to avoid possible infringements of the lower bound.…”

“…In order to cope with this situation, appropriate Load Flow (LF) calculations are needed to assess the allowed DG penetration level for a given network, in terms of active DG power that can be connected to a distribution network in accordance with technical constraints (and, obviously, with no modification in structures and no deterioration in reliability and quality of service). However, a realistic evaluation of where and when a constraint infringement occurs can be difficult to obtain by simply using traditional Deterministic LF analysis (DLF), [10]- [14], that neglects the uncertainties of many parameters affecting power system operation.…”

“…overvoltage and overcurrent, is developed in [11]. Three kinds of limits are adopted in [14]: thermal limits, i.e. current limit of each branch, voltage limits (i.e., supply voltage variations) for each bus, and rapid voltage changes associated to sudden variations (e.g.…”