Voltage Control on LV Distribution Network: Local Regulation Strategies for DG Exploitation

The presence of Dispersed Generation (DG) in LV distribution networks affects voltage profiles along distribution feeders, specifically over-voltages may occur at the DG Point of Common Coupling. This study focuses on a voltage control system that exploits DG units in order to mitigate overvoltage violations. The proposed approach is based on a local-corrective control strategy that modulates the reactive power injected/absorbed by the DG power plants. A chronological analysis is carried out on an annual basis to assess the performance of the control laws proposed and the sensitivity of the LV network characteristics on voltage regulation, i.e., the effectiveness of the LV reactive injections regulation model. From the results obtained by extensive numerical simulations it can be pointed out that the local-corrective regulation approach is a viable solution useful to increase the Hosting Capacity (HC) of existing networks, without the need for complex new infrastructures that entail huge investments. Finally, a novel DG coordination procedure is proposed, this approach has been designed in order to minimize the communication channel requirements, i.e., to allow coordinated voltage control without requiring complex real time apparatus and calculations (measurements, state estimation, Optimal Power Flow, etc.), considered to be impractical for LV grid applications.