Real-Time Power Flow Monitoring and Control System for Microgrids Integration in Islanded Scenarios

This article presents an enhanced system for real-time power flow monitoring and control (PFMC) for microgrids integration in medium-voltage (MV) distribution networks. The developed solution includes both system architecture and the monitoring and control algorithms, and it has low implementation and installation costs. It is based on the use of hardware and software solutions previously proposed by the authors, i.e., a distributed measurement, a control and communication architecture, and a supervisory control and data acquisition (SCADA) software, which have been enhanced and integrated for the considered application. The SCADA implements a load flow (LF) algorithm for real-time power flows estimation in the MV network branches based only on the load powers measurements at low-voltage level. The system architecture includes new devices specifically designed for distributed generators (DGs) and energy storage systems (ESSs) remote control. The algorithm implemented on the developed PFMC system has been enhanced by including a real-time verification of LF results, which allows detecting devices' unavailability or malfunction occurrence. The PFMC has been implemented in the islanded scenario of the MV distribution network of Ustica Island (Mediterranean Sea) and it has been verified experimentally, in a measurement campaign of one year. In order to deal with different scenarios of DGs/ESSs presence in the microgrid, different operating conditions were reproduced during the measurement campaign, including the case of power flow inversion; such conditions have been obtained by means of an ad hoc developed on-field DG emulator which was remotely controlled by the SCADA system.