Voltage Stability Analysis Using Energy Function Considering the Transmission-Microgrid Coupling and Microgrid Operation in Islanded Mode

The significant benefits associated with microgrids (MG) lead to their increasing insertion in electrical power systems. The presence of intermittent sources, load demand variations, and the possibility for the MG to operate connected or isolated from the main grid demand an assessment of the transmission-microgrid coupling. Thus, this paper proposes voltage stability analysis in transmission systems considering the transmission-microgrid interaction using an energy function. The methodology identifies if the system is close to the voltage collapse and identifies the best microgrids to have load shedding, alleviating the system's overall condition. The proposed methodologies are validated in a modified IEEE 37 node test feeder and IEEE 30 bus system.