Transient Stability Analysis of Islanded MV Microgrid Under Variable Load and Fault Events

The paper analyses the Electromagnetic Transient (EMT) stability analysis of a modified Medium Voltage (MV). This Microgrid (MG) comprises a Diesel Generator (DG) and a Photovoltaic (PV) source under balanced load conditions. The system model was operated in a stable grid-connected mode with only DG's, but the authors proposed a new system with DG and PV in an islanded operation scenario. Islanded MG must operate in a stable mode where controllers can take prompt action in the fault event and make the system more reliable. In this regard, the droop control and PI control manage DG's active power and PV system's power operation, respectively. The Western Electricity Coordination Council (WECC) plant control is utilised as the benchmark model with PV only for a large-scale PV plant model. The control parameters are optimised for both machines to improve the system's dynamic response. The effectiveness and robustness of the MV islanded system are examined under different operating conditions through extensive simulation studies in the DigSILENT PowerFactory software.