Evaluation of New Grid Codes for Converter-Based DERs From the Perspective of AC Microgrid Protection

The ever-increasing penetration levels of converter-based distributed energy resources (DERs) in medium and low voltage (MV/LV) distribution networks necessitates new revised standards or connection requirements generating units. These standardized to be met by DERs are called grid codes. This paper reviews European IEEE codes MV/LV presents an evaluation selected applicable for AC microgrid protection. evaluated both grid-connected islanded modes operation. settings different protection schemes including symmetrical components-based quick fault detection isolation during the most challenging unbalanced faults modes. extent dynamic reactive power (Q) injection according is effect Q-injection on coordination observed. generic grid-forming DER model with coupled dq-control has been enabled provide enough current help additional Q-source. It concluded that code requirement can Q-source minimum capacity equal twice apparent individual mode. same also useful reliable directional element design A five-cycle overvoltage ride-through (OVRT) curve suggested smooth transition