Addressing Fault Ride-Through Challenges in DC Microgrids via Supercapacitor Integration

Due to the increasing penetration of power electronic converter-based distributed energy sources in the grid, countries suggest grid codes for the proper operation and stability of power systems and their components. One of such grid code requirements for power electronic converter is to remain connected under grid fault conditions and provide reactive power to support grid stability. As the DC microgrid is connected to the grid through a bidirectional power electronic converter (BPEC), its compliance with the grid code is mandatory. When a fault occurs on the grid side of the BPEC, the DC microgrid faces high voltage fault (HVF) and low voltage fault (LVF) events in the DC link voltage, which can risk the operation of the DC microgrid. Thus, to avoid the HVF and LVF events and simultaneously provide maximum reactive power support, this article proposes an integration of supercapacitor in the DC microgrid to remain connected with the grid and ensure grid stability during fault events. Various simulation case studies have been carried out in the Real-Time Digital Simulator (RTDS) platform to validate the efficacy of the proposed control strategy,