Power Sharing and Stability Assurance using Grid Forming Inverter Control in HVDC Connected Offshore Microgrid Cluster

Abstract

This paper focuses on accurate power-sharing and maintaining stability among offshore microgrids (MGs) connected to a multi-terminal High Voltage DC (HVDC). The MG cluster containing three AC micro grids is connected to one of the four terminals of the HVDC system. Each MG in the cluster is equipped with multiple Marine Hydrokinetic (MHK) sources and a battery energy storage (BES) which serve its loads. This paper proposes a P-V droop-based Grid Forming (GFM) inverter control technology applied to the BES converter, enabling the parallel-connected MGs to operate independently as well as cooperatively at the time of grid outage. Simulations performed in PSCAD are presented to demonstrate the transient stability of the system with the proposed controls.