Energy Transition: Electrification with Power from Shore in the North Sea

To reduce CO2 emissions, an oil and gas company has electrified two platforms in the Norwegian North Sea. The two platforms had several large gas turbines (GT's) driving 50MW of compression and 60MVA of power generation. The project has connected electric power from shore and discontinued the GT's. A subsea power cable delivers 150MW of power from the 50Hz Norwegian grid (powered by hydro electricity) to the two platforms; a static frequency converter (SFC) is required to feed the existing offshore platform 60Hz loads. This SFC will operate in grid forming mode to provide all the power, protection, and fault clearing functionality for the 60Hz grid. The SFC is 4 quadrant, and the active front end (AFE) will provide grid support for the power from shore cable to improve voltage and frequency disturbance events. The AFE will also export VARs to correct the power factor of the cable feeding power from shore. The compression load to be driven by AFE Variable Speed Drive (VFD)s and will also support the grid with disturbance ride through and power factor correction. Simulation results of the disturbance events will be presented as well as the CO2 reduction calculation. The system was successfully started in 2024 without any shutdown of the platform, a "hot" switch over was achieved.