Offshore Electrification: Power from Shore with Active Front End Grid Forming Static Frequency Converters

To reduce offshore CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> emissions, an oil and gas company is electrifying two platforms in the Norwegian North Sea. The two platforms have several large gas turbines (GT's) driving 50MW of compression and 60MVA of power generation. The intent is to connect electric power from shore and remove the GT’s. A subsea power cable will deliver 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 become the grid forming system required 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 provide VARs to correct the power factor of the cable feeding power from shore. The compression load to be driven by AFE ASD’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 CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> reduction calculation.