Subsea direct electrical heating power supply system, direct electrical heating system and method of operating a subsea direct electrical heating power supply system

摘要

A subsea direct electrical heating power supply system includes at least one input device adapted to couple the direct electrical heating power supply system to a power supply and a subsea variable speed drive, for receiving electrical power from the at least one input device and for providing an AC output, including a plurality of series-connected power cells. Each power cell includes an inverter and a bypass device to selectively bypass the power cell. The system further includes an adjustable subsea capacitor connected to the AC output of the subsea variable speed drive; an output device adapted to couple the direct electrical heating power supply system to a subsea pipeline section; and a controller, adapted to adjust the capacitance of the adjustable subsea capacitor such that upon the system output voltage being reduced, the current output by the direct electrical heating power supply system is increased.