System for Driving Elongated Electric Machines

A system for driving mechanisms in narrow remote locations, like downhole, in a well (40), pipeline or a tunnel, supplied with DC voltage via a long cable (42), comprising:

• a power & control electronics unit (11) comprising:
• a power line communication module (12),
• a control system (13),
• a common DC bus (14),
• a DC/DC buck converter (15),
• a plurality of DC/AC inverters (16a-b) fed from said common DC bus (14), and
• an electromechanical unit (20) comprising:
• a plurality of electric rotating motors (21a-d) each having a shaft, said motors axially aligned and mounted mechanically in series by connecting first and second ends of said shafts by means of a coupling (23), where the number of said DC/AC inverters (16a-b) is lower than the number of said motors (21a-d),
• wherein said power and control electronics unit (11) and said electromechanical unit (20) are connected by power and control cables extending between said power and control electronics unit (11) and said electromechanical unit (20).