Abstract: The device comprises: yarn advancing elements subjected to the action of motor devices controlled by frequency converters or changers, supplied by a common direct current bus; a monitoring/control system supplied by the same direct current bus; and processors for processing the yarns provided in the form of power spindles particularly being subjected to the action of individual motor devices, controlled by frequency converters or changers. The power spindles are not supplied by the direct current bus, but are self-powered and autonomous. The set of yarn advancing elements are on the direct current bus whose supply is maintained by a flywheel so that the two systems are, in total, electrically independent, and only the value of the ramps of both avoids any voltage fault.