Method of management of an electric propulsion system and electric propulsion system implementing the method

An electric propulsion system comprising a first and a second propulsion line, operatively connectable individually to a common driving axle, each propulsion line comprising

• an electric motor,
• a gearbox including at least two gear ratios,
• a clutch to connect/disconnect the related propulsion line from the driving axle,
• the system comprising processing means configured to distribute a requested torque between the first and second propulsion lines and to select, for each propulsion line, a relating transmission ratio and wherein when it is requested to vary the transmission ratio of both the first and second propulsion lines, the processing means are configured for commanding:
• interruption of the supply of driving torque and consequent variation of the transmission ratio, first in a first propulsion line which has a lower maximum deliverable torque between the two propulsion lines and, at the end of the variation of the transmission ratio, reactivation of the torque delivery of a first transmission line, interruption of torque delivery and consequent variation of the transmission ratio, in the other propulsion line and, at the end of the variation of the transmission ratio, and
• reactivation of the torque delivery of the other transmission line.