Propulsion system for a vehicle

A vehicle comprising a drive system wherein the drive system comprises an output shaft in a combustion engine, an input shaft of a gearbox, an electrical machine comprising a stator and a rotor, a planetary gear comprising three components in the form of a sun wheel, a ring gear and a planetary wheel carrier, wherein the output shaft of the combustion engine is connected with a first of said components in the planetary gear, so that a rotation of such shaft leads to a rotation of such first of said components, wherein the input shaft of the gearbox is connected with a second of said components of the planetary gear, so that a rotation of such shaft leads to a rotation of such second of said components, and wherein the rotor of the electrical machine is connected with a third of said components in the planetary gear, so that a rotation of the rotor leads to a rotation of such third of said components, wherein the drive system also comprises a first locking means, which may be moved between a locked position in which two of said components are locked together so that the three components rotate with the same rotational speed, and a release position in which the components are allowed to rotate at different rotational speeds, wherein the drive system comprises a second locking means, which may be moved between a locked position in which the combustion engine's output shaft is locked to said first of said components, and a release position, in which the output shaft of the combustion engine is disconnected from said first of said components, and is allowed to rotate independently.