The invention relates to a drive system comprising a liquid-cooling electric machine (1), and to a method for liquid-cooling the stator winding of said type of machine (1). In order to use said system at very low temperatures and in the most simple way possible, said drive system also comprises a cooling circuit (2) for cooling the liquid of a stator winding of the electric machine (1), a pump (3) for pumping a liquid through the coolant circuit (2), a converter (4) for feeding the stator winding and a control device (5) for controlling the converter in such a manner that said converter, prior to activating the pump (3), feeds a heating flow to the stator winding for heating the cool liquid.