A system and method for controlling a power train of a motor vehicle having an electric motor includes regulating the currents in the rotor and stator of the electric motor so that they reach required current values using control signals of the electric motor. The currents to be regulated and the control signals being expressed in a rotating reference frame including a plurality of axes. The control signals result from a transformation including a change of variable allowing the dynamic decoupling of the regulation along each of the axes. Regulating each axis includes an application to the current to be regulated of two different linear operators as a function of the value of the current to be regulated of that axis with respect to its required value, the result of the application of the two linear operators having to be substantially equal to the control signal of that axis.