The invention refers to a computer-implemented method for determining a parameter of a field-oriented control, FOC, model for an electric power unit, the electric power unit comprising a three-phase electric motor and an inverter drive for driving the electric motor, the method comprising the steps of: sending a control signal to the inverter drive; applying a predefined electric voltage to at least two of the phases of the electric motor by the inverter drive in response to the control signal; measuring an electric current that flows in the at least two phases of the electric motor in response to the applied electric voltage; and determining the parameter of the control model for the electric power unit using a value of the applied predefined electric voltage and a value of the measured electric current. Further, a corresponding apparatus for determining a parameter of a control model for an electric power unit is provided. The accuracy of the parameters determined by the method according to the invention is based on the precision of the applied voltages and for this reason it is necessary to foresee a hardware and software function to obtain this precision.