a method for determining the position of the rotor of a synchronous alternating - current permanent - magnet machine , its particularity consisting of the fact that it comprises the steps that consist in : injecting in the machine a high - frequency voltage superimposed on the voltage delivered by the machine control system ; measuring the current of the motor and extracting a current that is linked to the injected voltage ; obtaining from the injected voltage and from the corresponding current the electrical angle θ suitable to identify the position of the rotor .