Performance improvement in electrical motor drives is today constant task in many research centres around the world. Following from stated, my thesis investigates sensorless field-oriented control (FOC) of multiphase machine (n > 3). To measure rotors position and compute shaft’s speed, typically a position sensor is mounted on rotor’s shaft, but various problems may arise (i.e. higher drive cost, electromagnetic interference). In many applications these sensors increase the mounting and maintenance cost i.e. reduce the reliability of the whole system, hence are not used. Practical and attractive alternative nowadays to the motor control with mechanical sensors is cost-saving sensorless motor control.