Device and method for determining the position of a rotor

摘要

The invention relates to a device and a method for determining an electrical starting rotor angle of an electromotor. According to the invention, the electromotor ( 10 ) is subjected to an approximately sinusoidal voltage and the corresponding current path (i) that is established is then detected. The electromotor ( 10 ) is again subjected to an approximately sinusoidal voltage and again, the corresponding current path (i) is detected. A ratio of a measure of the fundamental wave (I 1 ) and the measure of the first harmonic wave (I 2 ) is then determined from the current paths (i) as a measure of the electrical starting rotor angle (delta).