Sensorless control method

A stator winding generates an AC current offset at a phase angle. The amplitude of an applied AC voltage generates a power output. By using phase position recognition, a power factor regulator can be changed with certain parameters. A set point value for a regulator run in a first set-up as a P regulator amounts to lambda =0.96. A correcting variable is the amplitude for a motor voltage and acceleration/ramp time amounts to about 1,000 revolutions per second. Dependence between an operating point defined by RPMs/load and phase shift is determined. A functional interrelationship is set out in a memory store available to a regulator. A point in time is determined, at which a current should alter its polarity sign to amount to a theoretical current zero crossing. The current in the theoretical current zero crossing is defined. The amplitude of the AC voltage drops if the current measured is negative. The amplitude of the AC current is increased if the current measured is positive. An Independent claim is also included for an electric motor for carrying out the method of the present invention.