Patent ID: 8493011

Claim:
A method of controlling the run-up of an electronically commutated electric motor from standstill, said electric motor including: a rotationally fixed standing stator defining a rotating field; a rotor configured to rotate about an axis in said rotating field of said stator; at least three field windings arranged offset one from the other by an angle of rotation; said field windings having coil terminals (U, V, W) electrically connected to each other; a voltage source configured to supply a voltage; an actuating unit for alternately applying said voltage to said coil terminals (U, V, W); and, a control unit configured to control said actuation unit for generating said rotating field in such a manner that said rotating field is advanced by a rotational angle in dependence upon the position of said rotor relative to said field windings; said method comprising the steps of: providing a changing measurement current (I M ); determining the inductance of the arrangement of said field windings from said measurement current; and, initiating the advance of said rotating field in the rotational direction of the rotor when said inductance reaches a maximum.