Method for operating an electric machine, device for operating an electric machine, and electric drive system

Abstract

The invention relates to a method for operating an electric machine (2) comprising a rotatably mounted rotor and a motor winding that is electrically connected to an electrical energy store (4) by means of a power electronics (3). In said method, the machine (2) and/or an apparatus comprising the machine (2) is/are monitored in respect of fault events, and the motor winding is short-circuited by triggering the power electronics (3) upon detection of a fault event. According to the invention, a desired trajectory (T) for an actual current vector (iactual,dq) of an electric motor current flowing through the motor winding is ascertained, said desired trajectory (T) extending from a current actual working point (AP1) of the machine (2) to a short-circuit working point (AP2) of the machine (2), a pilot control action is predicted according to the desired trajectory (T), and the power electronics (3) are triggered to short-circuit the motor winding according to the pilot control action in such a way that when the motor winding is short-circuited, a curve (V) of the actual current vector (iactual,dq) at least substantially matches the desired trajectory (T).

Dependencies are inferred from the claim text.