Electrical machine control method and apparatus

摘要

Method for controlling an electrical machine (14), in particular for an electric or hybrid drive train (12) of a motor vehicle (10), wherein the electrical machine (14) can provide a torque (T) both at positive and at negative speeds (n), having the steps of:—using a characteristic curve (M; G) to check whether a torque desired value (72; 74) can or may be provided by the electrical machine (14), wherein the characteristic curve (M; G) represents a limit torque with respect to the speed (n) and has a first section (A1; A4) for positive speeds and a second section (A2; A3) for negative speeds. In this case, the first section (A1; A4) and the second section (A2; A3) are arranged in the same quadrant (I; IV) of the characteristic curve (70).

主权项

1. A method for controlling an electric machine for a drive train of a motor vehicle, wherein the electric machine can provide a torque both at positive and also at negative rotation speeds, the method comprising:
performing a checking procedure with the aid of a characteristic curve as to whether a desired torque value can be provided by the electric machine, wherein the characteristic curve represents a limit torque with respect to the rotation speed and comprises a first section for positive rotation speeds and a second section for negative rotation speeds, the first section and the second section being arranged in the same quadrant of a graph; controlling the torque output by the electric machine and provided from the drive train to wheels so that the torque does not exceed the limit torque for the rotation speed; and during the procedure of starting up the electric machine from the rotation speed of zero, initially the particular section of the characteristic curve that has a lower limit torque in a start-up range is used in the checking procedure irrespective of an algebraic sign of the rotation speed.