PROTECTION OF A THREE-PHASE MOTOR IN THE FIELD-WEAKENING RANGE

摘要

The aim is to provide a drive apparatus and a method with which the problems of dangerous braking torques and overvoltages in the field-weakening mode are reduced. Therefore, the invention proposes a drive apparatus for a motor vehicle having a DC voltage source (1) which has a negative terminal (2) and a positive terminal (3), having a three-phase motor (4) of which the windings are combined at a star point (8), and having a converter (9) which is connected to the DC voltage source and to the three-phase motor and serves to convert a direct current into a three-phase alternating current. The star point (8) of the three-phase motor (4) is connected to the negative terminal (2) or the positive terminal (3) of the DC voltage source (1) by way of a switching element (10) so that the star point can be connected to the potential of one of the terminals in the event of a prespecified interruption in the drive apparatus.