METHOD FOR PREVENTING OVERVOLTAGES IN AN ELECTRICAL SYSTEM OF A MOTOR VEHICLE

摘要

A method for preventing overvoltages in an electrical system of a motor vehicle is provided. The electrical system has as voltages sources an electric machine coupled to an internal combustion engine and a motor vehicle battery. The electric machine has a stator winding, a rotor winding and a field regulator assigned to the rotor winding for controlling a field current flowing through the rotor winding. The voltage generated by the electric machine is limited to an upper voltage threshold value if (i) a rotational speed corresponding to the rotational speed of the electric machine is below a rotational speed threshold value, and (ii) a temperature corresponding to the temperature of the motor vehicle battery is below a temperature threshold value.