A method and apparatus for operating a converter system of a wind turbine for exchanging electrical power with an electrical supply grid at a grid connection point are provided. In the method and apparatus, the converter system is operated in a normal operating mode. An overload situation affecting the converter system is detected and operation of the converter system is changed to an overload operating mode when the overload situation is detected. An average switching frequency for generating an output current is reduced in the overload operating mode of the converter system in comparison with the normal operating mode, a higher load is permitted on the converter system, which may be in the form of an increased temperature or an increased output current, in the overload operating mode of the converter system for a predetermined maximum overload period.