Control device for an inverter, inverter for an asynchronous machine, vehicle and method for operating an inverter

Control device for an inverter which has a DC voltage input and a power unit with three half-bridges each being formed by two power switching elements, the control device being arranged to drive the power switching elements in a normal operating mode for converting a DC voltage applied to the DC voltage input into a polyphase AC current provided at an AC current output,

• wherein the control device is adapted to evaluate a signal state of a signal indicating a disconnection of a DC voltage source from the DC voltage input, and to control the power switching elements as a function of a result of evaluation for alternately adopting a first switching pattern which effects DC braking and a second switching pattern which effects freewheeling, and
• the first switching pattern includes, in one of three half-bridges, one power switching element connected to a first potential of the DC voltage input is in a blocking state and another power switching element is in a conducting state;
• in another of the three half-bridges, one power switching element connected to a second potential of the DC voltage input is in a blocking state and another power switching element is in a conducting state;
• and in another of the three half-bridges, both power switching elements are in a blocking state.