Converter system having an ac/dc converter, and method for operating a converter system

A converter system, comprising:

• an AC/DC converter;
• a series circuit including a braking resistor and a controllable switch connected to a terminal on a direct-voltage side of the AC/DC converter;
• a DC/AC converter, a terminal on a direct-voltage side of the DC/AC converter connected in parallel to the series circuit;
• an evaluation unit adapted to generate a control signal for the controllable switch and including a determination device adapted to determine electric power supplied to the braking resistor;
• a voltage-acquisition device adapted to supply an output signal to the evaluation unit;
• and
• a controller, the determination device adapted to supply an output signal to the controller, the controller adapted to regulate a set value toward the output signal of the determination device, the controller adapted to supply, directly and/or via a limiter, to a parameterizable filter adapted to convey an output signal to a switching element, the switching element adapted to generate an output signal to open and/or close the controllable switch as a function of exceeding and/or undershooting of a threshold value.

A method for operating a converter system including a series circuit, having a controllable switch and a braking resistor, connected at a direct voltage-side terminal of an AC/DC converter, and parallel thereto, a direct voltage-side terminal of a DC/AC converter, comprising:

• using a voltage acquired at the terminal of the DC/AC converter and/or the AC/DC converter on the direct voltage-side to determine electric power discharged to the braking resistor when the controllable switch is closed, and when the controllable switch is open, the electric power discharged to the braking resistor vanishes;
• supplying a time characteristic of the electric power discharged to the braking resistor to a controller to control a set value toward the time characteristic of the electric power discharged to the braking resistor;
• and
• supplying the set value of the controller, directly or via a limiter, to a parameterizable filter supplying an output signal to a switching element that controls the controllable switch.