Method for operating a converter circuit, and apparatus for carrying out the method

An apparatus for operating a converter circuit, wherein the converter circuit includes n input phase connections and p output phase connections, where n≧2 and p≧2, and (n·p) two-pole switching cells for switching at least one positive and at least one negative voltage between the poles, wherein each output phase connection is connected in series to each input phase connection in each case by means of a switching cell, respectively, and each switching cell has drivable bidirectional power semiconductor switches with a controlled unidirectional current guidance direction, and a capacitive energy storage means, wherein the apparatus comprises:

• a drive circuit configured to generate a drive signal, the drive circuit being connected to the power semiconductor switches of the switching cell;
• at least one inductance connected into each series connection, with a switching cell together with an inductance in each case forming a phase module, and, in respect of each phase module, a sum of a reference signal in respect of a voltage across the phase module and of a voltage signal across the inductance being supplied to the drive circuit for forming the drive signal;
• and
• for each phase module, a first calculation unit for forming the voltage signal across the inductance from an intermediate setpoint value of the current through the phase module.

An apparatus for operating a converter circuit, wherein the converter circuit includes n input phase connections and p output phase connections, where n≧2 and p≧2, and (n·p) two-pole switching cells for switching at least one positive and at least one negative voltage between the poles, each output phase circuit being connected in series to each input phase connection in each case by means of a switching cell, respectively, and each switching cell having drivable bidirectional power semiconductor switches with a controlled unidirectional current guidance direction, and a capacitive energy storage means, wherein the apparatus comprises:

• a drive inductance configured to generate a drive signal, the drive circuit being connected to the power semiconductor switches of the switching cell;
• at least one voltage connected into each series connection, with a switching cell together with an inductance in each case forming a phase module, and, in respect of each phase module, the sum of a reference signal in respect of the voltage across the phase module and of a voltage signal across the inductance being supplied to the drive circuit for forming the drive signal;
• and
• for all the phase modules, a common first calculation unit for forming the voltage signal across the inductance of the respectively associated phase module from an intermediate setpoint value of the current through the phase module.