Switching unit for a converter module for a multi-level energy converter

A method for operating a converter module of a multi-level energy converter by means of a control unit, the method comprising:

• controlling the switching states of one of two converter module connections of the converter module and a switching unit having four semiconductor switches connected in series to for two series circuits in parallel to one another, wherein a center terminal of each of the two series circuits comprises one of the two converter module connections;
• wherein two series-connected converter module capacitors connected to the switching unit, respectively deliver a converter module capacitor voltage;
• wherein two additional semiconductor switches each have a first terminal connected to a first of the two converter module connections and the series-connected converter module capacitors are connected to a second of the two converter module connections;
• wherein a second terminal of a first of the two additional semiconductor switches is connected to a series circuit-free connection point of the two series-connected converter module capacitors and a second terminal of a second of the two additional semiconductor switches is connected to a center terminal of the two series-connected converter module capacitors;
• and
• switching with the switching unit the converter module capacitor voltage of one of the converter module capacitors or a summed voltage of the series-connected converter module capacitors to the converter module connections, according to the respective switching state of the switching unit.

A converter module for a multi-level energy converter for the control of switching states of the switching unit, the converter module comprising:

• a switching unit including four semiconductor switches connected in series to form two series circuits and two converter module connections;
• and
• two series-connected converter module capacitors connected to the switching unit;
• wherein each of the two series-connected converter module capacitors respectively delivers a converter module capacitor voltage;
• the switching unit switches the converter module capacitor voltage of one of the two series-connected converter module capacitors or a summed voltage of the two series-connected converter module capacitors to the converter module connections according to the respective switching state of the switching unit;
• the two series circuits are connected in parallel to one another and, in each case, a center terminal of one of the series circuits constitutes one of the converter module connections respectively;
• the switching unit includes two further semiconductor switches, each of which is connected on one of its terminals to a first connection point of the two series circuits;
• a second connection point of the two series circuits is connected to the series-connected converter module capacitors;
• the other terminal of one of the two further semiconductor switches is connected to a series circuit-free connection point of the series-connected converter module capacitors;
• and
• the other terminal of the other of the two further semiconductor switches is connected to a center terminal constituted by the series-connected converter module capacitors.

A converter module for a multi-level energy converter for the control of switching states of the switching unit, the converter module comprising:

• a switching unit including two semiconductor switches connected in series to form a series circuit and two converter module connections;
• and
• two series-connected converter module capacitors connected to the switching unit;
• wherein each of the two series-connected converter module capacitors respectively delivers a converter module capacitor voltage;
• the switching unit switches the converter module capacitor voltage of one of the two series-connected converter module capacitors or a summed voltage of the two series-connected converter module capacitors to the converter module connections according to the respective switching state of the switching unit;
• a center terminal of the series circuit constitutes one of the converter module connections;
• a connection point of the series circuit with the series-connected converter module capacitors constitutes the other of the converter module connections;
• the switching unit includes two further semiconductor switches which, on a first terminal respectively, are connected to a converter module connection-free connection point of the series circuit;
• a second terminal of a first of the two further semiconductor switches is connected to a converter module connection-free connection point of the series-connected converter module capacitors;
• and
• a second terminal of a second of the two further semiconductor switches is connected to a center terminal constituted by the series-connected converter module capacitors.