Switch arrangement for a converter

A switch arrangement for a converter, wherein

• the switch arrangement comprises:
• a first series connection (SC1) of at least two switches (SL1, SR1) between two terminals (T1, T2) of the switch arrangement, wherein the two switches (SL1, SR1) are semiconductor switches;
• a second series connection (SC2) of a first capacitor (C1) and a first diode circuit (D1) electrically connected in parallel to a first part (P1) of the first series connection (SC1) between a first terminal (T1) of the two terminals (T1, T2) and a node (Nc) between the two switches (SL1, SR1), wherein the first diode circuit (D1) comprises at least one diode (D11);
• and
• a third series connection (SC3) of a second capacitor (C2) and a second diode circuit (D2) electrically connected in parallel to a second part (P2) of the first series connection (SC1) between a second terminal (T2) of the two terminals (T1, T2) and the node (Nc) between the two switches (SL1, SR1), wherein the second diode circuit (D2) comprises at least one diode (D21),
• wherein in case the first series connection comprises an even integer number of switches greater or equal to four:
• two switches, which are equally apart in terms of nodes from the node (Nc) of the first series connection (SC1), are a switch pair such that the first series connection (SC1) comprises a plurality of switch pairs;
• and
• for switching the switch arrangement between a conducting state and a non-conducting state, the switches (SLi, SL2, SL1, SR1, SR2, SRi) are configured to be controlled such that
• the two switches of each switch pair of the plurality of switch pairs are switched at the same time between the conducting state and the non-conducting state, and
• the switch pairs of the plurality of switch pairs are switched in sequence one after the other.

A converter system with

• at least one converter comprising at least one switch arrangement for controlling power conversion by the at least one converter;
• wherein
• the switch arrangement comprises:
• a first series connection (SC1) of at least two switch pairs between two terminals (T1, T2) of the switch arrangement, wherein the at least two switch pairs comprise semiconductor switches;
• a second series connection (SC2) of a first capacitor (C1) and a first diode circuit (D1) electrically connected in parallel to a first part (P1) of the first series connection (SC1) between a first terminal (T1) of the two terminals (T1, T2) and a node (Nc) between the at least two switch pairs, wherein the first diode circuit (D1) comprises at least one diode (D11);
• and
• a third series connection (SC3) of a second capacitor (C2) and a second diode circuit (D2) electrically connected in parallel to a second part (P2) of the first series connection (SC1) between a second terminal (T2) of the two terminals (T1, T2) and the node (Nc) between the two switches (SL1, SR1), wherein the second diode circuit (D2) comprises at least one diode (D21),
• wherein the switch arrangement is configured to provide a quasi-multilevel operation that switches the at least two switch pairs between a non-conducting state and a conducting state via at least one intermediate transient state that switches a first of at least two switch pairs before a second of the at least two switch pairs to thereby increase effective voltage capability of the at least two switch pairs between the two terminals (T1, T2) of the switch arrangement.