Multi-phase converter topology for multi-phase and single-phase operation

A multi-phase converter topology, comprising:

• an alternating voltage terminal block with three grid phase connections and a neutral conductor connection,
• a DC voltage terminal block with a plus connection and a minus connection,
• a power part comprising half-bridges configured to switch currents,
• an alternating voltage filter connected between the power part and the alternating voltage terminal block, the alternating voltage filter comprising a midpoint voltage connection and a ground connection,
• a DC voltage block and a first DC voltage filter block connected between the power part and the DC voltage terminal block,
• wherein the DC voltage block comprises a first diode, a second diode, a switch, a first midpoint voltage node, a second midpoint voltage node, a plus connection node and a minus connection node,
• wherein the first diode and the second diode are connected in series between the plus connection node and the minus connection node,
• wherein a midpoint between the first diode and the second diode forms the first midpoint voltage node and is connected to the midpoint voltage connection,
• wherein the switch is connected between the first midpoint voltage node and the second midpoint voltage node,
• wherein the first DC voltage filter block comprises two filter capacitors, wherein the two filter capacitors are connected in series between the plus connection node and the minus connection node, wherein a midpoint between the two filter capacitors is connected to the second midpoint voltage node,
• wherein the two-phase common-mode filter choke comprises a first coil connected between the first switching voltage node and a plus connection node and a second coil connected between the second switching voltage node and a minus connection node,
• wherein the second DC voltage filter block comprises two capacitors connected in series between the plus connection node and the minus connection node, and
• wherein the multi-phase converter topology is configured to selectively operate as a three-phase converter and as a single-phase converter, wherein when operating as a single-phase converter the three grid phase connections are connected in parallel to one another and form a first single-phase connection, and wherein the neutral conductor connection forms a second single-phase connection.

A multi-phase converter topology for the transmission of electrical energy from an alternating voltage input with m grid phase connections to a DC voltage output or vice versa, the multi-phase converter comprising:

• a power part comprising half-bridges configured to switch currents;
• an alternating voltage filter connected between the power part and the alternating voltage input, the alternating voltage filter comprising at least one alternating voltage filter stage with m+1 input connections, m+1 output connections, and a ground connection;
• one or more DC voltage blocks connected between the power part and the DC voltage output for filtering DC voltages;
• wherein the multi-phase converter topology has a single-phase mode of operation, in which:
• the m grid phase connections are connected in parallel to one another and form a first phase connection for the connection of a single-phase alternating voltage, and a neutral conductor connection of the alternating voltage filter is connected to a neutral conductor connection of the alternating voltage input, and the neutral conductor connection of the alternating voltage input forms a second phase connection for the connection of the single-phase alternating voltage;
• a DC/DC converter block having two DC/DC converters,
• wherein inputs of the two DC/DC converters are selectively switchable between a series and a parallel arrangement;
• wherein outputs of the two DC/DC converters are connected in parallel to form the DC voltage output;
• wherein the power part comprises half-bridges configured to form a converter having three voltage levels;
• and
• wherein the multi-phase converter topology comprises a control configured to operate the converter topology selectively
• in a multi-phase operation with three voltage levels and
• in a single-phase operation with two voltage levels.