Power electronic building block for modular multilevel converters

A power electronic building block (PEBB), comprising:

• a plurality of capacitors;
• a plurality of switch modules, each switch module of the plurality of switch modules including a first terminal, a second terminal and a third terminal, at least one first semiconductor switch connected between the first terminal and the third terminal, and at least one second semiconductor switch connected between the second terminal and the third terminal;
• a busbar arrangement including one or more busbars connecting the first terminals of the plurality of switch modules together, connecting the second terminals of the plurality of switch modules together, and connecting the plurality of capacitors in parallel across the first terminals and the second terminals of the plurality of switch modules, via a first plurality of connection points, wherein the busbar arrangement includes a capacitor busbar configured to connect the plurality of capacitors in parallel, and a switch busbar connected to the capacitor busbar configured to connect the plurality of capacitors in parallel across the first terminals and the second terminals of the plurality of switch modules;
• at least one AC busbar including a second plurality of connection points connecting the third terminals of the plurality of switch modules together via said at least one AC busbar, and at least one AC terminal point,
• wherein the second plurality of connection points of the at least one AC busbar are arranged symmetrically along a first direction with respect to a plane perpendicularly intersecting the first direction, and
• wherein the at least one AC busbar includes a hole elongated along the first direction and configured to balance one or more loop inductances between the at least one AC terminal point and the second plurality of connection points;
• and
• a DC crowbar thyristor and clamping apparatus connected in parallel with the plurality of capacitors, wherein the busbar arrangement further includes a clamp busbar connected to the capacitor busbar configured to connect the DC crowbar thyristor and clamping apparatus in parallel with the plurality of capacitors.

A power electronic building block (PEBB), comprising:

• a plurality of box type film capacitors;
• a plurality of switch modules, each switch module of the plurality of switch modules including a first terminal, a second terminal and a third terminal, at least one first semiconductor switch connected between the first terminal and the third terminal, and at least one second semiconductor switch connected between the second terminal and the third terminal;
• a busbar arrangement including one or more busbars connecting the first terminals of the plurality of switch modules together, connecting the second terminals of the plurality of switch modules together, and connecting the plurality of capacitors in parallel across the first terminals and the second terminals of the plurality of switch modules, via a first plurality of connection points, wherein the busbar arrangement includes a capacitor busbar configured to connect the plurality of capacitors in parallel, a main busbar connected to the capacitor busbar, and a switch busbar connected to the main busbar for connecting the plurality of capacitors in parallel across the first terminals and the second terminals of the plurality of switch modules via said main busbar;
• and
• at least one AC busbar including a second plurality of connection points connecting the third terminals of the plurality of switch modules together via said at least one AC busbar, and at least one AC terminal point,
• wherein the second plurality of connection points of the at least one AC busbar are arranged symmetrically along a first direction with respect to a plane perpendicularly intersecting the first direction, and
• wherein the at least one AC busbar includes a hole elongated along the first direction and configured to balance one or more loop inductances between the at least one AC terminal point and the second plurality of connection points.