US 12,132,415 B2
Inverter capable of switching between single- phase operation and three-phase operation
Dietmar Striegl, Wels-Thalheim (AT); Martin Mörtenhuber, Wels-Thalheim (AT); Roland Lecher, Wels-Thalheim (AT); and Stefan Wieser, Wels-Thalheim (AT)
Assigned to Fronius International GmbH, Pettenbach (AT)
Appl. No. 17/914,446
Filed by Fronius International GmbH, Pettenbach (AT)
PCT Filed Mar. 26, 2021, PCT No. PCT/EP2021/057987
§ 371(c)(1), (2) Date Sep. 26, 2022,
PCT Pub. No. WO2021/191434, PCT Pub. Date Sep. 30, 2021.
Claims priority of application No. 20166233 (EP), filed on Mar. 27, 2020.
Prior Publication US 2023/0120415 A1, Apr. 20, 2023
Int. Cl. H02M 7/487 (2007.01); H02M 1/00 (2006.01); H02M 7/537 (2006.01)
CPC H02M 7/487 (2013.01) [H02M 1/0043 (2021.05); H02M 7/537 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An inverter having a first input pole and a second input pole comprising:
a first phase branch with a first upper power switch and a first lower power switch connected in series to the first upper power switch via a first output pole;
a second phase branch, with a second upper power switch and a second lower power switch connected in series to the second upper power switch via a second output pole;
a DC link arranged between the first input pole and the second input pole, with a first DC link capacitor and a second DC link capacitor connected via a DC link center point to the first DC link capacitor;
a switching unit which is designed to switch the inverter from multi-phase operation to single-phase operation, in order to output a single-phase output AC voltage;
a third phase branch, having a third upper power switch and a third lower power switch connected in series to the third upper power switch via a third output pole;
a control unit which is designed, in a multi-phase operation, to control the first, second and third upper power switches and the first, second and third lower power switches of the first, second and third phase branches in such a way that an input DC voltage applied between the first input pole and the second input pole is converted into an output AC voltage applied to corresponding output poles,
wherein a center point connection switch is provided between the third output pole and the DC link center point,
wherein the switching unit is designed, in single-phase operation, to close the center point connection switch, in order to connect the third output pole to the DC link center point, and
wherein the switching unit is designed, in single-phase operation, to effect a control of the third upper switch and the third lower power switch of the third phase branch for symmetrizing DC link voltages at the first and second DC link capacitors.