US 12,316,119 B2
Filter apparatus with reconfigurable choke unit changeover switch and capacitor unit for different AC voltage networks
Robert Lange, Crimmitschau (DE); and Marco Seja
Assigned to Siemens Aktiengesellschaft, Munich (DE)
Appl. No. 18/003,624
Filed by Siemens Aktiengesellschaft, Munich (DE)
PCT Filed Jun. 18, 2021, PCT No. PCT/EP2021/066608
§ 371(c)(1), (2) Date Dec. 28, 2022,
PCT Pub. No. WO2022/002640, PCT Pub. Date Jan. 6, 2022.
Claims priority of application No. 20182913 (EP), filed on Jun. 29, 2020.
Prior Publication US 2023/0261470 A1, Aug. 17, 2023
Int. Cl. H02J 3/26 (2006.01); H02M 1/12 (2006.01); H02M 5/458 (2006.01)
CPC H02J 3/26 (2013.01) [H02M 1/123 (2021.05); H02M 1/126 (2013.01); H02M 5/458 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A filter apparatus configured for a first operation of a converter connected via a first AC cable to a three-phase AC voltage network having a grounded external conductor or to a three-phase AC voltage network without a ground connector and for a second operation of the converter on a three-phase AC voltage network with a grounded network star point, the filter apparatus comprising:
a choke unit comprising a first coil in a first AC voltage phase, a second coil in a second AC voltage phase and a third coil in a third AC voltage phase;
a changeover switch comprising a first contact unit with an actuatable switch for opening and closing a first electrical connection and a second contact unit with an actuatable switch for opening and closing a second electrical connection, the changeover switch configured to simultaneously and reversibly switch from a first switching state in which the first contact unit is closed and the second contact unit is open to a second switching state in which the first contact unit is open and the second contact unit is closed;
a capacitor unit connected to the second contact unit and configured to be connected to a grounded protective conductor for current dissipation of a current in the second switching state by the closed second electrical connection and to be disconnected from the grounded protective conductor in the first switching state by the opened second electrical connection; and
a saturation reducing unit comprising a fourth coil of the choke unit connected to the first contact unit and configured to activate the saturation reducing unit with a short circuit the fourth coil in the first switching state by the closed first electrical connection and to deactivate the saturation reducing unit in the second switching state by the open first electrical connection for reducing saturation of the choke unit when the first electrical connection is closed,
wherein the first, second, third and fourth coil have a common choke core.