US 12,074,482 B2
Electrical machines and methods to mitigate bearing currents
Lionel Durantay, Champigneulles (FR); Kum Kang Huh, Niskayuna, NY (US); Christophe Grosselin, Champigneulles (FR); Henri Baerd, Champagne sur Seine (FR); Ludger Luetkehues, Salzbergen (DE); and Giesbert Krueger, Salzbergen (DE)
Assigned to General Electric Renovables Espana, S.L., Barcelona (ES)
Filed by General Electric Renovables Espana, S.L., Barcelona (ES)
Filed on Jan. 5, 2023, as Appl. No. 18/093,524.
Claims priority of application No. 22382007 (EP), filed on Jan. 8, 2022.
Prior Publication US 2023/0223826 A1, Jul. 13, 2023
Int. Cl. H02K 11/40 (2016.01); H02K 5/173 (2006.01); H02K 7/08 (2006.01); H02K 7/18 (2006.01); F03D 9/25 (2016.01); F03D 80/70 (2016.01)
CPC H02K 11/40 (2016.01) [H02K 5/1732 (2013.01); H02K 7/083 (2013.01); H02K 7/1838 (2013.01); F03D 9/25 (2016.05); F03D 80/70 (2016.05); F05B 2220/706 (2013.01); F05B 2240/50 (2013.01); F05B 2260/98 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An electrical machine configured to be fed by pulse width modulation from a power converter, comprising:
a stator;
a rotor comprising a rotor shaft with a grounding assembly;
a load operatively connected to the rotor;
one or more bearings arranged between the rotor and the stator, the bearings comprising an inner ring, an outer ring, and rolling elements and lubricant between the inner ring and the outer ring;
one of the inner ring or the outer ring mounted to the rotor shaft and the other of the inner ring or the outer ring mounted to a bearing supporting stator portion;
a bearing electrical insulation arranged between the bearing supporting stator portion and a remainder of the stator; and
an electrical shunt arranged between the rotor shaft and a point of the stator at a bearing side of the bearing electrical insulation, wherein the shunt has an impedance at a high frequency of at least 1 MHz that is lower than an impedance of the lubricant of the bearing.