US 12,113,464 B2
Adjustable frequency drives using normalized modulation control signals to compensate for phase imbalance and methods of operating the same
Irving A. Gibbs, Mills River, NC (US); Geraldo Nojima, Fort Mill, SC (US); Stan Rex Simms, Arden, NC (US); Thomas A. Farr, Candler, NC (US); and Gabriel Braga, Belo Horizonte (BR)
Assigned to Eaton Intelligent Power Limited, Dublin (IE)
Filed by Eaton Intelligent Power Limited, Dublin (IE)
Filed on Jun. 16, 2022, as Appl. No. 17/807,162.
Prior Publication US 2023/0412105 A1, Dec. 21, 2023
Int. Cl. H02P 3/18 (2006.01); H02P 27/06 (2006.01)
CPC H02P 27/06 (2013.01) 9 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a plurality of DC buses;
a plurality of inverter circuits, respective ones of which are coupled to respective ones of the plurality of DC buses; and
a control circuit configured to generate a representative DC voltage signal based on DC voltage signals for respective ones of the DC buses, to generate a first modulation control signal from the representative DC voltage signal, to generate second modulation control signals for the respective inverter circuits from the representative DC voltage signal and the first modulation control signal that are normalized based on the DC voltage signals for the buses and the representative DC voltage signal, and to modulate the inverter circuits responsive to respective ones of the second modulation control signals, wherein the first modulation control signal comprises a first modulation amplitude index signal and an angle signal and wherein the control circuit is configured to apply an inverse Clarke transformation to the first modulation amplitude index signal and angle signal to generate respective second modulation amplitude index signals, to generate respective gain factors for the respective inverter circuits based on the voltage signals for the DC buses and the representative DC voltage signal, and to scale respective ones of the second modulation amplitude index signals by the respective gain factors to generate respective ones of the second modulation control signals.