Patent ID: 11909246
Assignee: ENPHASE ENERGY, INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 0:
1. A method for AC battery operation, comprising:
determining, at a battery management unit (BMU) coupled to an AC battery system comprising a power converter and a battery that is rechargeable, an equivalent series resistance estimation by correlating a ripple voltage and a ripple current, which exists on a DC battery during power conversion, at twice a line frequency, the equivalent series resistance estimation indicates a state of a charge (SOC) process of the AC battery system;
coupling, by a bias control module of the BMU, the equivalent series resistance estimation to the power converter for communicating, without a control area network, at least one of a state of health (SoH) of the battery or a degradation of the battery to and from the BMU and the power converter;
when one of a battery voltage reaches a high or low end of battery operation or a high or low end of estimated state of charge (SOC) of the battery, reducing a current when an estimated ESR increases;
determining, at each of the BMU and the power converter, a bias control voltage and SOC values; and
periodically synchronizing estimated SOC values with one another.