US 12,341,375 B2
Methods and systems for managing state of charge of an energy storage system during off-grid operation
Rasoul Ghadami, Diamond Bar, CA (US); Sandeep Narla, Newark, CA (US); Daidipya Patwa, San Francisco, CA (US); Udo Uebel, San Francisco, CA (US); and Joseph Griffin, Austin, TX (US)
Assigned to UNIRAC, INC., Albuquerque, NM (US)
Filed by Unirac, Inc., Albuquerque, NM (US)
Filed on Jan. 28, 2022, as Appl. No. 17/587,448.
Claims priority of provisional application 63/144,224, filed on Feb. 1, 2021.
Prior Publication US 2022/0247203 A1, Aug. 4, 2022
Int. Cl. H02J 7/00 (2006.01); H02J 7/35 (2006.01)
CPC H02J 7/35 (2013.01) [H02J 7/0048 (2020.01); H02J 2300/24 (2020.01)] 20 Claims
OG exemplary drawing
 
1. An electrical system, comprising:
an energy control system electrically coupled to a plurality of backup loads;
a photovoltaic (PV) power generation system electrically coupled to the energy control system, the PV power generation system configured to generate power; and
an energy storage system electrically coupled to the energy control system, the energy storage system comprising:
a battery configured to store the power generated by the power generation system and configured to discharge stored power to the energy control system, and
a storage converter electrically coupled to the battery and electrically coupled to the energy control system,
wherein the energy storage system is configured to operate according to a selected mode of operation of a plurality of modes of operation, wherein the plurality of modes of operation include:
a normal mode, wherein the battery and the storage converter are activated to discharge stored power to the energy control system,
a hibernation mode, wherein the storage converter is deactivated to prevent the discharge of stored power from the energy storage system to the energy control system, and
a suspension mode, wherein the battery and the storage converter are deactivated, and
wherein the energy control system is configured to select one of the normal mode, the hibernation mode, or the suspension mode as the selected mode of operation based on whether an estimated state of charge drop by the energy storage system over a duration of time is greater than a drop threshold over the duration of time.