US 12,246,615 B2
Current sensors for battery cells of a vehicle battery system
Mohamed Ahmed Kamel Ahmed, Birmingham, MI (US); Chandra S. Namuduri, Troy, MI (US); and Suresh Gopalakrishnan, Troy, MI (US)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed on Jan. 16, 2023, as Appl. No. 18/097,375.
Prior Publication US 2024/0239235 A1, Jul. 18, 2024
Int. Cl. B60L 58/12 (2019.01); G01R 31/3828 (2019.01); H02M 1/00 (2007.01)
CPC B60L 58/12 (2019.02) [G01R 31/3828 (2019.01); H02M 1/0009 (2021.05); B60L 2210/10 (2013.01); B60L 2240/54 (2013.01); H02J 2310/48 (2020.01)] 20 Claims
OG exemplary drawing
 
1. A battery system for an electric vehicle, the battery system comprising:
multiple battery cells each configured to store charge for powering an electric vehicle;
a high voltage bus electrically coupled with the multiple battery cells to provide power to an electric motor of the electric vehicle, the multiple battery cells coupled in series with the high voltage bus;
multiple DC-DC converters each electrically coupled with a corresponding one of the multiple battery cells;
a low voltage bus electrically connected between the multiple DC-DC converters and at least one vehicle electrical component, the low voltage bus configured to provide low voltage power to the at least one vehicle electrical component; and
multiple cell monitors each electrically coupled with a corresponding one of the multiple battery cells and a corresponding one of the multiple DC-DC converters, wherein each cell monitor includes a first current sensor configured to detect a first current from the corresponding one of the multiple battery cells to the corresponding one of the multiple DC-DC converters, each cell monitor includes a second current sensor configured to detect a second current through the corresponding one of the multiple battery cells along the high voltage bus, and each cell monitor includes a controller configured to:
estimate a state of charge of the corresponding one of the multiple battery cells according to the first current detected by the first current sensor and the second current detected by the second current sensor; and
adjust switching operation of the corresponding one of the multiple DC-DC converters according to the first current detected by the first current sensor and the second current detected by the second current sensor.
 
17. A battery system for an electric vehicle, the battery system comprising:
multiple battery cells each configured to store charge for powering an electric vehicle;
a high voltage bus electrically coupled with the multiple battery cells to provide power to an electric motor of the electric vehicle, the multiple battery cells coupled in series with the high voltage bus;
multiple DC-DC converters each electrically coupled with a corresponding one of the multiple battery cells;
a low voltage bus electrically connected between the multiple DC-DC converters and at least one vehicle electrical component, the low voltage bus configured to provide low voltage power to the at least one vehicle electrical component; and
multiple cell monitors each electrically coupled with a corresponding one of the multiple battery cells and a corresponding one of the multiple DC-DC converters, wherein each cell monitor includes a first current sensor configured to detect a first current from the corresponding one of the multiple battery cells to the corresponding one of the multiple DC-DC converters, a second current sensor configured to detect a second current through the corresponding one of the multiple battery cells along the high voltage bus, a transmitter, an antenna, and a controller configured to:
estimate a state of charge of the corresponding one of the multiple battery cells according to the first current detected by the first current sensor and the second current detected by the second current sensor; and
transmit the estimated state of charge to a central system controller wirelessly via the transmitter and the antenna.
 
19. A battery system for an electric vehicle, the battery system comprising:
multiple battery cells each configured to store charge for powering an electric vehicle;
a high voltage bus electrically coupled with the multiple battery cells to provide power to an electric motor of the electric vehicle, the multiple battery cells coupled in series with the high voltage bus;
multiple DC-DC converters each electrically coupled with a corresponding one of the multiple battery cells;
a low voltage bus electrically connected between the multiple DC-DC converters and at least one vehicle electrical component, the low voltage bus configured to provide low voltage power to the at least one vehicle electrical component;
multiple battery current sensors each coupled in series with a corresponding one of the multiple battery cells, wherein each battery current sensor is configured to detect a current through the corresponding one of the multiple battery cells along the high voltage bus; and
multiple cell monitors each electrically coupled with a corresponding one of the multiple battery cells and a corresponding one of the multiple DC-DC converters, wherein each cell monitor includes a converter current sensor configured to detect a current from the corresponding one of the multiple battery cells to the DC-DC converter, wherein each cell monitor includes a controller configured to:
determine a total current according to a combination of the current through the corresponding one of the multiple battery cells along the high voltage bus as detected by the corresponding one of the multiple battery current sensors, and the current detected from the corresponding one of the multiple battery cells to the corresponding one of the multiple DC-DC converters;
estimate a state of charge of the corresponding one of the multiple battery cells according to the total current; and
adjust switching operation of the corresponding one of the multiple DC-DC converters according to the total current.