US 12,282,072 B2
Battery monitoring device
Kazuo Matsukawa, Kariya (JP)
Assigned to DENSO CORPORATION, Kariya (JP)
Filed by DENSO CORPORATION, Kariya (JP)
Filed on Apr. 17, 2023, as Appl. No. 18/301,448.
Application 18/301,448 is a continuation of application No. PCT/JP2021/046290, filed on Dec. 15, 2021.
Claims priority of application No. 2020-208507 (JP), filed on Dec. 16, 2020.
Prior Publication US 2023/0314529 A1, Oct. 5, 2023
Int. Cl. G01R 31/396 (2019.01); G01R 31/3842 (2019.01); G01R 31/389 (2019.01); H01M 10/42 (2006.01); H01M 10/48 (2006.01); H02J 7/00 (2006.01)
CPC G01R 31/396 (2019.01) [G01R 31/3842 (2019.01); G01R 31/389 (2019.01); H01M 10/4264 (2013.01); H01M 10/482 (2013.01); H02J 7/0047 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A battery monitoring device for monitoring an assembled battery having a configuration in which a plurality of battery cells are connected in series, the battery monitoring device comprising:
a first voltage detection unit that detects voltages of the plurality of battery cells;
a second voltage detection unit that detects voltages of the plurality of battery cells for redundant monitoring;
a current application unit that applies an alternating current to the assembled battery;
a third voltage detection unit that detects voltages of the plurality of battery cells during a period in which the alternating current is applied to the assembled battery by the current application unit; and
a calculation unit that calculates an impedance of the battery cells, wherein:
the current applying unit includes:
a load element, a switching element and a shunt resistor connected in series between both terminals of the assembled battery; and
a drive control unit that controls driving of the switching element to apply the alternating current having a predetermined frequency to the assembled battery;
the calculation unit includes a current detection unit that detects currents flowing through the plurality of battery cells based on a terminal voltage of the shunt resistor;
the calculation unit calculates the impedance based on the voltages of the plurality of battery cells detected by the third voltage detection unit and the currents of the plurality of battery cells detected by the current detection unit; and
the drive control unit includes:
a PWM modulator that generates a drive signal for driving the switching element by pulse-width modulating an alternating current signal having a predetermined frequency;
a PDM modulator that generates the drive signal by pulse-density modulating the alternating current signal having the predetermined frequency; and
a switching unit that switches between a first drive state in which the switching element is driven by the drive signal generated by the PWM modulator and a second drive state in which the switching element is driven by the drive signal generated by the PDM modulator.