US 12,255,487 B2
Forced discharge control system for smoothing capacitor provided to inverter
Yuta Otsuka, Hiroshima (JP); Haruki Yamane, Hiroshima (JP); Takashi Yoshizaki, Hiroshima (JP); Shosuke Morimoto, Hiroshima (JP); Sho Kawanari, Hiroshima (JP); Hiroaki Kashihara, Hiroshima (JP); and Yusuke Kame, Hiroshima (JP)
Assigned to MAZDA MOTOR CORPORATION, Hiroshima (JP)
Filed by Mazda Motor Corporation, Hiroshima (JP)
Filed on Mar. 27, 2023, as Appl. No. 18/126,580.
Claims priority of application No. 2022-088708 (JP), filed on May 31, 2022.
Prior Publication US 2023/0387713 A1, Nov. 30, 2023
Int. Cl. B60K 6/26 (2007.10); H01M 10/04 (2006.01); H01M 10/42 (2006.01); H01M 10/46 (2006.01); H01M 10/64 (2014.01); H02J 7/00 (2006.01); H02J 7/34 (2006.01)
CPC H02J 7/345 (2013.01) [B60K 6/26 (2013.01); H01M 10/4264 (2013.01); H01M 10/46 (2013.01); H02J 7/00712 (2020.01); B60Y 2200/92 (2013.01); H01M 2220/20 (2013.01); H02J 2310/48 (2020.01)] 19 Claims
OG exemplary drawing
 
1. A forced discharge control system for a smoothing capacitor, the forced discharge control system comprising:
a drive battery that is mounted on a vehicle;
an inverter that includes the smoothing capacitor and a forced discharge circuit, the inverter controls electric power supplied from the battery, and outputs the controlled electric power to a drive motor;
at least one in-vehicle low-voltage component connected to a low-voltage circuit;
a step-down converter that steps down a voltage of the battery and supplies the stepped-down voltage to the at least one in-vehicle low-voltage component;
a high-voltage circuit that electrically connects the battery, the inverter, and the step-down converter; and
a power supply switch configured to switch the battery to a state of being connected to the high-voltage circuit or a state of being disconnected from the high-voltage circuit,
the forced discharge circuit having an active discharge circuit that includes a main resistor and an energization switch, the main resistor being arranged in parallel with the smoothing capacitor, and the energization switch configured to switch the main resistor to a state of being connected to the high-voltage circuit or a state of being disconnected from the high-voltage circuit,
the forced discharge control system further comprising:
a controller that controls the step-down converter, the power supply switch, and the energization switch, wherein
the controller initiates first discharge control when a specified forced discharge condition for forcibly discharging the smoothing capacitor is satisfied, and thereafter executes second discharge control when a voltage of the smoothing capacitor is reduced and reaches a specified threshold, in the first discharge control, electric charges that are stored in the smoothing capacitor being consumed by the at least one low-voltage component via the step-down converter in a state where the battery is disconnected from the high-voltage circuit by control by the power supply switch, and in the second discharge control, the electric charges of the smoothing capacitor are forcibly discharged in the active discharge circuit by control by the energization switch, and
the controller executes delay control to delay execution timing of the second discharge control in a case where a forced discharge, in which the forced discharge condition is satisfied, occurs within a specified time since a last forced discharge.