US 11,757,352 B2
Power conversion system for electrically driven mobility device and method for controlling same
Tae Jong Ha, Seoul (KR); Dae Woo Lee, Incheon (KR); and Byung Gu Kang, Hwaseong-si (KR)
Assigned to HYUNDAI MOTOR COMPANY, Seoul (KR); and KIA CORPORATION, Seoul (KR)
Filed by HYUNDAI MOTOR COMPANY, Seoul (KR); and KIA CORPORATION, Seoul (KR)
Filed on Sep. 9, 2021, as Appl. No. 17/470,107.
Claims priority of application No. 10-2021-0060933 (KR), filed on May 11, 2021.
Prior Publication US 2022/0368215 A1, Nov. 17, 2022
Int. Cl. H02M 1/32 (2007.01); H02J 1/02 (2006.01)
CPC H02M 1/32 (2013.01) [H02J 1/02 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A power conversion system for electrically driven mobility device, comprising:
a first energy storage device and a second energy storage device having a voltage output lower than a voltage of the first energy storage device;
a relay having one terminal connected to the first energy storage device;
a DC link capacitor connected to an other terminal of the relay;
a first DC converter positioned between the DC link capacitor and the second energy storage device, and capable of bidirectional voltage conversion;
a controller configured to control the first DC converter to convert a level of the voltage of the second energy storage device, and configured to apply the voltage having the converted level to the DC link capacitor before switching of the relay from an off state to an on state to charge the DC link capacitor to a preset voltage or higher, and then configured to switch the relay to the on state; and
a second DC converter connected between the DC link capacitor and the second energy storage device in parallel to the first DC converter;
wherein the second DC converter includes a first transformer and a plurality of diodes connected to a secondary coil of the first transformer;
wherein the controller is configured to operate the first DC converter in a reverse direction to charge the DC link capacitor to a preset initial charge voltage upon reception of input of a request for switching the relay; and
wherein when the DC link capacitor has been charged to the initial charge voltage, the controller switches on the relay, operates the second DC converter to drop the voltage of the DC link capacitor, and applies the dropped voltage to the second energy storage device.