Supplementary charging for low-voltage battery based on redundancy power conversion and system for the same

A low-voltage battery supplementary charging system of a vehicle, the system comprising:

• a high voltage junction box (HV J/BOX) that distributes a high voltage supplied from a main battery;
• a first active junction block (AJB) including a back to back switch (B2B), the first AJB receiving a first low voltage output from a first low-voltage direct current (DC) to DC converter (LDC) and supplying the received first low voltage to a first electrical load;
• a second AJB including a B2B, the second AJB receiving a second low voltage output from a second LDC and supplying the received second low voltage to a second electrical load;
• a power-net domain controller (PDC) configured to supply power of the first low voltage and the second low voltage to the first electrical load and the second electrical load;
• a first sub-battery module (SBM) including a first low-voltage battery which is charged by the first low voltage supplied from the first AJB and supplies power to the PDC and the first low-voltage load and a first intelligent battery sensor (IBS) which detects a state of the first low-voltage battery;
• a second SBM including a second low-voltage battery which is charged by the second low voltage supplied from the second AJB and supplies power to the PDC and the second low voltage load and a second IBS that detects a state of the second low-voltage battery;
• and
• a redundancy power converter (RPC) configured to convert power between the first low voltage and the second low voltage according to a power conversion request signal generated by one AJB among the first AJB and the second AJB and supply the converted power to the one AJB,
• wherein the PDC is further configured to collect SOC information of the first and second low-voltage batteries from the first IBS and the second IBS, transmit a supplementary charging request signal based on determining that supplementary charging is required, and transmit a smoothing supplementary charging request signal to the RPC based on determining that the supplementary charging is not possible,
• wherein the RPC is further configured to, in response to the smoothing supplementary charging request signal from the PDC, collect and compare the SOC information of the first and second low-voltage batteries from the first IBS and the second IBS and form a supplementary charging path between the first SBM and the second SBM, performing smoothing the supplementary charging.