# US 12,224,581 B2 · Bidirectional converter and control method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,224,581 B2 - Document ID: US12224581B2 - Status: Granted - Kind: B2 - Application number: 18/099,190 - Filed: 2023-01-19 - Published: 2024-02-29 - Granted: 2025-02-11 - Earliest claimed: 2022-08-23 - Assignees: Hyundai Motor Company; Kia Corporation - Applicants: Hyundai Motor Company; Kia Corporation - Inventors: Ho Joong Lee - Web page: https://patentgrep.com/patent/US12224581B2 ## CPC - H02J 1/084: {for selectively connecting the load or loads to one or several among a plurality of power lines or power sources} - B60L 1/00: Supplying electric power to auxiliary equipment of vehicles (circuit arrangements for charging batteries H02J7/00) - B60L 50/60: using power supplied by batteries (in combination with fuel cells B60L50/75) - B60L 58/12: responding to state of charge [SoC] - B60L 58/18: of two or more battery modules - B60L 58/20: having different nominal voltages - H02J 7/342: {The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging (with circuits for polarity protection H02J7/68)} - H02J 7/80: including monitoring or indicating arrangements - H02J 7/855: {with circuits adapted for supplying loads from the battery} - H02J 7/933: {the cycle being controlled or terminated in response to electric parameters} - H02M 1/0067: {Converter structures employing plural converter units, other than for parallel operation of the units on a single load} - B60L 2210/12: Buck converters - B60L 2210/14: Boost converters - B60L 2240/547: Voltage - B60L 2240/549: Current - H02J 2207/20: Charging or discharging characterised by the power electronics converter - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) ## Abstract A power supply device includes: a low-voltage direct current-direct current converter (LDC) to convert a voltage of a high-voltage battery to supply power; a first low-voltage battery to be charged by receiving power from the LDC and supply power to a general load; a bidirectional converter to convert a voltage supplied from the LDC and control a charge amount of a second low-voltage battery; the second low-voltage battery to be charged by receiving power from the bidirectional converter and supply power to a dual power source load; a first relay disposed between the LDC and the first low-voltage battery; a second relay disposed between the bidirectional converter and the second low-voltage battery; a second battery sensor to measure a voltage of the second low-voltage battery; and a control unit to control the bidirectional converter. ## Claims ### Claim 1 A power supply apparatus comprising: a low-voltage direct current-direct current converter (LDC) configured to convert a voltage of a high-voltage battery to supply power; a first low-voltage battery configured to be charged by receiving the power from the LDC and supply power to a predetermined load; a bidirectional converter configured to convert a voltage supplied from the LDC and control a charge amount of a second low-voltage battery; the second low-voltage battery configured to be charged by receiving power from the bidirectional converter and supply power to a dual power source load; a first relay disposed between the LDC and the first low-voltage battery; a second relay disposed between the bidirectional converter and the second low-voltage battery; a battery sensor configured to measure a voltage of the second low-voltage battery; and a control unit configured to control the bidirectional converter to charge the second low-voltage battery. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein an output of the bidirectional converter is controlled according to a result of comparing an output current of the LDC with a maximum efficiency current value of the LDC. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein the control unit is configured to reduce an output command of the bidirectional converter when the output current of the LDC exceeds the maximum efficiency current value. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the control unit is configured to reduce the output command of the bidirectional converter by a value obtained by subtracting the maximum efficiency current value from the output current of the LDC. ### Claim 5 (depends on 3) The apparatus of claim 3, wherein the control unit is configured to configure the output command of the bidirectional converter as a value limited to be greater than or equal to a lower limit value. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein the lower limit value is configured based on a maximum discharge power of the second low-voltage battery. ### Claim 7 (depends on 2) The apparatus of claim 2, wherein the control unit is configured to increase an output command of the bidirectional converter when the output current of the LDC does not exceed the maximum efficiency current value. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the control unit is configured to increase the output command of the bidirectional converter by a value obtained by subtracting the output current of the LDC from the maximum efficiency current value. ### Claim 9 (depends on 7) The apparatus of claim 7, wherein the control unit is configured to configure the output command of the bidirectional converter as a value limited to be less than or equal to an upper limit value. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the upper limit value is configured based on a maximum charging power of the second low-voltage battery. ### Claim 11 A power supply method comprising: driving a bidirectional converter; determining, by a control unit, whether a state of charge (SOC) value of an auxiliary battery exceeds a preconfigured first threshold value; when the SOC value of the auxiliary battery exceeds the first threshold value, determining, by the control unit, whether an output current of a low-voltage direct current-direct current converter (LDC) exceeds a maximum efficiency current value of the LDC; and controlling, by the control unit, an output of the bidirectional converter according to a result of comparing the output current of the LDC with the maximum efficiency current value to charge the auxiliary battery. ### Claim 12 (depends on 11) The method of claim 11, further including reducing an output command of the bidirectional converter when the output current of the LDC exceeds the maximum efficiency current value. ### Claim 13 (depends on 12) The method of claim 12, wherein the reducing of the output command includes reducing the output command of the bidirectional converter by a value obtained by subtracting the maximum efficiency current value from the output current of the LDC. ### Claim 14 (depends on 13) The method of claim 13, wherein the reducing of the output command further includes configuring the output command of the bidirectional converter as a value limited to be greater than or equal to a lower limit value. ### Claim 15 (depends on 14) The method of claim 14, wherein the lower limit value is configured based on a maximum discharge power of the second low-voltage battery. ### Claim 16 (depends on 11) The method of claim 11, further including increasing an output command of the bidirectional converter when the output current of the LDC does not exceed the maximum efficiency current value. ### Claim 17 (depends on 16) The method of claim 16, wherein the increasing of the output command includes increasing the output command of the bidirectional converter by a value obtained by subtracting the output current of the LDC from the maximum efficiency current value. ### Claim 18 (depends on 17) The method of claim 17, wherein the increasing of the output command further includes configuring the output command of the bidirectional converter as a value limited to be less than or equal to an upper limit value. ### Claim 19 (depends on 18) The method of claim 18, wherein the upper limit value is configured based on a maximum charging power of the second low-voltage battery.