# US 12,109,899 B2 · Power supply device for vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,109,899 B2 - Document ID: US12109899B2 - Status: Granted - Kind: B2 - Application number: 18/248,958 - Filed: 2021-09-17 - Published: 2023-11-30 - Granted: 2024-10-08 - Earliest claimed: 2020-11-02 - Assignees: Imasen Electric Industrial Co., Ltd. - Applicants: Imasen Electric Industrial Co., Ltd. - Inventors: Daisuke Makio; Koichi Yamanoue - Web page: https://patentgrep.com/patent/US12109899B2 ## CPC - B60L 3/0069: {relating to the isolation, e.g. ground fault or leak current} - H02J 7/54: Passive balancing, e.g. using resistors or parallel MOSFETs - B60L 3/0046: {relating to electric energy storage systems, e.g. batteries or capacitors} - B60L 3/04: Cutting off the power supply under fault conditions (protective devices and circuit arrangements in general H01H; H02H) - B60L 58/20: having different nominal voltages - B60L 58/22: Balancing the charge of battery modules - H02H 3/16: responsive to fault current to earth, frame or mass (with balanced or differential arrangement H02H3/26 {; monitoring earth connection H02H5/105}) - H02H 5/12: responsive to undesired approach to, or touching of, live parts by living beings - H02J 1/08: Three-wire DC power distribution systems; Systems having more than three wires - H02J 7/62: against overcurrent - H02J 7/82: Control of state of charge [SOC] - H02M 3/24: by static converters - B60L 50/60: using power supplied by batteries (in combination with fuel cells B60L50/75) - B60L 2210/10: DC to DC converters - B60L 2210/40: DC to AC converters - H02J 2105/37: exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - Y02T 10/92: Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles - 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 - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) - 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) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract In a vehicle power supply device mounted on a vehicle and obtaining a low voltage power supply from a high voltage power supply via a step-down means, electric shock to the human body is prevented without using an insulating means such as a transformer. A vehicle power supply device converts power from high voltage to low voltage by selectively connecting a predetermined power storage element group to a low voltage electric load from a high voltage power supply formed by connecting power storage elements in series. A leakage current from the high voltage power supply is measured during the dead time period when the power storage element group is not connected to the low voltage electric load. When the value exceeds a predetermined value, the connection between the power storage element group and the low-voltage electric load is interrupted, so that electric shock is prevented. ## Claims ### Claim 1 A power supply device for a vehicle, comprising: an electric load that operates at a predetermined low voltage; a high-voltage power supply that provides a high-voltage DC power supply by connecting in series a plurality of power storage elements constituting each node that supplies the predetermined low voltage; a plurality of switch means provided corresponding to the each node that supplies the predetermined low voltage to the electric load; a control means, wherein the control means supplies a voltage by turning on one of the switch means for supplying the voltage from at least one node and turning off the other switch means for supplying the voltage from the other nodes, and after setting a dead time period to turn off all the switch means once, by sequentially repeating turning on a next one of the switch means of a next node that supplies the voltage next and turning off the other switch means that supply the voltage from the other nodes so that the voltage is supplied from all the storage elements; and a leakage detection means that detects a leakage current between the high-voltage power supply and a ground potential and sends a signal to the control means, wherein the control means determines the signal sent from the leakage detection means during the dead time period in which all of the plurality of switching means are in an off state, and maintains the off state of all of the switching means for a predetermined period of time in a case where the leakage current is equal to or higher than a predetermined current. ### Claim 2 (depends on 1) The power supply device for the vehicle according to claim 1, wherein in the high-voltage power supply, (n (n: natural number)×N (N: natural number)) of the power storage elements constituting nodes, in which n pieces of the nodes make up the predetermined low voltage, are connected in series, and a DC power source having a high voltage N times higher than the predetermined low voltage is obtained. ### Claim 3 (depends on 1) The power supply device for the vehicle according to claim 1, wherein the control means controls the switch means so as to periodically change the plurality of selected nodes. ### Claim 4 (depends on 3) The power supply device for the vehicle according to claim 3, wherein the control means determines the node to be selected so that charge/discharge states of the plurality of power storage elements become substantially uniform. ### Claim 5 (depends on 3) The power supply device for the vehicle according to claim 3, wherein the control means determines a selective holding time of each node so that charge/discharge states of the plurality of power storage elements become substantially uniform. ### Claim 6 (depends on 1) The power supply device for the vehicle according to claim 1, wherein a time for connecting the each node to the electric load by the switch means is set so that a time during which the leakage current flows from the high voltage power supply to a human body is less than a time during which an electric shock accident is caused in the human body. ### Claim 7 (depends on 6) The power supply device for the vehicle according to claim 6, wherein the time for connecting the each node to the electric load by the switch means is set so as to be a time which is inversely proportional to a voltage value of the high voltage power supply, or a time which is inversely proportional to a current value detected by the leakage detecting means. ### Claim 8 (depends on 1) The power supply device for the vehicle according to claim 1, wherein the control means fixes all the switch means to the off state when a leakage detection value of the leakage detection means is equal to or higher than a predetermined current value. ### Claim 9 (depends on 1) The power supply device for the vehicle according to claim 1, wherein when a leakage detection value of the leakage detection means is equal to or higher than a predetermined current value, the control means repeats an operation in which the off state of all of the switch means is maintained for a predetermined time and subsequently the switch means selectively connect the each node and the electric load. ### Claim 10 (depends on 1) The power supply device for the vehicle according to claim 1, wherein the control means repeats the operation that when a leakage detection value of the leakage detection means is equal to or higher than a predetermined first threshold value, the switch means is turned off, and when the leakage detection value becomes equal to or lower than a predetermined second threshold value, the switch means is turned on again. ### Claim 11 (depends on 1) The power supply device for the vehicle according to claim 1, wherein the control means controls the switching means so that a product of a period in which the each node and the electric load are connected and a leakage detection value of the leakage detection means is 0.003 amperes×1 second or less. ### Claim 12 (depends on 1) The power supply device for the vehicle according to claim 1, wherein the control means sets a cycle for switching a node selected by the switching means to be a predetermined value or less so that a magnitude of a charge/discharge depth in each node of the power storage elements is equal to or less than a predetermined value. ### Claim 13 (depends on 1) The power supply device for the vehicle according to claim 1, wherein a capacitor is connected in parallel with the electric load. ### Claim 14 (depends on 13) The power supply device for the vehicle according to claim 13, wherein the dead time period or a capacitance value of the capacitor is set so that a voltage drop width applied to the electric load during the dead time period is not more than a predetermined value. ### Claim 15 (depends on 13) The power supply device for the vehicle according to claim 13, wherein the capacitor is arranged in parallel with each node of the power storage elements. ### Claim 16 (depends on 1) The power supply device for the vehicle according to claim 1, wherein from the each node of the high-voltage power supply that provides the high-voltage DC power supply by connecting in series the power storage elements, an AC power is supplied to the electric load by alternately reversing a polarity with a high potential side and a low potential side at predetermined periods when the electric load is connected by the switching means.