# US 12,015,301 B2 · Power supply system, DC/DC converter

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- Number: US 12,015,301 B2
- Document ID: US12015301B2
- Status: Granted
- Kind: B2
- Application number: 17/954,951
- Filed: 2022-09-28
- Published: 2023-03-30
- Granted: 2024-06-18
- Earliest claimed: 2021-09-29
- Assignees: Yazaki Corporation
- Applicants: Yazaki Corporation
- Inventors: Hiroaki Takamatsu
- Web page: https://patentgrep.com/patent/US12015301B2

## CPC

- 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)}
- H02M 3/158: including plural semiconductor devices as final control devices for a single load
- B60L 58/20: having different nominal voltages
- H02J 7/50: acting upon multiple batteries simultaneously or sequentially
- H02J 7/855: {with circuits adapted for supplying loads from the battery}
- H02M 3/1582: {Buck-boost converters (H02M3/1584 takes precedence)}
- B60L 2210/10: DC to DC converters
- B60L 2270/20: Inrush current reduction, i.e. avoiding high currents when connecting the battery
- H02J 2207/20: Charging or discharging characterised by the power electronics converter
- Y02T 10/70: Energy storage systems for electromobility, e.g. batteries
- H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- 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)
- 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
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A power supply system including: a first voltage subsystem including a first battery connected to a load via a relay; a second voltage subsystem including a second battery, the second battery having a lower voltage than the first battery; and a DC/DC converter disposed between the first voltage subsystem and the second voltage subsystem, wherein before switching the relay to be closed, the DC/DC converter is configured to: provide a lower voltage than a voltage of the second battery to the first voltage subsystem; subsequently provide the voltage of the second battery to the first voltage subsystem; and subsequently increase the voltage of the second battery to be equal to a voltage of the first battery and provide the voltage of the second battery to the first voltage subsystem.

## Claims

### Claim 1

A power supply system comprising:
a first voltage subsystem including a first battery connected to a load via a relay;
a second voltage subsystem including a second battery, the second battery having a lower voltage than the first battery; and
a DC/DC converter disposed between the first voltage subsystem and the second voltage subsystem,
wherein before switching the relay to be closed, the DC/DC converter is configured to:
provide a lower voltage than a voltage of the second battery to the first voltage subsystem;
subsequently provide the voltage of the second battery to the first voltage subsystem; and
subsequently increase the voltage of the second battery to be equal to a voltage of the first battery and provide the increased voltage of the second battery to the first voltage subsystem.

### Claim 2 (depends on 1)

The power supply system according to claim 1,
wherein the DC/DC converter includes an electronic device configured to be operated with a lower voltage than the voltage of the second battery.

### Claim 3 (depends on 1)

The power supply system according to claim 1,
wherein the DC/DC converter includes a switch configured to switch a connected state of the DC/DC converter to the second battery, and
wherein the DC/DC converter is configured to provide, from a side closer to the first voltage subsystem with respect to the switch, the lower voltage than the voltage of the second battery to the first voltage subsystem.

### Claim 4 (depends on 2)

The power supply system according to claim 2,
wherein the DC/DC converter includes a switch configured to switch a connected state of the DC/DC converter to the second battery, and
wherein the DC/DC converter is configured to provide, from a side closer to the first voltage subsystem with respect to the switch, the lower voltage than the voltage of the second battery to the first voltage subsystem.

### Claim 5 (depends on 1)

The power supply system according to claim 1, further comprising a voltage sensor,
wherein subsequently providing the voltage of the second battery to the first voltage subsystem is initiated upon detecting by means of the voltage sensor that the voltage of the lower voltage than the voltage of the second battery has been provided to the first voltage subsystem, and
wherein subsequently increasing the voltage of the second battery to be equal to the voltage of the first battery and providing the increased voltage of the second battery to the first voltage subsystem is initiated upon detecting by means of the voltage sensor that the voltage of the second battery has been provided to the first voltage subsystem.

### Claim 6 (depends on 1)

The power supply system according to claim 1,
wherein the DC/DC converter includes a precharge switch and a power supply configured to provide the lower voltage than the voltage of the second battery,
wherein the DC/DC converter is configured to provide the lower voltage than the voltage of the second battery to the first voltage subsystem by controlling the precharge switch to be closed.

### Claim 7 (depends on 6)

The power supply system according to claim 6,
wherein the DC/DC converter further includes a boost and buck circuit and a switch, the switch being configured to switch a connected state of the boost and buck circuit to the second battery,
wherein the power supply is connected between the switch and the first voltage subsystem, and
wherein the precharge switch is configured to switch connection/disconnection of the power supply to the first voltage subsystem.

### Claim 8 (depends on 6)

The power supply system according to claim 6, wherein the DC/DC converter is configured to provide the lower voltage than the voltage of the second battery to the first voltage subsystem while the second battery is electrically disconnected from the DC/DC converter and the first voltage subsystem.

### Claim 9

A DC/DC converter configured to be disposed between a first voltage subsystem and a second voltage subsystem, wherein the first voltage subsystem includes a first battery connected to a load via a relay and the second voltage subsystem includes a second battery, the second battery having a lower voltage than the first battery,
wherein before switching the relay to be closed, the DC/DC converter is configured to:
provide a lower voltage than a voltage of the second battery to the first voltage subsystem;
subsequently provide the voltage of the second battery to the first voltage subsystem; and
subsequently increase the voltage of the second battery to be equal to a voltage of the first battery and provide the increased voltage of the second battery to the first voltage subsystem.

### Claim 10 (depends on 9)

The DC/DC converter according to claim 9, further comprising a voltage sensor,
wherein subsequently providing the voltage of the second battery to the first voltage subsystem is initiated upon detecting by means of the voltage sensor that the voltage of the lower voltage than the voltage of the second battery has been provided to the first voltage subsystem, and
wherein subsequently increasing the voltage of the second battery to be equal to the voltage of the first battery and providing the increased voltage of the second battery to the first voltage subsystem is initiated upon detecting by means of the voltage sensor that the voltage of the second battery has been provided to the first voltage subsystem.

### Claim 11 (depends on 9)

The DC/DC converter according to claim 9, comprising a precharge switch and a power supply configured to provide the lower voltage than the voltage of the second battery,
wherein the DC/DC converter is configured to provide the lower voltage than the voltage of the second battery to the first voltage subsystem by controlling the precharge switch to be closed.

### Claim 12 (depends on 11)

The DC/DC converter according to claim 11,
wherein the DC/DC converter further includes a boost and buck circuit and a switch, the switch being configured to switch a connected state of the boost and buck circuit to the second battery,
wherein the power supply is connected between the switch and a connection portion of the DC/DC converter, the connection portion being configured to connect the DC/DC converter to the first voltage subsystem, and
wherein the precharge switch is configured to switch connection/disconnection of the power supply to the first voltage subsystem.

### Claim 13 (depends on 11)

The DC/DC converter according to claim 11, wherein the DC/DC converter is configured to provide the lower voltage than the voltage of the second battery to the first voltage subsystem while the second battery is electrically disconnected from the DC/DC converter and the first voltage subsystem.