Power supply device

• US 9,627,999 B2
• Filed: 11/07/2012
• Issued: 04/18/2017
• Est. Priority Date: 11/07/2012
• Status: Active Grant

• Current Assignee: UD Trucks Corporation (Isuzu Motors Limited)
• Original Assignee: Volvo Truck Corporation (AB Volvo)
• Inventors: Yamada, Yoshiaki, Tsuchiya, Takayuki, Hikiri, Kunihiko, Itani, Koichi, Toyama, Hiroshi, Miyake, Noriaki
• Primary Examiner(s): Ip, Paul
• Application Number:
  US14/441,301
• Publication Number:
  US 20150311831A1
• Time in Patent Office: 1,623 Days
• Field of Search: 318139, 318148, 307 91, 307 101
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/14 Boost converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60L 7/16 for vehicles comprising converters between the power source and the motor
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• CPC Class Codes: H02P 3/14 by regenerative braking
• CPC Class Codes: H02P 4/00 Arrangements specially adapted for regulating or controlling the speed or torque of electric motors that can be connected to two or more different electric power supplies vector control H02P21/00
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

A power supply device for supplying power to a load by combining a secondary battery and a capacitor includes a bypass switch which enables power to be directly supplied to the load from the capacitor by being switched to a connected state when a voltage of the capacitor is a voltage capable of driving the load, and a first DC-DC converter which enables the voltage of the capacitor to be stepped up and supplied to the load when the voltage of the capacitor drops below a minimum voltage capable of driving the load.

Claims

1. A power supply device for supplying power to a load by combining a rechargeable battery and a capacitor, comprising:

a first DC-DC converter connected between the capacitor and the load and configured to enable a voltage of the capacitor to be stepped up and supplied to the load;

a bypass switch enabling power to be directly supplied to the load from the capacitor by bypassing the first DC-DC converter when switched to a connected state; and

a controller configured to control the first DC-DC converter and a connecting state of the bypass switch;

wherein the rechargeable battery is connected to the load without going through the first DC-DC converter; and

wherein the controller is configured to;

switch the bypass switch to the connected state to directly supply power to the load from the capacitor when a voltage of the capacitor is a voltage capable of driving the load,

control the first DC-DC converter to step up the voltage of the capacitor to supply power to the load when the voltage of the capacitor drops below a minimum voltage capable of driving the load, and

switch the bypass switch to the connected state to directly supply a regenerative power to the rechargeable battery from the load when the voltage of the capacitor drops below the minimum voltage capable of driving the load.

2. The power supply device according to claim 1, further comprising:

a second DC-DC converter adapted to enable a voltage of the rechargeable battery to be stepped up and supplied to the load when the load is no longer drivable by power from the capacitor.

3. The power supply device according to claim 2, wherein:

the bypass switch is switched to a shut-off state when the voltage of the capacitor becomes lower than a voltage higher than the minimum voltage capable of driving the load by a margin voltage; and

the first DC-DC converter steps up the voltage of the capacitor and supplies the stepped-up voltage to the load when the bypass switch is switched to the shut-off state.

4. The power supply device according to claim 3, wherein:

the supply of power to the load from the first DC-DC converter is stopped and the supply of power to the load from the second DC-DC converter is started when the voltage of the capacitor becomes lower than a voltage higher than a minimum operating voltage of the capacitor by a margin voltage.

5. The power supply device according to claim 2, wherein:

the load is an inverter for driving an electric motor by the supply of power from the rechargeable battery and the capacitor.

6. The power supply device according to claim 5, wherein:

the first DC-DC converter is capable of stepping down power generated by the electric motor and charging the stepped-down power into the capacitor; and

the second DC-DC converter is capable of stepping down the power generated by the electric motor and charging the stepped-down power into the rechargeable battery.

7. The power supply device according to claim 5, wherein:

the bypass switch, when switched to the connected state, enables power generated by the electric motor to be directly charged into the capacitor without passing through the first DC-DC converter.

8. The power supply device according to claim 5, wherein:

each of the first and second DC-DC converters includes;

a reactor provided downstream of the rechargeable battery or the capacitor;

a step-down control transistor provided between the reactor and an upstream side of the electric motor that is capable of stepping down a charge voltage from the electric motor by switching; and

a step-up control transistor provided between the reactor and a downstream side of the electric motor that is capable of stepping up a supply voltage to be supplied to the electric motor by an induced electromotive force by switching a current of the reactor.

9. The power supply device according to claim 5, wherein:

the first DC-DC converter includes;

a first reactor provided downstream of the capacitor;

a step-down control transistor provided between the first reactor and an upstream side of the electric motor that is capable of stepping down a charge voltage from the electric motor by switching; and

a step-up control transistor provided between the first reactor and a downstream side of the electric motor that is capable of stepping up a supply voltage to be supplied to the electric motor by an induced electromotive force by switching a current of the first reactor; and

the second DC-DC converter includes a second reactor provided downstream of the rechargeable battery and that shares the step-down control transistor and the step-up control transistor with the first DC-DC converter.

10. The power supply device according to claim 5, wherein:

the first DC-DC converter includes;

a reactor provided downstream of the capacitor;

a step-down control transistor provided between the reactor and an upstream side of the electric motor that is capable of stepping down a charge voltage from the electric motor by switching; and

a step-up control transistor provided between the reactor and a downstream side of the electric motor that is capable of stepping up a supply voltage to be supplied to the electric motor by an induced electromotive force by switching a current of the reactor; and

the second DC-DC converter shares the reactor, the step-down control transistor and the step-up control transistor with the first DC-DC converter.