SECONDARY BATTERY CHARGING DEVICE, METHOD OF CHARGING IN SECONDARY BATTERY CHARGING DEVICE, PHOTOVOLTAIC GENERATOR, METHOD OF POWER GENERATION IN PHOTOVOLTAIC GENERATOR, PHOTOVOLTAIC-CHARGED SECONDARY BATTERY SYSTEM, ELECTRONIC DEVICE, AND ELECTRICAL VEHICLE

• US 20140197684A1
• Filed: 09/07/2012
• Published: 07/17/2014
• Est. Priority Date: 09/20/2011
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Masato, Tsuyoshi, Uesaka, Shinichi
• Granted Patent: US 9,853,472 B2
• Time in Patent Office: Days
• US Class Current: 307/9.1
• CPC Class Codes: B60L 2240/665 Light intensity
• CPC Class Codes: B60L 2240/72 Charging station selection relying on external data
• CPC Class Codes: B60L 2260/44 by parameter estimation
• CPC Class Codes: B60L 53/305 Communication interfaces
• CPC Class Codes: B60L 53/34 Plug-like or socket-like devices specially adapted for contactless inductive charging of electric vehicles positioning means for charging devices using inductive energy transfer B60L53/38
• CPC Class Codes: B60L 53/51 Photovoltaic means
• CPC Class Codes: B60L 53/68 Off-site monitoring or control, e.g. remote control
• CPC Class Codes: B60L 58/19 Switching between serial connection and parallel connection of battery modules
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60R 16/033 characterised by the use of electrical cells or batteries for propulsion puposes B60K1/04; supplying batteries to, or removing batteries from, vehicles B60S5/06; testing of charge state G01R31/36
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/0024 Parallel/serial switching of connection of batteries to charge or load circuit
• CPC Class Codes: 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 H02J7/0034
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: Y02B 10/10 Photovoltaic [PV]
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• 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
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles

Abstract

A battery charging device includes a battery pack including a plurality of battery cells connected in series, and a control unit. The control unit is configured to change a series connection of the battery cells in response to a variation in output voltage of a solar battery.

Claims

1. A battery charging device comprising:

a battery pack including a plurality of battery cells connected in series; and

a control unit configured to change a series connection of the battery cells in response to a variation in output voltage of a solar battery.

2. The battery charging device according to claim 1, wherein the control unit is configured to increase or decrease the number of battery cells in the series connection in response to the variation in output voltage of the solar battery.

3. The battery charging device according to claim 2,

wherein when the output voltage of the solar battery increases, the control unit is configured to decrease the number of battery cells in the series connection, and

wherein when the output voltage of the solar battery decreases, the control unit is configured to increase the number of battery cells in the series connection.

4. The battery charging device according to claim 1, wherein the battery pack includes a plurality of series-connection packs connected in parallel, and each series-connection pack includes a plurality of battery cells connected in series.

5. The battery charging device according to claim 4, wherein at a time of charging the battery cells, in a case where a number of battery cells forming the series-connection packs is reduced, the control unit is configured to combine a battery cell not serially connected in one of the series-connection packs with battery cells not serially connected in other series-connection packs to form a different series connection pack.

6. The battery charging device according to claim 1, wherein a current backflow prevention circuit is arranged in an input section of the battery charging device, and is connected between the solar battery and the control unit.

7. The battery charging device according to claim 6, wherein an MPPT circuit is arranged in parallel with the current backflow prevention circuit, and the control unit is configured to control switching between the current backflow prevention circuit and the MPPT circuit through a switch.

8. The battery charging device according to claim 1, wherein M*(V_cell+Δ

V_ch)≦

V_PV<

(M+1)*(V_cell+Δ

V_ch) is satisfied, where

V_cell is an open-circuit voltage in a charge state for one battery cell,

M is the number of battery cells connected in series,

Δ

V_ch is a voltage increase at a time of charge due to an internal resistance of the battery cell, and

V_PV is an output voltage from a photovoltaic generator connected to the battery pack.

9. The battery charging device according to claim 1, wherein the control unit estimates the output voltage at which output electrical power of the solar battery becomes a maximum based on solar radiation intensity measured by an optical sensor connected to the control unit.

10. The battery charging device according to claim 1, further comprising a switching device arranged between the control unit and the respective battery cells, wherein the switching device is a relay circuit.

11. The battery charging device according to claim 10, wherein the control unit includes,

a microcomputer configured to control an operation of the control unit,

an electrical power meter configured to accumulate electrical power from the solar battery,

a current/voltage measurement circuit for measuring a current and a voltage from the solar battery,

a switching device control section configured to control an operation of the switching device, and

an optical sensor for detecting outside light.

12. An electronic device comprising the battery charging device according to claim 1, wherein the control unit is further configured to supply power to at least one electrical power consuming device.

13. An electric vehicle comprising:

the battery charging device according to claim 1; and

a converter configured to receive a supply of electric power from the battery charging device, and to supply the power to a component of the electric vehicle.

14. A method of charging a battery charging device including a battery pack including a plurality of battery cells connected in series, the method comprising:

changing a series connection of the battery cells in response to a variation in output voltage of a solar battery.

15. The method of charging a battery charging device according to claim 14, further comprising increasing or decreasing the number of battery cells in the series connection in response to the variation in output voltage of the solar battery.

16. The method of charging a battery charging device according to claim 15, further comprising:

decreasing the number of battery cells in the series connection when the output voltage of the solar battery increases; and

increasing the number of battery cells in the series connection when the output voltage of the solar battery decreases.

17. The method of charging a battery charging device according to claim 14, wherein M*(V_cell+Δ

V_ch)≦

V_PV<

(M+1)*(V_cell+Δ

V_ch) is satisfied, where

V_cell is an open-circuit voltage in a charge state for one battery cell,

M is the number of battery cells connected in series,

Δ

V_ch is a voltage increase at a time of charge due to an internal resistance of the battery cell, and

V_PV is an output voltage from a photovoltaic generator connected to the battery pack.

18. A method of operating an electronic vehicle comprising:

charging a battery charging device according to claim 14; and

receiving a supply of electric power from the battery charging device, and supplying the power to a component of the electric vehicle.

19. A photovoltaic generator comprising:

a solar battery including a plurality of solar battery cells connected in series; and

a control unit configured to change a series connection of the solar battery cells in response to a variation in output voltage of the solar battery.

20. A method of generating power in a photovoltaic generator including a solar battery including a plurality of solar battery cells connected in series, the method comprising:

changing a series connection of the solar battery cells in response to a variation in output voltage of the solar battery.