POWER CONVERSION DEVICE, POWER GENERATION SYSTEM AND CHARGE AND DISCHARGE CONTROL METHOD

• US 20120223679A1
• Filed: 11/24/2010
• Published: 09/06/2012
• Est. Priority Date: 11/25/2009
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Iwai, Ryo, Shimizu, Yukihiro, Nishi, Shunsuke, Eguchi, Masaki
• Granted Patent: US 9,030,168 B2
• Time in Patent Office: Days
• US Class Current: 320/128
• CPC Class Codes: H01M 10/465 with solar battery as charging system
• CPC Class Codes: H02J 1/12 Parallel operation of dc generators with converters, e.g. with mercury-arc rectifier
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: Y02B 10/10 Photovoltaic [PV]
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A power conversion device includes: a DC/DC convertor (5) that performs DC/DC conversion on an output voltage of a direct-current power supply (for example, a solar battery module (1)); and a DC/AC invertor (6) that performs DC/AC conversion on an output voltage of the DC/DC convertor (5). The output power of the DC/AC invertor (6) is controlled such that the charge and discharge of a storage device (for example, a storage battery (3)) connected to a connection point between an output end of the DC/DC convertor (5) and an input end of the DC/AC invertor (6) are controlled.

Claims

1. A power conversion device comprising:

a DC/DC convertor that performs DC/DC conversion on an output voltage of a direct-current power supply; and

a DC/AC invertor that performs DC/AC conversion on an output voltage of the DC/DC convertor,

wherein an output power of the DC/AC invertor is controlled such that charge and discharge of a storage device connected to a connection point between an output end of the DC/DC convertor and an input end of the DC/AC invertor are controlled.

2. The power conversion device of claim 1,

wherein,when the storage device is charged, the control is performed such that the output power of the DC/AC invertor is lower than an output power of the DC/DC convertor, and

when discharge is performed from the storage device, the control is performed such that the output power of the DC/AC invertor is higher than the output power of the DC/DC convertor.

3. The power conversion device of claim 1,

wherein an output end of the DC/AC invertor is connected to a load and a commercial system, and

power supply to the load is preferentially performed in a following order:

a power generated by the direct-current power supply, a power stored in the storage device and a power of the commercial system.

4. The power conversion device of claim 1,

wherein, when a power discharged from the storage device drops below a lower limit of an allowable range, the output power of the DC/AC invertor is reduced, and, even if the load is being used, the power of the commercial system is preferentially used in the load as compared with the power generated by the direct-current power supply.

5. A power generation system comprising:

the power conversion device of claim 1;

the direct-current power supply that is connected to the DC/DC convertor of the power conversion device;

the storage device that is connected to the connection point between the output end of the DC/DC convertor and the input end of the DC/AC invertor of the power conversion device; and

the load that is connected to the output end of the DC/AC invertor,

wherein the output end of the DC/AC invertor is connected to the commercial system.

6. A power generation system comprising:

the power conversion device of claim 1;

the direct-current power supply that is connected to the DC/DC convertor of the power conversion device;

the storage device that is connected to the connection point between the output end of the DC/DC convertor and the input end of the DC/AC invertor of the power conversion device; and

the load that inputs a direct-current power output from the storage device,

wherein the output end of the DC/AC invertor is connected to the commercial system.

7. The power generation system of claim 5,

wherein the direct-current power supply is a solar battery,

the load is a charge stand that charges a charge target and

the DC/DC convertor controls an operation point of the solar battery by maximum power point follow control.

8. A method of controlling charge and discharge of a storage device, a power conversion device including a DC/DC convertor that performs DC/DC conversion on an output voltage of a direct-current power supply and a DC/AC invertor that performs DC/AC conversion on an output voltage of the DC/DC convertor, the storage device being connected to a connection point between an output end of the DC/DC convertor of and an input end of the DC/AC invertor of the power conversion device,

wherein an output power of the DC/AC invertor is controlled such that the charge and the discharge of the storage device are controlled.