Power source apparatus and control method of the power source apparatus

• US 7,906,934 B2
• Filed: 03/09/2006
• Issued: 03/15/2011
• Est. Priority Date: 03/31/2005
• Status: Expired due to Fees

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Nakada, Yasuhiro, Inoue, Toshio
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): TORRES RUIZ, JOHALI ALEJANDRA
• Application Number:
  US11/910,059
• Publication Number:
  US 20080272653A1
• Time in Patent Office: 1,832 Days
• Field of Search: 320/101
• US Class Current: 320/101
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/44 with means for ensuring correct phase sequence
• 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

Abstract

The present invention provides a solar cell that can be utilized as a stable electric power source for cloudy weather. An output voltage V1 of the solar cell 1 is lowered by a DC-DC converter 5. When a battery V2 is charged with an output of the converter 5, the converter 5 is stopped and the power of only the battery V2 is supplied to a low-voltage inverter circuit 6. The electric power supplied from the converter 5 is increased by boosting the output voltage of the converter 5 as well as starting to supply electric power from the battery V2. While the electric power of the converter 5 is increased, the performance of the solar cell 1 is judged. When the performance is decreased, the output voltage from the converter 5 is lowered and the amount of electric power supplied from the battery 2 is increased relatively.

Claims

1. A power source apparatus comprising:

a solar cell;

a DC-DC converter that controls an output of the solar cell;

a battery that is charged with an output of the DC-DC converter;

an inverter into which an output of said DC-DC converter and an output of said battery are input in parallel; and

converter driving means that drives said DC-DC converter when a remaining amount of said battery is below or equal to a predetermined amount so that the battery can be charged with the output of said DC-DC converter, wherein

said converter driving means supplies the output of said DC-DC converter to said inverter when an output electric power of said solar cell exceeds a predetermined value,

said converter driving means supplies the output of said DC-DC converter to said battery for charging the battery without supplying the output to said inverter when the output electric power of said solar cell is below or equal to the predetermined value, and

said converter driving means starts supplying electric power from the battery to said inverter when said battery is charged to a predetermined amount without supplying the output of said DC-DC converter to said inverter while the output electric power of said solar cell remains below or equal to the predetermined value.

2. The power source apparatus according to claim 1, further comprising means for gradually raising an output voltage of said DC-DC converter from a value lower than a voltage value of said battery until an output voltage of said battery becomes zero, when supply of electric power from said solar cell to the inverter is started.

3. The power source apparatus according to claim 1, wherein

an operation of said DC-DC converter is stopped when an output electric power of said solar cell is below or equal to a predetermined value that is detected by finding a switching duty of said DC-DC converter has risen above or equal to a predetermined value when an electric power supplied to said inverter is at a predetermined value.

4. The power source apparatus according to claim 3, wherein

supply of electric power from the battery to said inverter is stopped when a remaining amount of said battery becomes below or equal to a predetermined amount.

5. The power source apparatus according to claim 1, further comprising a power generator, wherein

said DC-DC converter is a voltage-lowering type, and

a voltage-booster converter that inputs an output of said battery into the inverter by raising a voltage of said battery and a rectifying circuit that supplies an output of said power generator to said inverter by rectifying the output of said power generator are connected in parallel.

6. A method of controlling a power source apparatus that includes a solar cell;

a DC-DC converter that controls an output of the solar cell;

a battery that is charged with an output of the DC-DC converter; and

an inverter into which an output of said DC-DC converter and an output of said battery are input in parallel, comprising the steps of;

raising an output voltage of said DC-DC converter to be above a voltage of said battery in a state in which an output electric power of said solar cell exceeds a predetermined value,

lowering the output voltage of said DC-DC converter to be below a voltage of said battery or stopping an operation of the DC-DC converter when the output electric power of said solar cell is below or equal to the predetermined value,

supplying an output of said DC-DC converter to said battery for charging the battery without supplying the output of said DC-DC converter to said inverter when a remaining amount of said battery is below a predetermined amount,

lowering the output voltage of said DC-DC converter to be below a voltage of said battery or stopping an operation of the DC-DC converter in a state in which the remaining amount of said battery has risen above or equal to the predetermined amount, and

providing electric power from the battery to said inverter when said battery has risen above or equal to the predetermined amount without supplying the output of said DC-DC converter to said inverter while the output electric power of said solar cell remains below or equal to the predetermined value.