Power Unit

• US 20080259666A1
• Filed: 09/15/2005
• Published: 10/23/2008
• Est. Priority Date: 09/30/2004
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Eguchi, Hiroyuki, Shimizu, Motohiro
• Granted Patent: US 7,830,680 B2
• Time in Patent Office: Days
• US Class Current: 363/131
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02M 3/33584 Bidirectional converters

Abstract

The invention makes it possible to secure a maximum output within the capacity range of an electrical power source by preventing an output from being cut by a protective function of a converter at the time of a temporary overload. A bidirectional DC-DC converter 4 for stepping up a voltage of DC power supplied from a battery 5 is provided. A stepped-up DC power is converted to an AC power by an inverter 3-2 via a regulator 3-1 and is outputted to the load side. An input voltage V1 of the regulator 3-1 is detected by a voltage detecting portion 15 and is inputted into an output limit determining portion 16. The output limit determining portion 16 determines an output voltage value for starting to limit an inverter output according to a distance from when the input voltage V1 fell below a limit starting voltage value Vlim to a limit voltage value Va. An inverter driving portion 17 limits an output by switching FETs in the inverter 3 in accordance with this output voltage value. When a temporary overload is eliminated, then the output recovers to a maximum value.

Claims

1. A power unit which includes a regulator which regulates generated power to a predetermined DC voltage, and an inverter which converts the direct current adjusted in voltage by the regulator into an alternating current with a predetermined frequency and outputs it, comprising:

control means which detects an input voltage of the regulator, and when the input voltage lowers to a predetermined value or less, limits the output of the inverter.

3. The power unit according to claim 1, wherein a generator and a rectifier circuit that rectifies an output of the generator are provided wherein an output of the rectifier is inputted into the inverter.

5. A power unit according to any of claims 1 through 4, wherein

the output of the inverter is limited by lowering an output target voltage of the inverter;

the output target voltage is calculated by the following formula;

voltage amplitude value (%)=(V1−

Vlim)/Va−

Vlim)×

100 

 

(Formula

     1)

based on the input voltage V1 so that the voltage amplitude value becomes 100% when the output target voltage is equal to or less than a limitation start voltage Va higher than a predetermined limit voltage Vlim, and the voltage amplitude value becomes 0% when the output target voltage is at the limit voltage Vlim.

2. A power unit which includes an inverter that converts generated power into an alternating current with a predetermined frequency and outputs it, comprising:

a second power source provided separately from the power source which generates electric power;

a converter for supplying a DC voltage supplied from the second power source to the inverter; and

control means which detects an input voltage of the converter, and when this input voltage lowers to a predetermined value or less, limits the output of the inverter.

4. The power unit according to claim 2, wherein a generator and a rectifier circuit that rectifies an output of the generator are provided wherein an output of the rectifier is inputted into the inverter.