Grid interconnection device, grid interconnection system, and electric power control system

• US 7,840,313 B2
• Filed: 01/29/2008
• Issued: 11/23/2010
• Est. Priority Date: 01/30/2007
• Status: Expired due to Fees

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Makino, Masahiro, Ito, Kazuo, Horio, Wataru
• Primary Examiner(s): DeCady; Albert
• Assistant Examiner(s): Lin; Jason
• Application Number:
  US12/021,441
• Publication Number:
  US 20080179966A1
• Time in Patent Office: 1,029 Days
• Field of Search: 700/292, 700/293, 700/286, 307/86
• US Class Current: 700/292
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 3/388 Islanding, i.e. disconnection of local power supply from the network

Abstract

Disclosed is a grid interconnection device that converts electric power from a power supply device into predetermined alternating-current power, and interconnects the power supply device to a power distribution system. The grid interconnection device includes a detector that detects islanding of the power supply device, and a receiver that receives power failure information including local area information indicative of an area in which a power failure occurs, through a predetermined transmission path. The detector enhances detection sensitivity for the islanding when the received power failure information includes the local area information indicative of a different area from the area to which the power distribution system belongs.

Claims

1. A grid interconnection device that converts electric power from a power supply device into predetermined alternating-current power and, interconnects the power supply device to a power distribution system, the grid interconnection device comprising:

a detector configured to detect islanding of the power supply device; and

a receiver configured to receive power failure information including local area information indicative of an area in which a power failure occurs, through a predetermined transmission path,

a determination unit configured to determine whether or not local area information contained in the power failure information is different from local area information Indicative of the interconnected power distribution system,

wherein the detector enhances detection sensitivity for the islanding when the determination unit determines that the local area information Included in the power failure information differs from the area information indicative of the interconnected power distribution system.

2. The grid interconnection device according to claim 1, wherein the detector enhances the detection sensitivity by lowering a detection threshold value for detection of the islanding, when the determination unit determines that the local area information included in the power failure information differs from the area information indicative of the interconnected power distribution system.

3. The grid interconnection device according to claim 1, further comprising an output controller configured to change an output condition of the alternating-current power according to an amount of active variation used for detecting the islanding,

wherein the detector detects the islanding on the basis of the output condition of the alternating-current power, and

the output controller enhances the detection sensitivity by changing the amount of active variation, when the determination unit determines that the local area information included in the power failure information differs from the area information indicative of the interconnected power distribution system.

4. The grid interconnection device according to claim 1, wherein the detector includes;

a first detector configured to detect the islanding; and

a second detector configured to detect the islanding by use of a different method from that of the first detector,

wherein the detector enhances the detection sensitivity by using the second detector in addition to the first detector, when the determination unit determines that the local area information included in the power failure information is different from the area information indicative of the interconnected power distribution system.

5. The grid interconnection device according to claim 1, wherein when a predetermined time passes after enhancement of the detection sensitivity, the detector resets the detection sensitivity to original level used before the enhancement of the detection sensitivity.

6. A grid interconnection system, comprising:

a power supply device; and

the grid interconnection device according to claim 1.

7. An electric power control system, comprising:

a power supply device;

a grid interconnection device configured to convert electric power from the power supply device into predetermined alternating-current power, and to interconnect the power supply device to a power distribution system; and

a power failure manager configured to transmit power failure information to the grid interconnection device through a predetermined transmission path, in order to inform the grid interconnection device of the occurrence of a power failure,

wherein the grid interconnection device includes;

a detector configured to detect islanding of the power supply device; and

a receiver configured to receive the power failure information from the power failure manager through the predetermined transmission path, the power failure information including local area information indicative of an area in which a power failure occurs,

wherein the detector enhances detection sensitivity for the islanding when the received power failure information includes the local area information indicative of a different area from the area to which the power distribution system belongs.