Sanyo Electric Co., Ltd.

Wataru Horio

Masahiro Makino

Kazuo Ito

Ryuzo Hagihara

Osamu Tajima

Takeo Ishida

Masaki Yugo

Yasuhiro Makino

Takehito Ike

Masahiro Maekawa

Etsuko Yamamoto

Haruhiko Tatsumi

Ding Lu

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.

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

A grid interconnection device includes a relay controller configured to control separation or interconnection of a relay; a receiver configured to receive, from a predetermined transmission path, power failure information containing at least local area information indicating an area in which a power failure occurs; a determination unit configured to determine an occurrence of a power failure in a power distribution system, when the power failure information includes local area information of an area to which the power distribution system belongs; and a detector configured to detect an islanding state. The detector increases detection sensitivity of the islanding state when the determination unit determines the power failure in the power distribution system. The relay controller performs separation control for the relay when the islanding state is detected by the detector.

Grid interconnection device, grid interconnection system and transfer trip system

A power inverter for use in the system interconnection of a direct-current supply with a commercial alternating-current supply includes an inverter circuit and a filter circuit. Feedback signals affecting the frequency of an output to be produced by the inverter circuit are taken from the filter circuit having frequency response characteristics such that the phase angle is reduced to 0.degree. at three frequencies consisting of a higher frequency, lower frequency and commercial frequency, the last of which lies halfway between the first and second. Under the normal condition, the frequency of the output produced by the inverter circuit is equal to the commercial frequency. In the event of a power failure or power cut in the commercial alternating-current supply system, deviation from the commercial frequency is caused by the characteristics of the filter circuit.

Power inverter for use in system interconnection

Growing community of inventors

Kobe, Japan

Wataru Horio