Sharp Kabushiki Kaisha Corporation

Tabuchi Electric Co., Ltd.

Hirofumi Nakata

Tsukasa Takebayashi

Hirokazu Kodama

Masaki Eguchi

Mitsuo Okamoto

Kozo Hiyoshi

Naoto Hirose

Yukitaka Sakamoto

Kiyoshi Nishida

Fumiya Kimura

Satoru Fujii

Regarding output suppression control of a plurality of dispersed power sources linked to a high-voltage-to-low-voltage transformer of a commercial power system, the partiality of the output suppression of a plurality of dispersed power sources is eliminated and, cost increase of the dispersed power sources is prevented. If a voltage at a power receiving point of a dispersed power sourceexceeds the upper limit of a proper value, then a power conditionersuppresses an output to a power receiving point to store a surplus power into a storage batteryand transmit an output suppression start signal to a management unit. The management unittransmits an output suppression command signal to the other dispersed power sourcesthroughof which the voltage at the power receiving point is not exceeding the upper limit of the proper value to make the other dispersed power sourcesthroughto suppress their outputs and store surplus power into storage batteries. The plurality of dispersed power sourcesthroughcan be thus made to impartially suppress the outputs, so that the capacity of the storage batteriescan be reduced.

Output suppressing method of a plurality of dispersed power sources and dispersed power source managing system

An enclosure is formed of an outer case and a lid. The outer case includes a first projecting strip portion provided on a top face side of the outer case and on an outer peripheral portion defining an opening, and extending to project outwardly from the outer case, and the lid includes a second projecting strip portion provided at a position facing the first projecting strip portion. With the opening of the outer case closed with the lid, the first and second projecting strip portions make close contact with each other along a direction in which these portions extend. This structure can protect the inside from an external factor such as rainwater or dust.

Outdoor-installed power conditioner device

A solar generation system includes a standard solar cell string and a substandard solar cell string. A DC voltage output from the substandard solar cell string is boosted by a booster unit to the level of the DC voltage output from the standard solar cell string, and the DC voltage from the standard solar cell string and the boosted DC voltage are applied to a DC/AC inverter, whereby an AC power is obtained, which is supplied to a utility power supply.

Solar generation system

There is provided an inverter apparatus islanding operation detecting method capable of surely detecting an islanding operation with a simple construction. A distortion for causing a variation in an output frequency of an inverter apparatus in an islanding operation stage is applied to an inverter output waveform. With this arrangement, even when the inverter apparatus is disconnected from an AC power system in a state in which a power factor of a load impedance is proximate to one, a frequency variation is generated in an inverter output, thereby ensuring detection of the islanding operation.

Inverter apparatus islanding operation detecting method and inverter apparatus capable of surely detecting an islanding operation with a simple construction

An inverter-control device includes a subtractor for detecting an error between a waveform of a reference current signal generated in synchronization with a waveform of an inverter output current signal and the inverter output current signal, a delay portion for delaying by a prescribed time period a signal obtained by amplifying and removing high frequency component by filtering the error, an error waveform integrating portion for integrating the delayed signal f' output from delay portion, a proportional control portion for amplifying the error, and an adding portion for adding an error amplified signal output from the proportional control portion and an inverter driving waveform pattern output from the error waveform integrating portion.

Device and method for controlling inverter performing feedback control

A pulse width of a pulse train signal used for PWM (pulse width modulation) control is monitored. When a variation of the pulse width substantially disappears within a specified time, it is determined that an operating point on an output characteristic curve of a photovoltaic array is located on the open-circuit voltage side of a maximum power point. When the variation of the pulse width does not disappear after the elapse of the specified time, it is determined that the operating point is located on the short-circuit current side of the maximum power point. Based on the determination result, the inverter control is performed such that the operating point follows the maximum power point.

Inverter control method and inverter apparatus using the method

In a method of controlling an inverter for adjusting a periodic inverter output waveform to a desired periodic waveform, an error waveform pattern between an inverter output waveform of the present prescribed period and a desired periodic waveform generated in synchronization with the prescribed period is formed, and the error waveform pattern is added to an inverter driving waveform pattern in the last prescribed period, whereby an inverter driving waveform pattern is updated.

Inverter control method and inverter control device performing feedback

A pulse train pulse-width modulated by PWM control using a sine-wave signal and a carrier signal is inverted alternately in positive-negative polarity. With a high-frequency AC signal obtained by the inversion, a primary side of a transformer for insulating input and output from each other is excited. This arrangement makes it possible to employ a high-frequency transformer which has a capacity ratio of about 1/30 and a weight ratio of about 1/20 relative to a commercial-frequency transformer, instead of using it. Thus, an inverter apparatus can be reduced in size and weight as compared with the system using the power-frequency transformer. A sine-wave AC waveform with substantially less distortion similar to the waveform output by the conventional PWM control can be obtained with a simple construction.

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Nara, Japan

Hirofumi Nakata