Omron Corporation

Kazuyoshi Imamura

Masao Mabuchi

Yasuhiro Tsubota

Nobuyuki Toyoura

Takao Mizokami

Kotaro Nakamura

Katsutaka Tanabe

Teruyuki Maeda

Mio Yamada

Shinichi Hosomi

Seiji Oka

Mio Miyamoto

Kohei Takahashi

Masaya Kato

A power conditioner that suppresses distortion in a waveform of a sinusoidal generated voltage includes a first and second group including two switches each connected in inverse parallel and in series. The power conditioner alternately turns on and off both switches in the first group at a prescribed chopping frequency and alternately turns on and off both switches in the second group at a PWM frequency higher than the chopping frequency. If control is performed with a dead-time provided in the on/off timing for both switches in each group, the power conditioner adjusts and controls the on/off duty for the second group switches to correspond to the effective on drive in one switch by each diode during the dead-time for each switch in the first group.

Power conditioner

A power conditioner that suppresses generation of voltage spikes in a part of a generated sinusoidal voltage waveform. An offset between the timing of chopping, which depends on whether the voltage difference between the voltage of a third pulse voltage series and a sinusoidal voltage is positive or negative, and the timing of the switching between on/off duty cycles of a seventh and eighth switch is calculated, and the on/off duty cycles of the seventh and eighth switches are controlled on the basis of the timing offset.

A power converter enhances conversion efficiency from DC power to AC power. A first chopper circuit chops DC voltage from a photovoltaic panel at a system frequency producing a first square-wave whose voltage level changes positively. A second chopper circuit chops the first square-wave at a frequency double the system frequency producing a second square-wave whose voltage level changes negatively and adds the first square-wave and the second square-wave to produce a third square-wave that changes positively and negatively in a sine-wave manner. A third chopper circuit charges and discharges by chopping the third square-wave at a third frequency fixed by timing according to a difference between the third square-wave and a sine-wave voltage. PWM control is performed on the charge and discharge outputs such that the difference is corrected, producing a sine-wave voltage that continuously changes positively and negatively. A spike noise of an output voltage is suppressed.

DC/AC chopper type power converter for non-insulated type power conditioner with gain calibration of measuring circuit

An isolated operation detecting method according to the present invention includes: a first step that injects a power fluctuation into the power system; a second step that measures a system cycle; a third step that adjusts the injection of the power fluctuation so that the system cycle increases when the system cycle is found increased than the previous system cycle as a result of the measuring, and decreases when the system cycle is found decreased than the previous system cycle; a fourth step that produces a change pattern of a latest system cycle on the basis of a deviation of the latest system cycle from a fixed number of cycle-passed previous system cycle; and a fifth step that determines an isolated operation on the basis of the change pattern.

Isolated operation detecting method, control apparatus for detecting isolated operation for distributed power supply

Growing community of inventors

Shiga, Japan

Kazuyoshi Imamura