Omron Corporation

Omron Coproration

Kotaro Nakamura

Masao Mabuchi

Katsutaka Tanabe

Nobuyuki Toyoura

Kenji Kobayashi

Yasuhiro Tsubota

Takao Mizokami

Kazuyoshi Imamura

Teruyuki Maeda

Mio Yamada

Kenichi Inoue

Akihiko Sano

Shinichi Hosomi

Kazumi Tsuchimichi

Takuya Nakai

Seiji Oka

Mio Miyamoto

Naoki Maki

Yuji Tsurukawa

Kunio Aono

Atsuo Minato

Kosuke Nomura

Makoto Ide

Kohei Nakagawa

Akiyuki Tsunaga

Hironobu Hisashi

The disclosure is provided to improve the accuracy of a ground fault position detected from a power conditioning system. A ground fault position calculation part () calculates a ground fault position (P) by using a power supply voltage of a solar cell string (), a ground fault current (I), and a ground potential of an input terminal (N) measured by a power conditioning system (). The ground fault position calculation part () sets a lower limit value of the power supply voltage to be used.

Ground fault detection device

A power converter capable of minimizing the amount of fluctuation in the input power value to the boost circuit when changing the number of operating circuits and the switching frequency; when reducing the number of boost chopper circuits operating and the switching frequency the controller reduces the duty cycle of the PWM signal to a circuit to be halted while said circuit scheduled for halt operates, whereafter the controller halts operation of said circuit scheduled for halt and changes the switching frequency to a frequency corresponding to the state determination value.

Power converter with a boost unit including at least two boost chopper circuits connected in parallel

A power storage power conditioner includes an input part, a voltage-transforming part, a first input-output part, a converting part and a second input-output part. The voltage-transforming part transforms the voltage of DC power from the input part and the converting part into a second predetermined voltage. The first input-output part outputs the DC power of the voltage-transforming part to a battery unit, and inputs DC power from the battery unit. The voltage-transforming part transforms a voltage of the DC power from the first input-output part into a third predetermined voltage. The converting part converts the DC power from the input part and the voltage-transforming part into AC power. The second input-output part outputs the AC power to a power system or a load, and inputs AC power from the power system. The converting part converts the AC power from the second input-output part into DC power.

Power storage power conditioner

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 conditioner of a photovoltaic system is configured operate at higher accuracy. A chopper circuit, a capacitor connected in parallel to the chopper circuit, and a control circuit that controls an ON/OFF status of switch elements in the chopper circuit to control charging and discharging of the capacitor are provided. The control circuit includes a measurement control section that measures an inter-end voltage of the capacitor and a control circuit section that performs a predetermined control operation from a measurement output of the measurement circuit section. The measurement circuit section includes a differential amplifier circuit that differentially amplifies the inter-end voltage of the capacitor. The circuit control section calibrates an in-phase component in the output of the differential amplifier circuit as an in-phase error and performs the control from the calibrated output from the differential amplifier circuit.

Control circuit, power conditioner including the control circuit, and photovoltaic system

A power conditioneris provided with a maximum power follow-up control portionfor setting a DC operating voltage of a power converter, which converts output power of a power generatorinto AC power, for making a power point corresponding to the output level of the power generator follow up with a maximum power point, and comprises an approximate function memoryfor storing approximate functions related to the maximum power point, a follow-up control portionfor making the present power point reach proximate of the maximum power point on the basis of the approximate function, and a hill-climbing method follow-up control portionfor making the present power point reach the maximum power point by using a hill-climbing method when the present power point has reached proximate of the maximum power point.

Maximum power follow-up control apparatus

An electric power conversion device comprises switching elements making up a push-pull converter, a pulse transformer T, a rectification diode D , a rectification diode D , a choke coil L, a smoothing capacitor C, a DC magnetic deviation prevention means , and an inverter . The DC magnetic deviation prevention means detects the coil currents I , I flowing in the primary windings M , M of the pulse transformer T. By controlling (shortening) the on time of the switching element having a greater amount of current, the coil currents I , I are balanced (I &equals;I ), thereby preventing the magnetic deviation phenomena of the pulse transformer T.

Electric power conversion device with push-pull circuitry

Growing community of inventors

Shiga, Japan

Kotaro Nakamura