Toshiba Mitsubishi-electric Industrial Systems Corporation

Tmeic Corporation

Ryoji Tsuruta

Hiroshi Masunaga

Tomohiro Tanaka

Masashi Nakamura

Toshiaki Oka

Hiromitsu Suzuki

Ritaka Nakamura

This uninterruptible power supply includes a switch that is turned off while an AC power supply is normal and turned on during power failure, a converter that converts AC power supplied from the AC power supply into DC power to supply resultant DC power to a DC link portion while the AC power supply is normal, and that supplies DC power supplied from a battery through the switch to the DC link portion during power failure, an inverter that converts DC power from the DC link portion into AC power to supply resultant AC power to a load, and a chopper circuit that allows DC power from the DC link portion to be stored in the battery while the AC power supply is normal.

Uninterruptible power supply

A power conversion device includes: a dead time application unit which applies a dead time to only one of a pair of pulse signals; a current polarity detection unit which detects a polarity of an output current; and a gate signal selection unit which, if the polarity of the output current is positive, selects the one pulse signal, to which the dead time has been applied, as a gate signal for a positive arm and selects the other pulse signal as a gate signal for a negative arm, and, if the polarity of the output current is negative, selects the one pulse signal, to which the dead time has been applied, as the gate signal for the negative arm and selects the other pulse signal as the gate signal for the positive arm.

Power conversion device

A power conversion device includes a transformer, a plurality of converter cells, and a control circuit that controls semiconductor switching elements in each of the converter cells to be turned on and off. The transformer includes: a primary winding group being connected in multiple phases to an AC power supply including multiple phases; and a plurality of secondary winding groups. Each secondary winding group includes, in each of the multiple phases, secondary windings each formed of a single-phase open winding. Each converter cell converts a single-phase AC voltage between AC nodes connected to the respective secondary windings into a DC voltage by control of the semiconductor switching elements to be turned on and off, and outputs the converted DC voltage between a pair of DC nodes. The DC nodes of the plurality of converter cells are connected in series between a first DC terminal and a second DC terminal.

Growing community of inventors

Chiyoda-ku, Japan

Ryoji Tsuruta