Kabushiki Kaisha Toshiba

Toshiba Energy Systems & Solutions Corporation

Toshiba Infrastructure Systems & Solutions Corporation

Shunsuke Tamada

Daichi Suzuki

Hiroshi Mochikawa

Yosuke Nakazawa

Yuji Watanabe

Mami Mizutani

Ryuichi Morikawa

Yushi Koyama

Koji Maki

Takeru Murao

Takuro Arai

Kei Sekiguchi

A voltage compensation device according to an embodiment includes a controller including first and second coordinate transformation circuits, and first and second arithmetic parts. The first coordinate transformation circuit generates first and second outputs that are mutually-orthogonal by performing a rotating coordinate transformation of the normal-phase components of a three phase AC. The first arithmetic part calculates a system voltage based on a DC component of the first output and generates a first compensation amount corresponding to a compensation voltage set to compensate a shift of the system voltage from a preset target voltage. The second coordinate transformation circuit generates third and fourth outputs that are mutually-orthogonal by performing a rotating coordinate transformation of reverse-phase components of the three-phase AC. The second arithmetic part generates second compensation amount of a reverse-phase component of the system voltage based on DC components of the third and fourth outputs.

Voltage compensation device

According to an embodiment, there is provided an apparatus which can hold down an energy loss and can avoid an increase in size. The apparatus includes a cell including a floating capacitor connected in parallel to an upper-side switching element and a lower-side switching element; an upper arm include including first switch circuits, each including a first switching element, a first diode and a first capacitor, are connected in series; a lower arm including second switch circuits, each including a second switching element, a second diode and a second capacitor, are connected in series; and a circuit which connects a low-side terminal of the cell and a low-side terminal of the first capacitor and connects a high-side terminal of the cell and a high-side terminal of the second capacitor.

Power conversion apparatus

An electric power conversion apparatus according to an embodiment includes, wherein when a constituent element constituted of a leg in which two switching elements provided with self-arc-extinguishing capability are connected in series, and a capacitor connected in parallel with the leg is made a converter unit, and a constituent element formed by connecting one or more converter units in series is made a phase arm, a phase arm on the positive side, a single-phase four-winding transformer, and a phase arm on the negative side are included in each of three phases, one end of the phase arm on the positive side is connected to the positive side of a secondary winding of the four-winding transformer, and the other end thereof is connected to a DC positive side terminal.

Electric power conversion apparatus

Growing community of inventors

Tokyo, Japan

Shunsuke Tamada