Kabushiki Kaisha Toshiba

Central Research Institute of Electric Power Industry

Toshiba Energy Systems & Solutions Corporation

Takeru Murao

Yosuke Nakazawa

Hiroshi Mochikawa

Ryuta Hasegawa

Atsuhiko Kuzumaki

Yushi Koyama

Hiromichi Tai

Shunsuke Tamada

Tadao Ishikawa

Shoichi Irokawa

Masahiro Takasaki

Toshiaki Kikuma

Masahiro Tsumenaga

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

A reactive power compensator according to an embodiment comprises: multilevel inverter circuits respectively constituting each of the three phases; a filter circuit for reducing harmonics connected between the output terminals of each of the multilevel inverter circuits and a power system interconnection terminal; and a control section for causing prescribed three-phase AC voltage to be output by controlling each of said multilevel inverter circuits. Each of the multilevel inverter circuits is constituted by connecting in series one or more single-phase full-bridge single-pulse inverters and is arranged to convert DC voltage to respective positive and negative single-pulse voltages once per cycle of the fundamental wave of the voltage instruction value.

Multilevel reactive power compensator

An inexpensive and space-saving power conversion device is provided which can eliminate a high-cost and large reactor like a buffer reactor. A device includes multiple switching elementsperforming conversion between DC and AC upon switching, a unitary unit C including the switching elements, and a capacitor, and unit armsP,N each including at least one unitary unit C. The primary side of a transformeris connected between the pair of unit armsP,N so as to suppress a short-circuit current by a leakage inductance component.

Power conversion device

Provided is a power converter having a switching circuit wherein a surge voltage of a plurality of switching elements connected in series is suppressed and loss is not concentrated to a specific switching element. The switching circuit is provided with: a non-latching type switching element having two main terminals and one control terminal; a voltage detecting means which detects a voltage applied between the main terminals of the switching element; a control current supply for supplying the control terminal with a control signal corresponding to the voltage detected by the voltage detector; and a delay device for delaying the control signal.

Power converter with switching circuits

Disclosed is a power conversion device which achieves reductions in switching loss due to a reverse recovery current and heat generation loss. Specifically disclosed is a power conversion device provided with a cascode element configured by electrically connecting a normally-on switching element and a normally-off switching element in series and connecting a gate terminal of the normally-on switching element and a source terminal of the normally-off switching element via a cascode connection diode, and a high-speed diode electrically connected in parallel with the cascode element and having a cathode region connected to a positive electrode terminal and an anode region connected to a negative electrode terminal.

Growing community of inventors

Saitama, Japan

Takeru Murao