Olympus Optical Company, Ltd.

Nagaoka University of Technology

Nissan Motor Company Limited

Murata Manufacturing Co., Ltd.

Fuji Electric Co., Ltd.

Panasonic Corporation

Olympus Corporation

Omron Corporation

Fuji Electric Holdings Co., Ltd.

National University Corporation Nagaoka University of Technology

Junichi Itoh

Yoshiya Ohnuma

Kouji Yamamoto

Takamasa Nakamura

Masao Saito

Hironori Koyano

Minoru Matsuzaki

Youji Watanabe

Tsutomu Matsukawa

Manabu Koshijo

Yuji Imai

Yoshiaki Kobayashi

Yoji Watanabe

Yoshinori Matsuzawa

Yasuo Tanbara

Hiroshi Yamamoto

Keiji Kunishige

Akira Watanabe

Masafumi Yamasaki

Toshiaki Ishimaru

Toshiyuki Toyofuku

Akio Toba

Shinichi Kodama

Koji Mizobuchi

Yuta Sato

Masaharu Hamada

Masahiro Dai

Yasunobu Otsuka

Hayato Higa

Yuichi Noge

Satoshi Miyazaki

Kazunori Mizokami

Azuma Miyazawa

Yoichiro Okumura

Yuichi Saito

Akihiro Funamoto

Tomokazu Sada

Minoru Hara

Kenji Fujibayashi

Toshio Horiguchi

Tatsuya Satoh

Hidetoshi Umida

Hisayuki Matsumoto

Akihiro Odaka

Koichi Ueki

Mitsuo Kawazoe

Koetsu Fujita

Shoji Kawamura

Katsutaka Tanabe

Kouetsu Fujita

Yasuo Tambara

Yasushi Toizumi

Koji Ando

Toru Komatsu

Kazutada Kobayashi

Ayumu Midorikawa

Koroku Nishizawa

Hiroyuki Yonezawa

Masato Miyazawa

Kouji Orikawa

A three-phase inverter includes three series circuits that are connected in parallel to a capacitor connected in parallel to a DC voltage source. Each of the three series circuits includes two semiconductor switching elements connected in series. A connection point between the two semiconductor switching elements is used as an AC output terminal for each phase. The three-phase inverter generates PWM pulses of three phases including a PWM pulse of one phase, whose pulse width of a positive side pulse in one switching cycle is the largest, and including PWM pulses of the other two phases such that a positional relationship between positive side pulses of the other two phases is a positional relationship in which an overlapping range on a time axis is smaller as compared with a state in which a positive side pulse of one phase encompasses a positive side pulse of the other pulse.

Three-phase inverter with reduced DC bus capacitor ripple

A DC-DC converter includes a first full-bridge circuit and a second full-bridge circuit isolated by a transformer. The first full-bridge circuit includes switching elements, a first floating capacitor, and a second floating capacitor. The first full-bridge circuit operates in at least one of a full-bridge operation mode and a half-bridge operation mode. In switching of the operation mode, switching phases of the first full-bridge circuit are shifted in two portions in one cycle of a drive frequency, and shift amounts of the phases are determined such that positive and negative output voltages of the first full bridge circuit are balanced before and after the operation mode is switched.

DC-DC converter

A switching element with a small current capacity is provided to be able to be used in a DC-DC converter. The DC-DC converter includes a switching circuit in which a first switching element, a second switching element, a third switching element, and a fourth switching element are connected in series, a flying capacitor that is connected between a connection portion between the first switching element and the second switching element and a connection portion between the third switching element and the fourth switching element, a reactor that is connected between a connection portion between the second switching element and the third switching element and a positive electrode of an input unit, and a control circuit that turns on/off the switching element, in which the control circuit turns on/off the switching elements so that a peak value in a reactor current becomes equal to or smaller than a predetermined value.

A DC-DC converter includes a full-bridge circuit connected to a primary winding of a transformer and a full-bridge circuit connected to a secondary winding of the transformer. The full-bridge circuit includes a first series circuit including a first set of switching elements, a second series circuit including a second set of switching elements, a first charge-discharge capacitor connected to a node between a first pair of the first switching elements and a node between a second pair of first switching elements, and a second charge-discharge capacitor connected to a node between the a first pair of the second switching elements and a node between a second pair of the second switching elements. The full-bridge circuit can operate in one of a full-bridge operation mode and a half-bridge operation mode. The disclosed DC-DC converter can constantly operate with high efficiency even when the variation range of a load is wide.

There is disclosed a power conversion apparatusfor converting polyphase ac power directly to ac power. A conversion circuit includes first switching devicesand second switching devicesconnected, respectively, with the phases R, S, T of the polyphase ac power, and configured to enable electrical switching operation in both directions. There are provided input lines R, S, T connected with input terminals of the switching devices and output lines P, N connected with output terminals of the switching devices. The output terminals of the first switching devices and the output terminals of the second switching devices are, respectively, arranged in a row. The first switching devices and second switching devices are arranged side by side with respect to a direction of the rows. The output lines are disposed below the input lines in an up and down direction.

Power conversion device

A power conversion apparatus is for converting polyphase ac power directly to ac power. A conversion circuit includes a plurality of first switching devicesand a plurality of second switching devicesconnected, respectively, with the phases R, S, T of the polyphase ac power, and configured to enable electrical switching operation in both directions. There are provided a plurality of condensersconnected with the conversion circuit. At least one of the condensers is provided, for each of the first switching devices and the second switching devices, between two of the phases of the polyphase ac power. It is possible to reduce a wiring distance between the condenser and the switching devices.

Three phase to single phase power conversion device with reduced wiring between condensers and switches

Provided is a power converterthat directly converts polyphase AC power to AC power. A converter circuit has a plurality of first switching elementsandthat are connected to each phase R, S or T of the polyphase AC power to enable switching for turning on current-carrying bidirectionally, and a plurality of second switching elementsandthat are connected to each phase to enable switching for turning on current-carrying bidirectionally. The converter circuit comprises input lines R, S and T connected to each input terminal, and output lines P and N connected to each output terminal. Parts of wiringandof protection circuitsare located between output lines P and N. The wiring distance between each protection circuitand the corresponding switching element can be shortened.

Power converter

Provided is a power converterthat directly converts polyphase AC power to AC power. A converter circuit has a plurality of switching elementsandwhich are connected to each phase R, S or T of the polyphase AC power to enable switching for turning on current-carrying bidirectionally. At least three condenserstoare provided between phases of the converter circuit. The three condensers are respectively placed at apexes of a triangle on a plane that is in parallel with a part-mounting surface on which the switching elements are actually mounted. The wiring distance between the condensers and the switching elements can be shortened.

Power conversion device with reduced wiring distance

Provided is a power converterthat directly converts polyphase AC power to AC power. A converter circuit has a plurality of first switching elementsandand a plurality of second switching elementsand, both of which are connected to each phase R, S or T of the polyphase AC power to enable switching for turning on current-carrying bidirectionally. Condenserstoare provided between phases. Input terminals of the first switching elements and those of the second switching elements are arranged to form respective lines. Some of the plurality of condensersandare arranged to be angled relative to the arrangement direction of the terminals. The wiring distance between the condensers and the switching elements can be shortened.

There is disclosed a power conversion apparatusfor converting polyphase ac power directly to ac power. A conversion circuit includes a plurality of first switching devicesand a plurality of second switching devicesconnected, respectively, with the phases R, S, T of the polyphase ac power, and configured to enable electrical switching operation in both directions. Output linesformed by a pair of busbars are connected with the conversion circuit. The first switching devices and the second switching devices are so arranged that output terminals are arranged in a row. The output linesare connected with the output terminals and drawn out rectilinearly in one direction.

A power converter is provided for direct conversion of multi-phase AC power to AC power. The power converter includes a conversion circuit, a plurality of input lines and a plurality of capacitors. The conversion circuit has first and second switching elements that are configured to be connected to the phases of the multi-phase AC power for bidirectional switching of energizing current. The input lines are connected to the conversion circuit. The capacitors are connected to the conversion circuit. The first and second switching elements are arranged such that paired input terminals line up in a row with the paired input terminals to an outside, and paired output terminals to an inside. The input lines extend in a direction in which the paired input terminals line up, and extend from one of the input terminals to another of the input terminals.

A power converter is provided for direct conversion of multi-phase AC power to AC power. The power converter includes a conversion circuit and a plurality of output lines. The conversion circuit has first and second switching elements that are configured to be connected to phases of the multi-phase AC power for bidirectional switching of energizing current. The output lines are connected to the conversion circuit. The first and second switching elements have output terminals. The output terminals of the first and second switching elements are arranged in first and second rows. The output terminals of the first and second switching elements face each other. The first output lines include two first output lines including first and second widely shaped bus bars connected to the output terminals of the first and second switching elements, respectively. The first output lines extending out in one direction, and line up in an upright direction.

An electric power conversion device comprises a conversion circuit having bi-directionally switchable plural pairs of switching elements connected to respective phases and converting an inputted AC power into an AC electric power. A first switching time is calculated using detected voltages detected by voltage sensors and an output command value. A second switching time is calculated using a carrier and the first switching time. A control signal generating section generates control signals to switch on and off of the switching elements using the first switching time and second switching time. In a case where a state is transited from the first switching time to the second switching time, a controller turns off one of on a state switching elements of either one of an upper arm circuit or a lower arm circuit and maintains on state of the other of the on state switching elements of the other arm circuit.

An electric power conversion device comprises a conversion circuit having bi-directionally switchable plural pairs of switching elements connected to respective phases and converting an inputted AC power into an AC electric power. A first switching time is calculated using detected voltages detected by voltage sensors and an output command value. A second switching time is calculated using a carrier and the calculated first switching time. The second switching time is such that, in one period of the alternating current electric power outputted from the conversion circuit, the second switching time included in a first half period of the one period is equal to the second switching time included in a second half period of the one period.

The AC converter converts a single-phase input AC voltage with a frequency f0 into a three-phase output AC voltage with a frequency f1 that is lower than f0. The AC converter includes a switching section with multiple switching elements and a switching control section that controls the conduction states of the respective switching elements. The switching control section supplies pulses that have been subjected to a pulse density modulation based on space vector modulation to the switching section, thereby getting the conversion into a three-phase output AC voltage done.

AC converter for converting a single-phase input AC voltage into a three-phase output AC voltage

Growing community of inventors

Tokyo, Japan

Junichi Itoh