Hitachi, Ltd.

Hitachi Computer Peripherals Co., Ltd.

Renesas Technology Corp.

Hitachi Maxell, Limited

Hitachi Maxwell, Ltd.

Hitachi Information & Telecommunication Engineering, Ltd.

Hitachi Haramachi Semi-conductor, Ltd.

Hitachi Media Electronics Co., Ltd.

Hitachi Engineering Co., Ltd.

Hitachi Appliances, Inc

Hitachi Industrial Products, Ltd.

Hitachi Mizusawa Electronics Co.

Tkr Corporation

Akihiko Kanouda

Kenichi Onda

Takashi Sase

Yasuaki Norimatsu

Takae Shimada

Fumikazu Takahashi

Masahiro Hamaogi

Yuuichi Mabuchi

Yoshihide Takahashi

Mutsumi Kikuchi

Hiroyuki Shoji

Hiroshi Kimura

Norikazu Tokunaga

Ryouhei Saga

Hideki Miyazaki

Koji Tateno

Katsunori Hayashi

Minehiro Nemoto

Yosuke Tsuyuki

Takuya Ishigaki

Masato Isogai

Kimihisa Furukawa

Hideaki Horie

Yuki Kawaguchi

Yasuo Kaminaga

Junpei Uruno

Mitsuhiro Kadota

Mizuki Nakahara

Masami Joraku

Mutsuhiro Mori

Ryotaro Kudo

Fumio Murabayashi

Yasuo Matsuda

Naoki Sakurai

Morinobu Endo

Masayoshi Sato

Tadahiko Chida

Shinichi Yoshida

Satoru Masuyama

Hidetoshi Arakawa

Yosuke Kawakubo

Syuya Hagiwara

Takashi Tanabe

Takao Gotou

Toshikatsu Miyata

Mikiya Nohara

Kazuhiro Takizawa

Isao Nemoto, Legal Representative

Nobuyuki Aihara

Hideaki Koyama

Eisaku Fujita

Yutaka Kobayashi

Akihiko Emori

Ryuichi Saito

Akira Ishii

Junichi Kimura

Noboru Akiyama

Takeshi Mochizuki

Kozo Watanabe

Kenji Kubo

Kozaburo Kurita

Makoto Suzuki

Seigou Yukutake

Satoshi Asano

Takayuki Ouchi

Shintaro Tanaka

Hiroshi Kamizuma

Keizo Shimada

Hiroshi Iwasawa

Takeshi Onaka

Kouzou Watanabe

Yoshimi Sakurai

Ko Takahashi

Noriyuki Uchiyama

Tetsunosuke Nakamura

Ryuji Kurihara

Minoru Moteki

Tadahiko Hashimoto

Sadamu Saito

Hideaki Kunisada

Katsuhiro Higuchi

Akira Kikuchi

Hideyasu Umetsu

Yoshihiko Sugawara

Tetsuya Obara

Akira Yonekawa

Tetsuya Nagayama

Fusao Sakuramori

Makoto Kawamura

Yoshio Miyamoto

Yasuo Abe

Takayasu Nakane

Abhijit Choudhury

Minglei Gu

Mutsuml Kikuchi

Kenichi Yokota

Kuniyoshi Watanabe

Manabu Murakawa

Kazuaki Adachi

Meirai Ko

A plurality of power conversion units, a current sensor that detects a current at an output terminal of the power conversion unit, and a control unit that measures a frequency component in a predetermined frequency range of a current detected by the current sensor are included, the power conversion unit includes an AC/DC converter that outputs AC power at an input terminal to an output terminal, a smoothing capacitor that is connected in parallel to the output terminal and smooths an output voltage, and a variable resistance switch connected between one end of the smoothing capacitor and one end of the output terminal, the control unit controls a resistance value of the variable resistance switch according to a magnitude of a predetermined frequency component detected by the current sensor, and the output terminals of the plurality of power conversion units are connected in parallel to constitute output terminals.

Power conversion device

This bidirectional DC-DC converter comprises: a transformer; a first bridge circuit for converting DC power and AC power to each other which are input and output between a first DC power supply and the primary side of the transformer; a second bridge circuit for converting DC power and AC power to each other which are input and output between a second DC power supply and the secondary side of the transformer; a first resonant circuit connectable between the first bridge circuit and the primary side of the transformer; a second resonant circuit connectable between the second bridge circuit and the secondary side of the transformer; a first bypass switch for switching the connection state of the first resonant circuit between the first bridge circuit and the primary side of the transformer; a second bypass switch for switching the connection state of the second resonant circuit between the second bridge circuit and the secondary side of the transformer; and a control unit for controlling each of the first bypass switch and the second bypass switch.

Bidirectional DC-DC converter with high control stability

Provided is a power conversion device that can be realized with a small circuit and is capable of stably converting AC power inputted from a three-phase power source system into DC power. In a power conversion device: an output terminal of a common converter cell in a J-numbered stage is connected, together with output terminals of common converter cells of the other two phases, to common lines; an output terminal of an independent converter cell in a K-numbered stage is connected to independent lines independently of converter cells of the other two phases; and a plurality of switches comprise a common switch for switching the connection relationship between the common lines and DC buses, and an independent switch for switching the connection relationship between the independent lines and DC buses.

Provided is a power supply device in which the output voltages of unit power converters can be controlled to be substantially constant even when the loads of the respective unit power converters are different from each other. The power supply device in which a plurality of unit power converters are connected in series with an AC system and power is supplied from the unit power converters to load devices is characterized by being provided with a control device for obtaining the degree of load imbalance among the load powers of the load devices and controlling the AC system side voltages of the unit power converters to operate by reducing the power factor of the AC system when the degree of load imbalance increases.

Power supply device

An object of the present invention is to sufficiently reduce a switching loss. A control device causes a positive electrode of a first voltage to appear at a second connection point by switching second and third switching elements to an ON state. Next, the control device causes the positive electrode of the first voltage to appear at a first connection point by switching the second and third switching elements to an OFF state. After that, fifth and eighth switching elements are switched to the OFF state, and sixth and seventh switching elements are switched to the ON state.

Power conversion device, power conversion device control device, and power conversion device control method

The power conversion device includes multiple converter cells. Each converter cell includes a pair of primary-side terminals and a pair of secondary-side terminals. The converter cell transmits power between the pair of primary-side terminals and the pair of secondary-side terminals. The primary-side terminals of the multiple converter cells are connected in series to a primary-side power supply system. The secondary-side terminals of the multiple converter cells are connected in series to a secondary-side power supply system. Among the multiple converter cells, the converter cell in which an absolute value of a ground voltage appearing in the pair of primary-side terminals is the highest is different from the converter cell in which an absolute value of a ground voltage appearing in the pair of secondary-side terminals is the highest.

Power conversion device and power conversion device connection method

A power conversion device that suppresses voltage pulsation of a capacitor of a power converter with respect to a control target whose effective power is to be controlled is provided. The power conversion device includes a plurality of power conversion cells that are connected to each other, and convert a primary-side system voltage into a secondary-side system voltage, a capacitor that is connected to each of the plurality of power conversion cells, and a power conversion cell driver that drives the power conversion cells to add a 3N order higher-harmonic-wave voltage of each of alternating voltages of the plurality of power conversion cells to the each of alternating voltages, and output a voltage made by adding the each of alternating voltages and the 3N order higher-harmonic-wave voltage, when N is a natural number.

A power conversion device includes three first power conversion cells each converting input power and outputting the converted power and having input terminals connected in parallel regarding a first power supply and three second power conversion cells each converting input power and outputting the converted power and having input terminals connected in parallel regarding a second power supply, wherein: the power output from the cell and the power output from the cell are combined to output a first phase power; the power output from the cell and the power output from the cell are combined to output a second phase power; and the power output from the cell and the power output from the cell are combined to output a third phase power. The first phase, second phase, and third phase powers are output as the phase powers or inter-line powers of a three-phase system.

Power conversion device and method for controlling power conversion device

In a power conversion device, a power conversion unit includes a single-phase inverter on a secondary side of a resonant type converter that has an input of a direct current. A power conversion unit group is configured by connecting outputs of the single-phase inverters of a plurality of power conversion units in series. Respective phases of three phase alternate current are formed with the three power conversion unit groups housed in a power conversion device housing. The plurality of power conversion units constituting the power conversion unit group are disposed along a longitudinal direction of the power conversion device housing. The respective three power conversion unit groups are disposed at an upper stage, a middle stage, and a lower stage in a height direction of the power conversion device housing. The power conversion device housing has one end side in the longitudinal direction as output terminals of the three power conversion unit groups. The power conversion device housing has the other end side in the longitudinal direction where terminals of the three power conversion unit groups are connected in common.

Power conversion device, cooling structure, power conversion system, and power supply device

If an input voltage of a DC/DC converter is lower than a first voltage value that is set in advance, a converter controller maintains an output voltage of the DC/DC converter within a first voltage range that is set in advance by changing an operation frequency of switching of the DC/DC converter in compliance with the input voltage as a first voltage maintaining control. If the input voltage is higher than a second voltage value that is higher than the first voltage value, the converter controller maintains the output voltage within a second voltage range that is higher than the first voltage range by changing the operation frequency in compliance with the input voltage as a second voltage maintaining control.

Power conversion apparatus with frequency operation change based on input voltage

Reduction in size and weight of transformer for grid tie applications is demanded and can be achieved by applying SST to the transformer. However, SST application to PCS for sunlight requires the following: handle a wide variation range of the voltage of solar power generation; reduce switching losses of power devices, DC/DC converter and inverter, in the power circuit to implement high frequency for SST application; increase voltage to the grid voltage; and reduce the dimensions of the high current path prior to step-up. Thus, LLC resonant converter configuration is applied with an inverter placed in the output, and series connected configuration is applied to the inverter. The LLC resonant converter is subject to constant frequency regulation with large output, step-up control with low output, and step-down control with the upper limit voltage according to MPPT voltage from sunlight, in order to achieve drive loss reduction and voltage range handling.

Power conversion device and power conversion control method for the same

Size and weight reduction of a transformer for system interconnection is needed. Applying an SST to the transformer can reduce the size and weight. However, it is also necessary to flexibly handle a wide range of voltages to match a high-voltage system or motor, reduce switching loss of a power device used in a power circuit such as a DC/DC converter and an inverter in association with frequency increase caused by application of the SST, and achieve size reduction of a cooling structure. Further, it is necessary to boost a voltage to a system voltage and reduce the size and weight of a large current path before the voltage boosting. Thus, an LLC resonant converter structure is applied, and a multiple-connection structure is employed in each of which a converter is arranged for an input or an inverter is arranged for an output. This enables handling of various voltage ranges by various combinations of the numbers of multiple connections of the inputs and the outputs. An insulation cooling structure is provided by a wind-tunnel structure in which two input and output substrates are opposed and are connected by insulation members, and another wind-tunnel structure arranged in the downstream of the wind-tunnel structure and including the LLC resonant structure therein. The wind-tunnel structures are integrated with each other.

Power supply apparatus

A power supply device of the invention includes a first switching leg including first and second switching elements between DC terminals; a second switching leg including third and fourth switching elements between the DC terminals; a first capacitor leg including first and second capacitors between the DC terminals; a second capacitor leg including third and fourth capacitors between AC terminals; a first inductor between a connection of the first and second switching elements and one of the AC terminals; a second inductor between a connection of the third and fourth switching elements and another of the AC terminals; a controller; an AC power supply connected to the AC terminals and the connection of the third and fourth capacitors; and a DC power supply between the DC terminals, wherein the controller charges the first and second capacitors to a voltage higher than a voltage crest of the AC power supply.

Power supply device operating switching elements of first and second switching legs to charge first and second capacitors to a voltage higher than a voltage crest value of an AC power supply and method of operating the power supply device

A battery pack includes a plurality of battery units mutually connected in parallel, each including a cell group in which one or two or more secondary cells are connected in series, and a first current control element that is connected in series with this cell group, a first control means that controls the charging/discharging current for each battery unit by controlling the operation of the first current control element included in each of the battery unit; a voltage measurement means that measures the voltage of the cell group or cells included in each of the battery unit, and a diagnosis means that diagnoses a deterioration level or a fault of each battery unit on the basis of the voltage of the cell group or cells measured by the voltage measurement means.

Battery pack and battery pack controller

Disclosed is a charging system for both plug-in charging systems and contactless charging systems, having a simple electrical configuration, and capable of achieving miniaturization and weight saving. The charging system includes a secondary cell charged via first/second coils of a transformer to which electrical power is supplied from a first power supply via a plug-in connector, and a third coil supplied with electrical power from a second power supply, a relative position of which to the second coil of the transformer is variable, and which can be magnetically coupled to the second coil when the second coil approaches the third coil, wherein the secondary cell is charged via magnetic coupling between first/second coils when charging the secondary cell by the first power supply, and the secondary cell is charged via magnetic coupling between the third coil and second coils when charging the secondary cell by the second power supply.

Charging system

Growing community of inventors

Hitachinaka, Japan

Akihiko Kanouda