Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Mitsubishi Denki Kabuhsiki Kaisha

Takahiro Urakabe

Akihiko Iwata

Tatsuya Okuda

Masaru Kobayashi

Matahiko Ikeda

Hirotoshi Maekawa

Takashi Hashimoto

Yoshikazu Tsunoda

Toshiyuki Kikunaga

Masaya Inoue

Masafumi Agari

Hidetada Tokioka

Takayoshi Nagai

Shigeki Harada

Ryuichi Hashido

Hidehiko Kinoshita

Yoshihito Asao

Mitsuo Inoue

Masashi Okabe

Kiyoharu Anzai

Takamasa Asai

Yuuya Tanaka

Tsunenobu Yamamoto

Yuuji Kuramoto

Takashi Ohsawa

Masaki Yamada

Nobuhiro Kihara

Hiroshi Okuda

Jun Someya

Norikazu Ito

Toshiyuki Yoshizawa

Kazutoshi Kaneyuki

Yuya Tanaka

Sadayuki Matsumoto

Kikuo Izumi

Fumito Uemura

Naoki Itoi

Takuto Yano

Takahiko Yamamuro

Masayoshi Maeda

Shinji Kawaguchi

Masao Karino

Takahito Nakanishi

Hideki Sugita

Atsutoshi Takada

Kenji Ishi

Taihei Kawasaka

Suehiro Gotoh

Suehiro Goto

Sigetada Gotou

Akihiron Suzuki

Shigetada Mitsubishi Denki KK Gotou

In a power converting apparatus which converts AC power into DC power, an inverter circuit including at least one series-connected single-phase inverter is connected in a downstream of a stage in which an AC input is rectified in series therewith. In the downstream stage of the inverter circuit, there are provided a smoothing capacitor connected via a rectifier diode and a short-circuiting switch for bypassing the smoothing capacitor. The short-circuiting switch is set to an ON state only in each of short-circuiting phase ranges of which midpoint matches each of zero-crossing phases and an output of the inverter circuit is controlled by using a current command so that a DC voltage of the smoothing capacitor follows a target voltage and an input power factor is improved.

Power converting apparatus

The main electric power source is connected to a lower-voltage side of a DC/DC converter by a first switch, and an electrical double-layer capacitor and a regulator circuit is connected to a higher-voltage side of the DC/DC converter. In addition, permanent magnets are disposed on a rotor so as to generate a magnetic field that is in a reverse direction to excitation by a field coil inside a claw-shaped magnetic pole portion of the rotor. A power supply control circuit controls opening and closing of the first switch so as to be in an open state when the engine is at rest, and so as to be set to a connected state after the regulator circuit is operated to make the alternator generate electric power to precharge the electrical double-layer capacitor after the engine is started.

Automotive electric power supply system

In a DC/DC converter, a first operation section calculates a first operation value, based on a difference voltage between an instruction value for a high-voltage-side voltage and a detected value of a high-voltage-side voltage, a second operation section calculates a second operation value, based on a difference voltage between a voltage instruction value for a charge-discharge capacitor and a voltage detected value of the charge-discharge capacitor, and a switching control section obtains a conduction ratio, based on the first operation value and the second operation value, and controls, based on the conduction ratio, switching operations of first to fourth semiconductor circuits, thereby controlling the high-voltage-side voltage, and the voltage of the charge-discharge capacitor.

DC/DC converter

An object of the present invention is to provide a DC/DC power conversion apparatus that can reduce the average power consumption over a wide range of DC voltage ratios. A control circuit () changes a switching frequency f at which IGBTs Sto Sperform ON/OFF operation, in accordance with a voltage ratio k (k=V/V) for DC voltage conversion, based on the following expressions, such that a magnitude &#x394;I of a current ripple flowing in a reactor Lc is a predetermined constant value irrespective of the voltage ratio k.

DC/DC power conversion apparatus

A power supply apparatus includes: an AC generator including an AC generating section, and a rectifier for rectifying an AC voltage generated in the AC generating section, and outputting a DC voltage; and a DC/DC converter for converting the output voltage of the rectifier into a DC voltage having a different voltage value, wherein the output voltage of the rectifier is set to be larger than the output voltage of the DC/DC converter in accordance with the rotation speed of the AC generating section and the amount of power supply to an electrical load connected to the DC/DC converter, and is stepped down and outputted by using the DC/DC converter. The power supply apparatus is capable of increasing an output power efficiently.

Power supply apparatus

A first DC/DC converter is connected to a higher-voltage output terminal of a rectifier by alternator wiring, a battery that supplies electric power to an on-board load is connected to the first DC/DC converter, a second DC/DC converter is connected to the higher-voltage output terminal of the rectifier by alternator wiring, and an electrical double-layer capacitor is connected to the second DC/DC converter.

Provided is a power supply device including: a magneto generator (), which includes: a rotor including a magnet forming a magnetic field; and a stator which generates an alternating current in stator windings by rotation of the rotor; a rectifying unit () which rectifies the alternating current generated by the magneto generator to a direct current; a variable transformation-ratio direct current voltage transformer () which transforms an output voltage of the direct current of the rectifying unit to a voltage between input terminals of an electrical load () to which electric power is supplied; and a voltage control unit () which controls a transformation ratio of the variable transformation-ratio direct current voltage transformer in accordance with at least one of an operating state signal regarding the rotation of the rotor of the magneto generator and an electrical load state signal of the electrical load.

Power supply device

A power converting unit supplies a predetermined current to each of light-emitting elements by controlling a duty ratio of a semiconductor switching element. A light-emitting-element selecting unit sequentially selects a light-emitting element to be supplied with the current from the power converting unit. A duty-ratio control unit controls the duty ratio of the semiconductor switching element based on a value obtained by multiplying a gain by a difference between an output current of the power converting unit and a target current. A gain selecting unit changes the gain according to selected light-emitting element.

Drive device for light-emitting element

Three or more circuits, in which series-connected low-voltage and high-voltage side switches including MOSFETs including parasitic diodes are connected across positive and negative terminals of each of smoothing capacitors, are connected in series. One of elementary series circuits, each including a capacitor and an inductor, is disposed between any adjacent two of the circuits with the elementary series circuits set to have the same period of resonance. The MOSFETs of rectifier circuits are brought into an ON state simultaneously with the MOSFETs of a driving inverter circuit and brought into an OFF state earlier than the MOSFETs of the driving inverter circuit by a period of time not exceeding a time period equal to (period of resonance)/2. A resonance phenomenon of the capacitor and the inductor is used and conduction loss in the rectifier circuits is reduced in DC/DC power conversion performed through charging and discharging operation of the capacitor.

DC/DC power converting apparatus

Three or more circuits including a driving inverter circuit and rectifier circuits are connected in series, each of the circuits including a high-voltage side MOSFET and a low-voltage side MOSFET connected in series as well as a smoothing capacitor having positive and negative terminals between which the MOSFETs are connected. LC series circuits, each including a capacitor and an inductor, are disposed individually between one specific circuit and the other circuits with periods of resonance of the LC series circuits made equal to one another. In performing DC/DC power conversion through charging and discharging operation of the capacitors, a resonance phenomenon of the LC series circuits is used to improve conversion efficiency and achieve a reduction in size of the apparatus structure.

A DC/DC power conversion device with smoothing capacitors including three column circuits share the smoothing capacitors to be connected in parallel, each column circuit have a plurality of circuits connected in series where two MOSFETs are connected in series between both ends of respective smoothing capacitors and LC serial bodies of capacitors and inductors with the same resonant cycle are disposed between the circuits at two middle terminals. Driving signals for the respective column circuits have the same driving cycle identical with the resonant cycle of the LC serial bodies, and are out of phase with each other by 2&#x3c0;/3(rad), and thus charge-discharge currents towards the smoothing capacitors are circulated among the column circuits and ripple currents flowing through the smoothing capacitors are reduced.

DC/DC power conversion device

In an inverter circuit configured with main circuit switches each having a control terminal and first and second main terminals through which the main current flows, and driving circuits each of which applies the driving voltage to the control terminal of each main circuit switch, and controls the main current in accordance with the voltage between the control terminal and the first main terminal, to switch the main circuit switch, between the main circuit switch and the driving circuit, noise-suppression circuits are provided, each of which is configured so as to detect fluctuations in the voltage between the first and the second main terminals of each main circuit switch, and, in accordance with the amplitude and the frequency of the detected voltage fluctuations, to bring to approximately zero the impedance across the control terminal and the first main terminal of each main circuit switch.

Inverter circuit

A DC/DC power conversion device includes n-stage circuits comprised of an inverter circuit for driving which is connected between positive terminals and negative terminals of smoothing capacitors, and a rectifier circuit which is connected between positive terminals and negative terminals of smoothing capacitors; a first circuit corresponding to at least one among the n-stage circuits and configured by connecting in parallel cell circuits of m, second circuits corresponding to a plurality of remaining circuits of (n&#x2212;1) among the n-stage circuits; capacitors for energy transfer connected between middle points of the cell circuits and middle points of the second circuits; and column circuits of m comprised of the cell circuits, the second circuits and the capacitors for energy transfer, wherein the middle points are contact points of high voltage sided elements and low voltage sided elements of the cell circuits and the second circuits; and driving signals for driving the respective column circuits have the same driving cycle and are out of phase with each other.

A motor controller is provided which can be reduced in the number of the wirings and power semiconductor devices required while maintaining the function equivalent to or higher than that of the motor controller adopting the existing winding changeover scheme, thereby realizing cost and size reduction and life increase. The motor is made in a structure having motor windings opened at both ends. The one end terminals of phase windings are respectively connected to the output terminals of a first inverter circuit while the other end terminals are respectively connected to the output terminals of a second inverter circuit. During power generation, any one of the inverter circuits is driven on all the phases by means of a same control pulse.

Motor controller

Signal lines for supplying signal currents to respective pixel circuits having light emitting elements are arranged. A signal line driving circuit generates, on a signal line, a signal current corresponding to the image data, by switching bit weighting currents output from bit weighting current source circuits provided for respective bits of the image data, using a switch circuit turned on/off dependent on the corresponding bit. Each current source circuit has a function of correcting the level of the bit weighting current output from itself, based on a reference current of the bit weighting current supplied from a reference current line. Therefore, even when the characteristics of TFTs forming respective current source circuits vary widely, variation in signal currents among the signal lines can be suppressed, and unevenness in emission luminance can be suppressed.

Display device

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Tokyo, Japan

Takahiro Urakabe