Sanken Electric Co., Ltd.

Rohm Co., Ltd.

Shimane University

Nagoya University

Mamoru Tsuruya

Hirotaka Otake

Hideki Asuke

Hideharu Takano

Masayoshi Yamamoto

Shigeyuki Funabiki

Shinji Aso

Makoto Sato

Yusuke Nakakohara

Masaki Kanazawa

Tatsuya Miyazaki

Takahiro Kawashima

Osamu Machida

Yuta Okawauchi

Hirotaka Hara

Masashi Ochiai

Hiroyuki Horii

An apparatus includes a control device configured to serve as a principal controlling agent in an electric power conversion device incorporating a switching circuit configured to be a bidirectional inverter. The control device is configured to subtract, from a reference signal that is determined in accordance with an operation mode of the electric power conversion device, a multiplied signal obtained by multiplying a control-target current of the switching circuit by a prescribed coefficient to generate, based on a result of the subtraction, a control signal for controlling the bidirectional inverter.

Control device for controlling an electric power conversion device incorporating a bidirectional inverter

AC power supply deviceincludes input capacitorsandconnected at a neutral point X of a three-phase output, transistor bridges* (where * denotes U, V, and/or W) each consisting of PWM control badgesandeach including two switch elements, transformers T* connected to output terminals of the transistor bridges*, reactors Ls* connected to the transformers T*, smoothing capacitors* connected to the reactors Ls*. The transformers T* are autotransformers including a core* and windings* and* coupled with each other via the core*. One ends of the windings are connected to output terminals of the PWM control bridgesand, respectively, while the other terminals are connected to the reactors Ls*. The windings* and* are wound in such directions that magnetic fluxes generated in the core* are cancelled with each other.

AC power supply device

The alternating-current power supply devicehas: an alternating-current generation bridgefor obtaining an alternating-current output; PWM control bridges, each including two switch components; and a coupling reactorconnected to the PWM control bridges. The coupling reactorincludes: a core; and windingswhich are connected at one end to respective output ends of the PWM control bridgeswhile being coupled with each other via the core. The windingsare respectively wound in such directions that magnetic fluxes generated in the corecancel each other out.

Alternating-current power supply device with windings wound in different directions

This DC power supply device comprises: a transformer having a primary magnetic core, a secondary magnetic core, at least one primary coil wound on the primary magnetic core, and a plurality of secondary coils wound on the secondary magnetic core; and at least one bridge composed of transistors. The DC power supply device has: a primary circuit connected to the primary coil; and a plurality of secondary circuits respectively connected to the plurality of secondary coils and each having a first secondary resonance capacitor, a second secondary resonance capacitor, and a smoothing circuit. The primary circuit and the plurality of secondary circuits are electrically insulated from each other by the transformer. In the plurality of secondary circuits, output parts of respective smoothing circuits are serially connected to each other. The primary magnetic core and the secondary magnetic core are disposed to face each other with an insulator disposed therebetween.

Direct-current power supply device with primary and secondary magnetic cores

A power supply device has resonance-type DC-DC converters of three phases connected in parallel, said converters respectively having operation phases shifted from each other by 120&#xb0;. The converters include switching circuits, series resonant circuits, and rectifying smoothing circuits, respectively. The series resonant circuits include first transformers, second transformers and resonance capacitors, respectively. Each of primary winding wires of the first transformers, each of primary winding wires of the second transformers, and respective resonance capacitors are connected in series. Each of secondary winding wires of the second transformers is connected to each of the rectifying smoothing circuits. The first transformers are provided with different cores, respectively, the primary winding wires and the secondary winding wires are insulated from each other by means of dividing bobbins, and the secondary winding wires of respective phases are connected in parallel.

Power supply device

In order to achieve an object to reduce a surge voltage and suppress noise generation, the present invention provides a DC-DC converter with a snubber circuit, which boosts a voltage Vi of a DC power supply. The snubber circuit includes: a series circuit connected to both ends of a smoothing capacitor Co and including a snubber capacitor Cs and a snubber resistor Rs; a snubber diode Dsconnected to a node at which the snubber capacitor Cs and the snubber resistor Rs are connected, and to a node at which a reactor Lrand an additional windingof a transformer Tare connected; and a snubber diode Dsconnected to the node at which the snubber capacitor Cs and the snubber resistor Rs are connected, and to a node at which a reactor Lrand an additional windingof a transformer Tare connected.

DC-DC converter with snubber circuit

A DC/DC converter has three half-bridge-type current resonant DC/DC converters that are connected in parallel, have a phase difference of 120 degrees, and are operated at a frequency higher than a resonant frequency. Each of the three half-bridge-type current resonant DC/DC converters includes a transformer having a primary winding, a secondary winding, and a tertiary winding, a series circuit connected to both ends of a DC power source and including first and second switching elements, a series circuit connected to both ends of the first or second switching element and including a resonant reactor, the primary winding of the transformer, and a resonant capacitor, and a rectifying circuit to rectify a voltage generated by the secondary winding and output the rectified voltage to a smoothing capacitor. The tertiary windings are annularly connected to a reactor.

Multiphase resonant DC/DC converter

The present invention provides a DC-DC converter including a first series circuit connected to both ends of a first switch and formed of a winding of a first transformer, a first reactor, a first diode, and a smoothing capacitor, a second diode connected to a connection point of a primary winding of the first transformer, the winding of the first transformer and the first switch, and to one end of the smoothing capacitor, a second series circuit connected to both ends of a second switch and formed of a winding of a second transformer, a second reactor, a third diode, and the smoothing capacitor, a fourth diode connected to a connection point of a primary winding of the second transformer, the winding of the second transformer and the second switch, and to the one end of the smoothing capacitor, a third reactor connected to both ends of a series circuit of a secondary winding of the first transformer and a secondary winding of the second transformer, and a control circuit which alternately turns on the first switch and the second switch every &#xbd; cycle, turns off the first switch during an on-period of the second switch, and turns off the second switch during an on-period of the first switch.

DC-DC converter

A current-mode controlled DC-DC converter includes a comparator comparing a first or second current detection signal with a first or second reference current that is based on an error voltage of a voltage detection signal, a pulse generator generating a first pulse signal whose ON time is longer than an interval between when the second current detection signal reaches a minimum value and when the second current detection signal reaches the second reference current, a pulse generator generating a second pulse signal whose ON time is longer than an interval between when the first current detection signal reaches a minimum value and when the first current detection signal reaches the first reference current, the second pulse signal being behind the first pulse signal by a half period, and a PWM circuit generating a first or second PWM signal according to the pulse signal and an output signal from the comparator, thereby turning on/off a switch.

Current-mode controlled DC-DC converter

A monolithic switching device including a main semiconductor region configured to provide a current-carrying channel as in the form of two-dimensional electron gas. Disposed symmetrically on a surface of the main semiconductor region are two main electrodes to be coupled to an electric circuit for switching control, two gate electrodes for individually controlling current flow between the main electrodes through the current-carrying channel, and two diode-forming electrodes electrically connected respectively to the two main electrodes. The device operates in either Switch On Mode, Switch Off Mode, Negative Current Mode, or Positive Current Mode depending upon voltages applied to the two gate electrodes.

Solid-state switch capable of bidirectional operation

A bi-directional DC-DC converter includes a first series circuit connected to ends of a first DC power source and including a first winding of a first reactor and a first switch; a second series circuit connected to ends of the first switch and including a second winding of the first reactor, a second reactor, a second switch, a third switch, and a second DC power source; a third series circuit connected to the ends of the first switch and including a fourth switch and the second DC power source; and a control circuit configured to turn on/off the switches and thereby carry out step-up and step-down operations between the first and second DC power sources.

Bi-directional DC-DC converter

A primary windingof a transformer T and a switch Qare connected in series with a DC power source Vdc. A series circuit composed of a switch Qand a snubber capacitor Cis connected in parallel with the primary winding or the switch Q. A saturable reactor SLis connected in parallel with the primary winding 5. A series circuit composed of a diode Dand a capacitor Cis connected in parallel with a secondary windingof the transformer T, to form a rectifying/smoothing circuit. A control circuitturns on and off the switches Qand Qalternately and turns off the switch Qwhen a current to the switch Qincreases.

DC converter

A DC converter has a transformer with loosely coupled primary and secondary windings, a main switch connected in series with the primary winding of the transformer, and a series circuit connected to ends of one of the primary winding and main switch. The series circuit includes a clamp capacitor and an auxiliary switch. The main and auxiliary switches are alternately turned on/off so that a voltage of the secondary winding of the transformer is synchronously rectified with synchronous rectifiers and is smoothed with smoothing elements, to provide a DC output. The DC converter also includes a tertiary winding provided for the transformer, tightly coupled with the primary winding, and configured to generate a voltage that drives the synchronous rectifiers.

DC converter including a tertiary winding for driving synchronous rectifiers

A power factor improving circuit including: a boost reactor that inputs a rectified voltage obtained by rectifying an AC power supply voltage of an AC power supply by a rectifier circuit; a main switch that inputs the rectified voltage through the boost reactor and is turned on/off; a converting section that converts a voltage obtained when the main switch is turned on/off into a DC output voltage; and a control section that controls turn-on/off of the main switch to shape an AC power supply current to a sine wave form, controls an output voltage of the converting section to a predetermined voltage, and controls a switching frequency of the main switch according to a value of current flowing into the AC power supply, or that of current flowing into the rectifier, or that of current flowing into the main switch.

Power factor improving circuit

A switching power supply apparatus comprising: a first transformer, one end of a primary winding thereof being connected to one end of a secondary winding of a converter transformer; a second transformer, one end of a primary winding thereof being connected to another end of the secondary winding of the converter transformer; a reactor connected to both ends of a series circuit having the secondary windings; a smoothing capacitor, one end thereof being connected to the primary windings of transformers; a first diode connected to a connection between the first winding and a second winding of the first transformer and the other end of the smoothing capacitor; and a second diode connected to a connection between a first winding and a second winding of the second transformer and the other end of the smoothing capacitor.

Growing community of inventors

Niiza, Japan

Mamoru Tsuruya