Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Research Development Corporation of Japan

Matushita Electric Industrial Co., Ltd.

Matshushita Electric Industrial Co., Ltd.

Makoto Kitabatake

Masao Uchida

Kunimasa Takahashi

Osamu Kusumoto

Kenya Yamashita

Toshiya Yokogawa

Masahiro Deguchi

Ryoko Miyanaga

Shun Kazama

Hideo Kurokawa

Masaki Tagome

Takeshi Uenoyama

Tetsuya Shiratori

Noriyoshi Nishiyama

Takashi Hirao

Akihisa Yoshida

Yasuhiro Kondo

Koichi Hashimoto

Kentaro Setsune

Masatoshi Kitagawa

Kiyotaka Wasa

Yorito Ota

Keisuke Koga

Tsuneo Mitsuyu

Kazuhiro Nobori

Kanji Imai

Hiroyuki Masato

Kazuhiko Asada

Yasuhito Kumabuchi

Kazuyuki Sawada

Toru Kawase

Hideki Omori

Masanori Ogawa

Tomohiro Sekiguchi

Nobuyoshi Nagagata

Hidekazu Yamashita

Toshifumi Sato

Masahiro Hagio

Osamu Yamazaki

Takao Tohda

Koji Miyazaki

Takashi Nishikawa

Yoichi Sasai

Takasi Hirao

Tetuhiro Koretika

Tetuo Kawasaki

Kumiko Hirochi

Nobuhiro Eimori

Akimitsu Hatta

Toshimichi Ito

Akio Hiraki

To aim to reduce ripple current flowing through a capacitor in a power converter apparatus including a converter, the capacitor and an inverter. A current sensoris connected between a capacitorand an inverter circuitfor detecting current Iinv flowing from the capacitorto the inverter circuit. A frequency detecting subunitperforms fast Fourier transform on a waveform of the current Iinv to detect a frequency of a frequency component having the largest amplitude. Also, the frequency detecting subunitdetects a zero-cross point of the frequency component having the largest amplitude. Then a carrier signal control subunitperforms control such that a frequency and a rise time of a PWM carrier signal for driving the converter circuitmatch the frequency and the zero-cross point that have been detected by the frequency detecting subunitand the phase detecting subunit

Electric power converting apparatus and induction heating apparatus

A synchronous motor drive system improves the design flexibility regarding torque characteristics as compared with conventionally available design flexibility. A synchronous motor has a rotor and a stator. Each of at least two adjacent stator teeth has a slit formed at the tip thereof. Each of a plurality of stator teeth has a main coil wound therearound in concentrated winding. Between each two adjacent teeth having a slit, a sub-coil is wound around in a manner of being accommodated in the respective slits. The drive device separately controls electric current supplied to the main coils and electric current supplied to the sub-coil.

Synchronous electric motor drive system having slit windings

A power converter for effectively reducing switching noise is provided. The power converter comprises a capacitor; switching devices Qand Qconnected to the capacitorin parallel; and a controllerthat controls each switching device individually to perform switching operations. Each of the switching devices Qand Qforms a closed circuit together with the capacitor. The controllercontrols the switching devices Qand Qto perform switching operations of switching ON or OFF at different timings such that at least two closed circuits including the switching devices Qand Qmutually cancel ringing voltages occurring therein, each ringing voltage occurring due to the switching operations performed by a corresponding switching device and having a frequency defined by an inductance of a corresponding closed circuit and an output capacity of a switching device included in the corresponding closed circuit.

Power converting apparatus suppressing switching noise by controlling switching operation

A semiconductor element according to the present invention can perform both a transistor operation and a diode operation via its channel layer. If the potential Vgs of its gate electrodewith respect to that of its source electrodeis 0 volts, then a depletion layer with a thickness Dc, which has been depleted entirely in the thickness direction, is formed in at least a part of the channel layerdue to the presence of a pn junction between a portion of its body regionand the channel layer, and another depletion layer that has a thickness Db as measured from the junction surface of the pn junction is formed in that portion of the body region. If the dielectric constant of the wide bandgap semiconductor is identified by &#x2208;s, the dielectric constant and the thickness of the insulating filmare identified by &#x2208;i and Di, respectively, the sum of Dc and Db is identified by Ds, and the absolute value of the turn-on voltage of the diode is identified by Vf0, then Ds&#x3c;Di&#xb7;&#x2208;s/(&#x2208;i(2/Vf0&#x2212;1)) is satisfied.

Semiconductor element

An inverter comprising: a circuit including arms connected in parallel, each of the arms including a first switch and a second switch connected in series; and a gate drive circuit configured to control, by pulse-width modulation using synchronous rectification, each of the first switch and the second switch to switch to an on-state or an off-state, wherein each of the first switch and the second switch includes: a channel region that is conductive in both a forward direction and a reverse direction in the on-state, and that is not conductive in the forward direction in the off-state; and a diode region that is combined as one with the channel region, and that is conductive only in the reverse direction, the diode region being unipolar, and the gate drive circuit synchronizes a timing at which the gate drive circuit outputs a signal for causing the first switch to switch to the on-state with a timing at which the gate drive circuit outputs a signal for causing the second switch to switch to the off-state, and synchronizes a timing at which the gate drive circuit outputs a signal for causing the first switch to switch to the off-state with a timing at which the gate drive circuit outputs a signal for causing the second switch to switch to the on-state.

Synchronous rectification type inverter

A small-sized load drive system which, even with three three-phase inverters, significantly reduces noise regardless of control duty ratio. The load drive system includes three-phase inverters, and first, second, and third control units. The inverters are connected to loads, respectively. The first control unit generates sawtooth wave voltage and controls the inverter according to the sawtooth wave voltage. The second control unit generates inverse sawtooth wave voltage and controls the inverter according to the inverse sawtooth wave voltage. The third control unit generates triangular wave voltage which has ramps respectively equal to the sawtooth/inverse sawtooth wave voltage and either has a same phase or is out of phase by half a period relative to the sawtooth/inverse sawtooth wave voltage, and also controls the inverter according to the triangular wave voltage.

Load drive system, motor drive system, and vehicle control system

A synchronous electric motor includes rotor having a plurality of radially-oriented magnetic dipoles and a stator. Stator teeth group with a plurality of sets of stator teeth are arranged in the same position in terms of an electrical angle with another stator teeth group to provide rotational symmetry about an axis of the rotor. In each of the stator teeth groups a predetermined number of stator teeth are arranged at intervals different from intervals of the rotor magnetic dipoles. A main coil is wound about a predetermined number of stator teeth with a sub-coil further wound around one or more a teeth. Phase and magnitude of a resulting magnetic field is adjusted by the number of loops of the main coil and sub-coil. A given stator tooth can produce maximum torque despite any difference between an alignment of the stator tooth and an inter-polar interval of the stator.

Synchronous electric motor

The present invention provides a synchronous motor drive system designed to realize reduced vibration and noise along with high output. The system includes: inverters, andfor converting a direct current to a three-phase alternating current; a current application control unitthat controls operations of the three-phase inverters; and a synchronous motordriven by three-phase alternating currents supplied from the three-phase inverters. The current application control unitdetermines, for each three-phase inverter, a current phase angle and a current amount of a three-phase alternating current to output, and each inverter supplies a three-phase alternating current having the determined current phase angle and current amount to a different one of three-phase coil groupsto

Synchronous electric motor drive system

Provided is a synchronous motor including a rotor having magnetic poles distributed circumferentially along a rotation direction of the rotor at equal intervals, and a stator having stator teeth arranged circumferentially along the rotation direction of the rotor, each tooth wound with a stator coil by concentrated winding. Every M consecutive stator teeth belong to one of stator teeth groups arranged at equal intervals. The M consecutive stator teeth in each stator teeth group are arranged at intervals different from the intervals of the magnetic poles of the rotor. The stator coils wound around the M consecutive stator teeth are connected to separate terminals. A motor driver supplies currents of different phases to the stator coils via the respective terminals.

Synchronous motor drive system

In a power conversion circuit operating with high frequency, an off-voltage control circuitof a lower-arm gate drive circuitcontrols the output voltage of a gate drive power supplyto change the output voltage to a voltage lower than a predetermined off voltage during a time period from termination of turn-off operation of a lower armuntil start of turn-on operation of an upper arm, and thereafter return the output voltage to the predetermined off voltage immediately after termination of the turn-on operation of the upper arm. With this control, short-circuiting through the upper and lower arms occurring due to a high voltage change dv/dt can be avoided, and the life of a switching element constituting the power conversion circuit improves, increasing the reliability of the power conversion circuit.

Power conversion circuit having off-voltage control circuit

A converter utilizing synchronous rectification comprises a first switch, a second switch connected in series to the first switch, and a gate drive circuit controlling each switch to switch to on/off-state using pulse-width modulation. Each switch includes a channel region that is conductive in both forward and reverse directions in on-state and is not conductive in the forward direction in off-state, and a unipolar diode region conductive only in the reverse direction. The gate drive circuit synchronizes output timing for signal with which the first switch switches to on-state with output timing for signal with which the second switch switches to off-state, and synchronizes output timing for signal with which the first switch switches to off-state with output timing for signal with which the second switch switches to on-state.

Converter with switches having a diode region that is unipolar-conductive only in the reverse direction

A semiconductor module () includes a heat sink (), an electronic component (), a semiconductor device (), and a thermally-conductive sheet member (). The thermally-conductive sheet member () covers a part of the semiconductor device () and has a lower part () and a side part (). The lower part () is in contact with a mounting face () of the heat sink (). The side part () extends from the lower part () and covers a first side surface () of the semiconductor device (). The electronic component () is disposed across the side part () of the thermally-conductive sheet member () from the semiconductor device ().

Semiconductor module and method for fabricating semiconductor module

In a semiconductor element () including a field effect transistor (), a schottky electrode () and a plurality of bonding pads (S,G), at least one of the plurality of bonding pads (S,G) is disposed so as to be located above the schottky electrode ().

Semiconductor element and electrical apparatus

Ion implantation is carried out to form a p-well region and a source region in parts of a high resistance SiC layer on a SiC substrate, and a carbon film is deposited over the substrate. With the carbon film deposited over the substrate, annealing for activating the implanted dopant ions is performed, and then the carbon film is removed. Thus, a smooth surface having hardly any surface roughness caused by the annealing is obtained. Furthermore, if a channel layer is epitaxially grown, the surface roughness of the channel layer is smaller than that of the underlying layer. Since the channel layer having a smooth surface is provided, it is possible to obtain a MISFET with a high current drive capability.

Semiconductor device and method for fabricating the same

An upper part of a SIC substrateis oxidized at a temperature of 800 to 1400&#xb0; C., inclusive, in an oxygen atmosphere at 1.4&#xd7;10Pa or less, thereby forming a first insulating filmwhich is a thermal oxide film of 20 nm or less in thickness. Thereafter, annealing is performed, and then a first cap layer, which is a nitride film of about 5 nm in thickness, is formed thereon by CVD. A second insulating film, which is an oxide film of about 130 nm in thickness, is deposited thereon by CVD. A second cap layer, which is a nitride film of about 10 nm in thickness, is formed thereon. In this manner, a gate insulating filmmade of the first insulating filmthrough the second cap layeris formed, thus obtaining a low-loss highly-reliable semiconductor device.

Semiconductor device and production method therefor

Growing community of inventors

Nara, Japan

Makoto Kitabatake