Tdk Corporation

Kabushiki Kaisha Toshiba

Toshiba Carrier Corporation

Carrier Japan Corporation

Takeshi Shibayama

Takashi Suzuki

Yukio Takahashi

Takahiro Sato

Hiroyuki Tanoue

Hidenobu Umeda

Masaki Takahashi

Yasuhiro Ito

Shinichi Sato

Makoto Yoshino

Tatsuro Suzuki

Takuo Hattori

Asuka Murai

Hiroki Choto

Shinichi Kondo

Sari Maekawa

Kouichi Kakuda

Kazunobu Nagai

Ryuichi Wada

Masashi Shimoyasu

Toshimitsu Aizawa

Yuya Oshima

Kenji Komorita

Akinori Ohi

Yukari Akita

Masahiro Kato

Yoshitaka Uchiyama

Naohito Kamiya

Mariko Kuboi

A motor control device of an embodiment includes a power supply unit that supplies AC power to a motor; a current detection unit that detects a current flowing through a winding of the motor; a speed and electric angle estimation unit that estimates a rotation speed and an electric angle of the motor based on a voltage outputted by the power supply unit and the current; a coordinate conversion unit that obtains an excitation current and a torque current based on the current and the electric angle; a torque current command determination unit that substitutes a predicted torque calculated based on a mechanical motion equation into a torque component current command value calculated based on a torque expression of a vector control coordinate, to generate a torque component current command value for bringing a difference between an inputted speed command and an estimated speed closer to zero; and a model prediction control unit that applies, to a plurality of predicted currents including a current change ratio determined depending on each of a plurality of switching patterns based on a space voltage vector that are able to be outputted by the power supply unit, an evaluation function to evaluate a size of a difference from a predicted current corresponding to each of the torque component current command value and an excitation component current command value inputted from outside, and that selects and outputs a switching pattern.

Motor control device and air conditioner

A ferrite composition includes main-phase particles, first sub-phase particles, second sub-phase particles, and a grain boundary. At least 10% or more of the main-phase particles contain a portion whose Zn concentrations monotonously decrease from a particle surface toward a particle central part along a length of 50 nm or more. The first sub-phase particles contain ZnSiO. The second sub-phase particles contain SiO. A total area ratio of the first sub-phase particles and the second sub-phase particles is 30.5% or more.

Ferrite composition and multilayer electronic component

A ferrite sintered body of the invention includes; a main component including 48.65 to 49.45 mol % of iron oxide in terms of FeO, 2 to 16 mol % of copper oxide in terms of CuO, 28.00 to 33.00 mol % of zinc oxide in terms of ZnO, and a balance including nickel oxide, and a subcomponent including boron oxide in an amount of 5 to 100 ppm in terms of BOwith respect to 100 parts by weight of the main component, in which the ferrite sintered body includes crystal grains having an average crystal grain size of 2 to 30 &#x3bc;m.

Ferrite sintered body and electronic component using thereof

A ferrite composition includes a main component and a sub-component. The main component includes 10.0 to 38.0 mol % of a Fe compound in terms of FeO, 3.0 to 11.0 mol % of a Cu compound in terms of CuO, 39.0 to 80.0 mol % (excluding 39.0 mol %) of a Zn compound in terms of ZnO, and a balance of a Ni compound. The sub-component includes 10.0 to 23.0 parts by weight of a Si compound in terms of SiO, 0 to 3.0 parts by weight (including 0 parts by weight) of a Co compound in terms of CoO, and 0.1 to 3.0 parts by weight of a Bi compound in terms of BiOwith respect to 100 parts by weight of the main component.

A ferrite composition includes a main component that includes more than 44.0 mol % to 50.0 mol % or less of an Fe compound, 5.5 to 14.0 mol % of a Cu compound, 4.0 to 39.0 mol % of a Zn compound, and a balance of less than 40.0 mol % of a Ni compound. The ferrite composition further includes a subcomponent that includes, with respect to 100 parts by weight of the main component, more than 3.0 parts by weight to 13.0 parts by weight or less of an Si compound, more than 2.0 parts by weight to 10.0 parts by weight or less of a Co compound, and 0.25 to 5.00 parts by weight of a Bi compound. A weight ratio of the content of the Co compound to the content of the Si compound is 0.4 to 2.9.

A ferrite composition includes a main component and an accessory component. The main component includes 18 to 30 mol % of iron oxide in terms of FeO, 4 to 14 mol % of copper oxide in terms of CuO, 0 to 6 mol % of zinc oxide in terms of ZnO, and a remaining part of nickel oxide. The accessory component includes 0.30 to 1.83 pts.wt. of silicon compound in terms of SiO, 2.00 to 10.00 pts.wt. of cobalt compound in terms of CoO, and 1.00 to 3.00 pts.wt. of bismuth compound in terms of BiOwith respect to 100 pts.wt. of the main component. A cobalt compound content in terms of CoOdivided by a silicon compound content in terms of SiOis a value of 5.5 to 30.0.

Ferrite composition and electronic device

A ferrite composition composed of a main component including 26 to 46 mol % of an iron oxide in terms of FeO, 4 to 14 mol % of a copper oxide in terms of CuO, 0 to 26 mol % of a zinc oxide in terms of ZnO, and a residue of 40.0 mol % or more of a nickel oxide in terms of NiO. The ferrite composition, with respect to 100 parts by weight of the main component, is also composed of a subcomponent including 0.8 to 10.0 parts by weight of a silicon compound in terms of SiO, 1.0 to 15.0 parts by weight of a cobalt compound in terms of CoO, and 0.7 to 30.0 parts by weight of a bismuth compound in terms of BiO. A value of the cobalt compound content in terms of CoOdivided by the silicon compound content in terms of SiOis 0.4 to 5.5.

Ferrite composition and electronic component

Provided is a composite ferrite composition including a magnetic substance material and a nonmagnetic substance material. The magnetic substance material is Ni&#x2014;Cu&#x2014;Zn based ferrite. The nonmagnetic substance material comprises a low dielectric constant nonmagnetic substance material, which is shown by a general formula: a(bZnO.cCuO).SiOand satisfies a=1.5 to 2.4, b=0.85 to 0.98, c=0.02 to 0.15, and b+c=1.00 in said general formula, and a bismuth oxide. A mixing ratio of the magnetic substance material and the low dielectric constant nonmagnetic substance material is 80 wt %:20 wt % to 10 wt %:90 wt %.

Composite ferrite composition and electronic component

An ESD (ElectroStatic Discharge) protection component has: first and second discharge electrodes arranged so as to be opposed to each other through a gap; and a discharge inducing portion kept in contact with the first and second discharge electrodes and configured to connect the first and second discharge electrodes to each other. The discharge inducing portion has metal particles, a ceramic material containing glass, and a dielectric material having a dielectric constant higher than that of the ceramic material. A content of the dielectric material is in the range of 7.5 to 40% by volume, with respect to a total volume of the ceramic material and the dielectric material.

ESD protection component

An electrostatic protection component includes: a body in which a plurality of ceramic substrates is laminated; and a pair of discharge electrodes which are formed within the body and which are spaced to face each other. The discharge electrodes include main body portions extending along a longitudinal direction, and the main body portions include tips in the longitudinal direction and side edges extending along the longitudinal direction. The pair of discharge electrodes are arranged such that both the main body portions are adjacent to each other in a short direction. The discharge electrodes face each other in the short direction between the side edges, and discharge occurs only between the side edges, between the discharge electrodes.

Electrostatic protection component

An inverter device driving an induction motor including main and auxiliary windings both having different winding specifications includes a three-arm inverter circuit having phase output terminals connected to the main winding, the auxiliary winding and a neutral winding of the induction motor respectively and converting a DC power supply to two-phase substantially sinusoidal PWM voltage, a current detector detecting currents of the respective main and auxiliary windings from a DC power supply current, a vector control computing unit obtaining balanced inductance values and resistance values from inductance values and resistance values of the respective main and auxiliary windings, determining a two-phase voltage to be supplied to the induction motor by vector control computing based on the balanced inductance values and resistance values, and a PWM signal forming unit forming a PWM signal controlling the inverter circuit according to the two-phase voltage.

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Tokyo, Japan

Takeshi Shibayama