Sumitomo Electric Industries, Limited

Toyota Jidosha Kabushiki Kaisha

Takeshi Ariyoshi

Takaaki Sano

Keiji Tashiro

Naoto Koshino

Hironobu Saka

Shinichi Iizuka

Takashi Hirakushi

Hitoshi Oyama

Yutaka Komatsu

Keiji Takizawa

Yasuhiko Nishi

Hiroyuki Imanishi

Tamio Tsurita

Tsuyoshi Shinzato

Takeshi Baba

Akinobu Yoshimura

A power conversion apparatus comprises a bidirectional conversion circuit that enables first conversion converting DC to AC and second conversion converting AC to DC and a filter circuit that is provided on an AC side of the bidirectional conversion circuit and that includes a capacitor. A control unit is provided for performing control such that the bidirectional conversion circuit makes the first conversion during the former stage of each half cycle of AC voltage, and such that the bidirectional conversion circuit makes the second conversion during the latter stage of each half cycle of AC voltage. The control unit performs control such that AC current of an opposite polarity to that of the AC voltage flows to the AC side during the former stage and AC current of the same polarity as that of the AC voltage flows to the AC side during the latter stage.

Power conversion apparatus and control method for power conversion apparatus

A power factor correcting device that controls switching of a converter that converts AC voltage inputted via a circuit with a capacitor through which reactive current flows into DC voltage calculates the magnitude of the reactive current based on the magnitude of the AC voltage inputted to the converter and the capacitance of the capacitor and corrects a power factor including the circuit, calculates a target value for a phase delay of the AC current with respect to the AC voltage based on the calculated magnitude and the magnitude of the AC current inputted to the converter or the magnitude of the DC power outputted from the converter, and calculates an operation amount for delaying the phase of the switching based on the calculated target value.

Power factor correcting device, bidirectional AC/DC conversion apparatus and computer program

Segment coils arranged as aligned in slot portions of an annular core each include a straight portion and a pair of coil end portions, and have a tip end of the coil end portion of the pair of coil end portions as a tip end portion for joint including a joint surface for joint to another segment coil. The tip end portion for joint has the joint surface in parallel to a radial direction of the annular core when viewed in an axial direction of the annular core.

Segment coil, stator including segment coil, and method of manufacturing segment coil

Each of segment coils arranged as aligned in a slot of a stator core includes a coil central portion accommodated in the slot and two coil end portions protruding outward. The coil end portion of the two coil end portions includes a pair of coil pieces formed by inclining a coil at different angles toward the coil central portion with a vertex lying therebetween. Any one of the pair of coil pieces includes in a region in the vicinity of the vertex, a recessed step portion formed from two sides in non-parallel to and at an angle with respect to an end surface of the stator core.

Segment coil, method of manufacturing segment coil, and stator including segment coil

A superconducting coil and a rotating device, the performances of which are improved, and a superconducting coil manufacturing method are provided. A superconducting coilis a saddle-shaped superconducting coil formed by winding a superconducting wire so as to form a race-track-like shape. The superconducting coil includes a curved portionand a straight portionconnected to the curved portion. In the curved portion, an upper edgeis positioned closer to an inner peripheral side than a lower edgeis, and in the straight portion, the upper edgeis positioned closer to an outer peripheral side than the lower edgeis.

Superconducting coil, rotating device, and superconducting coil manufacturing method

A direct current relay includes a plurality of contact pairs, and a plurality of magnets (). Each of the plurality of contact pairs is configured having contacts () with contact regions () disposed to allow opening and closure with respect to each other. The plurality of contact pairs are disposed such that the plurality of magnets () are disposed on one straight line, and the contact pairs are located between the magnets () on a line identical to the straight line. Each of the plurality of magnets () is provided to distort an arc generated between contacts () on an occasion of relay cut off in a direction crossing the straight line. Even if a backward current flows, arcs will not interfere with each other, allowing extinguishing in a short time. Accordingly, a direct current relay can be obtained, capable of cutting off a high direct current voltage in a short time even on an occasion of backward current while minimizing the number of magnets and allowing down-sizing with a simple structure.

DC relay

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Osaka, Japan

Takeshi Ariyoshi