Toshiba Mitsubishi-Electric Industrial Systems Corporation

The University of Tokyo

Tmeic Corporation

Yuichi Tsuboi

Tetsuo Yoshimitsu

Kunihiko Hidaka

Akiko Kumada

Hisatoshi Ikeda

Masaaki Furukawa

Toshihiro Tsuda

Haruyuki Kometani

Shinichiro Yamada

Yoshihiro Ishikawa

Takuma Sasai

Kodai Ushiwata

Hirotake Nakaji

Satoshi Kurita

Teruo Kanekawa

A squirrel-cage induction rotating electrical machine comprises: a solid rotor, a stator, and bearings. The solid rotor includes a shaft part, a columnar-shaped rotor core part integrally formed with the shaft part and having rotor slots formed therein, and a plurality of conductor bars passing through the respective rotor slots and coupled together at both axial ends outside the rotor core part. The stator includes a cylindrical stator core provided radially outside the rotor core part, and stator windings passing through a plurality of respective stator slots which are formed in the radially inner surface of the stator core. An outer wall and an inner wall of each rotor slot are tilted at a predetermined angle or more with respect to a plane including a rotation axis of the shaft part.

Squirrel-cage induction rotating electrical machine, solid rotor, and design method for squirrel-cage induction rotating electrical machine

A three-dimensional surface potential distribution measurement system for measuring a surface potential of a measurement object comprises: a laser light source; a Pockels crystal exhibiting Pockels effect in which a refractive index changes depending on potential difference between the first end surface and the second end surface; a mirror disposed so as to be attached stationarily to the second end surface of the Pockels crystal; a photodetector to detect a light intensity of the laser light corresponding to the potential difference of the Pockels crystal; a housing that holds those elements; a three-dimensional motion-driver capable of three-dimensionally moving the housing; and a driving controller that controls the three-dimensional motion-driver.

Three-dimensional surface potential distribution measurement system

A water-tree resistance evaluation material including: a material selection selecting a candidate insulation material; a test carrying out a water tree test on a test piece having electrode holes formed on a first surface; and a candidate insulation material evaluation evaluating characteristics of the candidate insulation material, including progress and speed of a water tree. The test includes: a system and condition setting for setting a test system; a voltage application for grounding a ground-side electrode that is immersed in the ground-side aqueous solution, while applying an AC voltage to an application-side electrode that is immersed in the application-side aqueous solution; a measurement step; and a period determination for determining whether a test period has exceeded a predetermined period.

Water-tree resistance evaluation method, insulation design method, and rotary electric machine

A three-dimensional surface potential distribution measurement apparatus includes: a laser light source; a Pockels crystal; a mirror; a light detector; a support structure which supports the aforementioned elements while maintaining a relative positional relationship therebetween; a movement driver which can move the support structure three-dimensionally; a rotary driver which supports the test object and can rotate the test object about an axis extending in a longitudinal direction of the test object; and a drive controller which controls the movement driver and the rotary driver. The drive controller coordinates a driving operation by the movement driver and by the rotary driver while maintaining a gap between the second end face of the Pockels crystal and a surface of the test object at a predetermined value such that the second end face of the Pockels crystal approaches all the surfaces of the electric field reduction system on the test object.

Three-dimensional surface potential distribution measurement apparatus

A water tree testing apparatus using a flat test piece comprising a candidate insulation material an d having a first surface having a plurality of electrode holes formed therein has: a liquid-permeable conductive first permeable member that is attached to the first surface and covers the electrode holes; a liquid-permeable conductive second permeable member that is attached to a second surface that is opposite side from the first surface, and extends along the second surface as to face the first permeable member with the test piece therebetween; a first water tank for immersing the first surface in the first aqueous solution; a second water tank for immersing the second surface in the second aqueous solution; a first electrode, and a second electrode.

Water tree testing method and water tree testing apparatus

A surface-potential distribution measuring device includes: a laser light source; a Pockels crystal; a mirror; a photodetector that detects light intensity of the laser beam reflected by the mirror; a holding and mounting part that holds and moves the Pockels crystal; a voltage correction database; and a calculation unit that identifies an input voltage corresponding to a testing output voltage as a surface potential of the electric-field-reduction system. The Pockels crystal is formed in such a way that a size of a cross section of the Pockels crystal that is perpendicular to an axial direction changes along the axial direction. The holding and mounting part has a protection unit to protect a structure of the Pockels crystal, a movement unit to that moves the Pockels crystal in order to measure a surface potential of the electric-field-reduction system, and a drive control unit to control the movement unit.

Surface potential distribution measuring device

In a surface potential distribution measuring device for an electric field reduction system of a rotating electrical machine, a Pockels crystal is used between a laser and the surface (test location) of the electric field reduction system. Light intensity of a laser beam reflected on a mirror provided between the Pockels crystal and the test location corresponds to an output voltage that is the voltage difference between the first end surface and the second end surface of the Pockels crystal. Even when an inverter voltage is generated, by using a light detector having a frequency band capable of following the high frequency components of the inverter pulse voltage, the light intensity is detected by the light detector. Therefore, from the light intensity (output voltage), the surface potential distribution measuring device can measure the surface potential of the electric field reduction system in which an inverter pulse voltage is generated.

Growing community of inventors

Tokyo, Japan

Yuichi Tsuboi