The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 19, 2006
Filed:
Jun. 16, 2004
Soichi Yoshinaga, Nagoya, JP;
Kenichi Wakabayashi, Kariya, JP;
Takatoshi Takai, Anjyo, JP;
Tatsuru Morioka, Okazaki, JP;
Hiroya Tsuji, Yokkaichi, JP;
Makoto Okamura, Nisshin, JP;
Shinobu Yamakawa, Kariya, JP;
Soichi Yoshinaga, Nagoya, JP;
Kenichi Wakabayashi, Kariya, JP;
Takatoshi Takai, Anjyo, JP;
Tatsuru Morioka, Okazaki, JP;
Hiroya Tsuji, Yokkaichi, JP;
Makoto Okamura, Nisshin, JP;
Shinobu Yamakawa, Kariya, JP;
Denso Corporation, Kariya, JP;
Abstract
The invention provides techniques for reducing or altering the magnetic noise of an AC rotary electric machine. A magnetic noise reducing harmonic current of order n, whose frequency is n times the frequency of the fundamental frequency component of a polyphase AC current fed to an armature of a polyphase AC rotary electric machine, is superimposed on the polyphase AC current, thereby reducing or altering a harmonic component having a frequency (n−1) times the frequency of the fundamental frequency component and occurring due to a radial magnetic excitation force acting radially on an iron core of the AC rotary electric machine. Magnetic noise is caused by a vibration whose energy is the sum of the circumferential and radial vibrations of the iron core occurring due to the magnetomotive force of the rotor, and altering the radial vibration is particularly effective in altering the magnetic noise; as the harmonic component of the radially acting magnetic excitation force, occurring due to harmonic components having frequencies 3, 5, 7, and 13 times the fundamental frequency, has a frequency 6 or 12 times the fundamental frequency, the magnetomotive force of the rotor can be effectively reduced or altered when a current having a frequency 7 or 13 times the fundamental frequency is superimposed on the stator current.