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:
Mar. 15, 1977
Filed:
Jan. 23, 1975
Yasuo Matsuda, Hitachi, JA;
Takeo Maeda, Hitachi, JA;
Kouzou Watanabe, Hitachi, JA;
Kazuo Honda, Hitachi, JA;
Hironori Okuda, Hitachi, JA;
Kunio Miyashita, Hitachi, JA;
Yasuyuki Sugiura, Takahagi, JA;
Hitachi, Ltd., , JA;
Abstract
A method and an apparatus for controlling the operation of the synchronous motor are disclosed in which the synchronous motor is started with a starting power supply and operated with a steadying power supply. The starting power supply is adapted to alternately repeat acceleration and deceleration of the synchronous motor in the neighborhood of the frequency thereby to bring the synchronous motor into the point where the synchronous motor is in synchronism with the steadying power supply. The starting power supply comprises a current control circuit and a phase angle control circuit, which circuits control the motor current in such a manner as to prevent the voltage drop due to the synchronous reactance of the motor from exceeding the induced voltage of the motor, while at the same time controlling the power factor angle to be in the range from a lead 90.degree. to the angle corresponding to a maximum output point produced by said motor current.