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:
May. 18, 1982
Filed:
Jun. 11, 1980
Hiroshi Nagase, Hitachi, JP;
Toshiaki Okuyama, Tokai, JP;
Yuzuru Kubota, Hitachi, JP;
Katsunori Suzuki, Ibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An electric control apparatus of an induction motor is provided with a flux current controller for controlling the flux current of the motor and a secondary current controller for controlling the secondary current of the motor. A pulse generator circuit is disposed to control the amplitude, frequency and phase angle of the primary current of the motor according to output signals of the flux current controller and secondary current controller. The primary voltage and frequency to be applied to the motor are controlled by pulse signals from the pulse generator circuit. This pulse generator circuit includes a primary voltage setting zone for setting the primary voltage of the induction motor and a primary voltage detecting zone for detecting the primary voltage of the motor. A voltage regulator is disposed to put out a signal equivalent to the change of the secondary resistance of the induction motor according to the deviation of the voltage between the primary voltage detecting zone and the primary voltage setting zone. A correcting controlling zone is disposed in the pulse generator circuit to perform a controlling action of correcting the frequency, which is one of the control objects of the pulse generator circuit, according to the output signal of the voltage regulator.