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:
Sep. 23, 1997
Filed:
Jun. 23, 1995
Michael John North, Taipei, TW;
Christopher Hall, Taipei, TW;
Thomas Mark Cyster, Taipei, TW;
Ching-Chuan Chen, Keelung, TW;
General Resource Corporation, Taipei, TW;
Abstract
This invention provides a means to maintain the rotational speed and the relationship of the electromagnetic fields of a three phase induction motor and to determine the minimum voltage to excite the motor without it stalling. The three phase induction motor is driven by an inverter bridge circuit which converts DC input power into three phase AC output power. Feedback of the current provided to the inverter bridge circuit is split into positive and negative current flow periods which are used to determine appropriate changes to the three phase AC power magnitudes and phase angles. The inverter bridge circuit uses six insulated gate bipolar transistors to control the three phase AC power magnitude and phase angles.