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:
Nov. 01, 1994
Filed:
Jan. 21, 1993
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
An inverter control apparatus comprises a controller, a mode decision circuit and a voltage reference conversion circuit. The mode decision circuit determines one of three kinds of modes which may be used to control the inverter, namely, a normal mode, a rectangle mode and zero correction mode selected according to values and polarities of multi-phase voltage reference signals. The voltage reference conversion circuit corrects the voltage reference signals according to the determined mode in the mode decision circuit. In the case of the normal mode, the mode decision circuit outputs the previous voltage reference signal V* without change as the new or corrected voltage reference signals. In the case of the rectangle mode, the circuit fixes the voltage reference signal V* having the greatest value of the three phase (U-phase, V-phase and W-phase) to a minimum voltage reference V.sub.min which is of opposite polarity to the selected greatest value signal, or, in another embodiment, to a zero value. Further the circuit converts the others voltage reference signals to corrected voltage reference signals without change of line voltage. The control circuit permits control of the inverter even in a regime of low reference voltage which would otherwise result in an uncontrolled region of the inverter.