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:
Aug. 20, 2002
Filed:
Feb. 20, 2001
Shinobu Tajima, Tokyo, JP;
Hiroshi Araki, Tokyo, JP;
Ikuro Suga, Tokyo, JP;
Kazuyuki Kobayashi, Tokyo, JP;
Other;
Abstract
A controller of an elevator for smooth speed control, using a cheap power accumulating device having a low capacity, even during a power failure. The controller has a converter, an inverter, a power accumulating device arranged between DC buses, a charging-discharging control circuit for controlling charging and discharging of the power accumulating device, a power failure detector, a current measuring instrument and a voltage measuring instrument for respectively detecting an output current and an output voltage of the inverter, a car load measuring instrument, an encoder, and a speed control circuit for controlling operation of the inverter, which has a table with required power set according to speed and car load, and calculates the power required from the table on the basis of a measured car load and a detected speed during a power failure, and also calculates speed commands for controlling the speed of the elevator within a range of discharging ability of the power accumulating device on the basis of a comparison of the output power of the inverter, the power required, and the discharging ability.