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:
Jul. 23, 2002
Filed:
Feb. 20, 2001
Shinobu Tajima, Tokyo, JP;
Hiroshi Araki, Tokyo, JP;
Ikuro Suga, Tokyo, JP;
Kazuyuki Kobayashi, Tokyo, JP;
Other;
Abstract
An elevator controller providing stable speed control using a cheap power accumulating device having a low capacity even in discharging. 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 the inverter. The speed control circuit calculates output power of the inverter, and calculates discharging power of the power accumulating device on the basis of a measured value of charging and discharging states. The speed control circuit calculates a maximum power as a sum of the discharging ability power and power of an AC power source, and changes speed commands on the basis of comparison of the output power of the inverter and the maximum power.