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:
Oct. 29, 2002
Filed:
Apr. 26, 2001
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An apparatus for controlling an elevator which has a high energy-saving effect based on charging while using a low-capacity and low-priced secondary battery. The apparatus has a converter for converting an alternating current from an ac power supply into a dc power by rectifying the alternating current, an inverter for driving an electric motor by converting the dc power from the converter into variable-voltage variable-frequency ac power, the motor being driven for the operation of the elevator, and a power accumulator connected to a dc bus between the converter and the inverter. The power accumulator accumulates dc power from the dc bus during regenerative operation of the elevator, and supplies the accumulated dc power to the dc bus during power-drive operation of the elevator. The apparatus also has charge/discharge control circuit for controlling charging/discharging of the power accumulator from or to the direct current bus, and a measuring device for measuring at least one of the temperature, current and voltage of the power accumulator. The charge/discharge control circuit adjusts the maximum value of the current for charging/discharging of the power accumulator according to an output from the measuring device.