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:
Apr. 05, 2022
Filed:
Apr. 30, 2020
Otis Elevator Company, Farmington, CT (US);
Prasanna Nagarajan, Farmington, CT (US);
Shashank Krishnamurthy, Glastonbury, CT (US);
Konda Reddy Chevva, Ellington, CT (US);
OTIS ELEVATOR COMPANY, Farmington, CT (US);
Abstract
A system includes a converter operatively connected to an alternating current (AC) power source and a direct current (DC) bus, an inverter operatively connected to a motor and the DC bus, and a controller. The converter includes a first plurality of switching devices in selective communication with each phase of the AC power source and the DC bus. The inverter includes a second plurality of switching devices in selective communication with each phase of a plurality of phases of the motor and the DC bus. The controller is operable to command dropping of a brake through a passive delay circuit responsive to detection of an emergency stop condition for a load driven by the motor and reduce a voltage on the DC bus by dropping at least one phase of the AC power source and/or using a dynamic braking resistor prior to the brake physically dropping.