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:
Mar. 24, 2020
Filed:
Dec. 21, 2018
Kone Corporation, Helsinki, FI;
Matti Mustonen, Helsinki, FI;
KONE CORPORATION, Helsinki, FI;
Abstract
The invention relates to a method for maintenance of a frequency converter for driving an electric motor of a transportation device, said frequency converter being supplied with AC mains power via a contactor, and including a rectifier circuit for providing a DC supply voltage, a capacitive intermediate circuit for leveling DC supply voltage, and an inverter circuit for providing power to the electric motor. In the method, after the transportation device has been vacant for a predetermined time period, said contactor is opened to disable power flow from mains supply to the frequency converter, and a test load is connected to the intermediate circuit, parallel to a capacity of the intermediate circuit. The DC supply voltage U(t) is detected, and the detected DC supply voltage U(t) is utilized for establishing a maintenance information indicating that a maintenance should be done on the frequency converter. Another aspect of the invention is a software program realizing the method when executed on a computer.