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. 16, 2019
Filed:
Mar. 12, 2015
Eaton Corporation, Cleveland, OH (US);
Eaton Intelligent Power Limited, Dublin, IE;
Abstract
A variable frequency drive (VFD) circuit includes an input connectable to an AC source, a rectifier to convert an AC power input to a DC power, a DC link to receive DC power from the rectifier and having a DC link voltage thereon, a DC link capacitor bank with one or more capacitors connected to the DC link, and a pre-charge circuit coupled to the DC link capacitor. The pre-charge circuit further includes one or more resistors, one or more pre-charge relays each operable in on and off states to selectively control a current flow through the resistor(s) so as to control an initial pre-charge of the DC link capacitor, and an overvoltage relay operable in on and off states to selectively cut-off a current flow to the DC link capacitor bank, so as to prevent an overvoltage condition in the DC link capacitor bank.