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:
Sep. 09, 2003
Filed:
Sep. 20, 2001
Russel J. Kerkman, Milwaukee, WI (US);
David W. Schlegel, Saukville, WI (US);
David Leggate, New Berlin, WI (US);
Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US);
Abstract
A method and apparatus for reducing parasitic distortion in terminal voltages connected to a PWM inverter, the method comprising the steps of receiving each of a command operating frequency and a command carrier frequency, comparing the command operating frequency to low and high threshold operating frequency values, and where the command operating frequency is less than the low threshold frequency, restricting the carrier frequency to a minimum carrier frequency, where the command operating frequency is greater than the high threshold frequency, setting the carrier frequency equal to the command carrier frequency and, where the operating frequency is between the low and high threshold frequencies, setting the carrier frequency to an intermediate value between the minimum carrier frequency and the commanded carrier frequency.