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. 31, 2001
Filed:
Feb. 29, 2000
Daming Ma, Toronto, CA;
Bin Wu, Toronto, CA;
Navid R. Zargari, Cambridge, CA;
Steven C. Rizzo, Cambridge, CA;
Rockwell Technologies, LLC, Thousand Oaks, CA (US);
Abstract
The drive for an a.c. induction motor features a rectifier for converting alternating current into direct current and a current source inverter for converting direct current into alternating current supplied to a motor. A d.c. link choke interconnects the rectifier and the inverter. The inverter includes a first control loop which provides a desired or command d.c. link choke current to a second control loop responsible for the rectifier. For the purposes of the second control loop the actual d.c. link choke current and an input voltage of the inverter are detected. The difference or error between the desired and actual d.c. choke currents are minimized by a compensator. The output of the compensator is added to the detected inverter input voltage, and the sum is fed to a switching pattern generator which controls the switches in the rectifier. In this manner the feedback of the inverter input voltage is decoupled from the compensator responsible for the d.c. link choke current. This makes the parameters of the second control loop substantially independent of the load, thereby enhancing the ease with which the control loop may be tuned and hence the stability of the drive.