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. 28, 2015
Filed:
Apr. 23, 2014
Yujing Liu, Ojersjo, SE;
Hongyang Zhang, Vasteras, SE;
Djordje Savinovic, Vasteras, SE;
ABB Technology AG, , CH;
Abstract
A synchronous electrical motor includes a rotor with a DC field winding. An exciter is configured to energize the DC field winding by generating a DC current in a first direction across the DC field winding when activated. A control system is configured to control a current flow across the DC field winding, the control system including a field discharge resistor and a by-passing circuitry. The by-passing circuitry is configured to implement a first by-passing to electrically by-pass the field discharge resistor during a current flow in the first direction across the DC field winding, and to implement a second by-passing to electrically by-pass the field discharge resistor during a current flow in a second direction across the DC field winding. The control system is able to direct all the DC current generated by the exciter to flow across the DC field winding.