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. 24, 1990
Filed:
Feb. 14, 1989
Siemens Aktiengesellschaft, Berlin & Munich, DE;
Abstract
A method and apparatus for commutating a load-independent current between the valve arms of a static converter device. Each valve arm has a valve device with blocking capability in the reverse direction, and a valve damping circuit. The valve device of a current-assuming valve arm is actuated at the time of commutation, and the valve device of the current-delivering valve arm reaches a zero current level upon commutation. In order to prevent a dangerous overvoltage via the inductance of the valve damping circuit, actuation of the valve device in the current-assuming valve arm is delayed until the valve device in the current-delivering valve arm substantially attains a zero current level after being turned off. During this delay, the current can commutate to the valve damping circuit of the current-delivering valve arm and generate a positive voltage there, thus expediently avoiding a reverse current and its dangerous consequences.