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:
Feb. 28, 2017
Filed:
Dec. 19, 2014
Sma Solar Technology Ag, Niestetal, DE;
SMA SOLAR TECHNOLOGY AG, Niestetal, DE;
Abstract
An inverter and a method for detecting a phase failure in an energy supply grid during operation of an inverter, which is connected to the energy supply grid for feeding electrical energy via a YNd transformer is disclosed. The method includes transforming the values of the output currents into a symmetrical positive-sequence current value and into a symmetrical negative-sequence current value of a coordinate system rotating at a fundamental frequency of the energy supply grid. The method further includes determining a ratio of the negative-sequence current value to the positive-sequence current value, and signalling a phase failure in the energy supply grid if the determined ratio is greater than a preset threshold value for longer than a preset time period. The disclosure furthermore relates to an inverter designed for implementing the method.