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.

Date of Patent:
Jun. 18, 2024

Filed:

Jun. 01, 2020
Applicant:

Zhejiang University, Hangzhou, CN;

Inventors:

Wuhua Li, Hangzhou, CN;

Qinghui Huang, Hangzhou, CN;

Chushan Li, Hangzhou, CN;

Heya Yang, Hangzhou, CN;

Xiaowei Gu, Hangzhou, CN;

Min Chen, Hangzhou, CN;

Huan Yang, Hangzhou, CN;

Xiangning He, Hangzhou, CN;

Assignee:

Zhejiang University, Hangzhou, CN;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05B 13/02 (2006.01); G01R 19/25 (2006.01); G01R 31/08 (2020.01); H02J 3/38 (2006.01);
U.S. Cl.
CPC ...
G01R 31/086 (2013.01); G01R 19/2513 (2013.01); G05B 13/022 (2013.01); H02J 3/388 (2020.01);
Abstract

A method for a direct current (DC) islanding detection based on positive feedback of a bus voltage at a specific frequency, essentially including three steps: extraction of a specific frequency component of the bus voltage, injection of a disturbance component of the specific frequency, and determination of DC islanding. The extraction of the specific frequency component of the bus voltage and the injection of the disturbance component of the specific frequency constitute a positive feedback mechanism in a power management unit control loop. In a grid-connected mode of a DC grid, the positive feedback mechanism fails due to a control action of a voltage management unit on a bus, and the bus voltage remains stable. In an islanding mode of the DC grid, under an action of the positive feedback mechanism, the power management unit allows the bus voltage to generate a self-excited oscillation at the specific frequency.


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