4.8 Article

Detecting Speed Improvement and System Stability Enhancement for DC Microgrids Islanding Detection Based on Impedance Characteristic Analysis

Journal

IEEE TRANSACTIONS ON POWER ELECTRONICS
Volume 38, Issue 3, Pages 3785-3802

Publisher

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
DOI: 10.1109/TPEL.2022.3221741

Keywords

Islanding; Microgrids; Power system stability; Voltage control; Impedance; Power quality; Resistance; Active-damping control; dc microgrids; impedance-based analysis; islanding detection; stability region

Ask authors/readers for more resources

The article studies the positive feedback islanding detection technique in DC microgrids, which has advantages in detection speed and nondetection zone. However, it may reduce the stability margin in the grid-connected state. In order to address this issue, the article develops a DC output impedance model to accurately reveal the dynamic interactions and instability mechanism caused by islanding detection. The stability region of the interconnected system is derived based on the output admittance model, and a grid-current-based active-damping control scheme is proposed to mitigate instability caused by the positive feedback loop. Simulations and experimental results validate the effectiveness of the proposed control method.
Islanding detection is the essential basis for the safety and protection of dc microgrids. Due to the advantages of rapid detection speed and small nondetection zone, the positive feedback islanding detection technique has attracted much interest in recent years. The implementation of a positive feedback loop facilitates the islanding detection for dc microgrids, but it may reduce the system stability margin at the grid-connected state. In this article, the dc output impedance model of voltage source converter and distributed generators are developed to reveal the dynamic interactions and instability mechanism accurately between the two subsystems considering the impact of islanding detection with voltage positive feedback of selected frequency (VPFOSF). Then, the stability region of the interconnected system based on the output admittance model is derived to guide the design method of the damping compensator. Moreover, a grid-current-based active-damping control scheme is further proposed to mitigate instability caused by the VPFOSF loop. Thus, the conflict among islanding detection rapidity, power quality, and grid-connected system stability is effectively addressed. In the end, both the simulations and experimental results are provided to validate the effectiveness of the proposed control method.

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.8
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available