Virtual impedance control for a regional dynamic voltage restorer. Issue 11 (2nd November 2018)

• Record Type: Journal Article
• Authors: Jian, Le; Cao, Wang; Jintao, Yang; Hao, Zhang; Xingrui, Li
• Is Part Of: International journal of electronics. Volume 105:Issue 11(2018)
• Page Start: 1881
• Page End: 1899
• Publication Date: 2018-11-02
• Subjects: Dynamic voltage restorer -- virtual impedance control -- fault current limit -- series compensation -- voltage sags; Electronics -- Periodicals; Electronic control -- Periodicals; 621.381
• DOI: 10.1080/00207217.2018.1494321
• Languages: English
• ISSNs: 0020-7217

Abstract

ABSTRACT: A dynamic voltage restorer (DVR) can be installed in a middle-voltage (MV) power grid, to concurrently protect a cluster of sensitive loads from voltage sags. To further improve its efficiency and reduce the difficulty in its implementation, a novel control strategy for operating such a DVR as a virtual impedance in series with sensitive loads is proposed in this paper. In addition to its usual function of compensating for voltage sags, such a DVR can also operate as a virtual inductance, to function as a fault current limiter (FCL) during a downstream fault, or a virtual capacitance, to function as a series compensator (SC) to compensate the voltage loss along the feeder line during heavy load. Based on a dual-loop control design, strategies for operating a DVR as a series virtual inductance and a virtual capacitance are proposed, and methods for tuning the parameter values and a stability analysis of the whole system are presented. The feasibility and effectiveness of the proposed method are verified by simulations using the PSCAD software, and experimental results obtained using a prototype DVR are presented.