Abstract
In this paper, based on the similarity, in structure and principle, between a grid-connected converter for a direct-driven permanent magnet synchronous generator (D-PMSG) and an active power filter (APF), a new D-PMSG-based wind turbine (WT) system configuration that includes not only an auxiliary converter in parallel with the grid-side converter, but also a coordinated control strategy, is proposed to enhance the low voltage ride through (LVRT) capability and improve power quality. During normal operation, the main grid-side converter maintains the DC-link voltage constant, whereas the auxiliary grid-side converter functions as an APF with harmonic suppression and reactive power compensation to improve the power quality. During grid faults, a hierarchical coordinated control scheme for the generator-side converter, main grid-side converter and auxiliary grid-side converter, depending on the grid voltage sags, is presented to enhance the LVRT capability of the direct-driven PMSG WT. The feasibility and the effectiveness of the proposed system’s topology and hierarchical coordinated control strategy were verified using MATLAB/Simulink simulations.
Highlights
Wind turbine technology has developed rapidly over the past decade into one of the most mature renewable power generation technologies
The wind turbine (WT) system can remain connected to the grid when the voltage at the point of common coupling (PCC) drops during a power grid fault and can even provide reactive power to the power grid to support grid voltage recovery until the power grid returns to normal
During the grid voltage dips, by switching the control strategy, the generator-side converter, the grid-side converter (GSC) and the auxiliary GSC are coordinately controlled to output required active and reactive powers that follow pre-established criteria; this process of hierarchical coordinated control maintains a stable DC-link voltage and provides reactive power support to the power grid to satisfy the low voltage ride through (LVRT) requirements of the grid code
Summary
Wind turbine technology has developed rapidly over the past decade into one of the most mature renewable power generation technologies. Studies investigating the control strategies for direct-driven WT systems have improved the LVRT capability of these systems [12,13,14,15] Various issues, such as the limited reactive power support for the power grid resulting from a limited current capacity of the grid-side converter (GSC), still remain. A new D-PMSG configuration is proposed for small- and medium-capacity wind turbine system in microgrid connected to the distribution network, by adding an auxiliary converter in parallel with the grid-side converter (GSC); this novel system resembles the structure and operating principles of a grid-connected converter for a direct-driven PMSG WT system and an APF. Compensation, LVRT and other functions, can subsequently be functionally integrated within the same system This scheme cannot only enhance the LVRT capability of the wind turbine system and improve the power quality of the power grid with relatively low cost.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
