Power Smoothing of a Variable-Speed Wind Turbine Generator Based on a Two-Valued Control Gain

Jae Ik Yoo, Yong Cheol Kang, Dejian Yang, Kyu Ho Kim, Jung Wook Park

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9 Citations (Scopus)


This article proposes a power-smoothing scheme for a variable-speed wind turbine generator (WTG) that can maintain the frequency within a narrow range under normal operations. The proposed scheme uses an additional control loop based on the frequency deviation that operates in conjunction with maximum power point tracking (MPPT). To improve the energy-Absorbing capability in the overfrequency section (OFS) and energy-releasing capability in the underfrequency section (UFS), the scheme suggests separate control gains, which are determined based on the ratio of the output of the additional loop to that of the MPPT loop. The ratio in the OFS is set to decrease with respect to the rotor speed whereas the ratio in the UFS is set to increase with respect to the rotor speed. The simulation results demonstrate that the proposed scheme can significantly lessen the WTG output power fluctuations by adjusting the control gains of the UFS and the OFS even though the WTG output power is severely fluctuating, thereby mitigating the frequency fluctuations. The scheme effectively uses the heavy rotating masses of a WTG as an energy storage system for enhancing the power grid flexibility in terms of frequency, particularly in high penetration levels of variable renewable energy.

Original languageEnglish
Article number9003284
Pages (from-to)2765-2774
Number of pages10
JournalIEEE Transactions on Sustainable Energy
Issue number4
Publication statusPublished - 2020 Oct

Bibliographical note

Funding Information:
Manuscript received July 17, 2019; revised November 25, 2019 and January 20, 2020; accepted February 11, 2020. Date of publication February 19, 2020; date of current version September 18, 2020. This work was supported in part by Korea Electric Power Corporation under Grant R18XA06-80 and in part by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education under Grant NRF-2018R1D1A1B07048098. Paper no. TSTE-00791-2019. (Corresponding authors: Yong Cheol Kang; Jung-Wook Park.) Jae Ik Yoo, Yong Cheol Kang, and Jung-Wook Park are with the School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, South Korea (e-mail: jake_yoo @yonsei.ac.kr; yckang33@yonsei.ac.kr; jungpark@yonsei.ac.kr).

Publisher Copyright:
© 2010-2012 IEEE.

All Science Journal Classification (ASJC) codes

  • Renewable Energy, Sustainability and the Environment


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