Open Access

ARTICLE

Ladder Time Stepwise Inertia Coordinated Control Method of Multiple Wind Farms to Suppress System Frequency Secondary Drop

by He Li¹, Xianchao Liu^2,*, Jidong Li¹, Yuchen Qiu²

1 Tongliao PowerSupply Company, State Grid East Inner Mongolia Electric Power Company, Tongliao, 028000, China
2 Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology, Northeast Electric Power University, Jilin, 132012, China

* Corresponding Author: Xianchao Liu. Email:

(This article belongs to the Special Issue: Wind Energy Development and Utilization)

Energy Engineering 2024, 121(8), 2293-2311. https://doi.org/10.32604/ee.2024.048752

Received 17 December 2023; Accepted 16 April 2024; Issue published 19 July 2024

Abstract

When employing stepwise inertial control (SIC), wind power generation can offer significant frequency support to the power system, concurrently mitigating energy shortages and suppressing secondary frequency drop. Nonetheless, further investigation is imperative for implementing stepped inertia control due to variations in frequency regulation capabilities and operational safety among diverse wind farm groups. Consequently, this paper advocates a multi-wind farm ladder timing SIC method designed to alleviate secondary drops in system frequency. Initially, the paper introduces the fundamental principles of stepped inertia control for a doubly-fed induction generator (DFIG) and deduces the relationship between support energy, wind power deficit at the exit, and SIC’s inertia power and support duration. Subsequently, the wind farm group is categorized into three groups using the classic wind speed zoning method, and the additional power reference for SIC is computed based on rotor safety requirements. A ladder time for the wind farm groups is introduced to address the potential exacerbation of secondary frequency drop issues resulting from the simultaneous activation of stepwise inertia control across all wind farms. The relationship between the initial kinetic energy loss of the wind farm group, the power deficit upon the exit of stepwise inertia control, and the ladder time is deduced. The NSGA-II multi-objective optimization algorithm is then employed to adjust the ladder time among multiple wind farm groups in the system. Finally, a modified IEEE-9 test system comprising three wind fields is constructed in MATLAB/Simulink to validate the proposed method. The results demonstrate the efficacy of the ladder time SIC coordinated strategy in providing robust frequency support, suppressing secondary frequency drops, streamlining control tasks, and enhancing the safety of wind power frequency regulation.

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Keywords

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