scholarly journals Two-Phase Short-Term Frequency Response Scheme of a DFIG-Based Wind Farm

2021 ◽  
Vol 9 ◽  
Author(s):  
Dejian Yang ◽  
Shun Sang ◽  
Xinsong Zhang
Keyword(s):  
Frequency Response ◽  
Wind Farm ◽  
Operating Conditions ◽  
Control Coefficient ◽  
Short Term ◽  
Two Phase ◽  
Term Frequency ◽  
Point Tracking ◽  
Control Gain ◽  
System Frequency

The kinetic energy stored in the doubly-fed induction generators (DFIG)-based wind farm can be utilized to sustain the dynamic system frequency. However, difficulties arise in determining the control gain to effectively improve the frequency nadir and smoothly return to the maximum power point tracking (MPPT) operation. This paper addresses a two-phase short-term frequency response (STFR) scheme to boost the frequency nadir and minimize the second drop in the system frequency based on a piecewise control gain. To achieve the first goal, a constant control coefficient, which is determined according to the initial operating conditions of the DFIG-based wind farm, is employed until the frequency nadir produces. To achieve the second goal, the control coefficient, which changes with time, facilitates to smoothly return to the MPPT operation. The effectiveness of the proposed two-phase STFR scheme is verified under various wind power penetration levels, wind speeds, and disturbances. The results reveal that the frequency nadir is improved, and simultaneously, it smoothly returns to the MPPT operation and minimizes the second drop in the system frequency.

Stable stepwise short-term frequency support of a DFIG-based wind farm

2017 ◽  
Vol 28 (3) ◽  
pp. e2495 ◽  
Author(s):  
Dejian Yang ◽  
Moses Kang ◽  
Jinho Kim ◽  
Junhee Hong ◽  
Yong Cheol Kang
Keyword(s):  
Wind Farm ◽  
Short Term ◽  
Term Frequency

scholarly journals Coordinated Sending-End Power System Frequency Regulation via UHVDC

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 1909
Author(s):  
Qiaoming Shi ◽  
Hongqing Liu ◽  
Kai Liu ◽  
Yongping Wang ◽  
Qingwu Zhang ◽  
...  
Keyword(s):  
Frequency Response ◽  
Operating Conditions ◽  
Frequency Deviation ◽  
Frequency Regulation ◽  
Control Parameters ◽  
Response Control ◽  
Response Characteristics ◽  
Frequency Response Characteristics ◽  
System Frequency ◽  
Inertia Response

The continuous improvement of new energy penetration reduces the inertia of the system, which leads to the frequency deviation and the rate of change of frequency (RoCoF) being easily exceeded. To improve the frequency stability of sending-end power systems with large-scale renewable energy access via ultra-high voltage direct current (UHVDC), the coordinated frequency control for UHVDC participating in system frequency regulation (FR) including primary FR and system inertial response is presented. Based on the simplified system model, the mechanism of UHVDC participation in system frequency support and its influence on receiving-end system frequency response characteristics are analyzed. Compared with the inertia response and primary FR of traditional synchronous generators, the parameter calculating method of UHVDC coordinated frequency response control is proposed. Based on the system root trajectory analysis, the influence of the frequency response control parameters on the sending-end system’s stability is analyzed, and the constraints of UHVDC participating in the system frequency response control are analyzed. Then, based on the RTDS verification platform containing the Lingshao ±800 kV UHVDC control and protection system, the system frequency response characteristics under different control strategies, operating conditions and control parameters are verified and analyzed. The experimental results show that the UHVDC frequency coordinated control can effectively increase the equivalent inertia of the sending-end system, restrain the RoCoF and the frequency deviation, and increase the FR capability of the UHVDC system.

Study of Multi-factor Coordinated Frequency Control Strategy by DFIG Wind Turbine

2019 ◽  
Vol 12 (1) ◽  
pp. 86-93
Author(s):  
Wang Yin-Sha ◽  
Li Wen-Yi ◽  
Li Zhi-Wen
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Frequency Response ◽  
Control Strategy ◽  
Large Scale ◽  
Frequency Control ◽  
Operating Conditions ◽  
Frequency Change ◽  
System Frequency ◽  
Inertia Response

Background: With the large-scale Doubly Fed Induction Generator (DFIG) wind turbine integrated into the power system, the DFIG inertia response of the wind turbine should be provided. Also, the frequency response should be similar to the conventional generation technologies. This paper investigated the influence of frequency response term and wind speed conditions on system frequency control. Methods: The specific operating conditions of four control strategies, including inertia control, droop control, over speed control and pitch angle control were researched in this paper. Multi-factor coordinated frequency control strategy of DFIG wind turbine was established based on the above researches. The strategy was composed of wind speed ranging from low to high. Results: According to the simulation results, the DFIG wind turbine, which was based on multifactor coordinated frequency control strategy, could respond to the system’s frequency change of power grid, effectively. Conclusion: It helps system frequency return to stable states better and faster than DFIG wind turbine and also could reduce the fluctuation of system frequency.

scholarly journals Short-Term Frequency Response of a DFIG-Based Wind Turbine Generator for Rapid Frequency Stabilization

Energies ◽  
2017 ◽  
Vol 10 (11) ◽  
pp. 1863 ◽  
Author(s):  
Dejian Yang ◽  
Moses Kang ◽  
Eduard Muljadi ◽  
Wenzhong Gao ◽  
Junhee Hong ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Frequency Response ◽  
Frequency Stabilization ◽  
Short Term ◽  
Turbine Generator ◽  
Term Frequency ◽  
Wind Turbine Generator

scholarly journals An Enhanced Frequency Response Strategy of a DFIG Based on Over-Speed De-Loaded Curve

2021 ◽  
Vol 11 (19) ◽  
pp. 9324
Author(s):  
Yien Xu ◽  
Hongmei Wang ◽  
Dejian Yang
Keyword(s):  
Frequency Response ◽  
Wind Power ◽  
Rate Of Change ◽  
Operating Conditions ◽  
Response Strategy ◽  
Maximum Power Point ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point ◽  
Doubly Fed

The increasing level of wind power penetration is seriously threatening the frequency stability of the power system. In this article, we suggest an enhanced frequency response strategy of a doubly fed induction generator (DFIG) based on over-speed de-loaded curve using a novel power function to boost the frequency nadir and settling frequency and reduce the maximum rate of change of frequency (ROCOF) with more efficiency. To achieve this objective, the reference power increases to the torque limit at the de-load operating point and then decreases with the rotor speed toward the maximum power point tracking operating conditions. The simulation results on various wind power penetrations clearly demonstrated that the enhanced frequency response strategy is beneficial to boosting the frequency nadir and settling frequency and reduce the ROCOF.

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