Research on an Improved Control Strategy for Enhancing LVRT Ability of DFIG System

2013 ◽  
Vol 291-294 ◽  
pp. 467-471
Author(s):  
Yan Feng Meng ◽  
Shu Ju Hu ◽  
Hong Hua Xu
Keyword(s):  
Wind Turbine ◽  
Experimental Verification ◽  
Control Strategy ◽  
Theoretical Basis ◽  
Large Scale ◽  
Circuit Switching ◽  
Transient Fault ◽  
Voltage Dip ◽  
Coordinating Control ◽  
Generator Stator

Aiming at operation problems of DFIG under grid fault condition, the improved control strategy of coordinating control rotor converter and Crowbar circuit switching logic for enhancing LVRT ability is proposed. The over-current cause on the stator and rotor of DFIG under grid fault is analyzed and complete improved control strategy flow chart is given during entire voltage dip. Experimental verification results show that adopting this improved control strategy can effectively suppress the generator stator and rotor over-current and over-voltage, enhance wind turbine operation ability, and provide important theoretical basis and reference for large-scale wind turbine to respond to grid transient fault.

scholarly journals Research on Zero-Voltage Ride Through Control Strategy of Doubly Fed Wind Turbine

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2287
Author(s):  
Kaina Qin ◽  
Shanshan Wang ◽  
Zhongjian Kang
Keyword(s):  
Wind Turbine ◽  
Wind Power ◽  
Control Strategy ◽  
Large Scale ◽  
Sliding Mode ◽  
Stable Operation ◽  
Wide Range ◽  
Dc Bus ◽  
Doubly Fed ◽  
Zero Voltage

With the rapid increase in the proportion of the installed wind power capacity in the total grid capacity, the state has put forward higher and higher requirements for wind power integration into the grid, among which the most difficult requirement is the zero-voltage ride through (ZVRT) capability of the wind turbine. When the voltage drops deeply, a series of transient processes, such as serious overvoltage, overcurrent, or speed rise, will occur in the motor, which will seriously endanger the safe operation of the wind turbine itself and its control system, and cause large-scale off-grid accident of wind generator. Therefore, it is of great significance to improve the uninterrupted operation ability of the wind turbine. Doubly fed induction generator (DFIG) can achieve the best wind energy tracking control in a wide range of wind speed and has the advantage of flexible power regulation. It is widely used at present, but it is sensitive to the grid voltage. In the current study, the DFIG is taken as the research object. The transient process of the DFIG during a fault is analyzed in detail. The mechanism of the rotor overcurrent and DC bus overvoltage of the DFIG during fault is studied. Additionally, the simulation model is built in DIgSILENT. The active crowbar hardware protection circuit is put into the rotor side of the wind turbine, and the extended state observer and terminal sliding mode control are added to the grid side converter control. Through the cooperative control technology, the rotor overcurrent and DC bus overvoltage can be suppressed to realize the zero-voltage ride-through of the doubly fed wind turbine, and ensure the safe and stable operation of the wind farm. Finally, the simulation results are presented to verify the theoretical analysis and the proposed control strategy.

The Control Strategy Study of Doubly-Fed Wind Turbine Participated in Frequency Regulation

2012 ◽  
Vol 512-515 ◽  
pp. 788-793
Author(s):  
Xiao Hua Zhou ◽  
Ming Qiang Wang ◽  
Wei Wei Zou
Keyword(s):  
Wind Turbine ◽  
Control Strategy ◽  
Large Scale ◽  
Control Strategies ◽  
Frequency Control ◽  
Frequency Regulation ◽  
Strategy Study ◽  
Fuzzy Control Strategy ◽  
Doubly Fed ◽  
System Frequency

Traditional decoupling control strategy of doubly-fed induction generator (DFIG) wind turbine makes little contribution to system inertia and do not participate in the system frequency control, the synchronization of large-scale wind power requires wind turbine have the ability to participate in the regulation of power system frequency. This paper adds a frequency control segment to traditional DFIG wind turbine and considers the doubly-fed wind turbine operating on the state of the super-synchronous speed, by analysis the effect of inertia and proportional control strategies, a fuzzy control strategy which combines the advantages of the former two control strategies is proposed, simulation results show that this control strategy can more effectively improve the system frequency response.

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.

The Research of Model-Free Adaptive Control for Large Scale Wind Turbine

2013 ◽  
Vol 433-435 ◽  
pp. 1293-1297
Author(s):  
Xing Jia Yao ◽  
Jiang Sheng Zhu ◽  
Kui Chao Ma ◽  
Qing Ding Guo
Keyword(s):  
Wind Turbine ◽  
Control Strategy ◽  
Large Scale ◽  
External Disturbances ◽  
Pitch Control ◽  
Model Free ◽  
Variable Speed Wind Turbine ◽  
Turbine Design ◽  
Individual Pitch Control ◽  
Large Wind

Dynamic load is a key consideration in large scale wind turbine design. It is approved that the performance of controller can distinguish impact wind turbine loads. For strong external disturbances and inaccurately modeled of large wind turbines, In this paper, we propose model-free adaptive (Model Free Adapt, MFA) individual pitch control algorithms. The controller was developed in to mitigate the rotor unbalance structural load for variable speed wind turbine. The controller is designed from a nonlinear model of the system which takes into account the blades, shaft and tower flexibilities. Bladed software was used for the control strategy and traditional PID control strategy simulation comparison. The results show that the new control strategy can effectively stabilize wind turbine power output and reduce aerodynamic loads.

scholarly journals Trailing-Edge Flap Control for Mitigating Rotor Power Fluctuations of a Large-Scale Offshore Floating Wind Turbine under the Turbulent Wind Condition

Entropy ◽  
2018 ◽  
Vol 20 (9) ◽  
pp. 676 ◽  
Author(s):  
Bofeng Xu ◽  
Junheng Feng ◽  
Tongguang Wang ◽  
Yue Yuan ◽  
Zhenzhou Zhao ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Control Strategy ◽  
Large Scale ◽  
Wind Condition ◽  
Trailing Edge ◽  
Turbulent Wind ◽  
Floating Wind Turbine ◽  
Power Fluctuations ◽  
Trailing Edge Flap ◽  
Offshore Floating Wind Turbine

A trailing-edge flap control strategy for mitigating rotor power fluctuations of a 5 MW offshore floating wind turbine is developed under turbulent wind inflow. The wind shear must be considered because of the large rotor diameter. The trailing-edge flap control strategy is based on the turbulent wind speed, the blade azimuth angle, and the platform motions. The rotor power is predicted using the free vortex wake method, coupled with the control strategy. The effect of the trailing-edge flap control on the rotor power is determined by a comparison with the rotor power of a turbine without a trailing-edge flap control. The optimal values of the three control factors are obtained. The results show that the trailing-edge flap control strategy is effective for improving the stability of the output rotor power of the floating wind turbine under the turbulent wind condition.

scholarly journals Research on optimization strategy of grid frequency modulation based on doubly-fed wind turbines

2020 ◽  
Author(s):  
Chao Wang ◽  
Jianyuan Xu ◽  
Liang Wang ◽  
Dan Song
Keyword(s):  
Wind Turbine ◽  
Wind Power ◽  
Wind Turbines ◽  
Frequency Modulation ◽  
Control Strategy ◽  
Large Scale ◽  
Synchronous Generator ◽  
Clean Energy ◽  
Frequency Regulation ◽  
Doubly Fed

Abstract The increasing global energy and environmental problems are encouraging to the development and utilization of renewable and clean energy in various countries. Wind power is one of the major source in large-scale renewable energy applications. However, the frequency regulation becomes a critical issue while the technology is spreading. Research on the frequency modulation (FM) technology of wind turbines and its control strategy for future power grids become significant. The paper proposes a novel coordinated frequency control strategy with the synchronous generator to solve the unmatched state between the output power of the doubly-fed wind turbines (doubly-fed induction generators) and the grid frequency, combined with the frequency response characteristics of the synchronous generator. The FM coordination strategy is formulated by the modulation coefficient from current wind speed and operation mode of each wind turbine. By coordinating the FM output of the doubly-fed wind turbine and the synchronous generator within the allowable range of frequency deviation, it will achieve the dual goal of reducing the frequency regulation pressure of the synchronous generator and indirectly reducing the abandoned wind volume of the wind turbine. The simulation is carried out on the MATLAB/SIMULINK platform. The results show that the presenting variable coefficient frequency modulation strategy could significant smooth the wind power fluctuation, and allow the reserve power of the doubly-fed wind turbine can fully engaged in frequency modulation which will reduces the frequency modulation pressure of the synchronous generator in the system.

Fluctuation-Suppression Pitch Control Strategy Study for Wind Turbine

2012 ◽  
Vol 463-464 ◽  
pp. 1605-1610
Author(s):  
Li Dong ◽  
Ming Fu Liao ◽  
Ming Qin ◽  
Li Xiang Sun
Keyword(s):  
Wind Turbine ◽  
Control Strategy ◽  
Vibration Amplitude ◽  
Large Scale ◽  
Rotation Speed ◽  
Power Fluctuation ◽  
Strategy Study ◽  
Pitch Control ◽  
Multi Body ◽  
Reference Input

With the large-scale direction development of wind turbine, the vibrations of wind turbines, which are rigid-flexible coupled multi-body systems, can be easily excited. Control system can be improved to reduce the vibration amplitude and load levels. Fluctuation-suppression pitch control strategy has been improved in this paper. The reference input rotation speed, which is normally constant, is required to change with rotation acceleration in pitch control in this new control strategy. Theory and simulation show that Fluctuation-suppression pitch control (FSPC) strategy can improve the vibration characters of wind turbine and suppress rotation speed and power fluctuation, and it is also quite effective for gust situation

Low Voltage Ride through of Wind Turbine Based on New SGSC Converter Structure

2013 ◽  
Vol 448-453 ◽  
pp. 2185-2190 ◽  
Author(s):  
He Nan Dong ◽  
Yun Dong Song ◽  
Gang Wang ◽  
Zuo Xia Xing
Keyword(s):  
Power Systems ◽  
Wind Turbine ◽  
Control Strategy ◽  
Large Scale ◽  
Reactive Power ◽  
Low Voltage ◽  
Short Circuit ◽  
Simulation Software ◽  
Low Voltage Ride Through ◽  
Doubly Fed

The proportion of wind power in power systems is increasing year by year. Large-scale wind turbine off the grid when grid system failures. So the wind turbine needs to low voltage ride through (LVRT) function of wind turbine. Aiming at this problem, which in this article by DIgSILENT simulation software build 1.5MW doubly-fed wind turbine(DFIG) model, using active Crowbar and series grid side converter (SGSC) control strategy to realize the simulation of low voltage ride through of wind turbine. The control strategy of active Crowbar is mainly through the short circuit of rotor side converter to realize LVRT, and needs to be matched with the active and reactive power control strategy. SGSC is a novel converter structure, which mainly through compensating stator flux drop to realize LVRT. Finally this two kinds of control strategies were compared, demonstrated SGSC control strategy can achieve the low voltage ride through capabilities of the doubly-fed wind turbine.

scholarly journals A Distributed Cooperative Control Strategy of Offshore Wind Turbine Groups with Input Time Delay

2020 ◽  
Vol 12 (7) ◽  
pp. 3032
Author(s):  
Bing Wang ◽  
Zhen Tang ◽  
Weiyang Liu ◽  
Qiuqiao Zhang
Keyword(s):  
Time Delay ◽  
Power System ◽  
Wind Turbine ◽  
Wind Power ◽  
Distributed Control ◽  
Control Strategy ◽  
Large Scale ◽  
Offshore Wind ◽  
Input Time ◽  
D Model

With large-scale development of offshore wind power and the increasing scale of power grid interconnection, more and more attention has been drawn to the stable operation of wind power units. When the wide area measurement system (WAMS) is applied to the power system, the time delay mainly occurs in the signal measurement and transmission of the power system. When 10MW wind turbines transmit information through complex communication network, time delay often exists, which leads to the degradation of performance and instability for system. This affects the normal operation of a wind farm. Therefore, in this paper, the distributed control problem of doubly fed wind turbines with input time delay is studied based on the Hamiltonian energy theory. Firstly, the Port-controlled Hamiltonian system with Dissipation (PCH-D) model is implemented with the Hamiltonian energy method. Then, the Casimir function is introduced into the PCH-D model of the single wind turbine system to stabilize the time delay. The wind turbine group is regarded as one network and the distributed control strategy is designed, so that the whole wind turbine cluster can remain stable given a time delay occurring in the range of 30–300 ms. Finally, simulation results show that the output power of the wind turbine cluster with input delay converges to the expected value rapidly and remains stable. Additionally, the system error caused by time delay is greatly reduced. This control method can effectively solve the problem of input time delay and improve the stability of the wind turbine cluster. Moreover, the method proposed in this paper can adopt the conventional time step of dynamic simulation, which is more efficient in calculation. This method has adaptability in transient stability analysis of large-scale power system, however, the third-order mathematical model used in this paper cannot be used to analyze the internal dynamics of the whole power converter.

Sign in / Sign up

Export Citation Format

Share Document