Adaptive Power Compensation Based Frequency Regulation Strategy of Wind Turbine System

 Abstract

Given the increasing penetration of wind power generation, the power system faces great challenges in frequency regulation due to reduction in system inertia. This paper proposes an adaptive power compensation based frequency regulation (FR)strategy of the wind turbine system (WTS). In a frequency transient event, the proposed strategy exploits power excitationmethod to estimate the disturbance level, which enables the WTS to timely and accurately participate in FR. After the system frequency and the rate of change of frequency meet their requirements, the droop control is adopted to smooth the WTS out of the FR mode and further improve the frequency quality. By analyzing the operation mode and determining the switching logic, detailed implementation of the proposed strategy is developed. Its excellent frequency response performance is verified via results of hardware-in-the-loop experiment and MATLAB/Simulink-based simulation.

Index Terms

Adaptive power compensation, frequency regulation, disturbance estimation, power excitation method, wind turbine system.

Block Diagram:

                                           Fig. 1. Block diagram of a single grid-tied WTS.

Expected Simulation Results:

Fig. 2. (a) Frequency, (b) RoCoF, and (c) active power results of single WTS.

                                  Fig. 3. Case switching process under the APC strategy.

Fig. 4. (a) Frequency, (b) RoCoF, and (c) active power of the 4M2A system.

CONCLUSION

In this paper, an adaptive control strategy of the WTS is developed for better FR support. Through theoretical and simulation analyses, the power excitation method developed in this paper, which makes use of a low power injection at the moment of disturbance, is proved to be feasible for online disturbance estimation. This serves as the foundation of proposed APC. Compared to the RPC control, the proposed strategy enables more effective WTS participation in the system FR based on the estimated disturbance. According to the real-time information of f and RoCoF, the APC strategy accurately switches between different cases, thereby improving the frequency response characteristics of the grid-tied WTS.

REFERENCES

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