基于转子动能调节的风电输出功率平滑控制策略比较与改进

Comparison and Improvement of Power Smoothing Control Strategies for Wind Power Output Based on Kinetic Energy Adjustment for Rotor

湍流风况下,基于传统最大功率点跟踪模式控制的风电机组输出功率剧烈波动,会对电能质量及电网稳定造成负面影响,而通过调节风电机组转子惯性动能可平滑快速波动的输出功率。文中从风电机组转子惯性动能控制的关键参数功率参考值出发,通过建立系统传递函数,比较现有文献中提出的两种转子动能控制方法,即一阶滤波法和二阶滤波法,分析功率平滑控制的机理。在此基础上,提出了一种基于模糊控制器的新型变参数二阶滤波器转子动能控制策略。通过模糊控制器在线调整滤波参数,提升了在强湍流风况下的风电输出功率平滑效果,且有效避免了转速越限造成的电磁功率突变。最后,仿真与实验结果表明了所提转子动能控制策略相较于传统方法具有更好的功率平滑能力。

Under turbulent wind conditions,the output power of the wind turbine controlled by the traditional maximum power point tracking mode fluctuates sharply,which has a negative impact on the power quality and power grid stability.However,the fast fluctuating output power can be smoothed through adjusting the rotor inertia energy of the wind turbine.Based on the power reference value,which is key parameter of rotor kinetic energy control,this paper establishes the system transfer function and analyzes the mechanism of power smoothing control by comparing the two rotor kinetic energy control methods proposed in the existing literature,namely the first-order filtering method and the second-order filtering method.On this basis,this paper proposes a rotor kinetic energy control strategy of novel varying-parameter second-order filter based on the fuzzy controller.By adjusting the filtering parameters online through the fuzzy controller,the smoothing effect of the output wind power under strong turbulence conditions is improved,and the sudden changes of electromagnetic power caused by the rotation speed exceeding its limit are effectively avoided.Finally,the simulation and experimental results show that the proposed rotor kinetic energy control strategy has better power smoothing ability than the traditional method.