电压跌落下的双馈风力发电机网侧变流器自适应变惯量控制方法

Adaptive Variable Inertia Control Method for Side Converter of Doubly-fed Wind Generator Under Voltage sag

提出电压跌落下的双馈风力发电机网侧变流器自适应变惯量控制方法,控制电压跌落时的直流电压波动,提升电网跌落时双馈风力发电机不间断运行能力。基于双馈风力发电机数学模型特点,引入虚拟同步发电机控制机制,设计用于增强与同步发电机相似的惯性响应和下垂属性的有功频率控制器,和用于调节机端电压和无功功率的励磁控制器,将两个控制器同时作用于网侧变流器,实现双馈风力发电机网侧变流器控制;并通过最优控制原理自适应整定转动惯量与阻尼系数,制定取值规则,使双馈风力发电系统的响应速度与超调量达到最优。实验证明:该方法能够在电压跌落情况下,通过有效控制网侧变流器,实现直流母线电压、无功及有功功率的平稳输出,保证发电机的持续运行,增强了双馈风力发电系统运行的稳定性与可靠性。

An adaptive variable inertia control method for the grid-side converter of the doubly-fed wind turbine generator under voltage sag was proposed to control the DC voltage fluctuation during voltage sag and improve the uninterrupted operation capability of the doubly-fed wind turbine generator during grid sag.Based on the characteristics of the mathematical model of doubly-fed wind turbine generator,the virtual synchronous generator control mechanism was introduced,and the active frequency controller used to enhance the inertia response and droop properties similar to the synchronous generator,and the excitation controller used to adjust the generator terminal voltage and reactive power were designed.The two controllers were applied to the grid-side converter at the same time to realize the grid-side converter control of doubly-fed wind turbine;Through the optimal control principle,the moment of inertia and damping coefficient were adjusted adaptively,and the value rules were formulated to optimize the response speed and overshoot of the doubly-fed wind power generation system.The experiment shows that this method can realize the stable output of DC bus voltage,reactive power and active power,ensure the continuous operation of the generator,and enhance the stability and reliability of the operation of the doubly-fed wind power generation system by effectively controlling the grid-side converter under the condition of voltage drop.