基于降阶线性扩张状态观测器的风电并网逆变器线性自抗扰控制*

针对风电并网逆变器直流母线电压易受电网电压波动和负载扰动影响的问题,文中提出了一种电压外环改进型线性自抗扰控制(LADRC)。首先建立了风电并网逆变器在d-q旋转坐标系下的数学模型,在此基础上,设计了基于降阶线性扩张状态观测器的线性自抗扰控制,减小了观测器的相位滞后,提高了系统的扰动观测精度；然后在观测器总扰动通道上增加了一个超前滞后的校正环节以减弱观测器的噪声放大效应；最后对改进型LADRC控制策略进行了频域特性分析。仿真结果表明,相比于传统LADRC控制策略,文中所提的控制策略对并网逆变器直流母线电压具有更好的控制效果。

Linear active disturbance rejection control of wind power grid connected inverter based on reduced order linear extended state observer

Aiming at the problem that the DC bus voltage of wind power grid connected inverter is easily affected by the grid voltage fluctuation and load disturbance, an improved linear active disturbance rejection control (LADRC) applied in the voltage outer loop is proposed in this paper. Firstly, the mathematical model of the wind power grid connected inverter in the d-q rotating coordinate system is established. On this basis, the linear active disturbance rejection control Based on the reduced order linear extended state observer is designed, which reduces the phase lag of the observer and improves the disturbance observation accuracy of the system. Then, a lead lag correction link is added to the total disturbance channel of the observer to reduce the noise amplification effect of the observer. Finally, the frequency domain characteristics of the improved LADRC control strategy are analyzed. The simulation results show that the proposed control strategy has better control effect on the DC bus voltage of grid connected inverter than the traditional LADRC control strategy.