基于自抗扰控制的风电并网变流器锁相环设计

DESIGN OF PHASE-LOCKED LOOP OF GRID CONNECTED CONVERTER BASED ON ACTIVE DISTURBANCE REJECTION CONTROL

在高比例可再生能源渗透环境下,电力系统呈现低惯性阻尼特性,传统基于PI控制器的同步参考坐标系锁相环更易受到新能源波动性的影响,造成锁相输出结果较差,从而引发跟网型风电变流器的一系列振荡问题。提出基于一阶线性自抗扰控制器的锁相环,通过对比分析一阶线性自抗扰锁相环和传统锁相环的频域特性,说明其抗扰性能的优势。提出一种简易的参数设计方法,简化锁相环参数设计。在相同带宽尺度比较下说明高阶自抗扰控制器应用于并网变流器锁相环的局限性。通过锁相环仿真和基于混合多电平并网变流器的实验结果表明,所提自抗扰锁相环在受扰动环境下具有更准确的锁相结果,更加适用于高比例可再生能源参与的新型电力系统。

In a high proportion of renewable energy infiltration penetration,the power system presents low inertia damping characteristics.The traditional synchronous reference coordinate phase-locked loop(SRF-PLL) based on PI controller is more vulnerable to the fluctuation of new energy,resulting in poor phase-locked output results,which leads to a series of oscillation problems of grid-following converter.A phase-locked loop based on first-order linear ADRC(LADRC-PLL)is proposed.By comparing and analyzing the frequency domain characteristics of first-order LADRC-PLL and traditional phase-locked loop based on PI controller(PIPLL),the advantages of its disturbance rejection performance are explained.A simple parameter design method is proposed to simplify the parameter design of PLL.Under the same bandwidth scale comparison,it shows the limitations of the application of high-order LADRC in the phase-locked loop of grid connected converter.The simulation of PLL and the experimental results based on hybrid active neutral point clamped(HANPC)grid connected converter show that the proposed LADRC-PLL has more accurate phase locking results in disturbed environment,and is more suitable for new power systems with high proportion of renewable energy.