双自由度PID-Ⅲ型锁相环在新能源系统的应用

Application of 2DoFs-PID based type-Ⅲ PLL in new energy system

针对电网故障(电压跌落、频率跳变、谐波、其他扰动等)对锁相环相位检测快速性和准确性产生很大影响的问题,文章提出一种基于双自由度PID补偿的快速准确跟踪配电网电压相位信息的锁相环技术,并结合Ⅲ型系统内模特性,给出了双自由度PID补偿器5个参数的设计方法,最后运用MATLAB/Simulink与两种传统的锁相环技术进行仿真对比。结果表明,文章所提锁相环技术能够抑制谐波、直流分量和不对称分量对锁频环的影响,利用PID微分补偿环节显著提高了响应速度,同时实现无静差跟踪加速度信号。

Grid faults(voltage sags,frequency jump,harmonic,other disturbances,etc.)have a large impact on the quickness and accuracy of the phase angle of phase-locked loop(PLL).In order to solve this problem,a novel type-Ⅲ PLL technology based on the two degrees of freedom PID(2DoFs-PID)and moving average filter is proposed in this paper,which can track the phase angle of grid voltage quickly and accurately.Then,based on the inner model property of type-Ⅲ system,a design method of five parameters of the 2DoFs-PID is also presented.Compared with the traditional phase locked loop technique,MATLAB/Simulink simulated results show that the proposed technology can suppress the influence of harmonics,dc and asymmetric components of grid voltage.It also can improve the response speed by differentiation element of PID and track acceleration signal without any error because of type-Ⅲ inner model.