基于穿越频次变步长的离散全程滑模锁相环控制  

A Frequency Crossing Switching Surface Based Variable-Step Digital Global Sliding Mode Phase-Locked Loop Control Strategy

作　　者：刘斌[1] 贺建军[1] 粟梅[1] 孙尧[1] 

机构地区：[1]中南大学信息科学与工程学院,湖南省长沙市410083

出　　处：《电网技术》2014年第12期3347-3353,共7页Power System Technology

基　　金：国家自然科学基金项目(61174125;61174132)~~

摘　　要：对于基于同步旋转坐标变换的数字锁相环,为实现更好的实时性和控制精度,更适合新能源并网逆变发电的应用,将一种基于全程滑模的变步长控制策略引入其中。基于同步坐标系数字锁相环的数学模型,研究了不同电网电压矢量初始相位角对锁相速度的影响,推导了电网电压矢量的d轴分量相对于原点进行坐标镜像变换的规则。在建立锁相环全程离散切换函数的基础上,根据非理想全程离散滑动模态的运动特点,提出了基于穿越切换面频次的瞬态判定方法。构建李雅普诺夫(Lyapunov)函数讨论了锁相环全程滑模控制的稳定性、存在性及可达性条件,基于此确定了变步长的极值。仿真和实验结果验证了此控制策略的有效性。To implement better dynamic response and control accuracy of synchronous rotating reference flame transformation based digital phase-locked loop （PLL） and make it more suitable fol： the application of grid-connection inverter for new energy power generation, a global sliding mode based variable-step control strategy is led into PLL. Based on mathematical model of synchronous reference frame based PLL, the impacts of different grid voltage vectors＇ initial phase angles on the phase-lock speed are researched, and the frame mirror image transform rule for d-axis component of grid voltage vector relative to coordinate origin is derived. On the basis of establishing global discrete switching function of PLL and according to the moving characteristic of non-ideal global discrete sliding mode, a frequency crossing switching surface based method to determine the transient state is proposed. A Lyapunov function is constructed to research the existence condition, the reachability condition and the stability of the digital PLL global sliding mode control strategy, and on this basis the extremum of the variable-step is decided. The effectiveness of the proposed control strategy is validated by simulation and experimental results.

关 键 词：全程滑模控制 数字锁相环 并网逆变器 瞬态初值 李雅普诺夫 

分 类 号：TM721[电气工程—电力系统及自动化]