弱电网下光伏并网逆变器自适应准PRD控制方法  

Adaptive Quasi-PRD Control Method of Grid-Connected PV Inverter in Weak Grid

作　　者：刘桂花[1] 石桐 马田源 王卫[1] 

机构地区：[1]哈尔滨工业大学电气工程及其自动化学院,黑龙江省哈尔滨市150001

出　　处：《电网技术》2017年第1期112-117,共6页Power System Technology

摘　　要：当光伏并网逆变器接入弱电网时,较高的电网等效阻抗值使逆变器控制系统带宽减小、控制性能下降。针对此问题,提出自适应准比例谐振微分(PRD)控制方法,该方法首先对传统PI控制器进行改进,采用准PRD控制器实现零稳态误差跟踪并扩大系统带宽,然后采用双谐波电流注入法实现对弱电网阻抗的在线检测,最后将检测到的电网阻抗值作为控制量在线调整准PRD控制器参数,实现并网逆变器对弱电网阻抗的自适应控制。仿真和实验结果表明,该方法可实现对参考信号良好的稳态跟踪特性和动态响应性能,提高系统对时变电网阻抗的自适应性,改善并网电能质量。When grid-connected photovoltaic（PV） inverter is connected to weak grid, high equivalent impedance of weak grid can lead to small bandwidth of control system and poor control performance. Aiming at this problem, this paper proposes an adaptive quasi proportion resonant differential（quasi-PRD） control method. This method firstly uses quasi-PRD controller to replace traditional PI controller to realize zero steady-state error tracking and expand system bandwidth. Then, double harmonic current injection method is applied to implement on-line detection of grid impedance. Finally, the detected impedance value is used to on-line adjust controller parameters of quasi-PRD. Simulations and experiments were performed, verifying that the proposed method can not only increase bandwidth and dynamic response speed of control system, but also improve system adaptability for different grid impedance values, and eventually improve power quality.

关 键 词：弱电网 准PRD控制 电网阻抗 自适应控制 

分 类 号：TM721[电气工程—电力系统及自动化]