摘要
快速准确的锁相环技术是保证并网系统安全、可靠并网的关键。针对传统EPLL的固有缺陷,设计了一种改进型EPLL算法,适用于以分布式电源为主的微网并网控制技术。首先,推导出输出电压频率和输入电压幅值之间的耦合关系,使用数学公式进行近似解耦。其次,搭建误差信号的成本函数,利用梯度下降法设计直流偏移量的估算环路,通过闭环负反馈回路消去输入信号中的直流偏置。然后,在锁相算法的所有估算环路中引入滑动平均值滤波器MAF(moving average filter),以增强控制系统的高频谐波抗干扰能力。最后,在Matlab/Simulink软件中搭建了单相锁相环算法的仿真模型,进行对比分析。仿真结果验证了所提算法的正确性和可行性。
The fast and accurate phase-locked loop(PLL)technology is the key to ensuring the safety and reliability of a grid-connected system.In view of the inherent defects of the traditional enhanced PLL(EPLL),an improved EPLL algorithm is designed,which is suitable for the grid-connected control technology for microgrid based on distributed generations(DGs).First,the coupling relationship between output voltage frequency and input voltage amplitude is derived,and the approximate decoupling is performed by means of mathematical formulas.Second,the cost function of error signal is constructed,the DC offset estimation loop is designed using the gradient descent method,and the DC offset in the input signal is eliminated through the closed-loop negative feedback loop.Then,a moving average filter(MAF)is introduced into all the estimation loops of the phase-locked algorithm,thus enhancing the high-frequency harmonic anti-interference capability of the control system.Finally,the simulation models of single-phase PLL algorithms are built in Matlab/Simulink for conducting comparative analysis,and simulation results verify the correctness and feasibility of the proposed algorithm.
作者
曾君
岑德海
陈润
刘俊峰
ZENG Jun;CEN Dehai;CHEN Run;LIU Junfeng(School of Electric Power Engineering,South China University of Technology,Guangzhou 510640,China;School of Automation Science and Engineering,South China University of Technology,Guangzhou 510640,China)
出处
《电源学报》
CSCD
北大核心
2020年第6期86-93,共8页
Journal of Power Supply
关键词
锁相环
EPLL算法
分布式电源
微网
滑动平均值滤波器
phase-locked loop(PLL)
enhanced phase-locked loop(EPLL)algorithm
distributed generation(DG)
microgrid
moving average filter(MAF)
作者简介
曾君(1979-),女,博士,教授,研究方向:电力电子应用、分布式发电的能量管理和智能控制,E-mail:junzeng@scut.edu.cn;岑德海(1995-),男,硕士研究生,研究方向:电力系统的锁相技术,E-mail:epcdh@mail.scut.edu.cn;陈润(1997-),男,硕士研究生,研究方向:并网逆变器控制,E-mail:eprchen@mail.scut.edu.cn;通信作者:刘俊峰(1978-),男,中国电源学会高级会员,博士,副教授,研究方向:电力电子应用、高频配电系统、运动控制,Email:aujfliu@scut.edu.cn。
