适用于微网并网控制技术的改进型EPLL算法研究  

Research on Improved EPLL Algorithm Suitable for Grid-connected Control Technology for Microgrid

作　　者：曾君[1] 岑德海 陈润 刘俊峰[2] 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)

机构地区：[1]华南理工大学电力学院,广州510640 [2]华南理工大学自动化科学与工程学院,广州510640

出　　处：《电源学报》2020年第6期86-93,共8页Journal of Power Supply

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.

关 键 词：锁相环 EPLL算法 分布式电源 微网 滑动平均值滤波器 

分 类 号：TM761[电气工程—电力系统及自动化]