计及锁相环非线性特性的跟网型逆变器暂态稳定性分析  

Transient stability analysis of grid⁃following inverters with nonlinear characteristics of PLL

作　　者：王素娥[1] 李康[1] 郝鹏飞[1] 刘煜帆 崔开源 陈景文[1] WANG Sue;LI Kang;HAO Pengfei;LIU Yufan;CUI Kaiyuan;CHEN Jingwen(School of Electrical and Control Engineering,Shaanxi University of Science and Technology,Xi’an 710021,China)

机构地区：[1]陕西科技大学电气与控制工程学院,陕西西安710021

出　　处：《电工电能新技术》2024年第7期12-22,共11页Advanced Technology of Electrical Engineering and Energy

基　　金：陕西省重点研发计划项目(2024GX⁃YBXM⁃468);陕西省重点研发计划项目(2023⁃YBGY⁃304);陕西省教育厅计划项目(22JC023);西安市科技计划项目(21XJZZ003)。

摘　　要：锁相环作为跟网型逆变器实现相位同步的关键环节,由于其本身所固有的非线性特性,在弱电网情况下,传统小信号模型可能存在不能准确预测锁相环暂态稳定性的问题。为保证受扰后锁相环的稳定运行,提出了一种基于非线性数学模型的稳定性分析方法。首先,根据锁相环工作原理,建立其二阶非线性微分方程,通过相平面法对锁相环输出特性进行定性分析,评估不同参数对锁相环暂态特性的影响;然后,基于等面积法则分析锁相环暂态失稳机理,鉴于传统等面积法则可能导致稳定性的误判,采用非线性动力学多尺度法对锁相环受扰后的暂态时域表达式进行求解,明确锁相环暂态稳定边界;最后,通过Matlab仿真和RT⁃LAB半实物平台验证了所得解析解和锁相环暂态稳定域的准确性,为弱电网条件下锁相环控制参数及电路参数选取提供一定参考。Phase⁃locked loop(PLL)is a key step to realize phase synchronization in grid⁃following inverter.Due to its inherent nonlinear characteristics,the traditional small⁃signal model may not be able to accurately predict the transient stability of PLL in weak grids.In order to ensure the stable operation of PLL after disturbance,a stability analysis method based on nonlinear mathematical model is proposed.First,according to the working principle of PLL,the second order nonlinear differential equation is established,and the output characteristics of PLL are qual⁃itatively analyzed by the phase plane method,and the effects of different parameters on the transient characteristics of PLL are evaluated.Then,based on the equal⁃area criterion(EAC),the transient instability mechanism of PLL is analyzed.Considering that traditional EAC may lead to misjudgment of stability,the nonlinear dynamics multi⁃scale method is used to solve the time⁃domain expression of the transient state after PLL is disturbed,and the tran⁃sient stability boundary of PLL is defined.Finally,the accuracy of the analytical solution and the PLL transient sta⁃bility domain is verified by MATLAB simulation and RT⁃LAB platform,which provides some reference for the se⁃lection of PLL control parameters and circuit parameters under weak grid conditions.

关 键 词：跟网型逆变器 锁相环 非线性 弱电网 暂态稳定性 多尺度法 

分 类 号：TM464[电气工程—电器]