基于快速延时信号相消滤波理论的改进VSG低电压穿越策略  

Improved Low Voltage Ride-through Strategy for VSG Based on Fast Delayed Signal Cancellation Filtering Theory

作　　者：刘国帅 李希年 于慧皓 LIU Guoshuai;LI Xinian;YU Huihao(School of Information and Electronic Engineering,Shandong Technology and Business University,Yantai 264005,China)

机构地区：[1]山东工商学院信息与电子工程学院,烟台264005

出　　处：《电力系统及其自动化学报》2025年第4期98-106,共9页Proceedings of the CSU-EPSA

基　　金：山东省自然科学基金资助项目(ZR2021ME236);山东省博士后资助项目(SDCX-ZG-202303085)。

摘　　要：针对传统虚拟同步发电机(virtual synchronous generator,VSG)在电网电压不平衡及谐波畸变工况下的输出电流越限、畸变及功率波动等问题,提出一种基于快速延时信号相消滤波(fast delayed signal cancellation,FDSC)理论的VSG低电压穿越控制策略。首先,根据不平衡电网下VSG输出功率波动的原因,建立平衡电流和恒定有功、无功功率的统一表达式,引入调节系数实现功率/电流的协调控制;然后,提出采用FDSC进行正负序分离与谐波抑制,并通过改进无功-电压环、加入虚拟阻抗及优化功率参考指令,来抑制过电流和提供电压支撑。仿真结果表明该策略能在电网电压畸变不平衡工况下实现功率/电流的协调故障穿越,且正负序分离环节滤波延时小、并网电流质量高、电网电压跌落及故障切除瞬间动态特性好。Aimed at the problems of output current over-limit,distortion and power fluctuations in a traditional virtual synchronous generator(VSG)under conditions of unbalanced grid voltage and harmonic distortion,a low voltage ride-through control strategy for VSG based on fast delayed signal cancellation(FDSC)is proposed.First,according to the reasons for VSG output power fluctuations under unbalanced power grid,a unified expression of balanced current and constant active and reactive power is established,and an adjustment coefficient is introduced to realize the coordinated control of power and current.Second,FDSC is used for positive-and negative-sequence separation and harmonic sup-pression.In addition,by improving the reactive-voltage loop,adding virtual impedance and optimizing the power refer-ence instructions,this strategy can suppress overcurrent and provide voltage support.Simulation results show that the proposed strategy can realize coordinated fault ride-through of power and current under conditions of unbalanced grid voltage distortion,and it has advantages of small filtering delay in the positive-and negative-sequence separation link,high grid-connected current quality and good dynamic characteristics when the grid voltage drops and faults are re-moved.

关 键 词：虚拟同步发电机 不平衡电网 谐波畸变 快速延时信号相消滤波 低电压穿越 协调控制 

分 类 号：TM46[电气工程—电器]