计及锁相环动态响应特性的光伏并网系统故障电流解析计算  

Fault Current Analysis of Photovoltaic Grid-connected System Considering Dynamic Response Characteristics of PLL

作　　者：郑涛 邹芃蓥 王子鸣 ZHENG Tao;ZOU Pengying;WANG Ziming(State Key Laboratory of Alernate Electrical Power System With Renewable Energy Sources(North China Electric Power University),Changping District,Beiing 102206,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市昌平区102206

出　　处：《电网技术》2022年第12期4656-4665,共10页Power System Technology

基　　金：国家自然科学基金联合基金项目(批准号:U2166205)。

摘　　要：锁相环(phaselockedloop,PLL)在光伏跟网型(grid-following,GFL)逆变器并网系统中发挥着重要的作用。当系统发生故障且导致公共耦合点(pointofcommon coupling,PCC)电压发生相位跳变时,由于锁相环存在动态响应过程,其锁相偏差会对故障电流特性产生较大影响。现有研究仅给出了PLL锁相偏差为常数下的故障电流解析表达式,考虑锁相环动态相位偏差的故障电流解析计算亟需进一步完善。针对这一问题,该文计及锁相环的动态响应特性,分析了锁相环的锁相偏差对光伏并网系统故障电流解析计算的影响。在忽略电流内环响应时间的基础上,建立了考虑锁相环动态响应特性的故障电流解析计算模型,揭示了故障期间锁相环的动态响应特性对故障电流的影响机理,明确了故障电流的谐波特性。最后,基于MATLAB/Simulink仿真分析,验证了所提故障解析计算模型的正确性。Phase Locked Loop(PLL) plays an important role in the grid-following(GFL) inverter grid-connected system.When the system fails and causes the point of common coupling(PCC) voltage to have a phase jump,the deviations of the PLL may have a great influence on the fault current characteristics due to the dynamic response process of the PLL.The existing studies only give the analytical expression of the fault current when the deviations is constant.The analytical calculation of the fault current considering the PLL dynamic phase locking error needs to be further improved.Considering the dynamic response characteristics of the PLL,this paper analyzes the influence of the PLL deviations on the analytical calculation of the fault current of the photovoltaic grid-connected system.Ignoring the response time of the current inner loop,the analytical calculation model of the fault current considering the dynamic response characteristics of the PLL is established.The influence mechanism of the dynamic response characteristics of the PLL on the fault current is revealed,and the harmonic characteristics of the fault current are clarified.Finally,the correctness of the proposed fault analytical calculation model is verified by the MATLAB/Simulink simulation.

关 键 词：光伏并网系统 故障电流计算 锁相环 动态响应特性 

分 类 号：TM721[电气工程—电力系统及自动化]