中国电机工程学报Issue(30)：5259-5268,10.DOI:10.13334/j.0258-8013.pcsee.2014.30.001
弱电网条件下锁相环对LCL型并网逆变器稳定性的影响研究及锁相环参数设计
Research on the Stability Caused by Phase-locked Loop for LCL-type Grid-connected Inverter in Weak Grid Condition
摘要
Abstract
For grid-connected inverter, the current injected into utility network has to be synchronized with the grid voltage, and Phase-Locked Loop (PLL) is widely used as an efficient approach to detect grid phase angle. The inverter uses detected grid phase angle to generate synchronized current reference, thus PLL itself acts as a part of the control loop of the inverter and it will certainly affect system stability. This article focused on the single-phase LCL-type grid-connected inverter, and presented the small signal model of PLL. Meanwhile, the impedance-based stability criterion was developed. Based on the criterion, it was pointed out that in stiff grid, where the grid impedance can be neglected, the stability of the inverter will not be affected by PLL. But if the grid is weak, PLL has strong effect on the stability of the inverter, and the effect mainly depends on the bandwidth of PLL, load condition and power factor of the inverter. In order to ensure the stability of the system, a method which design the control parameters of PLL based on phase margin requirements was also proposed in this paper. The experimental results were given to verify the validity of theoretical analysis presented above.关键词
LCL滤波器/并网逆变器/锁相环/稳定性/弱电网/电网阻抗Key words
LCL filter/gird-connected inverter/phase-locked loop (PLL)/system stability/weak grid/grid impedance分类
信息技术与安全科学引用本文复制引用
吴恒,阮新波,杨东升..弱电网条件下锁相环对LCL型并网逆变器稳定性的影响研究及锁相环参数设计[J].中国电机工程学报,2014,(30):5259-5268,10.基金项目
国家自然科学基金项目(50837003)；南京航空航天大学基本科研业务费(56XQA13014)。Project Supported by National Natural Science Foundation of China (50837003) （50837003）
The Basic Research Funding of Nanjing University of Aeronautics and Astronautics (56XQA13014) （56XQA13014）
