引用本文: | 刘人志,陈 卓,唐文博,等.弱电网下计及锁相环影响的LCL型并网逆变器控制策略[J].电力系统保护与控制,2022,50(5):178-187.[点击复制] |
LIU Renzhi,CHEN Zhuo,TANG Wenbo,et al.Control strategy of an LCL type grid-connected inverter with the influence of a phase-locked loop under a weak power grid[J].Power System Protection and Control,2022,50(5):178-187[点击复制] |
|
摘要: |
新能源并网逆变器在弱电网下易诱发宽频带振荡。为分析振荡失稳的发生机理,首先基于复矢量传递函数方法建立了计及锁相环影响的三相LCL型并网逆变器阻抗模型,然后分析了频率耦合的机理。在此基础上推导出并网逆变器系统与电网阻抗交互作用的等价输出阻抗模型,应用阻抗稳定性判据分析了锁相环对并网逆变器稳定性的影响。为抑制锁相环对并网逆变器系统稳定性带来的不利影响,提出了扰动电压前馈补偿的改进控制策略。最后通过Matlab/Simulink搭建模型进行仿真,验证了基于所建立阻抗模型判别稳定性的准确性和改进控制策略的有效性。 |
关键词: 弱电网 LCL型并网逆变器 锁相环 阻抗模型 复矢量 控制策略 |
DOI:DOI: 10.19783/j.cnki.pspc.210569 |
投稿时间:2021-05-15修订日期:2021-12-28 |
基金项目:贵州省科技计划项目资助([2018])5615) |
|
Control strategy of an LCL type grid-connected inverter with the influence of a phase-locked loop under a weak power grid |
LIU Renzhi,CHEN Zhuo,TANG Wenbo,ZHU Jiawen |
(College of Electrical Engineering, Guizhou University, Guiyang 550025, China) |
Abstract: |
In a new energy grid-connected inverter it is easy to induce wide-band oscillation under a weak power grid. To analyze the occurrence mechanism of oscillation instability, the impedance model of a three-phase LCL grid-connected inverter considering the influence of phase-locked loop is established based on the complex vector transfer function method. Then the mechanism of frequency coupling is analyzed. The equivalent output impedance model of the interaction between grid-connected inverter system and grid impedance is derived, and the influence of phase-locked loop on the stability of the grid-connected inverter is analyzed using, an impedance stability criterion. To limit the adverse effect of the phase-locked loop on the stability of the grid-connected inverter system, an improved control strategy of disturbance voltage feedforward compensation is proposed. Finally, a Matlab/Simulink model is built to verify the accuracy of the stability judgment based on the established impedance model and the effectiveness of the improved control strategy.
This work is supported by the Science and Technology Plan of Guizhou Province (No. [2018]5615). |
Key words: weak power grid LCL grid-connected inverter PLL impedance model complex vector control strategy |