摘要
针对弱电网下并网逆变器的稳定性控制问题进行了研究。该文以重塑的基于阻抗的稳定性判据为理论基础,以电流双闭环控制三相LCL型并网逆变器为模型,建立并网系统的诺顿等效串、并联阻抗数学模型;通过分析等效输出阻抗的特点,选择对逆变器的并联等效输出阻抗进行重塑;该阻抗重塑控制技术包含电网阻抗检测、相位裕度补偿和幅值矫正三个单元,重塑后的等效阻抗模型在电网阻抗宽范围变化时始终能够保持逆变器并网系统具有恒定的稳定裕度,与此同时在考虑电网阻抗存在检测误差的情况下,依旧能够保证系统具有良好的稳态和动态性能。最后,通过仿真和实验验证了文中理论分析的正确性以及所提阻抗重塑控制技术的有效性。
The stability control of grid-connected inverter in weak grid is studied.Based on the reconstructed impedance-based stability criterion,the current double closed-loop control of three-phase LCL grid-connected inverter is used as a model to establish a Norton equivalent series and parallel impedance mathematical model for the inverter grid-connected system.By analyzing the characteristics of inverter equivalent output impedance,the parallel equivalent output impedance of inverter is selected to be reconstructed.The impedance reconstruction control technology includes three units:grid impedance detection,phase margin compensation and amplitude correction.The reconstructed equivalent impedance model can always maintain a constant stability margin for the inverter grid-connected system when the grid impedance varies widely,meanwhile,considering the detection error of the grid impedance,the system can still maintain good steady-state and dynamic performance.Simulation and experimental measurements verify the analysis.
作者
涂春鸣
高家元
赵晋斌
张云飞
郭祺
Tu Chunming;Gao Jiayuan;Zhao Jinbin;Zhang Yunfei;Guo Qi(National Electric Power Conversion and Control Engineering Technology Research Center Hunan University,Changsha 410082 China;School of Electrical Engineering Shanghai University of Electric Power,Shanghai 200090 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2020年第6期1327-1335,共9页
Transactions of China Electrotechnical Society
基金
国家自然科学基金资助项目(51577055)。
关键词
弱电网
LCL
并网逆变器
阻抗判据
阻抗重塑
稳定裕度
Weak grid
LCL
grid-connected inverter
impedance criterion
impedance remodeling
stability margin
