LCL型并网逆变器大小信号模型比较与分析  

Comparison and analysis of large and small signal models of LCL grid-connected inverter

作　　者：李建文[1] 李戎[1] 吴滨源 孙伟 LI Jian-wen;LI Rong;WU Bin-yuan;SUN Wei(State Key Lab of New Energy and Power Systems,North China Electric Power University,Baoding 071003,China;State Grid Hebei Electric Power Co.Ltd.Baoding Power Supply Branch,Baoding 071000,China)

机构地区：[1]华北电力大学新能源电力系统国家重点实验室,河北保定071003 [2]国网河北省电力有限公司保定供电分公司,河北保定071000

出　　处：《电机与控制学报》2021年第5期60-70,共11页Electric Machines and Control

基　　金：中央高校基本科研业务费专项资金(2020MS095)。

摘　　要：为了研究应用LCL型并网逆变器大、小信号两种模型在分析并网系统稳定性的相关问题,着重比较两种模型的特点,探讨其应用范围:首先总结了LCL型并网逆变器系统大、小信号模型的搭建过程,归纳了系统参数与控制参数变化对系统稳定性影响;然后比较两模型的复杂程度、精确程度及异同点:其中大信号模型较小信号模型,未考虑PWM控制的影响以及PLL环节使得模型更为简单,输出导纳阶数较低,而二者得到的影响系统稳定性结论具有一致性;并针对多逆变器并网谐振失稳问题,提出大信号模型的适用性;最后,通过仿真验证与理论分析的一致性,探讨了大信号模型在多逆变器并网及不同控制类型逆变器并网应用,以及该模型分析确定谐振失稳点的有效性。In order to study the large and small signal models used to analyze related issues of system stability with LCL-filter-based grid-connected inverter, compare characteristics of the two models, and explore their scope of application, modeling process of the large and small signal models of LCL grid-connected inverter system was summarized, then conclusions obtained by applying two models that were used to analyze influence of parameter changes on system stability were summarized. Complexity, accuracy, similarities and differences of the two models wre compared. Between them, the large-signal model which does not consider influence of PWM control and PLL makes model simpler and the output admittance order is lower than the small-signal model. Conclusions obtained by the two models are consistent. Aiming at the problem of resonance instability caused by grid-connected multi-inverters, practicability of large-signal model was proposed. Finally, consistency of theoretical analysis were verified through simulation. Application of the large-signal model in grid-connected multi-inverters and grid-connected inverter with different control strategy is also discussed, and validity of the resonance instability point is analyzed and determined.

关 键 词：大信号模型 小信号模型 谐振 稳定性 适用性分析 LCL型并网逆变器 

分 类 号：TM464[电气工程—电器]