基于阻抗识别的单相并网逆变器自适应电压前馈控制  

Single⁃phase grid⁃connected inverter′s adaptive voltage feedforward control based on impedance recognition

作　　者：李国进[1] 龚豪 陈延明[1] LI Guojin;GONG Hao;CHEN Yanming(School of Electrical Engineering,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学电气工程学院,广西南宁530004

出　　处：《现代电子技术》2022年第11期153-160,共8页Modern Electronics Technique

基　　金：国家自然科学基金项目(51567004);广西重点研发计划(AB18126026)。

摘　　要：在传统大电网中,电网电压比例前馈因其可以有效地抑制电网电压谐波而广泛应用于LCL型并网逆变器中,但是在微电网中由于电网阻抗的影响,系统的相位裕度会随着网侧感性阻抗的增加大幅减小,严重时会导致逆变器系统不稳定。为了减小微电网阻抗对系统造成的影响,提高入网电能质量,提出一种改进前馈策略的阻抗识别自适应控制方法。该方法在传统电压比例前馈的基础上,首先对传统电网电压比例前馈进行改进,即在比例前馈通道上加入一个积分环节,在一定程度上提高了系统的相位裕度;之后采用谐波注入法测量网侧感抗,根据辨识结果自适应地调整控制器参数,进一步保证系统具有良好的相位裕度,提高了逆变器的鲁棒性;最后在Matlab/Simulink中进行仿真实验,并与传统电压比例前馈策略对比,仿真结果证实了该方案的可行性,可以提高逆变器的鲁棒性。In the traditional large power grid,the grid voltage proportional feedforward is widely used in the LCL grid⁃connected inverter because it can effectively restrain the grid voltage harmonics.However,in the microgrid,due to the influence of the grid impedance,the phase margin of the system will decrease greatly with the increase of the inductive impedance on the grid,which will lead to the instability of the inverter system in severe cases.In order to reduce the influence of microgrid impedance on the system and improve the power quality,an impedance recognition adaptive control method based on improved feedforward strategy is proposed.On the basis of the traditional voltage proportional feedforward,the traditional grid voltage proportional feedforward is improved,that is,an integral link is added to the proportional feedforward channel to improve the phase margin of the system to a certain extent.And then,the harmonic injection method is used to measure the network side inductance and adaptively adjust the controller parameters according to the identification results,so as to further ensure that the system has a good phase margin,which improves the robustness of the inverter.Simulation experiments were carried out with Matlab/Simulink.In comparison with the traditional voltage proportional feedforward strategy,the simulation results show that the scheme is feasible and can improve the robustness of the inverter.

关 键 词：电压前馈控制 并网逆变器 阻抗识别 自适应控制 相位裕度 电能质量 

分 类 号：TN876-34[电子电信—信息与通信工程] TM46[电气工程—电器]