弱电网下三相电压源型逆变器并网谐振抑制及畸变电网情况下并网电流改善控制策略研究  

Researchon Grid Resonance Suppression and Grid Current Improvement Control Strategy of Three-Phase Voltage Source Inverter under Weak Grid

作　　者：钟草茂 张志[1] 李义云 ZHONG Caomao;ZHANG Zhi;LI Yiyun(School of Electrical Engineering&Intelligentization,Dongguan University of Technology,Dongguan 523808,China)

机构地区：[1]东莞理工学院电信工程与智能化学院,广东东莞523808

出　　处：《东莞理工学院学报》2023年第5期71-82,共12页Journal of Dongguan University of Technology

摘　　要：三相电压源型并网逆变器因滤波器与电网阻抗易构成欠阻尼特性而造成系统谐振,以及网侧电压含谐波导致并网电流畸变进而影响并网电流质量。针对滤波器带来的谐振问题,分析了谐振机理并提出了电容电流前馈有源阻尼控制策略对谐振进行抑制;针对网侧电压含谐波的工况,提出了一种基于VSG电压电流双环等效模型的虚拟阻抗重塑方法来改善并网电流波形,给出了谐波阻抗选取的依据,并通过根轨迹分析了系统的稳定性。最后通过仿真证明了所提控制策略的正确性和有效性。Three-phase voltage-source grid-connected inverters cause system resonance due to the under-damping characteristics of the filter and grid impedance,and the grid-side voltage contains harmonics,which leads to grid current distortion and affects the quality of grid current and system stability.For the resonance problem caused by the filter,the resonance mechanism is analyzed and a capacitor-current feedforward active damping control strategy is proposed to suppress the resonance;for the condition that the grid-side voltage contains harmonics,a control strategy based on the harmonic virtual impedance of the virtual synchronous generator(VSG)voltage and current double-loop equivalent model is proposed to improve the grid-connected current,the basis for the selection of harmonic virtual impedance is given,and the stability of the system is analyzed by the root locus.Finally,the correctness and effectiveness of the proposed control strategy are proved by simulation and experimental results.

关 键 词：有源阻尼 谐振抑制 并网电流质量 虚拟阻抗 

分 类 号：TM464[电气工程—电器]