Robust Control Design for High-Power Density PV Converters in Weak Grids
Robust Control Design for High-Power Density PV Converters in Weak Grids
复制标题
弱电网中高功率密度光伏变流器的鲁棒控制设计
DOI：
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发表时间：
2019
影响因子：
4.8
通讯作者：
S. A. Khajehoddin
中科院分区：
文献类型：
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作者：
Nima Amouzegar Ashtiani;S. Azizi;S. A. Khajehoddin
针对带<italic>LCL</italic>滤波器的单相光伏变换器，提出了一种基于<inline-formula><tex-math notation="LaTeX">μ</tex-math></inline-formula>综合法和<inline-formula><tex-math notation="LaTeX">H_{infty }$</tex-math></inline-formula>法的鲁棒电流控制器和直流侧电压控制器。的<inline-formula><tex-math notation="LaTeX">$mu $</tex-math></inline-formula>合成CC保证系统的鲁棒性，对电网阻抗变化和电压谐波等弱电网的不确定性。此外，控制器补偿系统延迟所产生的计算，脉宽调制，零阶保持，以及延迟的不确定性。CC仅使用电网电流反馈，这消除了对在部分或全部状态反馈系统中使用的附加回路或状态测量的要求。此外，直流母线电压控制器还能最大限度地减小光伏发电系统发电量变化引起的母线电压波动。<inline-formula><tex-math notation="LaTeX"></tex-math></inline-formula>此外，控制器确保系统对这种功率变化的鲁棒性，这是常规控制器无法实现的。此外，功率解耦是通过控制系统实现的，而无需任何辅助电路。此外，锁相环的稳定性和鲁棒性的性能在一个弱的电网与主要的阻抗变化进行了验证。仿真和实验结果证明了所提出的控制器的上级性能的标称系统和系统的偏离参数的情况下。
This paper proposes a robust current controller (CC) and dc-link voltage controller based on <inline-formula> <tex-math notation="LaTeX">$mu $ </tex-math></inline-formula>-synthesis and <inline-formula> <tex-math notation="LaTeX">$H_{infty }$ </tex-math></inline-formula> method, respectively, for a single-phase photovoltaic (PV) converter with an <italic>LCL</italic>-filter under weak grid operation. The <inline-formula> <tex-math notation="LaTeX">$mu $ </tex-math></inline-formula>-synthesis CC guarantees system robustness against weak grid uncertainties such as grid impedance variations and voltage harmonics. Moreover, the controller compensates the system delays arising from the calculation, pulsewidth modulation, and zero order hold, as well as delay uncertainties. The CC only uses the grid current feedback which eliminates the requirement for additional loops or state measurements utilized in partial or full state-feedback systems. In addition, the <inline-formula> <tex-math notation="LaTeX">$H_{infty }$ </tex-math></inline-formula> dc-link voltage controller minimizes the bus voltage fluctuations caused by variations of PV system power generation. Also, the controller ensures system robustness against such power variations, which conventional controllers fail to perform. Moreover, power decoupling is achieved by the control system without any auxiliary circuit. In addition, the stability and robust performance of the phase-locked loop in a weak grid with major impedance changes is verified. Simulation and experimental results prove the superior performance of the proposed controllers in both cases of a nominal system and a system with deviated parameters.