基于状态观测器的单相并网逆变器复合控制

针对光伏并网逆变器的特定次谐波抑制与控制延时补偿，提出了一种基于状态观测器的准比例谐振（Quasi-proportional Resonant, Quasi-PR）控制加重复控制（Repetitive Control, RC）的复合控制策略。其中，准PR控制器用于实现对并网电流基频分量的无静差控制，重复控制器用于抑制特定次谐波分量；同时，考虑到系统的控制延时，采用状态观测器进行延时估计，并基于状态观测器设计了合适的延时补偿环节；此外，针对LCL的谐振尖峰，进行基于电容电流反馈的有源阻尼。最后通过仿真与实验，验证所提复合控制策略的可行性与有效性。

Compound Control of Single-phase Grid-connected Inverter with State Observer

In this paper, an improved compound control strategy for single-phase LCL-type PV grid-connected inverter was designed to aim at harmonic suppression and delay compensation. Firstly, a quasi-PR controller was employed for achieving zero steady-state fundamental frequency error, then a repetitive controller was designed to suppress the certain harmonic current component, at the same time, the digital control delay was compensated by using state observer, so the good dynamic performance of the system can be achieved. In addition, the active damping of LCL-type filter was realized due to capacitance current feedback. Finally, the feasibility and validity of the proposed strategy were verified by the simulation and experiment.