Standalone operation of an inverted-based distributed generation unit is performed in voltage control mode. In this mode, it is important that the controller provides tracking and rejection of periodic signals. Strategies like Repetitive Control (RC) are well suited in the voltage control of power inverters. However, the robustness of repetitive controllers is importantly affected by the connected loads. The reason is that the load modifies the dynamics of the system where the design of the RC relies on. Having a low bandwidth action can reduce the problem but with the cost of degrading the voltage waveform and transient response. As an alternative, an $H_{\infty }$ design is proposed for the RC of voltage source inverters. In this proposal the load is directly treated as an unstructured uncertainty. With this approach, the design procedure directly maximizes the robust stability margin of the system against load variations/uncertainty. Additionally, the analysis provides some insight about the design of the inverter LC filter. Experimental results show that a remarkable Total Harmonic Distortion and good transient response are obtained for a large variety of loads.

中文翻译：

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用于 DG 系统中独立运行的功率逆变器的稳健重复控制

逆变式分布式发电机组的独立运行是在电压控制模式下进行的。在这种模式下，控制器提供对周期性信号的跟踪和拒绝是很重要的。重复控制 (RC) 等策略非常适合电源逆变器的电压控制。然而，重复控制器的鲁棒性受到连接负载的重要影响。原因是负载改变了 RC 设计所依赖的系统动态。低带宽操作可以减少问题，但代价是降低电压波形和瞬态响应。作为替代方案，为电压源逆变器的 RC 提出了 $H_{\infty }$ 设计。在这个提议中，负载被直接视为非结构化的不确定性。通过这种方法，设计程序直接最大化系统针对负载变化/不确定性的鲁棒稳定性裕度。此外，该分析还提供了有关逆变器 LC 滤波器设计的一些见解。实验结果表明，对于各种负载，都获得了显着的总谐波失真和良好的瞬态响应。