中文摘要：

采用即时采样技术可有效地减小采样延迟，提高LCL并网逆变器有源阻尼控制的鲁棒性。然而，该采样方法受到频率混叠的影响，导致信号采样不准确，限制了其实用性。为分析并解决频率混叠问题，该文建立了基于实际数字信号处理器（digitalsignalprocessor，DSP）I作模式的频率混叠分析模型，系统地分析了采样时刻与频率混叠程度的关系。分析表明，无论是传统的采样方案还是即时采样方案，均存在一定的频率混叠现象，但相对来说，传统采样方案混叠程度较轻。在此基础上，结合LCL并网逆变器有源阻尼控制对信号采样的需求，分析了多次采样和即时采样附加高通滤波两种频率混叠抑制方案，给出了相应的仿真与实验结果。多次采样方案增加了软硬件的实现难度，而附加高通滤波器的方案较为简便，更具实用性。

英文摘要：

Real-time sampling technique is able to highly reduce the sampling and computation delay and improve the robustness of the active damping control for grid-connected LCL-filtered inverter. However, the practicability of this approach would be limited by the aliasing problem of sampling. In order to solve the aliasing problem, a systematic analysis is done to figure out the relation between the sampling instant and the aliasing harmonics by establishing an aliasing analysis model based on the actual digital signal processor （DSP） working mode. Results show that the aliasing with the traditional synchronous sampling is lighter than that with the real-time sampling. Besides, on the basis of acquiring the demand of signal sampling for active damping, two methods including the multiple sampling and the real-time sampling with a high-pass filter are presented to suppress the aliasing-deduced harmonics. Finally, simulation and experimental results prove that the multiple sampling scheme increases the difficulty in both software and hardware implementations, while the proposed real-time sampling with additional high-pass filter is simple and practical.