Switching Harmonics Suppression of Single-loop Multi-sampling Control of Grid-connected Inverter

Multi-sampling control provides an attractive way to reduce the control delays in LCL grid connected inverters, then the bandwidth and stability margin will be improved. However, high frequency switching harmonics (SHs) are introduced in the control loop, which may cause low frequency aliasing and deteriorate the power quality. In this paper, the multi-sampled currents are reconstructed through the double-sampled average currents, which is simple and easy to implement in a microprocessor. As a result, most of the SHs are removed and the power quality is better than the conventional multi-sampling control. Finally, a single-loop pseudo-derivative-feedback control with inverter current feedback is employed, and the effectiveness of the proposed method is verified through simulation.