In connection with the grid-connected inverter with an LCL filter

a multi-sampling-based single closed-loop current control strategy is researched. In a switching period

data is sampled many times and the modulation signal is updated at the same time. As a result

the delay caused by digital control is greatly reduced without changing switching frequency

achieving high control bandwidth and large stability margin. The control delay based on multi-sampling is quantitatively analyzed

and the control performance of the grid-connected inverter with an LCL filter by multi-sampling is analyzed. Compared with the regular active damping method with multiple loops

the scheme adopting single current loop is seen to realize system stability without increasing sensors. Finally

experimental results show that the control scheme is effective. This work is supported by National Natural Science Foundation of China (No. 51277051).