A fast-transient repetitive control strategy for programmable harmonic current source

The repetitive control (RC) strategy is widely used in AC power systems because of its high performance in tracking period signal and suppressing steady-state error. However, the dynamic response of RC is determined by the fundamental period delay T₀ existing in the internal model. In the current study, a (nk ± i)-order harmonic RC structure is proposed to improve dynamic performance. The proposed structure has less data memory and can improve the tracking speed by n/2 times. T₀ proves the effectiveness of the (nk ± i)-order RC strategy. The simulation and experiments of (6k ± 1)-order and (4k ± 1)-order RC strategy used in the voltage source inverter is conducted in this study to control the harmonic current source, which shows the validity and advantages of the proposed structure.