Finite-time current control of LCL-filter for grid-connected three-phase voltage-source inverter

In this paper, an effective deadbeat current control method for a third-order LCL filter in voltage source inverter applications of wind energy is presented. The novel method is not only to damp the LCL resonance but also to achieve time-optimal responses of the grid-side currents. Based on the theoretical analysis of the LCL-filter with the deadbeat current control algorithm in the α-β stationary reference frame, the settling time is set to three times of the sampling period and only two current sensors are required in the experiment for detecting the inverter currents. In addition, the state identification algorithm is only adopted in order to achieve the detection of the inverter currents. The effectiveness of the proposed deadbeat current algorithm is substantially confirmed by the simulation and experimental results.