Discrete Domain Current Control Strategy for LCL Grid-Connected Inverter with Background Harmonic Suppression Capability

Due to the low switching frequency of the high-power grid-connected inverter, the delay and discretization error have a great influence on the control performance, resulting in slow dynamic response and large influence of grid background harmonics. Therefore, this paper proposes a state-space current control method for high-power Icl-type inverters designed in discrete domain, which combines the discrete grid voltage feedforward function to reconstruct the output impedance. The experimental results indicate that the proposed control strategy has high dynamic performance and strong background harmonic suppression performance.