Robust current controller for grid-connected voltage source inverter

The development of a dead-beat current controller with a disturbance estimator for grid-connected single phase (1ϕ) voltage source (VS) inverter is presented in this paper. The 1ϕ VS inverter is connected to the grid using L-type filter. Disturbance estimator is employed to reject any disturbances due to controller time delay, inductance mismatch, and/or grid voltage disturbances. The design and analysis of the proposed controller is verified using simulation. Moreover, experimental testing under several disturbance conditions is carried out using 10 kW grid-connected 1ϕ inverter. The traditional predictive current controller is also tested with the same disturbance conditions to demonstrate the advantages of the proposed controller. Experimental results show the capabilities of the proposed controller in rejecting disturbances and maintaining the grid current at the command value.