Adaptive Damped Circular Current Limit Control for PV Grid-Tied System

This article deals with a double-stage photovoltaic (PV) grid-tied three-phase system with a higher order passive filter. It gives a solution to some real issues, such as load balancing, harmonics compensation, reduced filter size, and power loss, in the distribution network. The improved adaptive damped circular current limit (ADCCL) control -filter-based technique is used for harmonics elimination in this system. The maximum power is tracked from a PV array by an incremental conductance maximum power point tracking algorithm. However, the boost converter is used for extracting the maximum power from the PV array and feeds it to the grid and a proportional–integral controller used to maintain the dc-link voltage of the voltage-source converter. The ADCCL control is used to mitigate the power quality issues with the grid current total harmonic distortion below 5%. A feed-forward term of PV array is added with total active component, which improves the dynamic response. The power quality issues are mitigated and demonstrated by the test results. Moreover, the comparison is made with different controls under various dynamic conditions.