Photovoltaic system operation as DSTATCOM for power quality improvement employing active current control
Nirav Patel, Nitin Gupta, B. Chitti Babu
Abstract
This paper presents photovoltaic (PV) system control as distributed static compensator (DSTATCOM), termed as PV‐DSTATCOM, operated with active current control (ACC) and feed‐forward control loop (FFCL). Besides active power injection into the utility grid, the proposed PV system autonomously transforms into a DSTATCOM to provide various ancillary services including source current harmonic suppression, load reactive current compensation, zero sequences component mitigation, and power factor correction. Since PV‐DSTATCOM operates with ACC, it precisely extracts the fundamental in‐phase and quadrature components of current. It introduces high‐gain at the third‐order harmonic and thereby alleviates stationary errors in the current control loop of PV inverter. The proposed ACC+FFCL structure is computationally efficient and unconditionally stable. Practically, FFCL addresses the challenges emerged due to nonlinearity introduced by the PV unit and ensure a rapid power balance between the PV unit and electric grid. Further, a simplified perturb and observe based maximum power point tracker has been employed to evacuate the maximum power from the PV array. The proficiency of the developed ACC+FFCL structure is investigated through a comprehensive set of transient studies using MATLAB/Simulink software. Finally, a laboratory setup has been developed using the dSPACE‐1104 platform and experimental results are recorded with detailed comparative evaluation.