Voltage Unbalance and Harmonic Compensation for Islanded Droop Controlled Microgrid Inverters

Objectives: This study proposes a droop controlled voltage unbalance reimbursement technique in an islanded microgrid. Methods/Analysis: The control system is executed in áâ static reference frame work. Here the distributed generators (DGs) inverters are managed appropriately to compensate imbalance in allocating active as well as reactive powers. The control system includes active as well as reactive power droop controllers, virtual impedance loop, voltage as well as current controllers. An unbalance compensator is provided for restoring the voltage amplitude as well as frequency at output of the DG inverter. Findings: Voltage unbalance factor, which is considered as the index of voltage unbalance is reduced from >3% to <1.5%. THD of output voltage is reduced to 5.51% from 19.77%. Improvement: The obtained results show that voltage unbalance is well compensated by utilizing this control technique. Harmonics in microgrid are reduced by compensation of selective main harmonics by resonant controllers.