DQ transformation based control of single-phase grid-tied inverter

Direct quadrature (DQ) synchronous reference frame transformation-based current controllers are utilized due to their superior performance, while they drive on dc quantities, attaining zero steady-state error, and are highly compatible for single-phase grid-tied inverters. Therefore, in this paper, the DQ reference frame is used to control active and reactive power by employing proportional Integral (PI) control in a single-phase grid-tied inverter. By using the phase-locked loop (PLL), the injected grid current and voltages are set to be in phase. An LCL filter is applied at inverter output to reduce the harmonics. The LCL filter is designed from the perspective of control for active and reactive power, and total harmonic distortion (THD). The MATLAB/Simulink based simulation results are presented, while the output of the inverter is controlled to meet the desired load active and reactive power requirement. The simulation outcomes depict the efficiency of the proposed PI control strategy regarding a low THD of 1.68% and a steady-state time of 0.03s.