Control Techniques for Single Phase Inverter to Interface Renewable Energy Sources with the Micro grid

In this paper, a novel current control technique is proposed to control both active and reactive power flow from a micro grid system fed by a renewable energy source through a single phase parallel-connected inverter. The parallel connected inverter ensures active and reactive power flow from grid with low total harmonic distortion even in the presence of non linear load. A p-q theory based approach is used to find the reference current of the parallel connected inverter to ensure desired operating conditions at the grid terminal. The proposed current controller is simple to implement and gives superior performance over conventional current controllers, such as rotating frame proportional-integral controller or stationary frame proportional resonant controller. The stability of the proposed controller is ensured by direct Lyapunov method. Detailed simulation are carried out in MATLAB/SIMULINK and the results are presented to show the efficacy of the proposed current control scheme along with the proposed nonlinear controller to control the active and reactive power flow in a single-phase microgrid under different operating conditions.