Modeling and Experimental Investigation on Vector Control of Grid-connected Inverter-Based Distributed Generation

ABSTRACTAs the distributed generation (DG) systems based on small hydro, wind turbine and solar energy etc., are intermittent power sources, the grid-connected inverter is employed as an interfacing device to maintain voltage at the point of common coupling (PCC) and power quality. If these systems are not well controlled then their connection to the utility network can lead to grid instability or even failure. In order to solve this problem, current controller plays an important role on grid-connected inverter system. In this article vector control of grid connected-inverter system based on grid-flux oriented reference frame is presented. In addition, a modified delta-sigma modulator in the inner feedback loop is proposed to maintain voltage quality at the utility end with sinusoidal current injection. Moreover, the proposed control strategy ensures independent control of active and reactive power flowing into the grid. The overall performance of proposed control strategy is analyzed in MAT-LAB-Simulink ...