A grid voltage sensor-less operational approach of interconnecting distributed generating source based inverter to unbalanced generalized three-phase grid together with local load at PCC

In this paper, a novel grid voltage sensor-less operation of the generalized three-phase grid connected distributed generating source based inverter operation is proposed. The method also takes into consideration the presence of a local load at the point of common coupling (PCC). In the proposed method, the same inverter current controller is used to estimate the grid voltages and to control the inverter to achieve the control on grid active and reactive power flow along with the sinusoidal grid currents. The proposed system is implemented directly in the a-b-c frame and Spatial Repetitive Controller (SRC) is used as the main control algorithm of the proposed scheme. Experimental results are provided to show the efficacy of the proposed sensorless control methodology.