Design of a Spatial iterative learning controller for single phase series connected PV module inverter for grid voltage compensation

In this paper, a new type of controller is proposed for series connected PV inverter for grid voltage compensation. The inverter operates during the day time as an active power compensator as well as load voltage regulator under grid voltage sag, swell or even under normal condition. The compensating voltage provided by the inverter is added vectorially in series with the grid voltage in such a way that the load voltage magnitude is maintained constant along with power control facility. In micro grid scenario, the grid may suffer from frequency variation also. The proposed Spatial ILC is able to track the required load voltage along with eliminating the grid harmonics. The control system ensures load voltage is auto synchronized with the grid voltage even in the case of grid frequency variation. This control strategy is simple to implement and provides improved performance as compared to other conventional tracking controllers. Experimental as well as simulation results presented demonstrate the efficacy of the proposed controller.