Improved Current Source Inverter with Lesser Input Inductor for PV-Grid Interface

Current Source Inverter for Photovoltaic-Grid interface is not much researched at the distribution level, though it is advantageous in many aspects. This is mainly because of the necessity of high value of input inductor and poor dynamic response as related to Voltage Source Inverter. In this paper, a modified Current Source Inverter that requires lesser value of input side inductor as compared to the conventional CSI is presented. A capacitor in series with a controllable switch is added such that the capacitor can supply the 100Hz ripple resulting in a great decrease in the value of input inductor. Design of passive elements of the improved CSI and the methodology used in the control are discussed in detail in the paper. Simulation results that validate the design are presented for conventional as well as for the improved CSI.