Controller tuning for a single phase grid-connected current source inverter

Current source inverter (CSI) is an alternative option to a voltage source inverter (VSI) for grid interfacing of distributed generation (DG) systems. However, literature lacks proper controller tuning procedures for grid-connected CSI that take into consideration the effects of control and sample delays when implemented using a digital signal processors (DSP). This paper presents a step-by-step approach in determining the controller gains by analyzing the system in discrete domain. Furthermore, proportional resonant (PR) and proportional integral (PI) controllers are also considered in the analysis to better understand the advantages they offer in controlling grid-connected CSI. The accuracy of the calculated gains are verified both through bode plots and Matlab simulations.