A synchronous reference frame PI current controller with dead beat response

Abstract

In this paper, a new structure of a proportional integral (PI) current controller implemented in a synchronous d, q reference frame (SRF-PI), for grid-tied voltage inverters, is presented. The controller has deadbeat response for current reference tracking, reaching it in two samples. It also keeps the main feature of the SRF-PI controller: its ability to track without error, in the absence of other disturbances, a positive sequence current reference of fundamental frequency. Furthermore, the controller ensures the full decoupling between the currents of axes dand q. The controller is compared, through simulation and experimental results, with one SRF-PI controller recently published in the literature. It is verified that the proposed controller introduces noticeable improvements in both the transient response and in the steady-state response to perturbations in the control loop.