Evaluation of dead beat current controllers for grid connected converters

The voltage source converters (VSCs) are widely preferred topologies for grid connection of renewable energy systems. This paper aims to evaluate the various types of deadbeat (DB) current controllers for the VSCs, which offer fast and finite settling time. The type of DB current controllers discussed in this paper aims to achieve the current command in one and two sampling time delay. Two compensation methods for one sampling time delay of DB control are the reducing the proportional gain method and Smith Predictor method. In the two sampling time delay of DB current controllers, two different implementation schemes are designed, which are based on the development of an internal model control through the feedback transfer function. In this paper four types of controllers are investigated in detail in terms of control algorithm design, system stability analysis and sensitivity analysis of plant parameter variations. In addition, PSCAD based computer simulation studies are presented in the paper to evaluate the performance of each controllers.